JP6221720B2 - Uninterruptible power system - Google Patents

Description

  The present invention relates to an uninterruptible power supply, and particularly to generation of a power supply switching operation signal when a control device that outputs a power supply switching operation signal is abnormal.

  FIG. 7 shows a single connection diagram of the main body of an uninterruptible power supply (hereinafter referred to as UPS) in a constant inverter feeding system. This UPS is a rectifier REC that converts alternating current into direct current, and an inverter INV that converts direct current into alternating current. , A chopper CHP that converts a DC voltage of an energy storage device such as a storage battery into an arbitrary voltage value, a thyristor switch TS that bypasses the UPS and supplies AC to the load, a bypass-side power switch 83B, and an inverter-side power switch A container 83I is provided. Note that 52R is an AC input electromagnetic switch, and 72B is a DC input electromagnetic switch.

  A UPS having a bypass power supply normally has an inverter power supply that supplies alternating current to the load via an inverter INV, and a bypass power supply that switches the bypass power supply from a commercial AC power supply or private power generator to supply alternating current to the load. Then, the power switch 83I connected in series with the inverter INV is normally in the on state and adopts the inverter power feeding method.

  When the inverter power supply cannot be continued due to a failure of the control device or the like during the inverter power supply, the power supply switching unit 83I is opened and the power supply switching unit 83B is turned on to perform the bypass power supply for supplying power from the bypass power source to the load. By switching on the thyristor switch TS at the time of switching the power, the power is switched without interruption. Therefore, when a failure occurs in the UPS control device, switching of AC output without interruption is impossible.

  Patent document 1 etc. are well-known as what solves this problem. In Patent Document 1, an output switching circuit for executing AC output switching is duplicated so that bypass power feeding can be performed when inverter power feeding is stopped.

JP2013-110887A

In general, processing of a signal for a power supply switching operation in the UPS is performed in a UPS control device composed of a CPU, FPGA, or the like, and an operation command TS for the gate signal TS- _GATE of the thyristor switch TS is directly from the control device. -cmd is output, and a turn-on command 83B-cmd for the power switch 83B is also directly output to the power switch 83B via a turn-on signal 83BY.

Depending on the power supply control system for the load, not only power is supplied by only one UPS, but also a plurality of UPSs are connected in parallel to a three-phase AC input power source to supply power to the load. In this case, when a failure occurs in one of the plurality of units, the power source switching to bypass power feeding is not performed, but the power source switching units 83I and 83B are left open as they are, and power feeding is continued with a sound UPS.
That is, the operation mode with respect to the power switch is different when an abnormality occurs during single UPS operation and parallel operation of multiple units.

In any of these power supply control systems, the power supply switching operation in the UPS is performed based on a command generated by the UPS control device. For this reason,
If the control power supply is lost or an abnormality occurs in the CPU constituting the control device and the control device does not function normally, a correct power supply switching operation cannot be performed.
In addition, as operation at the time of abnormality occurrence, there is bypass power supply switching (switching the power switch from the inverter side to the bypass side), or parallel release (making the power switch not in the inverter side or the bypass side), A circuit is provided to always turn off the power switch 83I when an abnormality occurs.

  An object of the present invention is to provide an uninterruptible power supply device that enables a normal power supply switching operation even when an abnormality occurs in a UPS control device.

Claim 1 of the present invention includes an inverter power supply that supplies AC power to a load via an inverter, and a bypass power supply function that supplies AC power to the load via a switching device in which a thyristor switch and a power switch are connected in parallel. An uninterruptible power supply that supplies power to a load by switching between inverter power supply and bypass power supply according to an operation signal from the controller of the uninterruptible power supply.
Operation signals output power switching controller provided in the control device, the power supply switching control unit includes an operation signal storage unit an operation signal for turning on the thyristor switch and the power switch is set in advance,
An operation signal selector for the presence or absence of a reset signal by switching the one of the operation signal and sets the operation signal storing unit operation signal from the control unit outputs an operation signal to the thyristor switch and the power switch ,
The backup power source is created based on the voltage of the control power source of the control device, and includes a backup power source for supplying power to the operation signal storage unit.

Claim 2 of the present invention, the operation signal storage unit includes a first latch circuit for operation signal of the thyristor switch is set in advance, a second latch circuit for operation signal of the power switch is set in advance Have
The operation signal selection unit includes a first selection circuit by the reset signal switches the operation signal is set to the the operation signal first latch circuit for the thyristor switch from the control device, the control by the reset signal a second selection circuit for switching the operation signal is set to the operation signal and the second latch circuit for the power switch from the device,
It is characterized by having.

Claim 3 of the present invention, the backup power source as a power source of the operation signal storage unit, the voltage of the backup power supply when the control power of the control device, the output of the power switching controller until it exceeds a predetermined threshold value It is characterized by being configured to suppress.

Claim 4 of the present invention, the operation signal of the thyristors switch and the battery switch is set to the operation signal storage unit are respectively set in advance by a high state at the inverter power supply, and the voltage of the control power supply is less than or equal to the threshold is in when the reset signal becomes low level, is obtained by characterized by being configured to output an operation signal of the thyristors switch and power switch set in the operation signal storage unit.

Claim 5 of the present invention, the operation signal of the thyristors switch and the battery switch is set to the operation signal storage unit are respectively set in advance by a high state at the inverter power supply, the reset signal becomes low level is obtained by characterized by being configured to output an operation signal of the thyristors switch and power switch set in the operation signal storage unit when.

Claim 6 of the present invention, an uninterruptible power supply to multiple parallel operation, the operation signal of the thyristors switch and the battery switch is set to the operation signal storage unit are set in each previously low state at the inverter power supply is one in which was characterized by being configured so as not to output an operation signal to the thyristor switch and the power switch when abnormality in the control device.

Claim 7 of the present invention, the operation signal is set to the operation signal storage unit, a previously low state an operation signal of the thyristors switch, advance to the high state operation signal of the power switch, the reset signal is high The operation signal is output to the power switch when the state changes from low to low.

As described above, according to the present invention, loss of control power, and even if the control unit processing operation of the abnormality occurs to the control device to no longer performed normally, and outputs an operation signal of a normal battery switch Is possible. In addition, it is possible to use switching signals such as bypass power supply switching without instantaneous interruption, bypass power supply switching with instantaneous interruption, and parallel release depending on the operation status of the UPS when the control device is abnormal It is.

The block diagram of the power supply switching control part which shows embodiment of this invention. The operation waveform figure at the time of control power activation. The operation waveform figure at the time of control power loss. FIG. 6 is an operation waveform diagram when an abnormality occurs in the control device during power supply for one UPS. The operation waveform figure at the time of abnormality of a control device during UPS parallel operation. FIG. 6 is an operation waveform diagram of instantaneous interruption switching when an abnormality occurs in the control device. Single connection diagram of UPS main unit.

  FIG. 1 is a configuration diagram of a power supply switching control unit showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a power supply switching control unit, and this power supply switching control unit 1 has an operation signal storage unit 2 and an operation signal selection unit 3. 4 is a backup power source, and 5 is an operation signal input unit from the control device.

The operation signal storage unit 2 is composed of latch circuits 21 and 22. The voltage BK- _RESET from the backup power source 4 is applied to each / PRE terminal of the latch circuits 21 and 22, and the VccBK from the backup power source 4 to the / CLR terminal. Is applied. The backup power supply 4 is a RESET-IC for setting the / PRE terminal of the operation signal storage unit 2 to a low state and suppressing the output of TS- _GATE and 83BY until the control power supply is established when the power is turned on. Even if the control power supply is lost, a voltage generating unit 41 is formed which is composed of an electrolytic capacitor for continuing to supply power to the power supply switching control unit 1 for a predetermined time. When the / PRE terminal of the operation signal storage unit 2 is low, the / Q terminal is in a low state regardless of the input to the D terminal. This / Q terminal is connected to the D terminal when the / PRE terminal is high. Output in response to input. As a result, the output of TS- _GATE and 83BY is suppressed until the voltage VccBK of the backup power supply 4 is established as when the power is turned on.

An operation signal TS-set for switching the power supply of the thyristor switch TS generated by a UPS control device (not shown) is set to the D terminal of the latch circuit 21 via the operation signal input unit 5. Further, the power supply switching operation signal TS-buf is output from the / Q terminal of the latch circuit 21 to the terminal A of the selection circuit 31 of the operation signal selection unit. The operation signal TS-cmd for switching power from the control device is directly inputted to the terminal B of the selection circuit 31. In the selection circuit 31, TS-cmd or TS-buf is selected by the reset signal RESET, and TS _-Output as the gate signal of thyristor switch TS as _GATE .

  A power switching operation signal 83B-set of the power switch 83B generated by the UPS control device is input to the D terminal of the latch circuit 22 and set in the latch circuit 22. Further, the power switching operation signal 83B-buf is output from the / Q terminal of the latch circuit 22 to the terminal A of the selection circuit 32 of the operation signal selection unit. The terminal B of the selection circuit 32 is directly input with the operation signal 83B-cmd for switching power from the control device. In the selection circuit 32, 83B-cmd or 83B-buf is selected by the reset signal RESET, and the power switching is performed. The operation signal 83BY is output to the device 83B.

In the selection circuits 31 and 32 , when the control device is in a normal state, the output applied to each B terminal, that is, the TS-cmd and 83B-cmd signals are output as TS- _GATE or 83BY, and the control device has an abnormality. TS-buf (TS- _GATE ), 83B-buf while the signals TS-set and 83B-set that have been set in the latch circuits 21 and 22 are continuously held when the reset signal RESET is in a low state. (83BY) is output via the operation signal selector 3.
The operation of the power supply switching control unit 1 will be specifically described below based on the waveform signal.

(1) Operation when the control power supply is turned on FIG. 2 is an operation waveform diagram when the control power supply Vcc is turned on. When the power supply is turned on at time t1, the voltage of Vcc increases. Since RESET is in a low state until the control power supply Vcc exceeds a certain threshold value, power supply switching operation signals TS-set and 83B-set set in the operation signal storage unit 2 are output. At this time, since BK- _RESET by the voltage generation unit 41 of the backup power supply 4 is low, the outputs TS-buf and 83B-buf of the operation signal storage unit 2 are also low to prevent malfunction.

When the control power supply Vcc exceeds a predetermined threshold at time t2, the CPU included in the control device starts signal processing. At time t3, when the voltage VccBK of the backup power supply 4 reaches a predetermined threshold, BK- _RESET goes high, and TS-buf and 83B-buf also go high. Thereafter, at time t4 when the initialization of the CPU is completed, RESET is set to high, and the operation signal for switching the power source is switched to the signals TS-com and 83B-cmd from the control device. When RESET is in the high state, the signals TS-cmd and 83B-cmd are output from the control device at time t5 regardless of the operation signal, and the switching operation for the thyristor switch TS and the power switch 83B is performed.

(2) Operation at the time of loss of control power supply during UPS power supply FIG. 3 is an operation waveform diagram at the time of loss of power supply of the UPS control apparatus. Further, the backup power supply 4 functions when the control power supply Vcc is lost.
As shown when the power is turned on in FIG. 2, signals TS-set and 83B-set from the control device are set in the operation signal storage unit 2 in advance at time t2.

When the control power supply is lost at time t21 and the control power supply Vcc becomes below a certain threshold at time t22 and RESET goes low, TS-set and 83B-set also go low, but TS-buf and 83B-buf The high state is held by the latch circuits 21 and 22. Therefore, TS- _GATE and 83BY are both high, the thyristor switch TS is turned on, and the contact of the power switch 83B is turned on to start bypass power feeding. Since the power supply of the operation signal storage unit 2 after the loss of the control power supply is supplied from the backup power supply 4, the operation signal set during the normal operation is continuously held.

(3) Operation when an abnormality occurs in the control device during power supply to one UPS FIG. 4 is an operation waveform diagram when an abnormality occurs in the control device during power supply to one UPS. When this abnormality occurs, there is no instantaneous interruption from inverter power supply to bypass power supply. The switching operation at is performed. That is, in the operation signal storage unit 2, TS-set and 83B-set are both set to a high state until time t31 during normal operation (inverter power supply).

In this state, when an abnormality occurs in the UPS control device and RESET changes from high to low, the operation signal selection unit 3 switches the power supply switching operation signal from the terminal B to A and outputs TS- _GATE and 83BY. Accordingly, even if an abnormality occurs in the control device during the operation of the UPS, the operation signal set in the operation signal storage unit 2 is output, so that a normal switching operation can be performed.

(4) Operation when an abnormality occurs in the control device during UPS parallel operation FIG. 5 is an operation waveform diagram when an abnormality occurs in the control device during parallel operation of UPS. If abnormalities occur when UPSs are operating in parallel and switching to bypass power feeding, other healthy UPSs will be affected. Therefore, when an abnormality occurs in the control device during parallel operation, parallel release of only the corresponding UPS is performed.

The TS-set and 83B-set are both set to a low state in the operation signal storage unit 2 during parallel operation so that disconnection control is possible when an abnormality occurs. At time t41, an abnormality occurs, RESET changes from high to low, and the power switch 83I connected to the output side of the inverter where the abnormality has occurred is turned off (opened). At the same time, the operation signal selection unit 3 switches from the terminal B to the A side , that is, the operation signal storage unit 2 side when RESET becomes low. However, since the preset operation signal is low, TS- _GATE And 83BY are not output, the thyristor TS and the power switch 83B are not turned on, and switching to the bypass side is not performed. Therefore, parallel cancellation can be performed without affecting another healthy UPS.

(5) Operation when instantaneous interruption switching is performed when an abnormality occurs in the UPS control apparatus FIG. 6 is an operation waveform diagram when instantaneous interruption switching is performed when an abnormality occurs in the control apparatus. When an abnormality occurs in the control device, such as when the inverter power supply is operated asynchronously with the bypass power supply, switching to bypass power supply is performed with a momentary interruption. In this case, during normal inverter power feeding, TS-set is set to low and 83B-set is set to high in the operation signal storage unit 2 in advance.

When an abnormality occurs in the control device at time t51 and RESET changes from high to low, the operation signal selection unit 3 is switched, 83B-set previously latched high by the latch circuit 22 becomes low, and 83B-buf becomes 83BY. Thus, the power switch 83B is turned on via the operation signal selector 3. At this time, since TS- _GATE is not output, the OFF state is continued, and therefore, the bypass power supply switching is performed by the power switch 83B.

  As described above, according to the present invention, even when the processing operation of the control device does not operate normally due to the loss of the control power supply, or when the processing operation of the control device stops operating normally due to an abnormality in the control device. A normal operation signal can be output to the power switch. In addition, the operation signal at the time of abnormality can be selectively used for bypass power supply switching without instantaneous interruption, bypass power supply switching with instantaneous interruption, and parallel release according to the operation state of the UPS.

DESCRIPTION OF SYMBOLS 1 ... Power supply switching control part 2 ... Operation signal storage part 3 ... Operation signal selection part 4 ... Backup power supply TS ... Thyristor switch 83B ... Power supply switching device 83I ... Power supply switching device

Claims (7)

An uninterruptible power supply with an inverter power supply that supplies AC power to a load via an inverter and a bypass power supply function that supplies AC power to the load via a switching device in which a thyristor switch and a power switch are connected in parallel. In the case of supplying power to the load by switching between the inverter power supply and the bypass power supply by the operation signal by the control device of the uninterruptible power supply,
A power supply switching control unit is provided on the operation signal output side of the control device, and the power supply switching control unit includes an operation signal storage unit in which operation signals for turning on the thyristor switch and the power switch are set in advance.
An operation signal selector that outputs an operation signal to the thyristor switch and the power switch by switching between an operation signal from the control device and an operation signal set in the operation signal storage unit depending on the presence or absence of a reset signal; ,
An uninterruptible power supply comprising a backup power supply that is created based on a voltage of a control power supply of the control device, and that supplies power to the operation signal storage unit. The operation signal storage unit is
A first latch circuit in which an operation signal of the thyristor switch is preset; and a second latch circuit in which an operation signal of the power switch is preset.
The operation signal selector is configured to switch between an operation signal for the thyristor switch from the control device and an operation signal set in the first latch circuit by the reset signal, and the control by the reset signal. A second selection circuit for switching between an operation signal from the apparatus to the power switch and an operation signal set in the second latch circuit;
The uninterruptible power supply according to claim 1. The backup power source serving as the power source for the operation signal storage unit is configured to suppress the output of the power source switching control unit until the voltage of the backup power source when the control power source of the control device is turned on exceeds a predetermined threshold value. The uninterruptible power supply according to claim 1 or 2. The operation signals of the thyristor switch and the power switch set in the operation signal storage unit are set in a high state in advance when the inverter is fed, and the reset signal is in a low state because the voltage of the control power source is lower than a threshold value. and when it becomes uninterruptible according to any one of claims 1 to 3, characterized by being configured to output an operation signal of the thyristors switch and power switch set in the operation signal storage unit Power supply. The operation signals of the thyristor switch and the power switch set in the operation signal storage unit are set in a high state in advance when the inverter is fed, and are set in the operation signal storage unit when the reset signal becomes a low state. The uninterruptible power supply apparatus according to any one of claims 1 to 3, wherein an operation signal of the thyristor switch and a power supply switching unit is output.   When operating a plurality of uninterruptible power supply units in parallel, the operation signals of the thyristor switch and the power switch set in the operation signal storage unit are set in a low state in advance when the inverter is fed, and when the control device is abnormal The uninterruptible power supply apparatus according to any one of claims 1 to 3, wherein an operation signal is not output to the thyristor switch and the power switch. The operation signal set in the operation signal storage unit is set when the operation signal of the thyristor switch is set to a low state in advance, the operation signal of the power switch is set to a high state in advance, and the reset signal changes from a high state to a low state. The uninterruptible power supply according to any one of claims 1 to 3, wherein an operation signal is output to the power switch.

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