JP2009011081A - Power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply system which prevents deterioration caused by overdischarge of a storage battery, automatically executes recovery from a stop state, and resumes system control operation and power feeding to a load. <P>SOLUTION: The power supply system has a battery pack 3 formed by connecting a plurality of batteries, a charger 1 for converting AC power into DC power and charging the battery pack 3, and an inverter 2 for converting the power discharged from the battery pack 3 into AC power. The power supply system is provided with a structure in which a control section 4 for monitoring and controlling the state of the power supply system is provided, the control section 4 is supplied with operation power from the battery pack 3 or the charger 1 via two power feeding lines, a relay using a coil 8a and a contact point 8b as constituents is provided, both ends of the coil 8a are connected to the two power feeding lines and the contact point 8b is inserted into at least any one of the two power feeding lines. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply system, and more particularly to a backup power supply system having an overdischarge prevention relay that supplies input power to a load while charging the storage battery, and supplies power output from the storage battery to the load in the event of a power failure.

  Nickel metal hydride storage batteries have a higher energy density than lead storage batteries and are characterized by long battery life and low environmental impact. Since it is lightweight, small and easy to carry, it has been rapidly spreading in recent years as a storage battery for vehicles and a storage battery for disaster countermeasures.

  When using a nickel-metal hydride storage battery as a power source, for example, a single cell (rated voltage 1.2 V, capacity 95 Ah) 10 in series is used as one set.

Patent Documents 1, 2, and 3 listed below describe a power supply device that includes a plurality of assembled batteries, a charge control unit, and a discharge control unit. Patent Document 1 describes the assembly based on the manufacturing date of the assembled battery. It is described that the battery usable period is calculated and the assembled battery replacement date is displayed, and Patent Document 2 describes that a battery monitoring unit for performing a discharge capacity test of the assembled battery is provided, and Patent Document 3 describes It is described that the battery monitoring means calculates the remaining capacity of the assembled battery and determines the auxiliary charging time of the assembled battery based on the result.
JP 2004-119112 A JP 2004-120856 A JP 2004-120857 A

  By combining a storage battery, a discharger, and a charger, it is possible to configure a backup power supply system for operating an electric device (load) even during a power failure. Such a power supply system, for example, as shown in FIG. 4, includes an assembled battery 3 formed by combining a plurality of batteries, a circuit that bypasses an AC input from a commercial AC power supply 7, and converts AC power into DC power. The battery charger 1 that charges the assembled battery 3, the inverter 2 that converts the power output from the storage battery into AC power, and the switch 17.

  When the AC input is received, the input power is directly output to the load 6 via the bypass circuit, and is converted into DC by the charger 1 to charge the assembled battery 3.

  At the time of a power failure, the switching device 17 switches to the inverter output side to set the device output, and the energy discharged from the assembled battery 3 is supplied to the load 6 through the inverter 2.

  In order to ensure the safety of the storage battery and prevent battery deterioration, the power supply system needs to monitor the state of the storage battery, detect full charge during charging, and stop charging / discharging of the storage battery in the event of an abnormality. For this reason, a control unit 4 is added to the system.

  Since the storage battery deteriorates when the discharge is continued below the discharge end voltage, it is necessary to stop the discharge when the discharge end voltage is reached. The control unit 4 monitors the voltage of the assembled battery 3 and stops the inverter 2 and stops power feeding to the load 6 when a predetermined set value is reached.

  The control unit 4 has an electric circuit in which a program is recorded, and performs battery monitoring and charge / discharge control using electric signals. Therefore, a control power supply is necessary for the control unit 4 to operate, and power is supplied from the assembled battery 3 to the control power supply in order to continue the control operation even during a power failure.

  For this reason, even after the assembled battery 3 falls below the end-of-discharge voltage and the inverter 2 stops, as long as the control power supply is connected to the assembled battery 3, the power supply to the control unit 4 continues and the discharge from the assembled battery 3 continues. Continues, and the assembled battery 3 is overdischarged, causing a problem of deterioration.

  The above problem is not limited to lead storage batteries or nickel metal hydride storage battery systems, but is a common problem that occurs in power supply systems that combine secondary batteries such as lithium ion batteries.

  The present invention has been made in view of the above problems, and the problem to be solved by the present invention is to charge a storage battery while supplying commercial power to the load, and to discharge the power from the storage battery and supply it to the load during a power failure It is an object of the present invention to provide a power supply system that prevents deterioration due to overdischarge of a storage battery, further automatically returns from a stopped state, and resumes system control operation and power supply to a load.

In the present invention, in order to solve the above problem, as described in claim 1,
In a power supply system having an assembled battery formed by connecting a plurality of batteries, a charger that converts AC power into DC power and charges the assembled battery, and an inverter that converts electric power discharged from the assembled battery into AC power A control unit having an electric circuit for monitoring and controlling the state of the power supply system, and operating power of the control unit is supplied from the assembled battery or the charger through two power supply lines; A first relay having a first coil and a first contact as constituents, and both ends of the first coil are connected to the two feeders, respectively, and the first contact is the two The power supply system is characterized by being inserted into at least one of the feeder lines.

In the present invention, as described in claim 2,
2. The power supply system according to claim 1, wherein the first contact is inserted into the power supply line between one end of the first coil and the control unit. Constitute.

In the present invention, as described in claim 3,
3. The power supply system according to claim 2, further comprising: a second relay including a second coil and a second contact as constituent elements, wherein the other end of the first coil includes the second contact. A diode that passes power only in the output direction is provided at the output of the charger, the output voltage of the charger is applied to the second coil, and the first photo A first photocoupler comprising a diode and a first phototransistor as a constituent element is provided, the first phototransistor is connected in parallel to the second contact, and the voltage of the assembled battery is When the voltage is equal to or higher than a predetermined first set value, the first photodiode emits light, and when the voltage of the assembled battery is less than the first set value, the first photodiode is extinguished. It is characterized by To construct a power supply system to be.

In the present invention, as described in claim 4,
3. The power supply system according to claim 2, further comprising: a first photocoupler including the first photodiode and the first phototransistor as constituent elements, wherein the second photodiode and the second phototransistor are configured. A second photocoupler as an element is provided, and the other end of the first coil is connected to the power supply line via the second phototransistor, and the output of the charger is only in the output direction. A diode for passing electric power is provided, and an output voltage of the charger is applied to the second photodiode, and the first phototransistor is connected in parallel to the second phototransistor, When the voltage of the assembled battery is equal to or higher than a predetermined first set value, the first photodiode emits light, and the voltage of the assembled battery is set to the first setting value. When it is less than the value, the first photodiode constituting the power supply system, which is a quenching.

In the present invention, as described in claim 5,
5. The power supply system according to claim 3, wherein a manual switch that is short-circuited only when pressed is connected in parallel with the first phototransistor. .

In the present invention, as described in claim 6,
6. The power supply system according to claim 1, further comprising: a switch that switches between one of the input AC power and the AC output of the inverter and outputs the load to the load. A power supply system is provided that is supplied through a power feed line.

In the present invention, as described in claim 7,
7. The power supply system according to claim 1, wherein the assembled battery is a nickel hydride storage battery or a lead storage battery.

  By implementing the power supply system of the present invention, in the power supply system that charges the storage battery while supplying commercial power to the load, and discharges the storage battery from the storage battery and supplies it to the load in the event of a power failure, the deterioration due to overdischarge of the storage battery is prevented. It is possible to provide a power supply system that automatically recovers from the stopped state and resumes the control operation of the system and the power supply to the load.

  In addition, after the system is stopped, it can be restored by replacing the battery and pressing the manual switch.

  In the power supply system according to the present invention, for example, an assembled battery formed by connecting a plurality of batteries, a charger that converts AC power into DC power and charges the assembled battery, and electric power discharged from the assembled battery is AC. In a power supply system having an inverter for converting into electric power, the power supply system includes a control unit having an electric circuit for monitoring and controlling the state of the power supply system, and the operation power supply of the control unit is a power supply line from the assembled battery or the charger A first relay on a control power supply line, a second relay operated by the output voltage of the charger, and a photocoupler operated by the control unit, the control unit comprising: Control is performed such that the photocoupler emits light (short-circuit) when the voltage of the assembled battery is equal to or higher than a predetermined set value, and extinguishes (opens) when the voltage is lower than the set value.

  In addition, for example, a manual switch for operating the first relay, which is short-circuited only when pressed, is connected.

  Hereinafter, embodiments of the present invention will be described by way of example in which the battery is a lead storage battery or a nickel hydride storage battery, but the present invention is not limited to this.

<Embodiment 1>
FIG. 1 is a diagram for explaining an embodiment of the present invention. In the figure, a lead-acid battery (single cell rating 2V, 200Ah) is connected in series with 6 cells to form an assembled battery 3 (12V, 200Ah). The assembled battery 3 is charged via the charger 1 by the commercial AC power source 7 or supplies output power to the load 6 via the inverter 2 and the switch 17. The charger 1 converts the AC power supplied from the commercial AC power source 7 into DC power, outputs DC 12V, charges the assembled battery 3, and supplies power for the control power of the control unit 4 and the switch 17. Supply.

  When the commercial AC power source 7 is effective, the commercial AC power source 7 is connected to the load 6 through the bypass circuit by the function of the switch 17. When a power failure occurs, the switch 17 detects this and switches the power supply to the load 6 with the output of the inverter 2. The inverter 2 receives the operation signal from the control unit 4 and converts the electric power discharged from the assembled battery 3 into alternating current power, and supplies power to the load 6 via the switch 17. When the operation signal is reset, the inverter 2 operates. Stops and no AC power is output.

  The control unit 4 has a function of stopping discharge so that the battery does not overdischarge, a failure detection function, and a status display function. A control power supply is required for the control unit 4 to operate, and is supplied from the charger 1 or the assembled battery 3.

  A control power supply is also required for the switch 17 to operate, and is supplied from the charger 1 or the assembled battery 3 in the same manner as the control unit 4. Even during a power failure, the control power of the control unit 4 and the switch 17 is necessary, and power is supplied from the assembled battery 3. When the discharge continues and the voltage of the assembled battery 3 reaches the minimum operating voltage (10 V), the control unit 4 can stop the inverter 2 and stop the power supply to the load 6. The power supply to 17 is continued. If the discharge is continued below the minimum operating voltage, the deterioration of the battery proceeds. Therefore, a relay 8 (relay) is added to the input line of the control power supply to stop the power supply to the control power supply.

  The first relay 8 includes a (first) coil 8a and a (first) contact 8b as constituent elements, and the open / close state of the contact 8b changes depending on the voltage applied to both ends of the coil 8a. When the potential difference between both ends of the coil 8a is 0V, the contact 8b is open, and when the forward voltage of the coil 8a becomes 11V or more thereafter, the contact 8b is short-circuited. Further, when the forward voltage of the coil 8a becomes 10V or less thereafter, the contact 8b is opened, and the forward voltage of the coil 8a needs to be 11V or more to be short-circuited again.

  Both ends of the coil 8a are connected to the power supply line of the control power source, and the positive electrode and the negative electrode are connected so that the forward voltage is applied by the charger 1 and the assembled battery 3 respectively. Since the contact 8b is connected so that the supply of the control power can be stopped by being opened, it is inserted into either one of the power supply lines of the control power.

  When the commercial AC power supply 7 is effective, the forward voltage applied to the coil 8 a is 11 V or more, so the contact 8 b is a short circuit, and the control power is supplied to the control unit 4 and the switch 17. When the commercial AC power supply 7 fails, the control power is supplied from the assembled battery 3. However, as long as the voltage of the assembled battery 3 is 10 V or higher, the contact 8b is short-circuited and the supply of the control power is continued. When the battery pack 3 continues to be discharged due to a power failure and the voltage of the battery pack 3 falls below 10V, the applied voltage of the coil 8a also becomes less than 10V, the contact 8b is opened, the supply of control power is stopped, and the control unit 4 and the switch The operation of 17 stops. Further, when the control unit 4 stops, the operation signal to the inverter 2 is also reset, so the operation of the inverter 2 is also stopped, and the discharge from the assembled battery 3 is completely stopped.

  Thereafter, when the commercial AC power supply 7 recovers, the charger 1 outputs DC power, so that the forward voltage 12V is applied to both ends of the coil 8a, the contact 8b is short-circuited, and the control power is supplied. The inverter 2 and the switch 17 operate, and the assembled battery 3 is charged.

  If the battery pack 3 is replaced with a fully charged battery (12V) instead of returning to the commercial AC power supply 7 after the discharge is stopped, the voltage (12V) of the replaced battery pack 3 is Applied to the coil 8a, the contact 8b is short-circuited, and the operation of the system is resumed.

  In this way, it is possible to construct a power supply system that can automatically restore the system while preventing overdischarge of the battery.

  In the present embodiment, the position of the contact 8b is between one end of the coil 8a and the control unit 4 (switch 17), but between the coil 8a and the assembled battery 3 (position indicated as A in FIG. 1). There is also a way to do it. In this case, after the discharge of the assembled battery 3 is stopped, even if the commercial AC power supply 7 is restored or the assembled battery 3 is replaced, no voltage is applied to the coil 8a, so that the system cannot be automatically restored. When the voltage of the assembled battery 3 decreases and the contact 8b is opened, the control power is not supplied and the inverter 2 is stopped, and the discharge of the assembled battery 3 is completely stopped.

<Embodiment 2>
FIG. 2 is a diagram for explaining an embodiment of the present invention. In the figure, nickel-metal hydride storage batteries (single cell rating 1.2 V, 95 Ah) are connected in series to form a battery pack 3, and three sets (3 a, 3 b, 3 c) are connected in parallel. The assembled battery 3 is charged via the charger 1 by the commercial AC power source 7 or supplies the output power to the load 6 via the inverter 2 and the high-speed switch 5 serving as a switch. The charger 1 converts AC power supplied from the commercial AC power source 7 into DC power, and supplies power for the control power source of the inverter 2, the control unit 4, and the high-speed switch 5 while charging the assembled battery 3.

  A diode 12 a for preventing backflow that passes power only in the output direction of the charger 1 is connected to the power supply line from the charger 1 to the inverter 2.

  When the commercial AC power supply 7 is effective, the commercial AC power supply 7 is connected to the load 6 through the bypass circuit by the action of the high-speed switch 5 as a switch.

  When a power failure occurs, the high-speed switch 5 detects this and switches the power supply to the load 6 with the output of the inverter 2 within 10 milliseconds. The inverter 2 converts the electric power discharged from the assembled battery 3 into AC power and supplies power to the load 6 via the high-speed switch 5, but is in a no-load operation standby state when the commercial AC power supply 7 is effective, Electric power necessary for no-load operation is supplied from the charger 1.

  In a nickel metal hydride storage battery, it is necessary to charge at a constant current and completely cut off the charging current when the battery reaches full charge. For this reason, the control part 4 which uses charge switch 16 (16a, 16b, 16c) and performs charge control is needed. In addition to charge control, the control unit 4 has a function of stopping discharge so that the battery does not overdischarge, a failure detection function, and a state display function.

  The control unit 4 acquires the charge / discharge current by measuring the potential difference across the series resistor 14 (14a, 14b, 14c) connected to the assembled battery 3, and measures the voltage and temperature of the assembled battery 3. The remaining discharge capacity of the battery pack 3 is calculated based on the accumulated charge / discharge current amount or the number of days elapsed, and charging is started when the remaining capacity falls below a predetermined value. Charging is terminated when the temperature rise gradient or voltage of the assembled battery exceeds a predetermined value, when the voltage of the assembled battery 3 starts to decrease, or when the charging time reaches the upper limit. During discharge of the assembled battery 3, the discharge is stopped when the voltage of the assembled battery 3 falls below the discharge end voltage. When the measured value input to the control unit 4 deviates from a predetermined range as a normal value, it is regarded as a failure and the system is stopped. Further, the control unit 4 is provided with a liquid crystal display device, and displays the failure content in addition to the remaining discharge capacity, voltage, temperature measurement value, charge / discharge state of the assembled battery 3 when a failure occurs. Note that it is desirable to set the display device in an energy saving mode during a commercial power failure.

  A control power supply is required for the control unit 4 to operate, and is supplied from the charger 1 or the assembled battery 3. Also, a control power supply is necessary for the high-speed switch 5 to operate, and it is supplied from the charger 1 or the assembled battery 3 in the same manner as the control unit 4. It cannot be output from either inverter side.

  The control power supply for the control unit 4 and the high-speed switch 5 is required even during a power failure, but in order to prevent overdischarge of the assembled battery 3, a relay 8 having a coil 8a and a contact 8b as constituent elements in the input line of the control power supply. (Relay). This is a first relay having the (first) coil 8a and the (first) contact 8b as components. A backflow preventing diode 10c and a contact 8b are inserted into one of the input lines.

  Also, one end of the coil 8a is connected to + of the input line, and the other end is connected to-of the input line via the (first) phototransistor 9d. The diode 10b connected in parallel to the coil 8a absorbs the back electromotive force when the forward voltage of the coil 8a rapidly decreases. The phototransistor here is used together with a photodiode, and this combination is a so-called photocoupler. The (first) photodiode 9c corresponding to the (first) phototransistor 9d is built in the control unit 4, and the photodiode 9c and the phototransistor 9d are components of the first photocoupler. .

  Further, the (second) phototransistor 9b and the manual switch 11 are connected in parallel to the phototransistor 9d. The manual switch 11 is short-circuited only while being manually pressed.

  When the power failure continues, and when the assembled battery 3 reaches the end-of-discharge voltage and the power supply to the load 6 stops, all devices that require power in the system are stopped. In order to resume the power supply, a resistor 15, a Zener diode 13, and a (second) photodiode 9 a connected in series are connected in parallel to the output of the charger 1. The (second) photodiode 9a corresponds to the (second) phototransistor 9b, and the photodiode 9a and the phototransistor 9b are constituent elements of the second photocoupler.

  While the charger 1 starts operation and outputs DC power, the photodiode 9a emits light, the light is guided to the phototransistor 9b, and the 9b is short-circuited. As a result, a current flows through the coil 8a, the contact 8b is short-circuited, and power is supplied to the control unit 4.

  When the charger 1 stops due to a power failure, the photodiode 9a that is not supplied with power from the assembled battery 3 does not emit light because of the diode 12a, and the phototransistor 9b is opened.

  The resistor 15 has a role of ensuring a current sufficient for the photodiode 9a to short-circuit the phototransistor 9b and preventing the current from flowing further. The Zener diode 13 has an output voltage of the charger 1 lower than about 5V. This function stops the light emission of the photodiode 9a.

  During commercial power reception, the photodiode 9a emits light, the phototransistor 9b is short-circuited, the photodiode 9c in the control unit 4 emits light, the phototransistor 9d is short-circuited, and a forward voltage is applied to the coil 8a. 8b is a short circuit.

  At the time of a power failure, since the output of the charger 1 stops, the light emission of the photodiode 9a stops and the phototransistor 9b is opened. At this time, the phototransistor 9d remains short-circuited, and the voltage applied to the coil 8a is sufficient to short-circuit the contact 8b. When the voltage of the assembled battery 3 (3a, 3b, 3c) is equal to or higher than a predetermined first set value, the (first) photodiode 9c emits light (first ) When the phototransistor 9d is short-circuited, and the voltage of the assembled battery 3 is less than the first set value, the photodiode 9c is extinguished and the phototransistor 9d is open. When the assembled battery 3 reaches the end-of-discharge voltage, the control unit 4 stops the light emission of the photodiode 9c, and the phototransistor 9d is opened, so that the voltage applied to the coil 8a decreases and the contact 8b The power supply to the control unit 4 is stopped.

  When the commercial power supply recovers, the charger 1 outputs DC power and the photodiode 9a starts to emit light, so the phototransistor 9b is short-circuited, the output voltage of the charger 1 is applied to the coil 8a, and the contact 8b is short-circuited. Is done. Control power is supplied to the control unit 4 and the high-speed switch 5 to enable control operation and switching operation.

  The control unit 4 detects the input / output current (measured by the series resistors 14a, 14b, and 14c), the voltage, and the presence or absence of a power failure of the assembled battery 3, and detects the charging switch 16 (16a, 16b, and 16c), the high-speed switch 5, and the photo The diode 9c is controlled. FIG. 3 is a diagram illustrating a control flow of the control unit 4.

  When the control power is not supplied to the control unit 4, the inverter 2 is stopped because there is no operation signal to the inverter 2, and the load 6 is connected to both the commercial side and the inverter side because there is no switching signal to the high speed switch 5. Since the photodiode 9c is not emitting light, the phototransistor 9d is open, and since there is no signal for short-circuiting the charge switch 16, all the charge switches 16 are open.

  When control power is supplied to the control unit 4 and a control operation is started, a signal for operating the inverter 2 and connecting the high-speed switch 5 to the commercial side is generated in step 1 (denoted by S1 in the figure, the same applies hereinafter) In step 2, the photodiode 9c emits light.

  In step 3, it is determined whether the commercial AC power source 7 is valid. If commercial AC power is being received, the process proceeds to step 4;

  In step 4, a signal for short-circuiting the corresponding charging switch 16 so as to charge the assembled battery 3 specified by the external signal is generated, and the charging switch 16 corresponding to the assembled battery 3 whose external signal does not instruct charging. Reset the short circuit signal.

  If a power failure occurs in step 3, a signal for switching the high-speed switch 5 to the inverter side is generated in step 5 so that the switching operation is performed within 10 ms.

  In Step 6, it is determined whether or not the voltage of the assembled battery 3 (voltage at the 3 series parallel connection point) is 10V or less. If 10V or less, the process proceeds to Step 9. If it is higher than 10V, the process proceeds to Step 7. .

  In step 7, it is determined whether or not the commercial AC power supply 7 is valid. If a power failure occurs, the process returns to step 6. If power is received, the high-speed switch 5 is switched to the commercial side in step 8, and the process returns to step 3.

  In step 9, the operation signal of the inverter 2 is reset, and in step 10, the light emission of the photodiode 9c is stopped.

  3 is executed, power is supplied to the load 6 through the bypass circuit while the commercial power source is effective. When a power failure occurs, the output of the inverter 2 is connected to the load 6 within 10 ms. When the battery 3 is backed up and the assembled battery 3 reaches the end-of-discharge voltage, the power supply to the load 6 is stopped, the control operation is stopped, and the discharge from the assembled battery 3 is completely stopped.

  Further, when the commercial power supply is restored, switching to the bypass circuit side is performed. Further, when the commercial power supply is restored after the assembled battery 3 is completely discharged and the system is stopped, the photodiode 9a emits light by the activation of the charger 1, the phototransistor 9b is short-circuited, and the coil 8a is output from the charger 1. By sensing the voltage, the contact 8b is short-circuited and the control power is supplied to the control unit 4 to start the control. The control power is also supplied to the high-speed switch 5 and the commercial AC power supply 7 is supplied to the load 6 through the bypass circuit. Connected.

  When returning the system by battery replacement when the system is stopped, the battery pack 3 is replaced with one having a high charge state, and then the manual switch 11 is pressed. While pressing, the control unit 4 starts because the coil 8a senses the voltage of the assembled battery 3 and short-circuits the contact 8b, and the phototransistor 9d is short-circuited. Continuously, power is supplied to the load 6 via the inverter 2.

  In the present embodiment, the operation state of the charger 1 is detected by the second photocoupler including the (second) photodiode 9a and the (second) phototransistor 9b as constituent elements. This can also be done by a relay, as in the power supply system according to claim 3. The second relay is configured by replacing the photodiode 9a (including the resistor 15 and the Zener diode 13) with the (second) coil and the phototransistor 9b with the (second) contact, whereby the charger 1 If the contacts are opened and closed depending on the presence or absence of the output, the same function as when a photocoupler is used can be achieved.

  The features of the power supply system according to the present invention include, for example, an assembled battery formed by connecting a plurality of batteries, a charger that converts AC power into DC power and charges the assembled battery, and electric power that is discharged from the assembled battery. A power supply system having an inverter for converting into alternating current power, comprising a control unit having an electric circuit for monitoring and controlling the state of the power supply system, wherein the operating power of the control unit is from the assembled battery or the charger A power supply line, a relay connected to a power supply line of a control power source, a relay operated by an output voltage of the charger, and a photocoupler operated by the control unit; For controlling the photocoupler to emit light (short circuit) when the voltage is equal to or higher than a preset value, and to extinguish (open) when the voltage is less than the set value, and to operate the relay 1, Is to connect the manual switch is shorted only when the beat.

  With this feature, in a power supply system that charges a storage battery while supplying commercial power to the load, discharges the storage battery during a power failure, and supplies the load to the load, it prevents deterioration due to overdischarge of the storage battery and automatically returns from the stopped state. Therefore, it is possible to provide a power supply system that restarts the control operation of the system and the power supply to the load. In addition, after the system is stopped by a manual switch, it is possible to perform recovery after replacing the battery.

  As described above, the embodiment of the present invention has been described by taking the case where the battery is a lead storage battery or a nickel hydride storage battery as an example, but the present invention is not limited thereto.

  Below, the effect produced by this invention is demonstrated.

  (1) In a power supply system that supplies power output from a secondary battery to a load, the secondary battery continues to discharge below a discharge end voltage due to power consumption of a control unit that controls charging and discharging of the secondary battery. There arises a problem that the deterioration due to the overdischarge proceeds.

  According to the present invention, the discharge of the secondary battery is stopped before it becomes overdischarged, so that the secondary battery can be prevented from deteriorating and the battery life can be extended.

  (2) In order to avoid overdischarge of the secondary battery, there is a method of inserting a switch in the power supply line to the load and opening this switch when the voltage of the secondary battery reaches the discharge end voltage. There is no way to restore the system after opening.

  According to the present invention, after the system is stopped, the control power is automatically supplied to the control unit by the power recovery of the commercial power, and the control operation of the system and the power supply to the load can be resumed. Further, the manual switch can be used to return the system after it has been stopped by replacing the battery.

It is a figure explaining the example of embodiment of this invention. It is a figure explaining the example of embodiment of this invention. It is a figure explaining an example of the control flow in this invention. It is a block diagram of the power supply system which supplies commercial power to a load, charging a storage battery, and supplies the electric power which a storage battery outputs to a load at the time of a power failure.

Explanation of symbols

  1: charger, 2: inverter, 3: assembled battery, 3a, 3b, 3c: nickel metal hydride storage battery, 4: control unit, 5: high-speed switch, 6: load, 7: commercial AC power supply, 8a: coil, 8b: Contact, 9a, 9c: Photodiode, 9b, 9d: Phototransistor, 10b, 10c: Diode, 11: Manual switch, 12a, 12d, 12e, 12f, 12g, 12h, 12i: Diode, 13: Zener diode, 14a, 14b, 14c: series resistance, 15: resistance, 16a, 16b, 16c: charge switch, 17: switch.

Claims (7)

In a power supply system having an assembled battery formed by connecting a plurality of batteries, a charger that converts AC power into DC power and charges the assembled battery, and an inverter that converts electric power discharged from the assembled battery into AC power ,
A controller having an electric circuit for monitoring and controlling the state of the power supply system;
The operation power of the control unit is supplied from the assembled battery or the charger via two power supply lines,
A first relay having a first coil and a first contact as constituents is provided, both ends of the first coil are connected to the two feeders, and the first contact is the 2 A power supply system, wherein the power supply system is inserted into at least one of the power supply lines. The power supply system according to claim 1,
The power supply system according to claim 1, wherein the first contact point is inserted into the power supply line between one end of the first coil and the control unit. The power supply system according to claim 2,
A second relay comprising a second coil and a second contact as constituents is provided;
The other end of the first coil is connected to the power supply line via the second contact,
A diode that passes power only in the output direction is provided at the output of the charger,
An output voltage of the charger is applied to the second coil,
A first photocoupler comprising a first photodiode and a first phototransistor as constituent elements;
The first phototransistor is connected in parallel to the second contact;
When the voltage of the assembled battery is equal to or higher than a predetermined first set value, the first photodiode emits light, and when the voltage of the assembled battery is less than the first set value, The power supply system, wherein the first photodiode is extinguished. The power supply system according to claim 2,
A first photocoupler comprising a first photodiode and a first phototransistor as constituent elements;
A second photocoupler comprising a second photodiode and a second phototransistor as constituent elements;
The other end of the first coil is connected to the power supply line via the second phototransistor,
A diode that passes power only in the output direction is provided at the output of the charger,
The output voltage of the charger is applied to the second photodiode,
The first phototransistor is connected in parallel to the second phototransistor;
When the voltage of the assembled battery is equal to or higher than a predetermined first set value, the first photodiode emits light, and when the voltage of the assembled battery is less than the first set value, The power supply system, wherein the first photodiode is extinguished. The power supply system according to claim 3 or 4,
A power supply system, wherein a manual switch that is short-circuited only when pressed is connected in parallel to the first phototransistor. The power supply system according to any one of claims 1 to 5,
A switching device is provided that switches either the input AC power or the AC output of the inverter to output to the load,
An operation power supply of the switch is supplied via the two power supply lines. The power supply system according to any one of claims 1 to 6,
The assembled battery is a nickel hydride storage battery or a lead storage battery.

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