JP4763660B2 - Power system - Google Patents

Description

  The present invention relates to a power supply system, and more particularly to a backup power supply system that continues to supply power to a load even during a power failure.

The conventional power supply system used for backup of equipment in the event of a disaster or emergency is mainly UPS (Uninterruptible Power Supply). Usually, as shown in FIG. 4, the assembled battery 2 is a combination of a plurality of storage batteries. , An inverter 3 for converting DC power to AC power, a rectifier 1 for converting commercial AC power input via the commercial input 8 to DC power and charging a storage battery or supplying it to the inverter 3, and a system output as a commercial power source The switch 4 is connected to either one of the inverter outputs, and the controller 7 is configured to monitor and control the system (see Patent Document 1 below). When commercial power supply is effective, the input AC power is supplied to the load device as it is via the bypass circuit 5 or via the rectifier 1 and the inverter 3 via the output 10. When a power failure occurs, the electric power discharged from the assembled battery 2 is supplied to the load device via the inverter 3 and the output 10.
JP 2003-47168 A

  The backup time by a general UPS is about 10 to 30 minutes, and in order to operate the load device even during a long power outage longer than that, as shown in FIG. In other words, there is a method of connecting an emergency power source such as an engine generator to the input of the UPS. However, when a power source is connected to the input of the UPS, it is recognized that the commercial power source has been restored, and the input power is not only supplied to the load device but also consumed for charging the storage battery. Therefore, there is a problem that the duration of power supply is shortened and the utilization efficiency of the emergency power supply is reduced.

  As a countermeasure, there is a method of stopping the rectifier when the emergency power supply is connected, but the input power is supplied to the load device via the switch, and the switch is operating to continue feeding. It is necessary. When there is no operating power supply, the switch cannot connect the input power supply to the system output, and power supply to the load device is stopped. The operating power supply for the switching unit and the control unit is generally a direct current, and is supplied with power from a rectifier or a storage battery. When the rectifier is stopped, the voltage of the storage battery continues to decrease due to the consumption of the operating power of the switching device and control unit, and the switching device stops below the operable voltage of the switching device, and power is supplied to the load device. Stop.

  In this way, when the emergency power supply is connected, simply stopping the rectifier to prevent charging of the storage battery stops power supply to the load device when the storage battery voltage drops, regardless of the remaining capacity of the emergency power supply. Problems occur. In particular, this problem is likely to occur in an application where an emergency power supply is connected when a power failure continues and the storage battery capacity decreases. In addition, when the operating voltage of the switch is lower than the minimum operating voltage of the storage battery, there is a problem that the storage battery voltage falls below the minimum operating voltage due to continued discharge of the storage battery, leading to deterioration of the storage battery.

  The present invention has been made in view of the above-mentioned problems, and the problem to be solved by the present invention is to use efficiency when an emergency power supply is connected in a backup power supply system that continues to supply power to a load even during a power failure. It is intended to provide a power supply system that can prevent a decrease in power consumption and avoid power supply stoppage due to consumption of the storage battery and deterioration of the storage battery.

In the present invention, in order to solve the above problem, as described in claim 1,
A rectifier that converts AC power into DC power, a battery pack that combines a plurality of batteries, an inverter that converts DC power output from the battery pack or rectifier into AC power, and a commercial input that connects a commercial AC power supply An emergency input for connecting an emergency power supply, a selector switch for selecting and outputting either the commercial input or the emergency input, a control unit for controlling charging of the assembled battery, and the emergency input And a reference voltage generation unit that detects a power supply from the reference voltage and outputs a reference voltage as a charge prohibition signal to the control unit. The AC power output from the changeover switch passes through the rectifier and an inverter. Or via a bypass circuit, the switch selects and outputs either the output of the bypass circuit or the output of the inverter. One pole of the assembled battery is connected to one of the DC power supply lines from the rectifier to the inverter, and the other of the DC power supply lines from the rectifier to the inverter and the other pole of the assembled battery are switching elements. Separately connected by an inserted electric circuit and an electric circuit in which a diode that passes power only in the discharge direction of the assembled battery is inserted, and the control unit receives the reference voltage that is a charge prohibition signal When the charging command signal from the outside of the power supply system is received, the switching element is not short-circuited. Therefore, when the assembled battery is not charged and the reference voltage is not inputted, By receiving the charging command signal , the switching element is short-circuited to charge the assembled battery .

In the present invention, as described in claim 2,
2. The power supply system according to claim 1, wherein the reference voltage generating means includes a reference power supply and a relay that detects power supply from the emergency input as constituent elements .

In the present invention, as described in claim 3,
2. The power supply system according to claim 1, wherein the reference voltage generating means includes a reference power supply and an interlocking switch interlocked with the changeover switch as constituent elements .

  By implementing the power supply system of the present invention, in a backup power supply system that continues to supply power to the load even in the event of a power failure, the power use efficiency is prevented from being reduced when an emergency power supply is connected, and power supply is stopped due to storage battery consumption And it becomes possible to provide the power supply system which can avoid deterioration of a storage battery.

  In the power supply system according to the present invention, for example, a rectifier that converts alternating current power into direct current power, an assembled battery that combines a plurality of batteries, and an inverter that converts direct current power output from the assembled battery or the rectifier into alternating current power A control unit that controls charging of the assembled battery, a commercial input that connects a commercial AC power source, an emergency input that connects an emergency power source, and the commercial input and the emergency input. The AC power output from the changeover switch is supplied to the changer via the rectifier and inverter or via a bypass circuit. Select and output either the output of the bypass circuit or the output of the inverter, plus the DC power supply line from the rectifier to the inverter The negative electrode of the DC power supply line from the rectifier to the inverter and the negative electrode of the battery pack are connected to the positive electrode of the battery pack and the negative electrode of the battery pack, and power is supplied only in the discharge direction of the battery pack. A relay to which a voltage from the emergency input is applied is connected to an electrical path between the emergency input and the changeover switch, and is connected to the electrical path in which a diode to be inserted is inserted, and the relay has A power supply system, wherein a reference voltage is supplied to the control unit by closing a contact, and the control unit opens the switching element when the reference voltage is supplied by an operation of the relay. Constitute.

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

  FIG. 1 is a diagram for explaining an embodiment of the present invention. In the figure, 10 batteries of nickel-metal hydride storage batteries (single cell rated voltage 1.2V, current capacity 95Ah) are connected in series to form an assembled battery 2 (12V, 95Ah). The rectifier 1 that converts alternating current power into direct current power charges the assembled battery 2 and supplies power to the inverter 3 and the switch 4 (as an operating power source). The inverter 3 converts the DC power output from the rectifier 1 or the assembled battery 2 into AC power and outputs the AC power to the switch 4. The switch 4 includes a switch for switching AC power, and inputs either of the power output from the bypass circuit 5 and the inverter 3 to the output (terminal) 10.

  In the present embodiment, the power supply system outputs the commercial power as it is through the bypass circuit 5 during normal times (when receiving the commercial power), and the switch 4 outputs the output of the inverter 3 to the output 10 when a power failure occurs. Connect and perform backup power supply using the power of the battery pack 2. In order for the switching device 4 to perform such a switching operation, an operating power supply is required, and when there is no operating power supply, it is not connected to either the bypass side or the inverter side. Such a situation occurs when a power outage lasts for a long time and an emergency input cannot be obtained.

  The commercial input (terminal) 8 can be connected to a commercial AC power supply 100V, and the emergency input (terminal) 9 can be connected to an AC 100V power supply.

  During normal operation (when receiving commercial power), the changeover switch 6 is on the commercial input 8 side, the switch 4 is on the bypass circuit 5 side, and commercial power is loaded from the output 10 via the changeover switch 6 and the switch 4. When the assembled battery 2 needs to be charged, the control unit 7 receives an external signal (charging), applies a voltage at which the switching element 13 is closed to the gate of the switching element 13, and the rectifier Control is performed such that the assembled battery 2 is charged by the output of 1.

  When a power failure occurs, the assembled battery 2 supplies power to the inverter 3, the switch 4 is switched to the inverter 3 side, and the output of the inverter 3 is supplied from the output 10 to the load via the switch 4.

  When the remaining capacity of the assembled battery 2 is reduced due to the continued power failure, the power supply can be continued by connecting an AC 100V power source such as a generator to the emergency input 9. In order to switch the input power source from the commercial input 8 to the emergency input 9, the changeover switch 6 is operated. As the changeover switch 6, a manual switch for power changeover may be used.

  In order to control charging and discharging of the assembled battery 2 separately, the output of the rectifier 1 (the input of the inverter 3, the negative electrode of the assembled battery 2 is connected to the electric circuit into which the diode 14 a is inserted and the electric circuit into which the diode 14 b and the switching element 13 are inserted. It is connected separately to the negative of the input of the switch 4 operating power source. The diode 14a allows the assembled battery 2 to be discharged only, and the diode 14b allows the assembled battery 2 to be charged only. As the switching element 13, for example, a MOS transistor capable of flowing a charging current may be used.

  The control unit 7 controls charging of the assembled battery 2. Power supply to the control unit 7 may be performed from the rectifier 1 during normal times and from the assembled battery 2 during a power failure, or may be performed from the assembled battery 2 regardless of the presence or absence of a power failure. When the control unit 7 receives an external signal instructing charging and the reference voltage from the reference power supply 12 is not supplied, the control unit 7 performs charging with the switching element 13 short-circuited. Otherwise, the switching element 13 is opened and charged. Is prohibited.

  The relay 11 detects whether or not power is supplied from the emergency input 9 and notifies the control unit 7 of whether or not the assembled battery 2 can be charged. When an AC voltage is applied to the relay 11, the AC voltage is transmitted to the coil through the diode bridge circuit inside the relay 11, the contact is short-circuited, and the reference power source 12 (the reference voltage is, for example, 5V) is controlled. This is transmitted to the unit 7 and charging of the assembled battery 2 is prohibited.

  Therefore, for example, as the switching element 13, an element that becomes conductive when 5 V is input to the control electrode is selected, the reference power source 12 is set as the 5 V power source, the charging command is received, and the reference power source 12 is When the voltage is not supplied, the control unit 7 may output 5 V to the control electrode. For this purpose, for example, the control unit 7 is provided with an inverter that is turned on by a 5 V power supply in response to an external signal that commands charging, and the input from the reference power supply 12 is HL (high-low) converted by the inverter. The voltage may be applied to the control electrode. In this case, the voltage of the reference power supply 12 may exceed 5V.

  Since the reference power supply 12 only needs to apply the reference voltage to the control unit 7 only when the commercial power supply is interrupted and only when the emergency input 9 is supplying power to the system, the power consumption is extremely small. The battery voltage is measured periodically and after a power outage.If the voltage is above the reference value, leave it as it is.If the voltage is lower than the reference value, replace the primary battery with a new one. It ’s enough.

As the relay 11, a combination of a coil and a contact can be used. Alternatively, a photocoupler in which a light emitting diode and a phototransistor are combined may be used.

  In addition, as shown in FIG. 2, a method in which the relay 11 that detects power supply from the emergency input 9 directly controls charging without using the control unit 7 or the reference power supply 12 is also possible. The contacts in the relay 11 may be connected in series to the charging circuit, and the contact may be opened by applying an AC voltage to the relay 11 and short-circuited when there is no AC voltage. In the relay 11, the AC voltage is transmitted to the coil via the diode bridge circuit, the contact is opened, and even if an external signal commanding charging is received and the switching element 13 is turned on, the current in the charging direction Will not flow.

  Furthermore, as shown in FIG. 3, it is possible to know whether power is supplied from the emergency input 9 by detecting the state of the changeover switch 6. The relay 11 is replaced with an interlocking switch 15 that is interlocked with the changeover switch 6, and the interlocking switch 15 is open when the changeover switch 6 is on the commercial input 8 side, and short-circuited when it is on the emergency input 9 side. If the changeover switch 6 is on the commercial input 8 side, the reference voltage (5 V) of the reference power supply 12 is not transmitted to the control unit 7, so the assembled battery 2 can be charged, and the changeover switch 6 is on the emergency input 9 side. For example, the reference voltage (5 V) of the reference power supply 12 is transmitted to the control unit 7 and charging of the assembled battery 2 is prohibited. The operation of the control unit 7 in this case may be the same as that of the power supply system shown in FIG.

  As described above, the features of the power supply system according to the present invention include, for example, a rectifier that converts AC power into DC power, an assembled battery that is a combination of a plurality of batteries, and a DC that is output by the assembled battery or the rectifier. An inverter that converts electric power into AC power; a control unit that controls charging of the assembled battery; a commercial input that connects a commercial AC power supply; an emergency input that connects an emergency power supply; the commercial input and the emergency A power supply system having a changeover switch that selects either an input or an output, and the alternating-current power output from the changeover switch is switched via the rectifier and inverter or via a bypass circuit The switch selects and outputs either the output of the bypass circuit or the output of the inverter, and reaches from the rectifier to the inverter The positive electrode of the assembled battery is connected to the plus of the current feeding line, the minus of the DC feeding line from the rectifier to the inverter and the negative electrode of the assembled battery are an electric circuit in which a switching element is inserted, and the assembled battery A relay to which a voltage from the emergency input is applied is connected to a circuit between the emergency input and the changeover switch, which is separately connected by a circuit in which a diode that passes power only in the discharge direction is inserted. A reference voltage is supplied to the control unit by closing a contact of the relay, and the control unit opens the switching element when the reference voltage is supplied by an operation of the relay. is there. As a result, while receiving the power supply from the emergency power source, charging is not performed even if an external signal instructing charging is received.

  With this feature, in a backup power supply system that continues to supply power to a load even during a power outage, it is possible to prevent a decrease in power utilization efficiency when an emergency power supply is connected, and to avoid power supply stoppage and deterioration of the storage battery due to storage battery consumption A power supply system can be provided.

  As described above, the embodiment of the present invention has been described by taking the case where the battery is a nickel metal hydride storage battery as an example, but the present invention is not limited to this. Below, the effect produced by this invention is demonstrated.

  (1) When an emergency power supply is connected to the input of a backup power supply such as a UPS, it is recognized that the commercial power supply has been restored, and the input power is not only supplied to the load device but also consumed for charging the storage battery. The Therefore, there is a problem that the duration of power supply is shortened and the utilization efficiency of the emergency power supply is reduced.

  According to the present invention, it is possible to prevent a reduction in power utilization efficiency when an emergency power supply is connected.

  (2) When the emergency power supply is connected to the backup power supply input, the rectifier is simply stopped to prevent the storage battery from being charged. Stops, and another problem of storage battery deterioration due to continued discharge occurs.

  According to the present invention, it is possible to avoid power supply stoppage and deterioration of a storage battery due to consumption of the storage 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 the example of embodiment of this invention. It is a figure explaining the prior art example of a power supply system. It is a figure explaining the prior art example of a power supply system.

Explanation of symbols

1: rectifier, 2: assembled battery, 3: inverter, 4: switcher, 5: bypass circuit, 6: changeover switch, 7: control unit, 8: commercial input, 9: emergency input, 10: output, 11: Relay, 12: reference power supply, 13: switching element, 14a, 14b: diode, 15: interlocking switch.

Claims (3)

A rectifier that converts AC power into DC power, a battery pack that combines a plurality of batteries, an inverter that converts DC power output from the battery pack or rectifier into AC power, and a commercial input that connects a commercial AC power supply An emergency input for connecting an emergency power supply, a selector switch for selecting and outputting either the commercial input or the emergency input, a control unit for controlling charging of the assembled battery, and the emergency input A power supply system having a reference voltage generating means for detecting a power supply from and outputting a reference voltage as a charge prohibition signal to the control unit,
The AC power output from the changeover switch is supplied to the changer via the rectifier and an inverter or via a bypass circuit, and the changer outputs either the output of the bypass circuit or the output of the inverter. Select and output
One pole of the assembled battery is connected to one of the DC power supply lines from the rectifier to the inverter,
The other of the DC power supply line from the rectifier to the inverter and the other pole of the assembled battery are inserted with an electric circuit in which a switching element is inserted and a diode that passes power only in the discharge direction of the assembled battery. Connected separately by electrical circuit,
The controller is
When the reference voltage, which is a charge prohibition signal, is input, the switching element is not short-circuited even when a charge command signal is received from outside the power supply system. When no is inputted , the power supply system is characterized in that, by receiving a charge command signal from the outside of the power supply system , the switching element is short-circuited to charge the assembled battery .
The power supply system according to claim 1,
The reference voltage generating means includes a reference power supply and a relay that detects power supply from the emergency input as constituent elements . The power supply system according to claim 1,
The power supply system according to claim 1 , wherein the reference voltage generating means includes a reference power supply and an interlocking switch interlocking with the changeover switch .

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