JP7238638B2 - How to determine the mounting state of the current sensor - Google Patents

Description

The present invention provides a two-phase interconnected distributed power supply system in which output lines of a power converter are connected to either one of two voltage phases and a neutral phase of a single-phase three-wire power system, respectively, and includes two current sensors. It relates to a method for determining the mounting state of a current sensor for determining the mounting state of a current sensor.

Conventionally, in a distributed power supply system that connects three wires of a single-phase three-wire power system, U phase (voltage phase), V phase (voltage phase), and N phase (neutral phase), the connection point A device has been proposed that determines the mounting state of two current sensors that are mounted on the power system side of the power system (see, for example, Patent Document 1). This system includes a voltage detector that detects the voltage between the U-phase and the N-phase and the voltage between the V-phase and the N-phase, internal power loads such as heaters, and the connection of the internal power load to the power system between the U-phase and the N-phase. A connection mechanism (switch) for switching between the V phase and the N phase is provided. Then, when the internal power load is connected between the U-phase and the N-phase or between the V-phase and the N-phase by the connection mechanism, the mounting positions of the two current sensors and It determines the mounting direction.

WO2011/093109A1

By the way, a scheme has been proposed in which a distributed power supply system is connected to either of two voltage phases (U phase, V phase) and the neutral phase (N phase) of the single-phase three-wire system. In this method, since the distributed power supply system does not pull in the voltage phases that are not interconnected, it is not possible to connect internal loads to the voltage phases that are not pulled in. For this reason, in the method of connecting the distributed power supply system to either of the two voltage phases and the neutral phase of the single-phase three-wire, the method described in Patent Document 1 is used to determine the mounting position and mounting direction of the current sensor. Can not do it. In addition, this method cannot recognize whether the phases connected to the distributed power supply system are between the U phase and the N phase or between the V phase and the N phase. Either one or the neutral phase) cannot be determined whether the distributed power supply system (both output terminals of the inverter) is connected to the distributed power supply system (both output terminals of the inverter) in a normal or reverse connection. It is necessary to

The current sensor mounting state determination method of the present invention is a two-phase interconnection distributed type in which the output lines of the power converter are connected to either one of two voltage phases and the neutral phase of a single-phase three-wire power system. A main object of the present invention is to provide a mounting state determination method capable of determining the mounting orientation and mounting position of two current sensors in a power supply system.

The current sensor mounting state determination method of the present invention employs the following means in order to achieve the main object described above.

The first current sensor mounting state determination method of the present invention includes:
A distributed power source, a power conversion device that converts and outputs the power of the distributed power source, a voltage sensor connected between output lines of the power conversion device, and a voltage sensor connected between the output lines of the power conversion device. and an internal load, in a two-phase interconnected distributed power supply system in which the output lines of the power conversion device are connected to either one of the two voltage phases and the neutral phase of a single-phase three-wire power system, A current sensor mounting state determination method for determining the mounting state of the two current sensors when the two current sensors are mounted on the two voltage phases ,
a first step of identifying the neutral phase;
a second step of attaching two current sensors to the neutral phase identified in the first step and operating the internal load;
Based on the direction of change in the current measured by the two current sensors or the direction of change in the power measured by the two current sensors, which is specified based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load. a third step of determining the mounting orientation of the two current sensors;
One of the two current sensors attached to the neutral phase is attached to one of the two voltage phases different from the neutral phase while maintaining the same attachment orientation, and the other of the two current sensors is attached to the same attachment orientation. a fourth step of operating the internal load by attaching it to the other of the two voltage phases while maintaining
Based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load, whichever of the two current sensors measures the current change or the power change corresponding to the internal load. It is determined that the current sensor is attached to the interconnection phase, which is the voltage phase to which the distributed power supply system is interconnected, out of the two voltage phases, and the current corresponding to the internal load among the two current sensors. Fifth, determining that the one for which no change or power change is measured is the current sensor attached to the non-interconnected phase, which is the voltage phase to which the distributed power supply system is not interconnected, of the two voltage phases. a step;
a sixth step of correcting the mounting orientations of the two current sensors based on the determination result of the third step and correcting the mounting positions of the two current sensors based on the determination result of the fifth step;
The gist is to provide

In the first current sensor attachment state determination method of the present invention, a neutral phase is specified, two current sensors are attached to the specified neutral phase, and an internal load is operated. Subsequently, two current sensors are identified based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load. Determine the orientation of the current sensor. Next, one of the two current sensors attached to the neutral phase is attached to one of the two voltage phases different from the neutral phase while maintaining the same attachment orientation, and the other of the two current sensors is attached to the same attachment orientation. It remains attached to the other of the two voltage phases to operate the internal load. Before and after the operation of the internal load, one of the two current sensors that measures the current change or the power change is determined to be the current sensor attached to the interconnected phase, and the current change or the power change of the two current sensors is determined. is determined to be the current sensor attached to the non-interconnected phase. Then, the mounting orientations of the two current sensors are corrected based on the determination result of the mounting orientation, and the mounting positions of the two current sensors are corrected based on the mounting position determination result. As a result, in a two-phase interconnection distributed power supply system, it is possible to provide an installation state determination method capable of determining the installation orientation and installation position of the two current sensors.

A second current sensor mounting state determination method of the present invention includes:
A distributed power source, a power conversion device that converts and outputs the power of the distributed power source, a voltage sensor connected between output lines of the power conversion device, and a voltage sensor connected between the output lines of the power conversion device. and an internal load, in a two-phase interconnected distributed power supply system in which the output lines of the power conversion device are connected to either one of the two voltage phases and the neutral phase of a single-phase three-wire power system, A current sensor mounting state determination method for determining the mounting state of the two current sensors when the two current sensors are mounted on the two voltage phases ,
a first step of identifying the neutral phase;
a second step of attaching two current sensors to the neutral phase identified in the first step and operating the internal load;
Based on the direction of change in the current measured by the two current sensors or the direction of change in the power measured by the two current sensors, which is specified based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load. a third step of determining the mounting orientation of the two current sensors;
One of the two current sensors attached to the neutral phase is attached to one of the two voltage phases different from the neutral phase so that it is positive based on the determination result of the third step, and the two a fourth step of operating the internal load by attaching the other current sensor to the other of the two voltage phases so that the other current sensor is positive based on the determination result of the third step;
Based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load, whichever of the two current sensors measures the current change or the power change corresponding to the internal load. It is determined that the current sensor is attached to the interconnection phase, which is the voltage phase to which the distributed power supply system is interconnected, out of the two voltage phases, and the current corresponding to the internal load among the two current sensors. Fifth, determining that the one for which no change or power change is measured is the current sensor attached to the non-interconnected phase, which is the voltage phase to which the distributed power supply system is not interconnected, of the two voltage phases. a step;
a sixth step of correcting the mounting positions of the two current sensors based on the determination result of the fifth step;
The gist is to provide

In the second current sensor attachment state determination method of the present invention, the neutral phase is identified, two current sensors are attached to the identified neutral phase, and the internal load is operated. Subsequently, two current sensors are identified based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load. Determine the orientation of the current sensor. Next, one of the two current sensors attached to the neutral phase is attached to one of the two voltage phases different from the neutral phase so that the direction is positive based on the determination result of the attachment direction, and two currents are detected. The other of the sensors is attached to the other of the two voltage phases so as to be in the positive direction based on the determination result of the attachment direction, and the internal load is operated. Before and after the operation of the internal load, one of the two current sensors that measures the current change or the power change is determined to be the current sensor attached to the interconnected phase of the two voltage phases, and the current sensor of the two current sensors It is determined that the current sensor attached to the non-interconnected phase is the current sensor for which no current change or power change is measured. Then, based on the determination result, the mounting positions of the two current sensors are corrected. As a result, in a two-phase interconnection distributed power supply system, it is possible to provide an installation state determination method capable of determining the installation orientation and installation position of the two current sensors.

In the first or second current sensor mounting state determination method of the present invention, the third step comprises: the amount of change in the measured current or the amount of change in the measured power of the two current sensors before and after the operation of the internal load; is less than a predetermined amount as an absolute value, the occurrence of an error may be notified. In this way, the operator can be promptly notified of the occurrence of an installation abnormality or failure. It should be noted that, as a case corresponding to the above error, for example, there may be a case where the current sensor is disconnected, or a case where the current sensor is attached to the non-interconnected phase instead of the neutral phase.

Further, in the first or second current sensor mounting state determination method of the present invention, the fifth step comprises: If the determination of the direction is the same as the determination in the third step, the occurrence of an error may be notified. In this way, it is possible to promptly notify the operator of the occurrence of the mounting abnormality. As a case corresponding to the above error, for example, a case where the current sensor is still attached to the neutral phase can be considered.

Further, in the first or second current sensor mounting state determination method of the present invention, the fifth step is to determine whether the current corresponding to the internal load is detected in either of the two current sensors before and after the operation of the internal load. If a change or power change is measured, or if neither of the two current sensors measures a current change or power change corresponding to the internal load, an error may be reported. In this way, it is possible to promptly notify the operator of the occurrence of the mounting abnormality. In addition, as a case corresponding to the above error, for example, if both current sensors measure a current change or power change corresponding to the internal load, both current sensors are attached to the interconnected phase. If none of the two current sensors measure a current change or power change corresponding to the internal load, it is considered that the two current sensors are both attached to the non-tied phase.

1 is a configuration diagram showing an outline of the configuration of a distributed power supply system 20; FIG. FIG. 4 is an explanatory diagram showing a CT mounting state determination process; FIG. 4 is an explanatory diagram showing a CT mounting state determination process; It is explanatory drawing which shows a mode that current sensor CT1, CT2 is attached to N phase. It is explanatory drawing which shows the relationship between an electric power change and the attachment direction of current sensor CT1, CT2. FIG. 4 is an explanatory diagram showing how current sensors CT1 and CT2 are attached to separate phases other than the N phase; It is explanatory drawing which shows the relationship between a current change and the attachment position of current sensor CT1, CT2.

A mode for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing an outline of the configuration of a distributed power supply system 20. As shown in FIG. The distributed power supply system 20 is connected to a power receiving facility installed in a house or the like that receives power from a single-phase three-wire commercial power system 10, and is connected to one of the three phases of the commercial power system 10 and the middle voltage phase. It is configured as a system that is connected to two phases, the sex phase. For example, when the distributed power supply system 20 is installed outdoors, the distributed power supply system 20 can be connected to the commercial power system 10 using an outdoor outlet, and construction work for drawing a single-phase three-line outdoors, etc. No need. Hereinafter, of the three phases of the commercial power system 10, the neutral phase is also referred to as N phase (neutral phase) 12n, one of the two voltage phases is also referred to as U phase (voltage phase) 12u, and the other of the two voltage phases is referred to as U phase (voltage phase) 12u. is also called a V phase (voltage phase) 12v. The N phase 12n is grounded through a pole transformer (not shown). A domestic load (external load) 14u is connected between the U-phase and the N-phase, and a domestic load (external load) 14v is connected between the V-phase and the N-phase.

In this embodiment, the distributed power supply system 20 is a system that does not allow reverse power flow to the commercial power system 10. As shown in FIG. A power conditioner 24 that converts electric power into AC power, a parallel-off relay 26 (RY1, RY2) that connects/disconnects to commercial electric power system 10, U phase 12u and V phase 12v of commercial electric power system 10 The current sensor CT1 that measures the current flowing in the interconnected phase (the U phase 12u in this embodiment) to which the distributed power supply system 20 is interconnected, and the distributed power supply system 20 are not interconnected. A current sensor CT2 that measures the current flowing in the non-connected phase (in this embodiment, the V phase 12v) acts between the connected phase (U phase 12u) and the neutral phase (N phase 12n). A voltage sensor 32 for measuring a voltage (interconnection phase voltage), and an accessory 42 connected to an interconnection phase (U phase 12u) and a neutral phase (N phase 12n) via an accessory drive device 44. , and a control device 50 that controls the entire system.

The power generation device 22 includes, for example, a solid oxide fuel cell, an evaporator, a reformer, etc., and generates power using a reformed gas (hydrogen gas) produced by reforming the raw fuel gas and an oxidant gas. It is configured as a fuel cell device that Note that the power generator 22 may be configured by a combination of a prime mover (gas engine, gas turbine, etc.) and a generator that generates power from the power from the prime mover.

The power conditioner 24 includes a DC/DC converter that converts the voltage of the DC power generated by the generator 22, and an inverter that converts the DC power output from the DC/DC converter into AC power. Two output lines of the inverter are connected to U-phase 12 u and N-phase 12 n of commercial power system 10 via parallel-off relay 26 .

The current sensors CT1 and CT2 include CTs (Current Transformers) attached to the U-phase 12u and V-phase 12v of the commercial power system 10, and a CT measurement circuit connected to the CT windings. The CT is configured, for example, as a through-type current transformer. The CT measurement circuit, for example, has a resistance connected between the windings of the CT, and is configured as a measurement circuit that measures the current flowing through the wire to which the CT is attached by measuring the voltage acting on the resistance. be. The current sensors CT1 and CT2 also measure the current direction depending on whether the current waveform to be measured has the same phase or the opposite phase as the voltage waveform measured by the voltage sensor 32 .

The auxiliary equipment 42 is a peripheral device (internal load of the distributed power supply system 20) of the power generation device 22, and is, for example, a cogeneration system in which the distributed power supply system 20 includes a fuel cell and a hot water storage device that stores hot water using exhaust heat from the fuel cell. When applied to the system, the pump that supplies fuel gas to the fuel cell, the blower that supplies air as oxidant gas, the flow sensor that measures the flow rate of fuel gas, the flow sensor that measures the flow rate of air, and the hot water storage device A pump for circulating the stored hot water for exchanging heat with the exhaust heat of the fuel cell, a freeze prevention heater for preventing freezing in the piping of the hot water storage device, and the like can be mentioned.

Although not shown, the control device 50 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM as a work memory, an input/output port, and the like. Measurement signals from the current sensors CT1 and CT2 are input to the controller 50 through input ports. On the other hand, the control device 50 outputs a control signal to the power generation device 22, a control signal to the power conditioner 24, an on/off signal to the parallel-off relay 26, a display signal to the display 52, and the like through the output port. ing.

The controller 50 measures the current flowing through the U phase 12u and the current flowing through the V phase 12v of the commercial power system 10 using the two current sensors CT1 and CT2, and measures the current flowing through the U phase 12u and the N phase 12n (continuously) using the voltage sensor 32. system phase), and monitor the power flow direction based on the measured current and voltage. When it is determined that a reverse power flow (flow of active power from the distributed power system 20 to the commercial power system 10) has occurred, the parallel-off relay 26 is turned off to disconnect the distributed power system 20 from the commercial power system 10. Thereby, reverse power flow can be prevented in the distributed power supply system 20 in which reverse power flow is not allowed. As described above, the current sensors CT1 and CT2 are used to monitor the direction of the power flow, so if the mounting position or the mounting direction is incorrect, the power flow cannot be monitored correctly.

Next, when the distributed power supply system 20 configured in this way is installed in a house or the like, when the current sensors CT1 and CT2 are attached to the two voltage phases (the U phase 12u and the V phase 12v), the mounting directions and mounting positions thereof will be described. A process for determining is described. 2 and 3 are explanatory diagrams showing the CT mounting state determination process.

In the CT mounting state determination step, first, the N phase 12n is specified (step S100). In this step S100, for example, when the operator presses the voltage probe of the tester against any two of the U phase 12u, V phase 12v and N phase 12n and the measured value is about 200 V, the two phases is either the U phase 12u or the V phase 12v, and the remaining one phase is determined to be the N phase 12n. Subsequently, as shown in FIG. 4, the operator attaches two current sensors CT1 and CT2 to the identified N phase 12n (step S110), and measures the current with each current sensor CT1 and CT2 (step S120). , the power of the current sensors CT1 and CT2 is measured from the measured current and the grid phase voltage measured by the voltage sensor 32 (step S130).

Next, after controlling the accessory driving device 44 so that the accessory 42 as an internal load operates (step S140), the current is measured by the current sensors CT1 and CT2 in the same manner as in steps S120 and S130, and ( Step S150), the power of the current sensors CT1 and CT2 is measured based on the measured current and the interconnected phase voltage measured by the voltage sensor 32 (step S160).

When the current and power of the current sensors CT1 and CT2 are measured before and after the operation of the auxiliary machine 42 in this manner, the difference between the currents of the current sensors CT1 and CT2 before and after the operation of the auxiliary machine 42 is taken to calculate the amount of current change ( Step S170), the difference between the powers of the current sensors CT1 and CT2 is taken to calculate the amount of change in power (step S180).

After operating the auxiliary device 42, it is determined whether or not a specified time has elapsed (step S190). Here, the specified time is predetermined as the time required for the operation of the auxiliary machine 42 to stabilize. If it is determined that the specified time has not elapsed, the process returns to step S150 to repeat the processing of steps S150 to S180. is equal to or greater than the default value (step S200). Here, the default value is predetermined as a current change amount corresponding to the load of auxiliary machine 42 in the phase (N phase 12n) to which current sensors CT1 and CT2 are attached. If it is determined that the absolute value of the current change amount of either current sensor CT1 or CT2 is not equal to or greater than the predetermined value, the mounting position of the corresponding current sensor is incorrect (for example, the corresponding current sensor is connected to the distributed power supply system 20). (attached to a non-interconnected phase that is not connected) or disconnection has occurred in the corresponding current sensor, and the fact that an error has occurred is displayed on the display 52 (step S360), and this process is terminated. finish.

If it is determined in step S200 that the absolute value of the amount of change in the current of both the current sensors CT1 and CT2 is equal to or greater than the predetermined value, the mounting orientation of the current sensors CT1 and CT2 is determined and controlled based on the amount of change in power measured in step S180. It is stored in the RAM of device 50 (step S210). The determination in step S210 is performed using a CT installation orientation determination map illustrated in FIG. In this CT mounting direction determination map, as shown in FIG. 5, if the electric power change amount of the current sensor is on the increasing side ("Increase" in the drawing), it is determined that the current sensor is mounted in the positive direction. If it is determined that the amount of change in electric power of the current sensor is on the decreasing side ("decrease" in the figure), it is determined that the current sensor is installed in the opposite direction. When the mounting orientations of the current sensors CT1 and CT2 attached to the N phase 12n are thus determined, the determined mounting orientations are displayed on the display 52 to notify the operator (step S220).

Next, as shown in FIG. 6, the operator separates the current sensors CT1 and CT2 attached to the N phase 12n into separate phases ( U phase 12u, V phase 12v) (step S230). Subsequently, as in steps S120 to S190, the current and power of the current sensors CT1 and CT2 are measured before and after the operation of the accessory 42, and the amount of change in the current of the current sensors CT1 and CT2 before and after the operation of the accessory 42 is calculated. A power change amount is calculated (steps S240 to S310). Then, it is determined whether or not the sign of the power change amount of the current sensors CT1 and CT2 calculated in step S300 is the same as the sign of the power change amount of the current sensors CT1 and CT2 calculated in step S180 (step S320). . If it is determined that both power variations have the same sign, it is determined that the current sensors CT1 and CT2 have been incorrectly attached in step S230 (the corresponding current sensor remains attached to the neutral phase). , the error occurrence is displayed on the display 52 (step S360), and the process ends.

On the other hand, if it is determined that the signs of both power variations are not the same, the mounting positions of the current sensors CT1 and CT2 are determined based on the current variation calculated in step S290 (step S330). The determination in step S330 is performed using the CT mounting position determination map illustrated in FIG. In the CT mounting position determination map, as shown in FIG. 7, if the current sensor has a current change corresponding to the load of the auxiliary machine 42 ("Yes" in the figure), the current sensor detects the connected phase ( In this embodiment, if it is determined that the current sensor is attached to the U phase 12u) and there is no current change corresponding to the load of the auxiliary machine 42 (“No” in the figure), the current sensor is disconnected It is determined that it is attached to the phase (V phase 12v in this embodiment). That is, if only one of the current sensors CT1 and CT2 has a current change corresponding to the load of the auxiliary machine 42 ("YES" in step S340), the current sensor with the current change is attached to the interconnected phase. It is determined that the current sensor whose current has not changed is attached to the non-interconnected phase, and the process proceeds to S350. On the other hand, if there is a current change corresponding to the load of auxiliary machine 42 in both current sensors CT1 and CT2 or if there is no current change corresponding to the load of auxiliary machine 42 in both current sensors CT1 and CT2 ("NO" in step S340), current sensor CT1 , CT2 are both attached to the connected phase or both are attached to the non-connected phase, the error occurrence is displayed on the display 52 (step S360), and the present process ends.

After determining the mounting orientation and mounting position of each of the current sensors CT1 and CT2 in this manner, the current sensors CT1 and CT2 are corrected according to the determination results (step S350), and this process ends. Correction of the mounting direction is carried out by keeping the phase of the measured value as it is if the result of the determination of the mounting direction is "positive", and by inverting the phase of the measured value if the result of the determination of the mounting direction is "reverse". be In addition, when correcting the mounting position, if the mounting position is a connected phase, the measured value of the corresponding current sensor is recognized as the connected phase current, and if the mounting position is a non-connected phase, the corresponding current sensor This is done by recognizing the measured value as a non-tied phase current.

As described above, the current sensor mounting state determination method of the present embodiment specifies the neutral phase (N phase 12n), attaches the two current sensors CT1 and CT2 to the specified neutral phase, and The auxiliary machine 44 of is operated. Next, based on the change direction of the measured power of the two current sensors CT1 and CT2 specified based on the measured values measured by the two current sensors CT1 and CT2 and the voltage sensor 32 before and after the operation of the auxiliary device 44, The mounting directions of the two current sensors CT1 and CT2 are determined. Next, one of the two current sensors CT1 and CT2 attached to the neutral phase is attached to one of the two voltage phases (U phase 12u, V phase 12v) while maintaining the same attachment orientation, and the two current sensors The accessory 44 is operated by attaching the other to the other of the two voltage phases while maintaining the same attachment orientation. Before and after the operation of the auxiliary machine 44, the one of the two current sensors CT1 and CT2 that measures the current change corresponding to the load of the auxiliary machine 44 is interconnected among the two voltage phases (U phase 12u, V phase 12v). It is determined that the current sensor is attached to the phase (U phase 12u), and the non-interconnected phase (V phase 12v) of the two voltage phases for which the current change corresponding to the load of the auxiliary machine 44 is not measured. is the current sensor attached to the Then, the mounting orientations of the two current sensors CT1 and CT2 are corrected based on the determination result of the mounting orientation, and the mounting positions of the two current sensors CT1 and CT2 are corrected based on the mounting position determination result. As a result, in a two-phase interconnected distributed power supply system in which the output lines of the power conversion device are connected to either one of the two voltage phases and the neutral phase of the single-phase three-wire power system, It is possible to provide a mounting state determination method capable of determining the mounting direction and the mounting position.

In the embodiment, in step S210, the attachment orientation of the two current sensors CT1 and CT2 is determined based on the increase/decrease in the electric power variation of the two current sensors CT1 and CT2 before and after the operation of the accessory 44 (internal load). and However, the attachment orientation of the two current sensors CT1 and CT2 may be determined based on the increase or decrease in the amount of change in the current of the two current sensors CT1 and CT2 before and after the operation of the auxiliary device 44 (internal load).

In the embodiment, in step S230, the current sensors CT1 and CT2 attached to the N phase 12n are connected to separate phases (U phase 12u, V phase 12v ), and in step S350, the measured values of the current sensors CT1 and CT2 are corrected based on the determination result of the mounting direction in step S210. However, according to the determination result of the mounting direction of the current sensors CT1 and CT2 notified in step S220, the operator corrects the current sensors CT1 and CT2 mounted on the N phase 12n to the U phase 12u and V phase 12v, respectively. may be attached to the In this case, it is not necessary to correct the mounting orientation of the current sensors CT1 and CT2 in step S350.

In the embodiment, in step S330, the attachment positions of the two current sensors CT1 and CT2 are determined based on whether or not the currents of the two current sensors CT1 and CT2 change before and after the operation of the auxiliary device 44 (internal load). bottom. However, the attachment positions of the two current sensors CT1 and CT2 may be determined based on whether or not there is a change in the electric power of the two current sensors CT1 and CT2 before and after the operation of the auxiliary device 44 (internal load).

In the embodiments, the present invention is applied to the distributed power supply system 20 in which reverse power flow is permitted, but may be applied to a distributed power supply system in which reverse power flow is not permitted.

In the embodiment, the distributed power supply system 20 is configured as a distributed power generation system that includes the power generation device 22 , but may include a power storage device (battery) instead of the power generation device 22 .

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the power generator 22 corresponds to a "distributed power supply", the power conditioner 24 corresponds to a "power converter", the voltage sensor 32 corresponds to a "voltage sensor", and the auxiliary machine 42 corresponds to an "internal load ”, and the current sensors CT1 and CT2 correspond to the “current sensor”.

Note that the correspondence relationship between the main elements of the embodiment and the main elements of the invention described in the column of Means for Solving the Problem indicates that the embodiment implements the invention described in the column of Means to Solve the Problem. Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the embodiment should be based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

As described above, the mode for carrying out the present invention has been described using the embodiment, but the present invention is not limited to such an embodiment at all, and various forms can be used without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the manufacturing industry of distributed power supply systems.

10 commercial power system, 12u U-phase, 12v V-phase, 12n N-phase, 14u, 14v domestic load, 20 distributed power supply system, 22 generator, 24 power conditioner, 26, RY1, RY2 parallel-off relay, 32 voltage Sensor, 42 accessory, 44 accessory drive device, 50 controller, 52 indicator, CT1, CT2 current sensor.

Claims (5)

A distributed power source, a power conversion device that converts and outputs the power of the distributed power source, a voltage sensor connected between output lines of the power conversion device, and a voltage sensor connected between the output lines of the power conversion device. and an internal load, in a two-phase interconnected distributed power supply system in which the output lines of the power conversion device are connected to either one of the two voltage phases and the neutral phase of a single-phase three-wire power system, A current sensor mounting state determination method for determining the mounting state of the two current sensors when the two current sensors are mounted on the two voltage phases ,
a first step of identifying the neutral phase;
a second step of attaching two current sensors to the neutral phase identified in the first step and operating the internal load;
Based on the direction of change in the current measured by the two current sensors or the direction of change in the power measured by the two current sensors, which is specified based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load. a third step of determining the mounting orientation of the two current sensors;
One of the two current sensors attached to the neutral phase is attached to one of the two voltage phases different from the neutral phase while maintaining the same attachment orientation, and the other of the two current sensors is attached to the same attachment orientation. a fourth step of operating the internal load by attaching it to the other of the two voltage phases while maintaining the
Based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load, whichever of the two current sensors measures the current change or the power change corresponding to the internal load. It is determined that the current sensor is attached to the interconnection phase, which is the voltage phase to which the distributed power supply system is interconnected, out of the two voltage phases, and the current corresponding to the internal load among the two current sensors. Fifth, determining that the one for which no change or power change is measured is the current sensor attached to the non-interconnected phase, which is the voltage phase to which the distributed power supply system is not interconnected, of the two voltage phases. a step;
a sixth step of correcting the mounting orientations of the two current sensors based on the determination result of the third step and correcting the mounting positions of the two current sensors based on the determination result of the fifth step;
A mounting state determination method for a current sensor. A distributed power source, a power conversion device that converts and outputs the power of the distributed power source, a voltage sensor connected between output lines of the power conversion device, and a voltage sensor connected between the output lines of the power conversion device. and an internal load, in a two-phase interconnected distributed power supply system in which the output lines of the power conversion device are connected to either one of the two voltage phases and the neutral phase of a single-phase three-wire power system, A current sensor mounting state determination method for determining the mounting state of the two current sensors when the two current sensors are mounted on the two voltage phases ,
a first step of identifying the neutral phase;
a second step of attaching two current sensors to the neutral phase identified in the first step and operating the internal load;
Based on the direction of change in the current measured by the two current sensors or the direction of change in the power measured by the two current sensors, which is specified based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load. a third step of determining the mounting orientation of the two current sensors;
One of the two current sensors attached to the neutral phase is attached to one of the two voltage phases different from the neutral phase so that it is positive based on the determination result of the third step, and the two a fourth step of operating the internal load by attaching the other current sensor to the other of the two voltage phases so that the other current sensor is positive based on the determination result of the third step;
Based on the measured values measured by the two current sensors and the voltage sensor before and after the operation of the internal load, whichever of the two current sensors measures the current change or the power change corresponding to the internal load. It is determined that the current sensor is attached to the interconnected phase, which is the voltage phase to which the distributed power supply system is interconnected, of the two voltage phases, and the two voltage phases are determined.
The one of the two current sensors that does not measure the current change or power change corresponding to the internal load is assigned to the non-interconnected phase, which is the voltage phase to which the distributed power supply system is not interconnected, of the two voltage phases. a fifth step of determining an attached current sensor;
a sixth step of correcting the mounting positions of the two current sensors based on the determination result of the fifth step;
A mounting state determination method for a current sensor. The current sensor mounting state determination method according to claim 1 or 2,
In the third step, an error is notified when the amount of change in the measured current or the amount of change in the measured power of the two current sensors before and after the operation of the internal load is less than a predetermined amount as an absolute value.
How to determine the mounting state of a current sensor. A current sensor mounting state determination method according to any one of claims 1 to 3,
In the fifth step, when the determination result of the change direction of the measured current or the change direction of the measured power of the two current sensors before and after the operation of the internal load is the same as the determination result of the third step to notify that an error has occurred,
How to determine the mounting state of a current sensor. A current sensor mounting state determination method according to any one of claims 1 to 4,
In the fifth step, before and after the operation of the internal load, either the current change or the power change corresponding to the internal load is measured by either of the two current sensors, or the Notify the occurrence of an error if the current change or power change corresponding to the internal load is not measured.
How to determine the mounting state of a current sensor.

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