JP6448941B2 - Battery charging circuit, power supply device, cogeneration system, and battery charging method - Google Patents

Description

The present invention relates to a charging technology such as a battery mounted on a cogeneration system.

  The cogeneration system is equipped with a battery that stores electricity necessary for power generation when the system power supply is blacked out. This battery is charged by the system power supply or generator output.

Regarding charging of this battery, it is known that the voltage applied to the battery is controlled in accordance with the charging current flowing through the battery to make the voltage between the terminals of the battery constant (for example, Patent Document 1). In a stabilized DC power supply device, it is known that a DC voltage obtained by rectifying an AC voltage stepped down by a transformer is compared with a reference value, and a stabilized DC output is obtained by switching the transformer according to the comparison result. (For example, Patent Document 2). Regarding battery charging circuit, it is known to charge the battery with the voltage obtained by rectifying the output AC voltage of the generator, and switch the switch to short-circuit the generator when the charging voltage of the battery exceeds a predetermined voltage. (For example, Patent Document 3).

JP 7-95733 A Japanese Patent Laid-Open No. 11-110054 JP 2009-189160 A

  By the way, a voltage control system is used for a battery charging circuit for charging a battery. In this voltage control method, the charging current that flows through the battery is controlled according to the charging voltage. A large charging current required for charging may be supplied at a stage where the charging voltage is low, but if the charging of the battery proceeds and the charging voltage increases, the charging current flowing through the battery may be reduced. However, in the control of the charging current according to the detection of the charging voltage, there is a problem that charging with a weak current is difficult and the safety of battery charging is reduced. In addition, there is a problem that the durability of the battery and the charging circuit is lowered, and the components of the charging circuit cannot be reduced in size. In addition, when a large current is passed through the battery at a stage where the charging voltage has increased, there is a problem that the battery load is heavy and the battery life is reduced.

Therefore, in view of the above problems, an object of the present invention is to reduce the burden on the battery and to realize appropriate charging of the battery.

In order to achieve the above object, according to one aspect of the battery charging circuit of the present invention, a battery charging circuit for charging a battery, which is provided in a side path of the battery and detects a charging voltage of the battery. A first control current element provided on a side path of the battery and the detection unit, wherein a part of the charging current of the battery is supplied to the first control current element according to a detection voltage in the voltage detection unit; A voltage control unit that controls the voltage applied to the battery by shunting, a current detection unit that is connected in series to the battery and detects the charging current, and is connected to the voltage control unit; control current element have a, Ru and a current control unit for controlling the charging current by depending on the detection current draw some of the current diverted to the first control current element.

In order to achieve the above object, according to one aspect of the battery charging circuit of the present invention, a battery charging circuit for charging a battery, which is provided in a side path of the battery and detects a charging voltage of the battery. A first control current element provided on a side path of the battery and the detection unit, wherein a part of the charging current of the battery is supplied to the first control current element according to a detection voltage in the voltage detection unit; The voltage control unit for controlling the voltage applied to the battery by dividing the current into the battery and the current divided into the first control current element are detected, and the power supply output to the battery is controlled according to the detected current. a switching power supply circuit, is connected in series with the battery, a current detector for detecting the charging current, is connected to the voltage control unit has a second control current element, the current sensing Depending on the detected current parts Ru and a current control unit that controls the power supply output of the switching power supply circuit by drawing a portion of the current diverted to the first control current element.

  In the battery charging circuit, the current detection unit may include a current detection resistor, and may detect the current flowing through the battery by converting it into a voltage.

In the battery charging circuit, the switching power supply circuit receives control information of one or both of a voltage detection unit and a current detection unit for detecting a charging voltage of the battery, and the voltage applied to the battery and the voltage detection unit You may provide the control power supply part by which an electric current is controlled by the said control information.

In order to achieve the above object, according to one aspect of the power supply device of the present invention, a battery power supply comprising a battery or connected to the battery, wherein a charging current is passed through the battery to charge the battery. The battery charging circuit is provided in a side path of the battery, detects a charging voltage of the battery, is provided in the side path of the battery, and includes a first control current element. wherein, a voltage control unit for controlling a voltage applied to the battery by diverting a portion of the charging current of the battery according to the detected voltage at the voltage detector to the first control current element, the battery are connected in series, a current detector for detecting the charging current, is connected to the voltage control unit, it has a second control current device, the first control depending on the detection current Ru and a current control unit for controlling the charging current by drawing a portion of the current diverted to the flow element.

In order to achieve the above object, according to one aspect of the power supply device of the present invention, a battery power supply comprising a battery or connected to the battery, wherein a charging current is passed through the battery to charge the battery. The battery charging circuit is provided in a side path of the battery, detects a charging voltage of the battery, is provided in the side path of the battery, and includes a first control current element. A voltage control unit that controls a voltage applied to the battery by diverting a part of the charging current of the battery to the first control current element according to a detection voltage in the voltage detection unit; detecting a current that is diverted to one of the control current element, against the switching power supply circuit feeding an output to said battery in response to the detected current is controlled, in series with said battery Is a current detector for detecting the charging current, is connected to the voltage control unit has a second control current element, in response to said detection current of the current detection unit a first control current element Ru and a current control unit that controls the power supply output of the switching power supply circuit by drawing a portion of the diverted current.

In order to achieve the above object, according to one aspect of the cogeneration system of the present invention, a battery that supplies power to a load at the time of a power failure of a system power supply, a charging current is passed to the battery when the system power supply is normal, A battery charging circuit for charging, wherein the battery charging circuit is provided in a side path of the battery, and is provided in a voltage detection unit for detecting a charging voltage of the battery, and provided in a side path of the battery. Voltage control for controlling the voltage applied to the battery by diverting a part of the charging current of the battery to the first control current element in accordance with the detection voltage of the voltage detection unit. and parts, are connected in series with the battery, a current detector for detecting the charging current, is connected to the voltage control unit, have a second control current element, the detection current Depending by drawing a portion of the current diverted to the first control current element Ru and a current control unit for controlling the charging current.

In order to achieve the above object, according to one aspect of the cogeneration system of the present invention, a battery that supplies power to a load at the time of a power failure of a system power supply, a charging current is passed to the battery when the system power supply is normal, A battery charging circuit for charging, wherein the battery charging circuit is provided in a side path of the battery, and is provided in a voltage detection unit for detecting a charging voltage of the battery, and provided in a side path of the battery. Voltage control for controlling the voltage applied to the battery by diverting a part of the charging current of the battery to the first control current element in accordance with the detection voltage of the voltage detection unit. and parts, detecting the first current diverted to the control current element, a switching power supply circuit feeding an output to said battery in response to the detected current is controlled, Are connected in series to the serial battery, a current detector for detecting the charging current, is connected to the voltage control unit has a second control current element, in response to said detection current of the current detecting unit Ru and a current control unit that controls the power supply output of the switching power supply circuit by drawing a portion of the current diverted to the first control current element.

To achieve the above object, according to one aspect of the battery charging method of the present invention, a bypass comprising a first control current element is formed in the battery to be charged, and detect the charging voltage and charging current of the battery The voltage applied to the battery is controlled by diverting a part of the charging current of the battery to the first control current element according to the charging voltage, and the side path and the charging current are controlled according to the charging current. the second control current elements connected, by pulling a portion of the current diverted to the first control current element, to control the charging current.

  According to the present invention, any of the following effects can be obtained.

  (1) If the charging voltage of the battery is low, it can be charged by current control, and if the charging voltage reaches a predetermined voltage, it can be appropriately charged by voltage control.

  (2) It is possible to charge with a low current circuit, and the safety of battery charging can be improved.

  (3) The durability of the charging circuit is increased, and the components of the charging circuit can be reduced in size.

(4) The burden on the battery can be reduced, and the battery can be used for a long time.

It is a figure which shows an example of the battery charging circuit which concerns on 1st Embodiment, or the charging method of a battery. It is a figure which shows operation | movement of a battery charging circuit. It is a figure which shows an example of the power supply device which concerns on 2nd Embodiment. It is a circuit diagram which shows an example of a power supply device. It is a figure which shows operation | movement of a power supply device. It is a figure for demonstrating voltage control and electric current control. It is a figure which shows an example of the cogeneration system which concerns on 3rd Embodiment. It is a figure which shows the experimental result of the power supply device carrying a battery charging circuit.

[First Embodiment]

  FIG. 1 shows a battery charging circuit and a battery charging method according to the first embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to such a configuration.

  The battery charging circuit 2 charges the battery 4. For example, a small control valve type lead storage battery is used for the battery 4. The battery charging circuit 2 may be charged with a rechargeable secondary battery such as another lead storage battery or a lithium ion battery.

  The battery charging circuit 2 includes a switching power supply circuit 5 having a voltage control function, and the switching power supply circuit 5 includes a control power supply unit 6. In the switching power supply circuit 5, a voltage Vc and a current Ic necessary for charging are applied from the control power supply unit 6 to the battery 4. The control power supply unit 6 may be configured by, for example, a DC-DC converter. The control power supply unit 6 rectifies the power supply from the system power supply 7 to generate a direct current output for charging the battery 4. Either one or both can be controlled.

  The battery charging circuit 2 includes a voltage control circuit 10 and a current control circuit 12 that control charging of the battery 4. The battery 4 includes a voltage detection unit 10-1 of the voltage control circuit 10 in parallel, and the voltage detection unit 10-1 detects a charging voltage that appears in the voltage between the terminals of the battery 4. The voltage detection unit 10-1 may detect the voltage between the terminals of the battery 4 by dividing it, or may detect the voltage between the terminals by non-voltage division.

  The detection voltage of the voltage detector 10-1 is provided to the voltage controller 10-2. The voltage control unit 10-2 controls a voltage Vc that is an applied voltage of the battery 4 in accordance with the detected voltage. That is, the voltage control unit 10-2 outputs the voltage control information 8-1 according to the detected voltage and provides it to the control power supply unit 6. Thereby, the voltage Vc which is the applied voltage of the battery 4 is controlled.

  The battery 4 is connected to the current detection unit 12-1 in series on the negative electrode side, and the current detection unit 12-1 detects the charging current of the battery 4. The current detection unit 12-1 may directly detect the current flowing from the negative electrode side of the battery 4, or may indirectly detect it with a current transformer or the like.

  The detection current of the current detection unit 12-1 is provided to the current control unit 12-2. The current control unit 12-2 controls the charging current of the battery 4 according to the detected current. That is, the current control unit 12-2 outputs the current control information 8-2 according to the detected current and provides it to the control power source unit 6. Thereby, the current Ic which is the charging current of the battery 4 is controlled.

  FIG. 2 shows an example of the operation of the battery charging circuit 2. In FIG. 2, A shows the transition of the charging voltage, and B shows the transition of the charging current corresponding to the charging voltage.

  In this operation example, by providing a charging relay (not shown), the start and end of charging of the battery 4 are restricted to a certain time Tm. The fixed time Tm is set to 24 [hours] in consideration of the capacity of the battery 4 and the like.

  At time t1, the charging relay is turned on, and charging of the battery 4 is started. At this time t1, the charging voltage is in the state of the minimum voltage Vmin [V] of the battery 4, and the charging current Ic is in the state of Ic = 0 [A] until immediately before time t1. Charging is started from this time t1, that is, the voltage Vc and the current Ic are applied from the control power supply unit 6 to the battery 4. As a result, charging is started, and t1 to tn: constant current control period T1, and tn to t2: constant voltage control period T2 are set at the time tn between time t1 and time t2 when charging ends.

  The voltage between the terminals of the battery 4 slightly rises from Vmin [V] to Vn [V] at time t1, and from Vn [V] through constant current control in the constant current control period T1, the maximum voltage Vmax at time tn. [V] is reached. This maximum voltage Vmax [V] is kept constant in a constant voltage control period T2 between time tn and time t2.

  The charging current Ic of the battery 4 rises from Ic = 0 [A] to the constant current Imax from the time point t1, and this constant current Imax is maintained constant by the constant current control, and gradually passes through the constant current control period T1 at the time point tn. And reaches the minimum current Imin [A] at time t2.

  Thus, the battery 4 is charged to a predetermined charging voltage by voltage control by the voltage control circuit 10 and current control by the current control circuit 12.

<Effect of the first embodiment>

  The battery charging circuit 2 and the battery charging method described above have the following functions and effects.

  (1) For example, a small switching power supply may be used for the control power supply unit 6. By using the voltage control function of the voltage control circuit 10 and the current control function of the current control circuit 12 together, constant voltage control and constant current control are possible. The battery 4 can be charged.

  (2) When the charging voltage is low, the battery 4 is charged by current control. When the charging voltage reaches a predetermined voltage, the battery 4 can be charged by voltage control.

  (3) According to such a battery charging circuit 2, charging with a low current circuit is possible, and the safety of battery charging can be improved.

  (4) The durability of the battery 4 and the battery charging circuit 2 can be increased, and the components of the battery charging circuit 2 can be reduced in size.

  (5) The burden on the battery 4 can be reduced, which contributes to extending the life of the battery 4.

[Second Embodiment]

  FIG. 3 shows a power supply device 20 according to the second embodiment. The power supply device 20 is an example of the power supply device of the present invention, and includes the battery charging circuit 2 described above. In FIG. 3, the same parts as those in FIG.

  A battery charging circuit 2 is connected to the battery 4, and the battery charging circuit 2 includes a charging relay 21. When the battery 4 is charged, the charging relay 21 is turned on, and the output of the battery charging circuit 2 is given to the battery 4.

  The battery charging circuit 2 includes a switching (SW) power supply unit 22 that converts direct current into alternating current by switching. The SW power supply unit 22 is an example of the control power supply unit 6. The AC output of the SW power supply unit 22 is applied to the rectifying unit 26 via the transformer 24 and rectified. The rectified output of the rectifying unit 26 is smoothed by the smoothing unit 28 and applied to the voltage control circuit 10 and the current control circuit 12. For example, a diode rectifier circuit may be used as the rectifier 26. In this case, as an example, the voltage control circuit 10 is a constant voltage control circuit that applies a constant charging voltage to the battery 4, and similarly, the current control circuit 12 is a constant current control circuit that supplies a constant current to the battery 4.

  Control information 8 obtained by the voltage control circuit 10 and the current control circuit 12 is applied to the SW power supply unit 22 via the photocoupler 30.

  A system power supply 7 or an inverter power supply 34 is provided on the input side of the SW power supply unit 22 and any one of these rectified outputs is applied. The system power supply 7 may be, for example, a commercial AC power supply AC100 [V]. The inverter power supply 34 may be, for example, a power supply of AC 100 [V] used in place of the system power supply 7. The system power supply 7 or the inverter power supply 34 is switched by an AC switching relay 36 which is an example of a switching unit. The system power supply 7 or the inverter power supply 34 selected by the AC switching relay 36 is rectified by the rectification unit 38 and then supplied to the SW power supply unit 22.

  FIG. 4 shows a circuit configuration example of the power supply device 20. 4, the same parts as those in FIGS. 1 and 3 are denoted by the same reference numerals. In the power supply circuit 20 of FIG. 4, the charging relay 21 and the AC switching relay 36 described above are omitted.

  The voltage detection unit 10-1 that detects the charging voltage of the battery 4 is configured by a series resistance circuit including resistors 40 and 42, and this series resistance circuit is connected to the battery 4 in parallel. The charging voltage of the battery 4 is detected by being divided by the resistance ratio of the resistors 40 and 42. This detected voltage is a control input of the three-terminal regulator 44. The three-terminal regulator 44 constitutes a voltage control element that is an example of the voltage control unit 10-2. The three-terminal regulator 44 is connected in series with the resistor 46 and the photodiode 30-1 of the photocoupler 30, and these series circuits are connected in parallel with the battery 4. For this reason, a series circuit including the three-terminal regulator 44 is connected in parallel to the battery 4 to constitute a side path for diverting the charging current. Therefore, a current corresponding to the detected voltage of the battery 4 flows through the three-terminal regulator 44, and this current flows through the photodiode 30-1 and the resistor 46. As a result, the photodiode 30-1 emits light and a voltage drop occurs in the resistor 46.

  A resistor 48 is used for the current detector 12-1 that detects the charging current of the battery 4. This resistor 48 is connected in series to the negative electrode side of the battery 4. A charging current flows through the resistor 48, causing a voltage drop. The value of this voltage drop is proportional to the product of the resistance value of the resistor 48 and the charging current. Therefore, if the resistance value is, for example, 1 [Ω], the value of the voltage drop becomes the detected current value.

  A voltage representing the detected current detected by the resistor 48 is provided to the current control unit 12-2. The current control unit 12-2 includes an operational amplifier 50 and a three-terminal regulator 52. The operational amplifier 50 is an example of a voltage comparator. The non-inverting input terminal (+) of the operational amplifier 50 is supplied with the battery negative side voltage of the resistor 48 via the resistor 54 and the reference voltage Vref of the reference power source 56 via the resistor 58. Yes. A voltage at the transformer side of the resistor 48 is input to the inverting input terminal (−) of the operational amplifier 50 via the resistor 60, and an output is fed back via the resistor 62. Therefore, an output current is obtained on the output side of the operational amplifier 50 according to the amount of voltage generated in the resistor 48.

  A series circuit of resistors 64 and 66 is connected to the output side of the operational amplifier 50. An output voltage corresponding to the output current of the operational amplifier 50 is obtained at the connection point of the resistors 64 and 66. This output voltage is the control voltage for the three-terminal regulator 52. The three-terminal regulator 52 is connected between a connection point between the photodiode 30-1 and the three-terminal regulator 44 and a reference potential point (ground). The three-terminal regulator 52 has a current corresponding to the detection current of the resistor 48. Is drawn from the photodiode 30-1. As a result, the current of the photodiode 30-1 is controlled.

  The SW power supply unit 22 includes a switching (SW) IC (Integrated Circuit) 68 and a switching (SW) element 70. The SWIC 68 controls the switching of the SW element 70. For example, an FET (Field Effect Transistor) may be used as the SW element 70. The SW element 70 is switched by the switching output of the SWIC 68.

  The current detected by the phototransistor 30-2 of the photocoupler 30 is added as control information 8 to the SWIC 68, whereby the duty of the switching pulse of the SWIC 68 is controlled. Thereby, switching of the SW element 70 is controlled.

  The SWIC 68 generates a switching operation by the output of the secondary coil 24-3 of the transformer 24. The output of the secondary coil 24-3 of the transformer 24 is rectified by the diodes 74-1 and 74-2 through the resistor 72, and the rectified output of the diode 74-1 is smoothed by the capacitor 76 and then applied to the SWIC 68. Yes. The output of the diode 74-2 is divided by resistors 78 and 80 and then applied to the SWIC 68.

  In this embodiment, the AC input from the system power supply 7 is full-wave rectified by the rectifier 38, smoothed by the capacitor 82, and applied to the SW element 70 via the primary coil 24-1 of the transformer 24. For example, a diode bridge circuit may be used for the rectifying unit 38.

  The output of the rectifying unit 38 is connected to the primary coil 24-1 of the transformer 24 via the SW element 70 and the resistor 84. Due to the switching of the SW element 70, an intermittent current flows through the primary coil 24-1. Therefore, an induced voltage and an induced current corresponding to the turn ratio with the primary coil 24-1 flow through the secondary coils 24-2 and 24-3. The voltage and current generated in the secondary coil 24-2 are rectified by the diode 86 of the rectifying unit 26, smoothed by the capacitor 88 of the smoothing unit 28, and supplied to the battery 4.

  FIG. 5 shows a charging operation of the battery 4 by the power supply device 20.

  FIG. 5A shows the transition of the charging voltage of the battery 4. The charging relay 21 is turned on at time t1, charging of the battery 4 is started, and the constant current control period T1 is entered. Due to the start of constant current control from time t1, a constant current Icc flows as shown in FIG.

  When charging shifts to constant voltage control at time tn, the constant current Icc decreases, and Icc = 0 [A] from the time when the charging voltage of the battery 4 reaches a predetermined maximum voltage Vmax.

  Thus, charging is performed at a constant current of constant current Icc in the constant current control period T1, and the charging current is decreased in the constant voltage control period T2, and the charging current is released when the predetermined charging voltage Vmax is reached.

  On the other hand, when the constant current control by the current control circuit 12 is not performed, as shown in FIG. 5C, a large current flows from the start of charging, and the burden on the battery 4 increases. As described above, taking such a charging form not only adversely affects the battery 4, but also causes problems in the safety of the charging circuit.

<Effects of Second Embodiment>

  The following functions and effects can be obtained in the power supply device 20 including the battery charging method and the battery charging circuit 2 described above.

  (1) The battery 4 can be charged by using voltage control by the voltage control circuit 10 and current control by the current control circuit 12 in combination.

  As shown in FIG. 6, in the battery charging circuit 2 and the power supply device 20, a series circuit of a three-terminal regulator 44, a photodiode 30-1 of the photocoupler 30, and a resistor 46 is connected in parallel to the side of the battery 4. A three-terminal regulator 44, which is a current control element, is included in the side path. The charging voltage of the battery 4 is detected by the voltage detector 10-1, and the current flowing through the three-terminal regulator 44 is controlled by this detected voltage. Thereby, when a part of charging current of the battery 4 flows to the side path, the charging current of the battery 4 is controlled and the charging voltage is controlled.

  A three-terminal regulator 44 is connected to the side path of the battery 4, and the current Ib flowing through the side path is divided into a current Ib 1 flowing through the three-terminal regulator 44 and a current Ib 2 flowing through the three-terminal regulator 52. In this case, the charging current Ic of the battery 4 is detected by the current detection unit 12-1, the voltage generated in the current detection resistor 48 is converted by the voltage conversion unit 90, and the output voltage becomes the control voltage of the three-terminal regulator 52. ing. Therefore, the current Ib2 flowing through the three-terminal regulator 52 is controlled according to the charging current of the battery 4, and a part of the current Ib flowing through the photodiode 30-1 is drawn into the three-terminal regulator 52. As a result, the charging current applied from the SW power supply unit 22 to the battery 4 is controlled. In the above embodiment, the voltage conversion unit 90 is configured using the operational amplifier 50. However, this is an example, and the voltage detected by the current detection resistor 48 is converted to the control voltage of the three-terminal regulator 52. Any circuit may be used.

  (2) In the above embodiment, the constant current control is performed by the constant current control period T1 for a predetermined time from the start of charging of the battery 4, and the constant voltage control is performed by the constant voltage control period T2 after the constant current control period T1. Thus, the battery 4 can be charged to a predetermined charging voltage.

  (3) Since the battery 4 can be charged with a weak current by the constant voltage control after the charging voltage of the battery 4 reaches the predetermined voltage by the constant current control, the burden of charging the battery 4 can be reduced, and the battery charging is safe. Increases sex.

  (4) The durability of the battery 4 and the battery charging circuit 2 can be increased, and the components of the battery charging circuit 2 can be reduced in size.

  (5) By reducing the burden on the battery 4, the durability of the battery 4 is maintained, which contributes to a longer life.

[Third Embodiment]

  FIG. 7 shows a cogeneration system according to the third embodiment. The cogeneration system 100 is an example of a battery charging circuit, a power supply device, or a cogeneration system according to the present invention, and includes the battery charging circuit 2 described above. 7, the same parts as those in FIG. 3 are denoted by the same reference numerals.

  This cogeneration system (hereinafter simply referred to as “system”) 100 is an example of the power supply device 20 described above.

  The system 100 includes a distribution board 102, a power generation unit 104, a blackout unit 106, and a hot water storage unit 108. The distribution board 102 distributes the system power supply 7 to the power generation unit 104 and supplies power. The power generation unit 104 generates power by supplying power from the system power supply 7 or the blackout unit 106. The blackout unit 106 generates an emergency power output when the system power supply 7 fails. The hot water storage unit 108 stores hot water heated by the exhaust heat of the power generation unit 104.

  For the system power supply 7 connected to the distribution board 102, for example, a commercial power supply such as a single-phase three-wire system 100 [V] or 200 [V] may be used. Electric power is supplied from the distribution board 102 to the general load 110 and also supplied to the power generation unit 104 and the blackout unit 106 via the cogeneration breaker 112.

  The power generation unit 104 includes a power control unit (hereinafter referred to as “PCU”) 114, a power generation control unit (hereinafter referred to as “ECU”) 116-1, a generator 118, and a surplus power heater 120. Is provided. The PCU 114 executes power generation of the power generation unit 104, power supply switching at the time of power failure of the system power supply 7, battery check provided in case of power failure of the system power supply 7, and the ECU 116-1 executes these controls.

  When the system power supply 7 is normal, the PCU 114 is supplied with the system power supply 7 via the leakage relay 122 and the filter 124. The earth leakage relay 122 detects the earth leakage of the main circuit connected to the system power supply 7 and cancels the power supply of the system power supply 7 at the time of the earth leakage. The filter 124 removes, for example, high-frequency noise and distorted waves included in the AC input.

  The PCU 114 includes a booster circuit 126, a bridge circuit 128, a system interconnection relay 130, a power supply relay 132, a motor inverter circuit 134, and a heater control circuit 136. The grid interconnection relay 130 is an example of a power supply switching unit, and connects the bridge circuit 128 to the main circuit side when the grid power supply 7 is normal. When the system power supply 7 is out of power, the bridge circuit 128 is disconnected from the main circuit side. The bridge circuit 128 is an example of a rectifier circuit that converts alternating current into direct current, and may be configured by bridge-connecting a plurality of rectifier elements. The rectified output of the bridge circuit 128 is boosted by the booster circuit 126 and applied to the motor inverter circuit 134 and the heater control circuit 136.

  The power relay 132 is an example of a power supply switching unit. The power supply relay 132 generates an output by supplying power from the system power supply 7. When the system power supply 7 is normal, the power supply relay 132 is turned on, power is supplied from the system power supply 7 to the PCU 114, and the PCU 114 is in an operating state.

  The motor inverter circuit 134 supplies an inverter output to the generator 118. The generator 118 is driven by the rotation of the engine 138 to generate power. Surplus power is supplied to the surplus power heater 120 to the heater control circuit 136. When the battery is checked, the motor inverter circuit 134 is driven by the battery 4, the output of the motor inverter circuit 134 is supplied to the generator 118, and the generator 118 is used as a starter for the engine 138. That is, after the engine 138 is started, the generator 118 operates as a generator that is the original function.

  The blackout unit 106 includes a plurality of batteries 4, the battery charging circuit 2 described above, the interconnection relay 140, the system voltage detection unit 142, and a blackout control unit (hereinafter referred to as “BCU”) 116-2. The functional part is included.

  The battery 4 is an example of a secondary battery. The battery charging circuit 2 charges the battery 4 with the rectified output of the system power supply 7 when the system power supply 7 is normal. The interconnection relay 140 includes a system side contact a, a battery side contact b, and a movable contact, and closes the system side contact a when the system power supply 7 is normal, and closes the battery side contact b when the system power supply 7 fails. The system voltage detection unit 142 is an example of a monitoring unit for the system power supply 7, detects the voltage value of the system voltage, and the detection output is taken into the BCU 116-2.

  The BCU 116-2 is an example of a control unit, and controls the blackout unit 106 and performs a link operation with another unit through the system communication unit 144.

  The blackout unit 106 includes the following functions.

  a) When the system power supply 7 is normal, the battery 4 is charged.

  b) At the time of a power failure of the system power supply 7, the output of the battery 4 is fed to the power generation unit 104 and the hot water storage unit 108 side. That is, the power generation output of the generator 118 is output from the booster circuit 126, the bridge circuit 128, and the grid interconnection relay 130.

  c) After a lapse of a certain time T from a reference time point such as a battery check, for example, after 30 days, the system power supply 7 is normal, and when the generator 118 is started, the output of the battery 4 generates power for the battery check. Power is supplied to the unit 104. Thereby, an operation check is performed.

  When the system power supply 7 is normal, the rectified output of the system power supply 7 is applied to the battery 4. The system voltage of the system power supply 7 is detected by the system voltage detection unit 142. This system voltage is rectified by a diode 146 which is an example of a rectifier circuit, and this rectified output is applied to the substrate power supply 148 and the battery charging circuit 2. The output of the battery charging circuit 2 is supplied to the battery 4 via the charging relay 21 described above. The charging relay 21 is turned on during charging.

  At the time of a power failure of the system power supply 7, the interconnection relay 140 is switched from the system side contact a to the battery side contact b, and the battery 4 is discharged. The output of the battery 4 is applied to the booster circuit 152 via the fuse 150. The output of the booster circuit 152 is output from the bridge circuit 154 to the hot water storage unit 108 from the battery side contact b side of the interconnection relay 140 and also output to the emergency outlet 158 via the outlet relay 156. The outlet relay 156 is closed to the emergency outlet 158 side when the bridge circuit 154 is output.

<Effect of the third embodiment>

  The system 100 including the battery charging circuit 2 described above has the following functions and effects.

  (1) The battery charging circuit 2 or the power supply device 20 described above can be used for charging the battery of the system 100, and the advantages described above that the battery charging circuit 2 or the power supply device 20 have can be utilized in the system 100.

  (2) Since the battery charging circuit 2 or the power supply device 20 can be reduced in size, it contributes to reducing the weight and size of the system 100.

  (3) Since the burden of charging the battery 4 in the system 100 can be reduced and the durability can be increased, the reliability of the system 100 is improved.

<Test results>

  FIG. 8 shows the result of the charge test of the battery 4 by the battery charging circuit 2 in the power supply device 20 described above.

  In this charging test, charging relay 21 was turned on to start charging, and the voltage and current waveforms immediately after starting charging were observed. Since no current abnormality was observed, A in FIG. 8 shows only the voltage waveform immediately after the start of charging. In order to observe the waveform form of this voltage waveform, B in FIG. 8 shows an enlarged portion between time points ta and tb.

  From this test result, it was confirmed that the voltage level was small at the start of charging although the voltage increased. Moreover, no current anomaly was observed.

  Further, FIG. 8C shows a charging result when the charging of the battery 4 is continued for 30 hours. In FIG. 8C, the current I decreases exponentially at a time t3 after 30 hours after a predetermined charging current is maintained at a time t2 when 5 hours have elapsed from the time t1 when charging starts. On the other hand, the voltage V exhibits an exponential increasing tendency from the time point t1 until 10 hours elapses, and thereafter becomes a stable and substantially constant value until reaching the time point t3.

  From such experimental results, it was confirmed that the battery charging circuit 2 or the power supply device 20 can perform stable battery charging and obtain highly reliable charging characteristics.

[Other Embodiments]

  (1) In the above embodiment, the power supply device 20 and the cogeneration system 100 are exemplified as the usage forms of the battery charging circuit 2, but are not limited thereto. It can be widely used for charging a battery in various power sources including a rechargeable battery such as a lithium ion battery.

  (2) In the above embodiment, the circuit configuration in which the current control circuit 12 performs current control of the voltage control circuit 10 is illustrated, but the voltage control circuit 10 performs voltage control of the current control circuit 12 in the form of a control power supply. It is good also as a structure which controls the part 6. FIG.

  (3) In the above embodiment, a single photocoupler 30 is provided and the control information 8 of the voltage control circuit 10 and the current control circuit 12 is notified to the control power supply unit 6. The control information of the circuit 10 and the current control circuit 12 may be individually transmitted to the control power supply unit 6 by, for example, the photocoupler 30 to control the output of the control power supply unit 6.

  (4) In the above embodiment, the resistor 48 is used as the charging current detection element. However, an active element such as a transistor or a diode capable of detecting current may be used, and the current detected by the active element is directly controlled. The charging current may be controlled as follows.

  (5) In the above embodiment, the current control unit 12-2 controls the current flowing through the three-terminal regulator 44 in the voltage control unit 10-2. However, the current control unit 12-2 and the three-terminal regulator 44 are controlled. A charging current of the battery 4 may be controlled by providing a three-terminal regulator so that current flows separately. If the three-terminal regulator is shared as in the above embodiment, the components can be omitted, which contributes to simplification of the configuration.

As described above, the most preferable embodiment of the technology of the present invention has been described. The present invention is not limited to the above description. Various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the embodiments for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention.

According to the present invention, the battery is charged by using both voltage control by the voltage control circuit and current control by the current control circuit, or the power supply output to the battery is controlled according to the charge voltage of the battery. Since the battery is charged by controlling the power supply output of the battery, it is possible to reduce the burden caused by charging the battery, and it is beneficial to reduce the charging safety and weight.

DESCRIPTION OF SYMBOLS 2 Battery charging circuit 4 Battery 5 Switching power supply circuit 6 Control power supply part 7 System power supply 8 Control information 8-1 Voltage control information 8-2 Current control information 10 Voltage control circuit 10-1 Voltage detection part 10-2 Voltage control part 12 Current Control Circuit 12-1 Current Detection Unit 12-2 Current Control Unit 20 Power Supply Device 21 Charging Relay 22 Switching (SW) Power Supply Unit 24 Transformer 24-1 Primary Coil 24-2 and 24-3 Secondary Coil 26 Rectification Unit 28 Smoothing Unit 30 Photocoupler 30-1 Photodiode 34 Inverter power supply 36 AC switching relay 38 Rectifier 40, 42 Resistor 44 Three-terminal regulator 46 Resistor 48 Resistor 50 Operational amplifier 52 Three-terminal regulator 54 Resistor 56 Reference power supply 58 Resistor 60 Resistor 62 Resistor 64, 66 Resistance 68 Switching (SW) I C
DESCRIPTION OF SYMBOLS 70 Switching (SW) element 72 Resistance 74-1, 74-2 Diode 76 Capacitor 78, 80 Resistance 82 Capacitor 84 Resistance 86 Diode 88 Capacitor 90 Voltage conversion part 100 Cogeneration system 102 Distribution board 104 Power generation unit 106 Blackout unit 108 Hot water storage unit 110 General load 112 Cogeneration breaker 114 Power control unit (PCU)
116-1 power generation control unit (ECU)
116-2 Blackout Control Unit (BCU)
118 Generator 120 Surplus Power Heater 122 Earth Leakage Relay 124 Filter 126 Booster Circuit 128 Bridge Circuit 130 System Linked Relay 132 Power Relay 134 Motor Inverter Circuit 136 Heater Control Circuit 138 Engine 140 System Linked Relay 142 System Voltage Detection Unit 144 System Communication Unit 146 Diode 148 Board power supply 150 Fuse 152 Booster circuit 154 Bridge circuit 156 Outlet relay 158 Emergency outlet

Claims (9)

A battery charging circuit for charging a battery,
A voltage detection unit provided in a side path of the battery to detect a charging voltage of the battery ;
A first control current element is provided in a side path of the battery, and a part of the charging current of the battery is shunted to the first control current element in accordance with a detection voltage in the voltage detection unit. A voltage control unit for controlling the voltage applied to the battery,
A current detector connected in series to the battery to detect the charging current ;
Is connected to the voltage control unit, it has a second control current element, to control the charging current by depending on the detection current draw some of the current diverted to the first control current element current A control unit ;
Battery charging circuit, characterized in that to obtain Bei a. A battery charging circuit for charging a battery,
A voltage detection unit provided in a side path of the battery to detect a charging voltage of the battery;
A first control current element is provided in a side path of the battery, and a part of the charging current of the battery is shunted to the first control current element in accordance with a detection voltage in the voltage detection unit. A voltage control unit for controlling the voltage applied to the battery,
A switching power supply circuit that detects a current shunted to the first control current element and controls a power supply output to the battery according to the detected current ;
A current detector connected in series to the battery to detect the charging current;
The switching unit includes a second control current element connected to the voltage control unit, and draws a part of the current shunted to the first control current element according to a detection current of the current detection unit. A current control unit for controlling the power supply output of the power supply circuit ;
Battery charging circuit, characterized in that to obtain Bei a.   The battery charging circuit according to claim 2, wherein the current detection unit includes a current detection resistor, and detects the current flowing through the battery by converting the voltage into a voltage. The switching power supply circuit receives control information of one or both of a voltage detection unit and a current detection unit that detect a charging voltage of the battery, and the voltage and the current applied to the battery are determined by the control information. The battery charging circuit according to claim 2, further comprising a controlled power supply unit to be controlled. A power supply comprising or connected to a battery comprising:
A battery charging circuit for supplying a charging current to the battery and charging the battery;
The battery charging circuit is
A voltage detection unit provided in a side path of the battery to detect a charging voltage of the battery ;
A first control current element is provided in a side path of the battery, and a part of the charging current of the battery is shunted to the first control current element in accordance with a detection voltage in the voltage detection unit. A voltage control unit for controlling the voltage applied to the battery,
A current detector connected in series to the battery to detect the charging current ;
Is connected to the voltage control unit, it has a second control current element, to control the charging current by depending on the detection current draw some of the current diverted to the first control current element current A control unit ;
Power and wherein the obtaining Bei a. A power supply comprising or connected to a battery comprising:
A battery charging circuit for supplying a charging current to the battery and charging the battery;
The battery charging circuit is
A voltage detection unit provided in a side path of the battery to detect a charging voltage of the battery;
A first control current element is provided in a side path of the battery, and a part of the charging current of the battery is shunted to the first control current element in accordance with a detection voltage in the voltage detection unit. A voltage control unit for controlling the voltage applied to the battery,
A switching power supply circuit that detects a current shunted to the first control current element and controls a power supply output to the battery according to the detected current ;
A current detector connected in series to the battery to detect the charging current;
The switching unit includes a second control current element connected to the voltage control unit, and draws a part of the current shunted to the first control current element according to a detection current of the current detection unit. A current control unit for controlling the power supply output of the power supply circuit ;
Power and wherein the obtaining Bei a. A battery that supplies power to the load in the event of a grid power failure,
When the system power supply is normal, a charging current is supplied to the battery, and the battery is charged with the battery.
The battery charging circuit is
A voltage detection unit provided in a side path of the battery to detect a charging voltage of the battery ;
A first control current element is provided in a side path of the battery, and a part of the charging current of the battery is shunted to the first control current element in accordance with a detection voltage in the voltage detection unit. A voltage control unit for controlling the voltage applied to the battery,
A current detector connected in series to the battery to detect the charging current ;
Is connected to the voltage control unit, it has a second control current element, to control the charging current by depending on the detection current draw some of the current diverted to the first control current element current A control unit ;
Cogeneration system characterized by obtaining Bei a. A battery that supplies power to the load in the event of a grid power failure,
When the system power supply is normal, a charging current is supplied to the battery, and the battery is charged with the battery.
The battery charging circuit is
A voltage detection unit provided in a side path of the battery to detect a charging voltage of the battery;
A first control current element is provided in a side path of the battery, and a part of the charging current of the battery is shunted to the first control current element in accordance with a detection voltage in the voltage detection unit. A voltage control unit for controlling the voltage applied to the battery,
A switching power supply circuit that detects a current shunted to the first control current element and controls a power supply output to the battery according to the detected current ;
A current detector connected in series to the battery to detect the charging current;
The switching unit includes a second control current element connected to the voltage control unit, and draws a part of the current shunted to the first control current element according to a detection current of the current detection unit. A current control unit for controlling the power supply output of the power supply circuit ;
Cogeneration system characterized by obtaining Bei a. A battery charging method comprising:
Forming a side path including a first control current element in the battery to be charged;
Detecting a charging voltage and charging current of the battery,
In accordance with the charging voltage , the voltage applied to the battery is controlled by diverting a part of the charging current of the battery to the first control current element,
Depending on the charge current, the second control current element connected to said side channel, by drawing a portion of the current diverted to the first control current element, to control the charging current A battery charging method.

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