JP5980738B2 - Power system - Google Patents

Description

  The present invention relates to a power supply system, and more particularly to control for correcting a voltage sensor and / or a current sensor arranged in a power supply system configured to include a plurality of DC power supplies.

  In a power supply system configured to include a DC power supply, a voltage sensor and a current sensor are provided to control the operation of the system. As a technique for correcting the output error of such a sensor, Japanese Patent Application Laid-Open No. 2010-273523 (Patent Document 1) describes a method of correcting a reference value of a current sensor of a high voltage battery. Specifically, in a period in which the high voltage battery is not being charged / discharged due to power consumption by the auxiliary machine, the voltage between the terminals of the high voltage battery has changed even though the output of the current sensor is zero. In this case, it is described that the reference value of the current sensor is corrected.

  JP 2012-70514 A (Patent Document 2) discloses an operation mode (series connection mode) in which DC / DC conversion is performed in a state where two DC power sources are connected in series under the control of a plurality of switching elements. A configuration of a power converter capable of switching an operation mode (parallel connection mode) for performing DC / DC conversion in a state where two DC power supplies are used in parallel is described.

JP 2010-273523 A JP 2012-70514 A

  If an error occurs in the output of the sensor in the power supply system, the output may not be accurately controlled. Therefore, it is important to correct the output error of the sensor. In particular, as described in Patent Document 1, it is important for control to correct the sensor during the operation of the power supply system.

  As in the power supply system described in Patent Document 2, in a configuration having a plurality of DC power supplies, a voltage sensor and a current sensor are generally provided for each DC power supply. In addition, a plurality of voltage sensors are arranged. However, Patent Document 2 makes no mention of such sensor correction.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a power supply provided with a plurality of DC power supplies and a plurality of voltage detectors and / or current detectors. In a system, it is an efficient correction of the voltage detector and / or current detector.

  In one aspect of the present invention, a power supply system is a power supply system for outputting a DC voltage between first and second power lines connected to a load, and includes a first DC power supply and a second DC power supply. And first to third voltage detectors, first and second current detectors, first to fourth switching elements, first and second reactors, and a control device. The first voltage output device detects the voltage of the first DC power supply. The second voltage detector detects the voltage of the second DC power supply. The first current detector detects the current of the first DC power supply. The second current detector detects the current of the second DC power supply. The third voltage detector detects a DC voltage between the first and second power lines. The first to fourth switching elements are sequentially connected in series between the first and second power lines. The first reactor is electrically connected between the connection node of the second and third switching elements and the positive terminal of the first DC power supply. The second reactor is electrically connected between the connection node of the first and second switching elements and the positive terminal of the second DC power supply. The negative terminal of the first DC power supply is electrically connected to the second power line, and the negative terminal of the second DC power supply is electrically connected to the connection node of the third and fourth switching elements. The control device controls on / off of the first to fourth switching elements. One predetermined voltage detector of the first and second voltage detectors has higher detection accuracy than the other voltage detector, and the predetermined one current of the first and second current detectors. The detector has higher detection accuracy than the other current detector. The control device includes switching control means and correction means. The switching control means is configured to control the first to fourth switching elements so that the first and second DC power supplies are electrically connected in parallel or in series between the first and second power lines. A predetermined switching pattern is formed. The correction means includes a voltage detector correction process for correcting the other voltage detector or the third voltage detector based on a detection value by one voltage detector during a period in which a predetermined switching pattern is formed, and At least one of current detector correction processing for correcting the other current detector based on a detection value by one current detector is executed.

  Preferably, the voltage detector correction process is performed during a period in which the first and second DC power supplies are electrically connected in parallel between the first and second power lines according to a predetermined switching pattern. , Including a process of correcting the other voltage detector based on the detection value by one voltage detector.

  Preferably, the voltage detector correction processing is a period in which the state in which the first and second DC power supplies are electrically connected in series between the first and second power lines is maintained by a predetermined switching pattern. 3 includes a process of correcting the third voltage detector based on the detection values of the one voltage detector and the other voltage detector.

  Preferably, the voltage detector correction process includes first and second correction processes. In the first correction process, the control device detects one of the voltages in a period in which the first and second DC power supplies are maintained in a state of being electrically connected in parallel between the first and second power lines. The other voltage detector is corrected based on the detection value by the detector. In the second process, the control device is configured such that one of the voltage detectors is maintained during a period in which the first and second DC power supplies are maintained in a state of being electrically connected in series between the first and second power lines. The third voltage detector is corrected based on the detection value obtained by the above and the detection value obtained by the other voltage detector after the correction by the first correction processing.

  More preferably, the control device further includes zero point correction means. The zero point correction means is configured to obtain a current output value of the first and second current detectors when the current value is zero when the circuit state is such that no current flows through the first and second DC power supplies. The corresponding zero point.

  Preferably, the current detector correction process is a period in which the state in which the first and second DC power supplies are electrically connected in series between the first and second power lines is maintained by a predetermined switching pattern. 3 includes a process of correcting the other current detector based on the detection value by one current detector.

  Preferably, the power supply system further includes a third current detector. The third current detector detects an input / output current from the power supply system to the load via the first and second power lines. In the current detector correction process, one of the first and second DC power supplies is electrically connected in series between the first and second power lines according to a predetermined switching pattern. A process of correcting the other current detector and the third current detector based on a detection value by the current detector is included.

  Preferably, the power supply system applies one operation mode among a plurality of operation modes having different modes of power conversion between the first and second DC power supplies and the power line during the operation of the load. It is configured to control the voltage of the power line by operating. When the operation mode is selected such that the on / off patterns of the first to fourth switching elements coincide with a predetermined switching pattern during the operation of the load, the correction means performs the voltage detector correction process and the current detector correction. At least one of the processes is executed.

  Alternatively, preferably, the correction unit executes at least one of a voltage detector correction process and a current detector correction process when the correction mode is selected while the load is stopped.

  Preferably, the control device is configured to execute a correction mode for correcting the other voltage detector, the third voltage detector, and the other current detector. The control device includes zero point correction means and first to fifth correction mode means. In the correction mode, the zero point correction means sets the current output values of the first and second current detectors to zero when the circuit state is such that no current flows through the first and second DC power supplies. The corresponding zero point when. The first correction mode means maintains a state where the first and second DC power supplies are electrically connected in parallel between the first and second power lines after the zero point correction by the zero point correction means is completed. Therefore, the first to fourth switching elements are controlled so that the first switching pattern for forming the first switching pattern is formed. The second correction mode means corrects the other voltage detector based on the detection value by one voltage detector during the period in which the first switching pattern is formed. The third correction mode means maintains the state in which the first and second DC power sources are electrically connected in series between the first and second power lines after the correction of the other voltage detector is completed. The first to fourth switching elements are controlled so that the second switching pattern is formed. The fourth correction mode means is based on the detection value by one voltage detector and the detection value by the other voltage detector in a state where the second switching pattern is formed and the load is stopped. Then, the third voltage detector is corrected. The fifth correction mode means has a second switching pattern, and in the state where current is exchanged between the power supply system and the load, based on the detection value by one current detector. Correct the current detector.

  More preferably, the control device changes the current supplied to the load in a plurality of stages during the period in which the second switching pattern is formed, and based on the detection value by one current detector in each stage. Means are further included for correcting the other current detector.

  Alternatively, more preferably, the power supply system further includes a third current detector. The third current detector detects an input / output current from the power supply system to the load via the first and second power lines. In the correction mode, the control device corrects the third current detector together with the other current detector based on the detection value of the one current detector during the period in which the second switching pattern is formed. Further included.

  According to the present invention, in a power supply system provided with a plurality of DC power supplies and a plurality of voltage detectors and / or current detectors, the voltage detectors and / or current detectors can be corrected efficiently. Can do.

It is a circuit diagram which shows the structure of the power supply system containing the power converter according to embodiment of this invention. It is the schematic which shows the structural example of the load shown in FIG. It is a chart for demonstrating the several operation mode which the power converter shown in FIG. 1 has. It is a conceptual diagram which shows an example of the characteristic of both DC power supplies at the time of comprising the two DC power supplies shown in FIG. 1 with different types of power supplies. It is a conceptual circuit diagram for demonstrating the 1st voltage sensor correction process in the power supply system according to this Embodiment. It is a flowchart for demonstrating the control processing procedure in a 1st voltage sensor correction process. It is a conceptual circuit diagram for demonstrating the 2nd voltage sensor correction | amendment process in the power supply system according to this Embodiment. It is a flowchart for demonstrating the control processing procedure in a 2nd voltage sensor correction process. It is a flowchart for demonstrating the procedure of the zero point correction process of the current sensor in the power supply system according to the embodiment. It is a flowchart for demonstrating the control processing procedure of the current sensor correction process in the power supply system according to the embodiment. 12 is a flowchart for illustrating a control processing procedure of sensor correction mode processing according to the second embodiment.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

[Embodiment 1]
(Circuit configuration of power converter)
FIG. 1 is a circuit diagram showing a configuration of a power supply system including a power converter according to an embodiment of the present invention.

  Referring to FIG. 1, power supply system 5 includes a plurality of DC power supplies 10 a and 10 b and a power converter 50. A load 30 of the power supply system 5 is connected between the power lines 20 and 21.

  In the present embodiment, each of DC power supplies 10a and 10b is a secondary battery such as a lithium ion secondary battery or a nickel metal hydride battery, or a DC voltage excellent in output characteristics such as an electric double layer capacitor or a lithium ion capacitor. Consists of source elements. The DC power supply 10a and the DC power supply 10b correspond to a “first DC power supply” and a “second DC power supply”, respectively.

  Power converter 50 is connected between DC power supplies 10 a and 10 b and power lines 20 and 21. Power converter 50 controls a DC voltage (hereinafter also referred to as output voltage VH) between power lines 20 and 21 in accordance with voltage command value VH *. That is, power lines 20 and 21 are provided in common to DC power supplies 10a and 10b.

  The load 30 operates in response to the output voltage VH of the power converter 50. Voltage command value VH * is set to a voltage suitable for the operation of load 30. Voltage command value VH * may be variably set according to the operating state of load 30. Furthermore, the load 30 may be configured to be able to generate charging power for the DC power supplies 10a and 10b by regenerative power generation or the like.

FIG. 2 is a schematic diagram illustrating a configuration example of the load 30.
Referring to FIG. 2, load 30 is configured to include, for example, a traveling motor for an electric vehicle. Load 30 includes a smoothing capacitor CH, an inverter 32, a motor generator 35, a power transmission gear 36, and drive wheels 37.

  The motor generator 35 is a traveling motor for generating vehicle driving force, and is constituted by, for example, a multi-phase permanent magnet type synchronous motor. The output torque of the motor generator 35 is transmitted to the drive wheels 37 via a power transmission gear 36 constituted by a speed reducer and a power split mechanism. The electric vehicle travels with the torque transmitted to the drive wheels 37.

  Further, the motor generator 35 generates power by the rotational force of the drive wheels 37 during regenerative braking of the electric vehicle. This generated power is AC / DC converted by the inverter 32. This DC power can be used as charging power for DC power supplies 10 a and 10 b included in the power supply system 5.

  In a hybrid vehicle in which an engine (not shown) is mounted in addition to the motor generator, vehicle driving force required for the electric vehicle is generated by cooperatively operating the engine and the motor generator 35. At this time, it is also possible to charge the DC power supplies 10a and 10b using the power generated by the rotation of the engine.

  Thus, the load 30 can charge the DC power supplies 10 a and 10 b by the regenerative power generation of the motor generator 35. Furthermore, the load 30 may be configured to further include a “power generation mechanism” for generating charging power of the DC power sources 10a and 10b by other power sources such as an engine and a fuel cell (not shown).

  In the present embodiment, the electric vehicle comprehensively indicates a vehicle equipped with a traveling electric motor, and includes a hybrid vehicle that generates vehicle driving force by the engine and the electric motor, an electric vehicle that does not include the engine, and fuel. It includes both battery cars.

  The operation of the load 30 (motor generator 35) depends on the driving state of the electric vehicle (typically the vehicle speed) and the driver operation (typically the operation of the accelerator pedal and the brake pedal) or the required vehicle driving force or Control is performed to obtain a vehicle braking force. That is, an operation command for load 30 (for example, a torque command value for motor generator 35) is set by running control of the electric vehicle.

  Referring to FIG. 1 again, power converter 50 includes switching elements S1 to S4 and reactors L1 and L2. In the present embodiment, an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor) transistor, a power bipolar transistor, or the like can be used as the switching element. Anti-parallel diodes D1 to D4 are arranged for switching elements S1 to S4. Further, the switching elements S1 to S4 can control on / off in response to the control signals SG1 to SG4, respectively. That is, the switching elements S1 to S4 are turned on when the control signals SG1 to SG4 are at a high level (hereinafter, H level), and are turned off when the control signals SG1 to SG4 are at a low level (hereinafter, L level).

  Switching element S1 is electrically connected between power line 20 and node N1. Reactor L2 is connected between node N1 and the positive terminal of DC power supply 10b. Switching element S2 is electrically connected between nodes N1 and N2. Reactor L1 is connected between node N2 and the positive terminal of DC power supply 10a.

  Switching element S3 is electrically connected between nodes N2 and N3. Node N3 is electrically connected to the negative terminal of DC power supply 10b. Switching element S4 is electrically connected between node N3 and power line 21. Power line 21 is electrically connected to load 30 and the negative terminal of DC power supply 10a.

  As can be understood from FIG. 1, the power converter 50 has a boost chopper circuit corresponding to each of the DC power supply 10a and the DC power supply 10b. That is, for DC power supply 10a, a current bidirectional first step-up chopper circuit having switching elements S1 and S2 as upper arm elements and switching elements S3 and S4 as lower arm elements is configured. Similarly, for the DC power supply 10b, a current bidirectional second step-up chopper circuit is configured with the switching elements S1 and S4 as upper arm elements and the switching elements S2 and S3 as lower arm elements. .

  A power conversion path formed between the DC power supply 10a and the power line 20 by the first boost chopper circuit and a power conversion path formed between the DC power supply 10b and the power line 20 by the second boost chopper circuit. Both include the switching elements S1 to S4.

  In the configuration of FIG. 1, switching elements S1 to S4 correspond to “first switching element” to “fourth switching element”, respectively, and reactors L1 and L2 correspond to “first reactor” and “second reactor”, respectively. Corresponds to "reactor" respectively.

  The DC power supply 10a is provided with a voltage sensor 11a and a current sensor 12a. The voltage sensor 11a detects the voltage Va of the DC power supply 10a. The current sensor 12a detects the current Ia of the DC power supply 10a.

  Similarly, the DC power supply 10b is provided with a voltage sensor 11b and a current sensor 12b. The voltage sensor 11b detects the voltage Vb of the DC power supply 10b. The current sensor 12b detects the current Ib of the DC power supply 10b.

  Voltage sensor 11H is connected between power lines 20 and 21 to detect output voltage VH. The power line 20 (or the power line 21) may be provided with a current sensor 12H for detecting a current supplied to the load 30 (hereinafter also referred to as a load current IH). The arrangement of the current sensor 12H may be omitted.

  The currents Ia and Ib are expressed as positive values when the DC power supplies 10a and 10b are discharged, and are expressed as negative values when the DC power supplies 10a and 10b are charged. Similarly, the load current IH is expressed as a positive value when the load 30 consumes power, and is expressed as a negative value when the load 30 generates power.

  Relay RLa is connected between DC power supply 10 a and power converter 50. Relay RLb is connected between DC power supply 10 b and power converter 50.

  In the embodiment of the present invention, the predetermined one of the voltage sensors 11a, 11b, and 11H is configured with a sensor having higher detection accuracy than the other voltage sensors. For example, in the configuration example of FIG. 1, the voltage sensor 11a provided corresponding to the DC power supply 10a is configured with higher detection accuracy than the voltage sensors 11b and 11H. Similarly, the current sensor 12a is configured with higher detection accuracy than the current sensors 12b and 12H. Therefore, the voltage sensor 11a and the current sensor 12a correspond to the “reference sensor”.

  The control device 40 includes, for example, a CPU (Central Processing Unit) (not shown) and an electronic control unit (ECU) with a built-in memory. Based on a map and a program stored in the memory, the control device 40 detects a detection value by each sensor. It is comprised so that the used arithmetic processing may be performed. Alternatively, at least a part of the control device 40 may be configured to execute predetermined numerical / logical operation processing by hardware such as an electronic circuit.

  The output values of the voltage sensors 11a, 11b, 11H and the current sensors 12a, 12b, 12H are sent to the control device 40. The control device 40 generates control signals SG1 to SG4 for controlling on / off of the switching elements S1 to S4 in order to control the output voltage VH to the load 30. Furthermore, the control device 40 generates a control signal (not shown) for turning on and off the relays RLa and RLb in accordance with the start and stop of the power supply system 5. Relays RLa and RLb are turned on when power supply system 5 is activated, and are kept on during operation of power supply system 5. And according to the stop of the power supply system 5, relay RLa, RLb is turned off.

(Power converter operation mode)
The power converter 50 has a plurality of operation modes in which DC power conversion modes between the DC power supplies 10a and 10b and the power line 20 are different.

FIG. 3 shows a plurality of operation modes that the power converter 50 has.
Referring to FIG. 3, the operation mode includes “boost mode (B)” in which the output voltage of DC power supplies 10a and / or 10b is boosted in accordance with periodic on / off control of switching elements S1 to S4, and switching element S1. Are roughly divided into “direct connection mode (D)” in which the DC power supplies 10 a and / or 10 b are electrically connected to the power line 20 with the on / off state of S 4 being fixed.

  In the boost mode, a “parallel boost mode (hereinafter referred to as PB mode)” in which DC / DC conversion is performed in parallel between DC power supplies 10 a and 10 b and power line 20, DC power supplies 10 a and 10 b and power line 20 connected in series are performed. And “series boost mode (hereinafter referred to as SB mode)” for performing DC / DC conversion with the. The PB mode corresponds to the “parallel connection mode” in Patent Document 2, and the SB mode corresponds to the “series connection mode” in Patent Document 2.

  Further, in the boost mode, a “single mode by DC power source 10a (hereinafter referred to as aB mode)” for performing DC / DC conversion with the power line 20 using only the DC power source 10a, and a power line using only the DC power source 10b. “Single mode by DC power supply 10b (hereinafter referred to as bB mode)” that performs DC / DC conversion with 20 is included. In the aB mode, as long as the output voltage VH is controlled to be higher than the voltage Vb of the DC power supply 10b, the DC power supply 10b is maintained in a state of being electrically disconnected from the power line 20 and is not used. Similarly, in the bB mode, as long as the output voltage VH is controlled to be higher than the voltage Va of the DC power supply 10a, the DC power supply 10a is maintained in an electrically disconnected state from the power line 20 and is not used. The

  In each of the PB mode, SB mode, aB mode, and bB mode included in the boost mode, output voltage VH of power line 20 is controlled in accordance with voltage command value VH *. Control of switching elements S1 to S4 in each of these modes will be described later.

  In the direct connection mode, the “parallel direct connection mode (hereinafter referred to as PD mode)” in which the DC power supplies 10 a and 10 b are connected in parallel to the power line 20 and the DC power supplies 10 a and 10 b in series with the power line 20 are connected. “Series direct connection mode (hereinafter referred to as SD mode)” for maintaining the connected state is included.

  In the PD mode, the switching elements S1, S2, and S4 are fixed on, while the switching element S3 is fixed off. As a result, the output voltage VH becomes equal to the voltages Va and Vb (strictly, the higher voltage of Va and Vb) of the DC power supplies 10a and 10b. Since the voltage difference between Va and Vb causes a short circuit current in the DC power supplies 10a and 10b, the PD mode can be applied only when the voltage difference is small.

  In the SD mode, the switching elements S2 and S4 are fixed off, while the switching elements S1 and S3 are fixed on. As a result, the output voltage VH is equivalent to the sum of the voltages Va and Vb of the DC power supplies 10a and 10 (VH = Va + Vb).

  Furthermore, in the direct connection mode, “direct connection mode of DC power supply 10a (hereinafter referred to as aD mode)” in which only DC power supply 10a is electrically connected to power line 20 and only DC power supply 10b is electrically connected to power line 20 “ "Direct connection mode (hereinafter referred to as bD mode) of DC power supply 10b".

  In the aD mode, the switching elements S1 and S2 are fixed on, while the switching elements S3 and S4 are fixed off. As a result, the DC power supply 10b is disconnected from the power line 20, and the output voltage VH is equal to the voltage Va of the DC power supply 10a (VH = Va). In the aD mode, the DC power supply 10b is not used because it is kept electrically disconnected from the power line 20. When the aD mode is applied in a state where Vb> Va, a short-circuit current is generated from the DC power supplies 10b to 10a via the switching element S2. For this reason, Va> Vb is a necessary condition for applying the aD mode.

  Similarly, in the bD mode, the switching elements S1 and S4 are fixed on, while the switching elements S2 and S3 are fixed off. As a result, the DC power supply 10a is disconnected from the power line 20, and the output voltage VH is equal to the voltage Vb of the DC power supply 10b (VH = Vb). In the bD mode, the DC power supply 10a is not used because it is kept disconnected from the power line 20. When the bD mode is applied in a state where Va> Vb, a short-circuit current is generated from the DC power supplies 10a to 10b via the diode D2. For this reason, Vb> Va is a necessary condition for applying the bD mode.

  In each of the PD mode, SD mode, aD mode, and bD mode included in the direct connection mode, the output voltage VH of the power line 20 is determined depending on the voltages Va and Vb of the DC power supplies 10a and 10b, and therefore must be directly controlled. Can not be. For this reason, in each mode included in the direct connection mode, the output voltage VH cannot be set to a voltage suitable for the operation of the load 30, so that the power loss in the load 30 may increase.

  On the other hand, in the direct connection mode, since the switching elements S1 to S4 are not turned on / off, the power loss of the power converter 50 is significantly suppressed. Therefore, depending on the operating state of the load 30, the application of the direct connection mode increases the power loss reduction amount in the power converter 50 more than the power loss increase amount of the load 30. There is a possibility that it can be suppressed.

  FIG. 4 is a conceptual diagram showing an example of characteristics of both DC power supplies when the DC power supplies 10a and 10b are configured with different types of power supplies. FIG. 4 shows a so-called Ragon plot in which energy is plotted on the horizontal axis and power is plotted on the vertical axis. In general, since the output power and stored energy of a DC power supply are in a trade-off relationship, it is difficult to obtain a high output with a high-capacity battery, and it is difficult to increase the stored energy with a high-power battery.

  Accordingly, one of the DC power supplies 10a and 10b is constituted by a so-called high-capacity type power supply with high stored energy, while the other is constituted by a so-called high-output type power supply with high output power. It is preferable. In this way, the energy stored in the high-capacity power supply is used for a long period of time, while the high-power power supply is used as a buffer to output the shortage due to the high-capacity power supply. Can do.

  In the example of FIG. 4, the DC power supply 10a is configured with a high-capacity power supply, while the DC power supply 10b is configured with a high-output power supply. Therefore, the operating range 110 of the DC power supply 10a has a narrower power output range than the operating range 120 of the DC power supply 10b. On the other hand, the energy range that can be stored in the operation region 120 is narrower than that in the operation region 110.

  At the operating point 101 of the load 30, high power is required for a short time. For example, in an electric vehicle, the operating point 101 corresponds to a sudden acceleration due to a user's accelerator operation. On the other hand, relatively low power is required for a long time at the operating point 102 of the load 30. For example, in an electric vehicle, the operating point 102 corresponds to continuous high speed steady running.

  The operating point 101 can be dealt with mainly by the output from the high-power DC power supply 10b. On the other hand, the operating point 102 can be dealt with mainly by the output from the high-capacity DC power supply 10a. As a result, in the electric vehicle, by using the energy stored in the high-capacity battery for a long time, the travel distance by the electric energy can be extended, and the acceleration performance corresponding to the accelerator operation of the user can be achieved. It can be secured promptly.

  In this way, by combining DC power sources having different types and capacities, the stored energy can be effectively used in the entire system by utilizing the characteristics of each DC power source. Hereinafter, in the present embodiment, an example in which the DC power supply 10a is configured by a secondary battery and the DC power supply 10b is configured by a capacitor will be described.

  For example, a lithium ion secondary battery is known as a secondary battery having a high energy density. However, the lithium secondary battery needs to manage charging / discharging with high accuracy in order to prevent the deposition of metallic lithium. Therefore, when a lithium ion secondary battery is used as the DC power supply 10a, a sensor with high detection accuracy is applied to the voltage sensor 11a and the current sensor 12a for charge / discharge management. In such a case, the “reference sensor” can be efficiently configured by the voltage sensor 11a and the current sensor 12a.

  However, the combination of the DC power supplies 10a and 10b is not limited to this example, and can be configured by DC power supplies (power storage devices) of the same type and / or the same capacity. That is, regardless of the type of DC power supply applied, if there is a level of detection accuracy among a plurality of voltage sensors and current sensors in the power supply system, a voltage sensor and current sensor with a relatively high detection accuracy are used. By using the “reference sensor”, it is possible to apply the sensor correction processing according to the present embodiment to be described later to the power supply system 5.

  In the secondary battery, output characteristics may be reduced at low temperatures, and charging / discharging may be limited to suppress the progress of deterioration at high temperatures. In particular, in an electric vehicle, a temperature difference may occur between the DC power supplies 10a and 10b due to a difference in mounting position. Therefore, in the power supply system 5, it is preferable to use only one of the DC power supplies in accordance with the operating state (particularly the temperature) of the DC power supplies 10a and 10b or according to the demand of the load 30 as described above. There are cases that are efficient. By providing a mode (aB mode, bB mode, aD mode, bD mode) that uses only one of the DC power supplies 10a, 10b as described above, these cases can be handled.

  As described above, power converter 50 according to the first embodiment operates in any one of the plurality of operation modes shown in FIG. 3 according to the operation state of DC power supplies 10a and 10b and / or load 30. A mode is selected.

(Sensor correction processing)
Hereinafter, correction processing of the voltage sensor and / or current sensor (hereinafter also simply referred to as “sensor correction processing”) in power supply system 5 according to the present embodiment will be described. As will be apparent from the following description, the sensor correction process includes a voltage sensor correction process for correcting the voltage sensors 11b and 11H based on the output of the voltage sensor 11a that is a reference sensor, and a current sensor 12b that is a reference sensor. Current sensor correction processing for correcting the current sensors 12b and 11H based on the output of the current and zero point correction processing for correcting the zero points of the current sensors 12a, 12b and 12H. The voltage sensor correction process includes a first voltage sensor correction process for correcting the voltage sensor 11b and a second voltage sensor correction process for correcting the voltage sensor 11H.

  FIG. 5 is a conceptual circuit diagram for illustrating a first voltage sensor correction process in power supply system 5 according to the present embodiment.

  Referring to FIG. 5, in the first voltage sensor correction process, a switching pattern is formed in which switching elements S1 and S4 are turned on while switching elements S2 and S3 are turned off. A current path 52 including the DC power supply 10b is formed between the power lines 20 and 21 by turning on the switching elements S1 and S4.

  On the other hand, the current path 51 including the DC power supply 10a is formed when the diode D2 is conductive, that is, when the voltage Va of the DC power supply 10a becomes equal to the voltage Vb of the DC power supply 10b. Therefore, in the switching pattern shown in FIG. 5, it is understood that DC power supplies 10a and 10b are connected in parallel between power lines 20 and 21 when current Ia> 0.

  FIG. 6 is a flowchart for explaining a control processing procedure in the first voltage sensor correction processing for the voltage sensor 11b.

  Referring to FIG. 6, control device 40 forms the switching pattern shown in FIG. 5 in step S110. Thereby, the switching elements S1 and S4 are turned on while the switching elements S2 and S3 are turned off.

  Further, in step S120, control device 40 determines whether or not current Ia detected by current sensor 12a is flowing. When current Ia> 0 (when YES is determined in S120), control device 40 proceeds to step S130, and executes correction processing of voltage sensor 11b based on the output of voltage sensor 11a as the reference sensor. .

  In the state where the DC power supplies 10a and 10b are connected in parallel between the power lines 20 and 21, the same voltage is applied to the voltage sensors 11a and 11b. Therefore, when the detection value of the voltage sensor 11b is different from the detection value of the voltage sensor 11a as the reference sensor, the difference between the two can be regarded as a detection error of the voltage sensor 11b. For example, in the correction process in step S130, the correction value of the voltage sensor 11b is calculated based on the detection error at this time. After completion of the correction process, the voltage Vb is detected by correcting the detection value by the voltage sensor 11b according to the correction value.

  When the correction process is executed a plurality of times, the correction value may be calculated by learning the detection error calculated each time. For example, the correction value LN (n) can be calculated by learning the correction value LN (n) every time the detection error ER (n) is calculated according to the following equation (1).

LN (n) = (1−α) · LN (n−1) + α · ER (n) (1)
In the equation (1), LN (n−1) is a correction value calculated last time, and α is a learning coefficient (0 <α ≦ 1). The detection error ER (n) corresponds to a difference between detection values of the voltage sensors 11a and 11b. When α = 1, every time the detection error ER is calculated, the detection error is directly used as a correction value. Further, the correction value may be obtained for each voltage level.

  In this way, the voltage sensor 11b for detecting the voltage Vb of the DC power supply 10b can be corrected based on the output of the voltage sensor 11a that is a reference sensor.

  On the other hand, when current Ia = 0 (when NO is determined in S120), control device 40 is not in a state where DC power supplies 10a and 10b are connected in parallel between power lines 20 and 21. The correction process of the voltage sensor 11b is not executed. That is, the control apparatus 40 skips the process of step S130.

  FIG. 7 is a circuit diagram for illustrating a second voltage sensor correction process in power supply system 5 according to the present embodiment.

  Referring to FIG. 7, in the second voltage sensor correction process, a switching pattern is formed in which switching elements S1 and S3 are turned on while switching elements S2 and S4 are turned off. When switching elements S1 and S3 are turned on, DC power supply 10a and DC power supply 10b are connected in series between power lines 20 and 21.

  FIG. 8 is a flowchart for explaining a control processing procedure in the second voltage sensor correction processing for the voltage sensor 11H.

  Referring to FIG. 8, control device 40 forms the switching pattern shown in FIG. 7 in step S200. Thereby, the switching elements S1 and S3 are turned on while the switching elements S2 and S4 are turned off. Thereby, as shown in FIG. 7, DC power supplies 10 a and 10 b are connected in series between power lines 20 and 21.

  Further, in step S210, the control device 40 determines whether or not the correction of the voltage sensor 11b has been completed. For example, if the correction processing of the voltage sensor 11b has been executed a predetermined number of times (for example, once) after the power supply system 5 is started, step S210 is determined as YES, and if not, step S210 is determined as NO. It is said.

  When the correction of the voltage sensor 11b has been completed (when YES is determined in S210), the control device 40 proceeds to step S220 to output the output of the voltage sensor 11a that is the reference sensor and the corrected voltage sensor 11b. And the correction process of the voltage sensor 11b is executed based on the output of.

  With the switching pattern shown in FIG. 7, in a state where the DC power supplies 10a and 10b are connected in series between the power lines 20 and 21, a voltage corresponding to the voltage Va + Vb is applied to the voltage sensor 11H. Therefore, when the sum (Va + Vb) of the voltage Va detected by the voltage sensor 11a as the reference sensor and the voltage Vb detected by the corrected voltage sensor 11b is different from the detection value of the voltage sensor 11H, both Can be regarded as a detection error of the voltage sensor 11H.

  For example, in the correction process in step S220, the correction value of the voltage sensor 11H can be calculated based on the detection error at this time. The correction process can be the same as the control process in step S130. After completion of the correction process, the voltage VH is detected by correcting the detection value by the voltage sensor 11H according to the correction value. In this manner, the voltage sensor 11H for detecting the output voltage VH can be corrected based on the output of the voltage sensor 11a that is the reference sensor.

  On the other hand, when the correction of the voltage sensor 11b has not been completed (when NO is determined in S210), the control device 40 skips the process of step S220. That is, the correction of the voltage sensor 11H is not executed.

  Thus, during the period in which the switching elements S1 to S4 form the switching pattern in which the DC power sources 10a and 10b are connected in parallel or in series between the power lines 20 and 21, the output of the reference sensor is used. It becomes possible to correct | amend the voltage sensor of this online efficiently.

  In principle, the process of step S210 in FIG. 8 can be omitted, and the correction of the voltage sensor 11H can be executed independently of the correction of the voltage sensor 11b. However, the correction of the voltage sensor 11H requires not only the voltage Va detected by the voltage sensor 11a as the reference sensor but also the voltage Vb detected by the voltage sensor 11b. By permitting correction of the sensor 11H, the correction accuracy can be increased.

  Next, correction of the current sensor will be described. Normally, the current sensors 12a, 12b, and 12H are configured by sensors that detect the intensity of a generated magnetic field corresponding to the amount of current, typified by a Hall element. That is, the detected current value is generally obtained from the product of the Hall element output (Hall voltage) and the sensor gain. Therefore, it is necessary to consider both zero point correction (offset correction) and gain correction in the current sensor correction.

  FIG. 9 is a flowchart for illustrating a control processing procedure for correcting the zero point of the current sensor in power supply system 5 according to the embodiment.

  Referring to FIG. 9, control device 40 determines in step S310 whether or not the current zero condition is satisfied. If the current zero condition is satisfied (YES in S310), step S320 is performed. Then, the zero point correction of each of the current sensors 12a, 12b, 12H is executed. On the other hand, control device 40 skips the process of step S320 when the zero current condition is not satisfied (NO in S310). That is, zero point correction of each current sensor 12a, 12b, 12H is not executed.

  The zero current condition is set in advance so that the current does not flow through the current sensors 12a, 12b, and 12H, that is, when the circuit state is such that Ia = Ib = IH = 0. For example, when the relays RLa and RLb shown in FIG. 1 are OFF, no current flows through each of the current sensors 12a, 12b, and 12H. Therefore, it is possible to make the current zero condition that the relays RLa and RLb are off. In this way, zero point correction can be performed before the relays RLa and RLb are turned off when the power supply system 5 is started.

  Alternatively, even after the relays RLa and RLb are turned on, if the switching elements S1 to S4 are turned off, the currents Ia, Ib, and IH are not generated unless the diodes D1 and D2 are turned on. Therefore, the switching element S1 to S4 is off and VH is higher than both Va and Vb (when max (Va, VH)) can be set as a zero current condition. Thereby, the zero point of the current sensors 12a, 12b, and 12H can be corrected while the power supply system 5 is being used (online).

  In step S320, zero point correction is executed for the current sensor 12a so that the current detection value is the zero point corresponding to Ia = 0. After the zero point correction process, the current Ia is detected based on the difference from the zero point. Similarly, for the current sensor 12b, the current detection value is set to a zero point corresponding to Ib = 0, and for the current sensor 12H, the current detection value is set to a zero point corresponding to IH = 0. Zero point correction is executed. Thereby, the offset error of the current sensor can be eliminated.

  Referring to FIG. 7 again, according to the switching pattern shown in FIG. 7, when DC power supplies 10a, 10b are electrically connected in series between power lines 20, 21, current path 53 is formed. . In the current path 53, since the current sensors 12a, 12b, and 12H are connected in series, it is understood that the same current flows through each current sensor.

  FIG. 10 is a flowchart for illustrating a control processing procedure for current sensor correction in power supply system 5 according to the present embodiment.

  Referring to FIG. 10, control device 40 forms the switching pattern shown in FIG. 7 in step S200. Thereby, the switching elements S1 and S3 are turned on, while the switching elements S2 and S4 are turned off. Thereby, as shown in FIG. 7, the current path 53 including the current sensors 12a, 12b, and 12H connected in series is formed.

  In step S360, the control device 40 corrects the other current sensors 12b and 12H based on the output of the current sensor 12a that is the reference sensor within the period in which the switching pattern in step S350 is maintained.

  In the correction processing in step S360, the sensor gain of the current sensor 12b can be corrected according to the ratio between the output of the current sensor 12b and the current value detected by the reference sensor (current sensor 12a). The sensor gain may be obtained by updating the sensor gain calculated based on the detection value of the reference sensor by learning, as described in the correction process of the voltage sensor. It is also possible to correct the sensor gain for each current level.

  Similarly, for the current sensor 12H, the sensor gain can be corrected according to the ratio between the output of the current sensor 12H and the current value detected by the reference sensor (current sensor 12a).

  In this way, during the period in which the switching elements S1 to S4 form a switching pattern that electrically connects the DC power supplies 10a and 10b in series between the power lines 20 and 21, the current sensor 12a that is the reference sensor. The voltage sensor 12b for detecting the current Ib of the DC power supply 10b and the current sensor 12H for detecting the load current IH can be corrected on the basis of the output of.

  As described above, according to the power supply system 5 according to the present embodiment, the switching elements S1 to S4 form the switching pattern for connecting the DC power supplies 10a and 10b in parallel or in series between the power lines 20 and 21. During the time period, the output of the reference sensor can be used to efficiently correct other voltage and / or current sensors online.

  Note that the switching pattern shown in FIG. 5 is the same as the on / off pattern of the switching elements S1 to S4 in the PD mode and the bD mode shown in FIG. Similarly, the switching pattern shown in FIG. 7 matches the on / off pattern of the switching elements S1 to S4 in the SD mode shown in FIG.

  Therefore, the voltage sensor correction process and the current sensor correction process are shown in FIGS. 6, 8, and 10 during a period in which the SD mode, the PD mode, or the bD mode is selected during the operation of the load 30 by the power supply system 5. It can be executed according to the flowchart.

[Embodiment 2]
As described in the first embodiment, the voltage sensor correction process and the current sensor correction process according to the present invention can be executed accompanying the control of the power converter 50 during the operation of the load 30. On the other hand, the voltage sensor correction process and the current sensor correction process are performed even when the on / off of the switching elements S1 to S4 is controlled so as to form the predetermined switching pattern shown in FIGS. It is possible to execute.

  In the second embodiment, a sensor correction mode, which is a typical example of sensor correction during a load stop, will be described. The sensor correction mode according to the second embodiment can be executed, for example, when power supply system 5 is activated.

  FIG. 11 is a flowchart for illustrating a control processing procedure in the sensor correction mode according to the second embodiment.

  Referring to FIG. 11, control device 40 instructs the start of sensor mode when power supply system 5 is activated in step S500. When instructed to start the sensor correction mode, the control device 40 executes a control process for zero point correction of the current sensors 12a, 12b, and 12H shown in FIG. 9 in step S510. For example, the zero point correction can be executed before the relays RLa and RLb are turned on.

  When the zero point correction of the current sensors 12a, 12b, and 12H is completed, the control device 40 forms the switching pattern shown in FIG. 5 in step S520. Furthermore, the control apparatus 40 performs the correction process of the voltage sensor 11b by step S530. In step S530, the control processing of steps S120 and S130 shown in FIG. 6 is executed. Note that the control device 40 may control the operation of the load 30 so that current consumption occurs, if necessary, so that the current Ia> 0. For example, the operation of the load 30 can be controlled so that only the field current flows without the motor generator 35 outputting torque, that is, the motor generator 35 is subjected to zero torque control.

  Further, in step S540, the control device 40 forms the switching pattern shown in FIG. Thus, DC power supplies 10a and 10b are connected in series between power lines 20 and 21.

  When the switching pattern shown in FIG. 7 is formed, control device 40 determines whether each current Ia, Ib, or IH is zero in step S550. Since the zero point correction is executed in step S510, the determination in step S550 can be executed based on the outputs of the current sensors 12a, 12b, and 12H.

  When each of currents Ia, Ib, and IH is zero (when YES is determined in S550), control device 40 executes correction of voltage sensor 11H in step S560. In step S560, the same control process as in step S220 shown in FIG. 8 is executed.

  When each current is not zero (NO in S550), control device 40 stops the operation of load 30 in step S570. Thereby, when step S550 changes from NO determination to YES determination, correction of voltage sensor 11H by step S560 is performed.

  When the correction of voltage sensor 11H is completed, control device 40 adjusts the load current in step S580. As a result, the load current IH> 0. For example, as described above, the load current IH in the voltage sensor correction mode can be generated by controlling the motor generator 35 with zero torque.

  Control device 40 executes correction of current sensors 12b and 12H in a state where load current IH is adjusted in step S590. In step S590, the same control process as in step S360 shown in FIG. 10 is executed.

  In the current sensor, the relationship between the output of the Hall element (Hall voltage) and the passing current is not completely linear, and there is a possibility that the sensor gain differs between a small current and a large current. Therefore, it is preferable to perform correction of the sensor gain at a plurality of points having different current levels. For this reason, in the sensor correction mode, it is preferable to previously define a plurality of current operating points (load currents IH) for correcting the sensor gain of the current sensor. Then, the adjustment of the load current IH in step S580 is executed so as to realize the plurality of current operation points in order.

  If load 30 is equipped with a power generation mechanism for supplying charging power of DC power supplies 10a and 10b separately from motor generator 35, the load 30 is loaded in the region of IH <0 in step S580. It is also possible to adjust the current IH. In other words, the current operating point for sensor gain correction may include a current negative region.

  Control device 40 corrects current sensors 12b and 12H in step S590 while sequentially switching the current operating point in step S580. Step S600 is determined as NO until all of the plurality of predetermined current operating points are realized.

  Therefore, when correction of current sensors 12b and 12H at each of a plurality of predetermined current operating points is completed, step S600 is determined as NO. In response to this, the control device 40 proceeds to step S610 to end the sensor correction mode. As a result, the switching elements S1 to S4 are all turned off after completing the formation of the switching pattern (S560) shown in FIG. After the end of the sensor correction mode, the output of the power converter 50 can be controlled based on the corrected outputs of the voltage sensors 11a, 11b, 11H and the current sensors 12a, 12b, 12H.

  Thus, according to the sensor correction mode according to the second embodiment, the correction processing of voltage sensors 11b and 11H and current sensors 12b and 12H described in the first embodiment can be performed by a series of control processes. In particular, by executing the sensor correction mode as part of the startup process of the power supply system 5, the voltage sensors 11b and 11H and the current sensors 12b and 12H are corrected based on the outputs of the reference sensors 11a and 11b, and then the accurate sensor Based on the detected value, the operation of the power supply system 5 during the operation of the load 30 can be controlled.

  In the present embodiment, the detection accuracy of voltage sensor 11a and current sensor 12a provided corresponding to DC power supply 10a is higher than that of voltage sensor 11b and current sensor 12b provided corresponding to DC power supply 10b. Although the case has been described, the application of the present invention is not limited to such a configuration. That is, when the detection accuracy of the voltage sensor 11b and the current sensor 12b provided corresponding to the DC power supply 10b is higher than that of the voltage sensor 11a and the current sensor 12a provided corresponding to the DC power supply 10a, the voltage sensor It is possible to correct other voltage sensors 11a and 11H and current sensors 12a and 12H by using 11b and current sensor 12b as a “reference sensor”.

  Further, as described above, in the power supply system 5, the arrangement of the current sensor 12H may be omitted. In this case, for the current sensor correction when the switching pattern shown in FIG. 7 is formed, only the current sensor 12b is corrected based on the output of the current sensor 12a as the reference sensor.

  In addition, in the power supply system 5, the load 30 will be described in terms of confirmation that it can be configured by an arbitrary device as long as it is a device that operates with a DC voltage controlled by a power converter. That is, in the present embodiment, the example in which the load 30 is configured to include the electric motor for traveling of the electric vehicle has been described, but the application of the present invention is not limited to such a load.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  5 Power supply system, 10a, 10b DC power supply, 11H, 11a, 11b Voltage sensor, 12H, 12a, 12b Current sensor, 20, 21 Power line, 30 Load, 32 Inverter, 35 Motor generator, 36 Power transmission gear, 37 Drive wheel, 40 control device, 50 power converter, 51-53 current path, 101, 102 operating point, 110, 120 operating region, CH smoothing capacitor, D1-D4 antiparallel diode, IH load current, Ia, Ib current (DC power supply) , L1, L2 reactor, N1-N3 node, RLa, RLb relay, S1-S4 power semiconductor switching element, SG1-SG4 control signal (switching element), VH output voltage.

Claims (12)

A power supply system for outputting a DC voltage between first and second power lines connected to a load,
A first DC power supply;
A second DC power source;
A first voltage detector for detecting the voltage of the first DC power supply;
A second voltage detector for detecting the voltage of the second DC power supply;
A first current detector for detecting a current of the first DC power source;
A second current detector for detecting the current of the second DC power supply;
A third voltage detector for detecting the DC voltage between the first and second power lines;
First to fourth switching elements sequentially connected in series between the first and second power lines;
A first reactor electrically connected between a connection node of the second and third switching elements and a positive terminal of the first DC power supply;
A second reactor electrically connected between a connection node of the first and second switching elements and a positive terminal of the second DC power supply;
A negative terminal of the first DC power supply is electrically connected to the second power line;
A negative terminal of the second DC power supply is electrically connected to a connection node of the third and fourth switching elements;
A control device for controlling on / off of the first to fourth switching elements;
One of the first voltage detector and the second voltage detector has a higher detection accuracy than the other voltage detector,
One of the predetermined current detectors of the first and second current detectors has higher detection accuracy than the other current detector,
The controller is
Predetermining the first to fourth switching elements so that the state in which the first and second DC power supplies are electrically connected in parallel or in series between the first and second power lines is maintained. Switching control means for forming a switching pattern of
A voltage detector correction process for correcting the other voltage detector or the third voltage detector based on a detection value by the one voltage detector in a period in which the predetermined switching pattern is formed; and And a correction means for executing at least one of current detector correction processing for correcting the other current detector based on a detection value by the one current detector.   The voltage detector correction process is a period in which the state where the first and second DC power supplies are electrically connected in parallel between the first and second power lines is maintained by the predetermined switching pattern. The power supply system according to claim 1, further comprising: correcting the other voltage detector based on a detection value by the one voltage detector.   In the voltage detector correction process, a period in which the first and second DC power supplies are electrically connected in series between the first and second power lines by the predetermined switching pattern is maintained. 2. The power supply system according to claim 1, further comprising: correcting the third voltage detector based on a detection value obtained by the one voltage detector and the other voltage detector. The voltage detector correction process is:
In a period in which the state in which the first and second DC power supplies are electrically connected in parallel between the first and second power lines is maintained, the first and second DC power supplies are based on the detection value by the one voltage detector. A first correction process for correcting the other voltage detector;
In a period in which the state where the first and second DC power supplies are electrically connected in series between the first and second power lines is maintained, the detection value by the one voltage detector and the first 2. The power supply system according to claim 1, further comprising: a second correction process for correcting the third voltage detector based on a detection value by the other voltage detector after the correction by the correction process. The controller is
When the circuit state is such that no current flows through the first and second DC power supplies, the current output values of the first and second current detectors are set to the corresponding zero points when the current value is zero. The power supply system according to any one of claims 1 to 4, further comprising a zero point correcting means for achieving the above.   The current detector correction process is a period in which the state where the first and second DC power supplies are electrically connected in series between the first and second power lines is maintained by the predetermined switching pattern. The power supply system according to claim 1, further comprising a process of correcting the other current detector based on a detection value obtained by the one current detector. A third current detector for detecting an input / output current from the power supply system to the load via the first and second power lines;
The current detector correction process is a period in which the state where the first and second DC power supplies are electrically connected in series between the first and second power lines is maintained by the predetermined switching pattern. The power supply system according to claim 1, further comprising: correcting the other current detector and the third current detector based on a detection value by the one current detector. The power supply system applies one operation mode among a plurality of operation modes having different modes of power conversion between the first and second DC power supplies and the power line during the operation of the load. Configured to control the voltage of the power line by operating;
The correction means corrects the voltage detector when the operation mode is selected such that on-off patterns of the first to fourth switching elements coincide with the predetermined switching pattern during operation of the load. The power supply system according to claim 1, wherein at least one of a process and the current detector correction process is executed.   The said correction | amendment means performs at least one of the said voltage detector correction process and the said current detector correction process, when the correction mode is selected during the stop of the said load, The any one of Claims 1-7 Power supply system as described in. The control device is configured to execute a correction mode for correcting the other voltage detector, the third voltage detector, and the other current detector;
The controller is
In the correction mode, when the circuit state is such that no current flows through the first and second DC power supplies, the current output value of the first and second current detectors is the current value is zero. Zero point correction means for setting a zero point corresponding to
After completion of the zero point correction by the zero point correcting means, a first for maintaining the state where the first and second DC power sources are electrically connected in parallel between the first and second power lines. Means for controlling the first to fourth switching elements such that a switching pattern is formed;
Means for correcting the other voltage detector based on a detection value by the one voltage detector in a period in which the first switching pattern is formed;
Second switching for maintaining the state in which the first and second DC power supplies are electrically connected in series between the first and second power lines after the correction of the other voltage detector is completed. Means for controlling the first to fourth switching elements such that a pattern is formed;
In the state where the second switching pattern is formed and the load is stopped, based on the detection value by the one voltage detector and the detection value by the other voltage detector, Means for correcting the three voltage detectors;
In the state where the second switching pattern is formed and the current is exchanged between the power supply system and the load, the other current detector based on the detection value by the one current detector The power supply system of claim 1, comprising: means for correcting The controller is
In the period in which the second switching pattern is formed, the current supplied to the load is changed in a plurality of stages, and in each stage, the other current detection is performed based on the detection value by the one current detector. The power supply system of claim 10 further comprising means for correcting the vessel. A third current detector for detecting an input / output current from the power supply system to the load via the first and second power lines;
The controller is
In the correction mode, for correcting the third current detector together with the other current detector based on a detection value by the one current detector in a period in which the second switching pattern is formed. The power supply system according to claim 10 or 11, further comprising means.

Images