KR100868372B1 - Uninterruptible power supply apparatus and power failure compensating system - Google Patents

Abstract

When the commercial power source is sound, the high speed current limiting unit 3 supplies power to the load from the commercial power source via a DC reactor, and the preliminary power supply unit 4 has both active power and reactive power to be supplied to the load 9. PQ control is performed so as to be zero. In addition, the responsiveness of the PQ control is set longer than the accident detection cycle of the commercial power supply by the accident detection unit 2, and the spare power supply unit is loaded with respect to the load 9 and the accident point until an accident is detected by the accident detection unit 2. Power is supplied from (4) without instantaneous disconnection. Furthermore, the impedance of the DC reactor 14 is set to (100Z) / A or more so that in the event of an accident, the voltage of the load 9 does not fall below the allowable voltage drop rate. When the accident detection unit 2 detects a power failure, the PQ control is stopped by the spare power supply unit 4 and the high speed switches 13a and 13b are shut off.

Description

Uninterruptible Power Supply and Power Failure Compensation System {UNINTERRUPTIBLE POWER SUPPLY APPARATUS AND POWER FAILURE COMPENSATING SYSTEM}

The present invention relates to an uninterruptible power supply and a power failure compensation system for feeding power to a load without a momentary interruption when an accident such as an instantaneous voltage drop or power failure occurs in a commercial power supply.

Devices and systems, such as network servers and semiconductor manufacturing equipment, are subject to significant damage due to power outages or momentary voltage drops (hereinafter referred to as "lower levels"). (UPS: Uninterruptible Power Supply) is widely used. A typical uninterruptible power supply has a battery (battery), which charges the battery when it is healthy (normally), and supplies power to the device or system from the battery when a power trouble occurs to stop or malfunction the device or system. Prevent it from functioning normally.

The power feeding method of the uninterruptible power supply device includes a constant inverter method (see Patent Document 1, for example), a regular commercial power feeding method, and the like.

In the inverter type uninterruptible power supply, the output voltage is always constant regardless of the input power source, so that frequency confusion does not occur. In addition, when a power supply trouble occurs, it is possible to supply power by changing to a backup power supply without a momentary disconnection. However, this type of uninterruptible power supply uses an inverter circuit and a converter circuit to convert power from a commercial power supply twice, resulting in a conversion loss, resulting in an efficiency of about 85%, thereby reducing power consumption of the uninterruptible power supply itself. There is a problem that increases. In addition, since the circuit to be used becomes complicated, there is a problem that it becomes expensive.

On the other hand, the uninterruptible power supply of the commercially available power feeding method usually outputs the input AC power to the load as it is, and in case of a power supply, the power is switched to the storage battery to supply power, thereby reducing the power consumption of the uninterruptible power supply itself, and the battery life. Is also relatively long. In addition, it is inexpensive because there are few circuits to use and its structure is simple. Conventional commercial power supply uninterruptible power supply is a configuration as shown in FIG. 8 is a configuration diagram in which a commercial power supply and a load are connected to a conventional uninterruptible power supply device of a conventional commercial power supply system.

In the uninterruptible power supply 101, an input terminal 106 is connected to a commercial power supply 108, and an output terminal 107 is connected to a load 109. The uninterruptible power supply 101 includes a measuring transformer 111, a controller 112, a semiconductor switch 113, a battery 115, a battery output measuring unit 116, a converter 117 consisting of a charger and an inverter, and a filter. The circuit 118, the transformer 119, and the breaker 121 are provided.

The measuring transformer 111 lowers the voltage value of the utility power supply to a predetermined voltage and outputs it to the controller 112 in order to detect the power supply value supplied from the commercial power supply 108.

The controller 112 charges the battery 115 to the charger of the converter 117 when the power value of the battery output measurement unit 116 becomes less than a predetermined value. When the voltage value output from the measuring transformer 111 becomes less than or equal to the predetermined value, the control unit 112 cuts off the semiconductor switches 113 (thyristors 113a and 113b) and the The inverter is operated to supply power from the battery 115 to the load 109. The semiconductor switch 113 is provided with the thyristor 113a and the thyristor 113b, and is a switch which isolate | separates the load from the commercial power supply 108 when the power supply trouble, such as a short circuit accident, occurs in the commercial power supply 108. As shown in FIG.

The battery 115 supplies power to the load 109 when a power accident occurs and the semiconductor switch 113 is cut off.

The battery output measuring unit 116 measures the voltage and current of the battery 115 and outputs the result to the controller 112.

The charger of the converter 117 is a converter that converts AC power into DC power to charge the battery 115. The inverter of the converter 117 converts DC power into AC power and outputs the AC power.

The filter circuit 118 includes a reactor 118L and a capacitor 118C, and is a high frequency filter connected to the load side of the inverter in order to absorb noise generated when the power device switches inside the inverter.

The transformer 119 converts the power supplied from the commercial power supply 101 into a predetermined voltage. When the semiconductor switch 113 is shut off, the voltage value output from the inverter of the converter 117 is converted into the voltage value of the commercial power supply 108.

The breaker 121 is for supplying power directly from the commercial power source 108 to the load 109 at the time of maintenance of the uninterruptible power supply 101.

Next, the operation of the uninterruptible power supply 101 will be described. The control unit 112 normally turns on the semiconductor switch 113, and the control unit 112 stops the inverter of the converter 117 to stop the power supply from the battery 115. As a result, power is supplied from the commercial power supply 108 to the load 109. At this time, if the voltage value of the battery 115 measured by the battery output measurement unit 116 is less than the predetermined value, the controller 112 operates the charger of the converter 117 to charge the battery 115, If the voltage value of the battery 115 measured by the battery output measurement unit 116 is equal to or greater than a predetermined value, the charger of the converter 117 is stopped.

When an accident occurs in the commercial power supply 108 and the supply voltage drops, the control unit 112 detects the drop in the output voltage at a high speed (1/4 cycle or less) by the measuring transformer 111 and immediately turns on the semiconductor switch 113. ) And the inverter 117b is operated to supply power from the battery 115 to the load 109. The user can prevent the trouble by stopping the load normally until the battery 115 runs out.

When the commercial power supply 108 returns to a healthy state and the supply voltage reaches a normal value, the control unit 112 detects the change in the output voltage at a high speed (1/4 cycle or less) by the measuring transformer 111 and immediately releases the semiconductor. At the same time as the switch 113 is closed, the inverter of the converter 117 is stopped and the charger of the converter 117 is operated to charge the battery 115.

Patent Document 1: Japanese Patent Laid-Open No. 5-64378

As described above, the conventional uninterruptible power supply of the conventional commercial power supply type, after detecting the voltage drop from the commercial power supply 108, opens the semiconductor switch 113 and supplies power to the load 109 from the battery 115. Since it is supplied, it takes about half a cycle (8 to 10 msec) for switching during power failure, and a momentary break occurs in the meantime. Therefore, in the case of a load such as a semiconductor manufacturing apparatus that is affected by a short time voltage drop of about 2 msec, an uninterruptible power supply of a commercially available power supply system cannot be used at all times. The power supply device was used as a backup power supply.

It is an object of the present invention to provide an uninterruptible power supply and an outage compensation system of an ordinary commercially available power supply system capable of supplying electric power by changing the power supply to a standby power supply without interruption.

This invention is equipped with the following structures as a means to solve the said subject.

(1) accident detection means for detecting an accident of commercial power supply at a predetermined accident confirmation cycle;

When the commercial power supply is healthy, high-speed current-limiting current is supplied to the load from the commercial power supply, and when the accident detection means detects an accident in the commercial power supply, the electric current supplying power to the load is cut off from the commercial power supply. Blocking means,

When the commercial power is sound and the accident detecting means detects the accident of the commercial power, the active power and reactive power supplied to the load are all set to 0. The response time is determined by the accident detecting means. A PQ control which is set longer than an accident confirmation period of the commercial power supply, and immediately after the occurrence of the commercial power supply accident, the accident detection means detects the accident and the fast current blocking means supplies the electric power to the load from the commercial power supply. The power supply is supplied to the load and the accident point without interruption until it is interrupted, and when the accident detection means detects the accident of the commercial power supply, the PQ control is stopped, and the fast current limiting means stops from the commercial power supply. If you cut off the circuit that supplies power to the load, the power is supplied only to the load. Which it is characterized in that it includes a standby power unit.

In this configuration, power is normally supplied from the commercial power supply to the load, and when an accident occurs in the commercial power supply, power is supplied from the spare power supply means to the load immediately after that. Therefore, unlike the conventional uninterruptible power supply of the conventional commercial power supply system, it is possible to supply power without an instantaneous disconnection from the standby power supply when an accident of the commercial power supply occurs.

(2) accident detection means for detecting instantaneous voltage drop accidents and power failure accidents in a commercial power supply at predetermined accident confirmation intervals;

A single phase rectifying bridge circuit including a high speed switch for opening and closing a converter for supplying power to the load from the commercial power supply, and a DC reactor connected between two DC terminals of the single phase rectifying bridge circuit. The power is supplied from the commercial power supply to the load through the direct current reactor until it is healthy and the accident detection means detects the accident of the commercial power. When the accident detection means detects the accident from the commercial power, A fast current interrupting means for disconnecting a converter for supplying power to a load from a commercial power supply with said high speed switch;

A filter circuit including an AC reactor, an inverter, and a DC power supply are connected in series, and are supplied to the load until the commercial power is sound and the accident detection means detects the accident of the commercial power. PQ control to set both the active power and the reactive power to 0 together, and the accident detection means detects the accident immediately after the occurrence of the accident, so that the fast current interrupting means cuts off the converter supplying power to the load from the commercial power supply. Until the moment, the power is supplied to the load and the accident point without interruption, and when the accident detection means detects the accident of the commercial power supply, the PQ control is stopped, and the fast current limiting means stops the load from the commercial power supply. When a circuit for supplying power to the circuit is cut off, a reserve for supplying the necessary power to the load only Including power means,

The response of the PQ control is set to be longer than the accident confirmation period of the commercial power supply in the accident detection means.

In this configuration, since the uninterruptible power supply does not supply power to the load when the commercial power supply is healthy, the fast current interrupting means supplies power to the load via the DC reactor from the commercial power supply. In the preliminary power supply means, the PQ control is performed so that the active power and the reactive power supplied to the load become zero together. In addition, since the impedance of the DC reactor is apparently zero in the steady state, when the commercial power source is healthy, the DC reactor does not adversely affect the commercial power source, and power is stably supplied from the commercial power supply to the load. Therefore, since the power is not supplied to the load from the preliminary power supply means when the commercial power source is healthy, the uninterruptible power supply can supply power to the load only from the efficient commercial power source.

In this configuration, the accident detection means performs accident detection at a predetermined cycle, but in order to supply power without disconnecting momentarily from occurrence of an accident to detection of an accident, responsiveness of PQ control is commonly used in the accident detection means. It is set longer than the accident detection cycle of the power supply. Therefore, even if a momentary voltage drop or power failure occurs in a commercial power supply, the response of the PQ control is not immediately followed, so that PQ control is continuously performed under the same system conditions as before the accident occurred. At this time, an accident occurs on the system side, and the PQ control is not performed correctly because the PQ control is performed under the system condition before the occurrence of the accident. That is, PQ control is not performed correctly so that load current does not flow, and electric current flows from a preliminary power supply means to a system. In the present invention, power supply is continued to the load by the partial pressure action of the DC reactor and the AC reactor by using the current at this time. The PQ control stops at the next accident detection timing. After this stop, power is supplied from the spare power supply means. As described above, in the period from the accident occurrence timing to the accident detection timing, electric power is supplied to the load and the accident point without any interruption from the preliminary power supply means.

Furthermore, in this configuration, when the accident detection means detects an accident such as a low voltage or a power failure in the commercial power supply, PQ control is performed in the preliminary power supply means, and the converter is cut off by the high speed switch of the high speed current limiting means, and the commercial power is disconnected. All. Therefore, after the fast current interrupting means cuts off the converter, it is possible to supply the necessary power from the preliminary power supply means without lowering the voltage to the load.

(3) When the allowable voltage drop rate for the load is A% and the AC reactor impedance is Z, the impedance of the DC reactor is set to (100Z) / A.

In this configuration, even when a ground fault or short circuit occurs in the commercial power supply, the voltage of the preliminary power supply means is divided by the DC reactor and the AC reactor so that the voltage of the load does not drop below the allowable voltage drop rate.

(4) A control means is provided for controlling the voltage of the preliminary power supply means and the voltage of the commercial power supply with the same phase and the same amplitude.

In this configuration, since the phase and amplitude of the commercial power supply and the power supply of the standby power supply are controlled to have substantially the same values, the phase and amplitude are shifted from the backup power supply to the load when an accident occurs in the commercial power supply. Power can be supplied immediately. On the other hand, in the PQ control, the load current is controlled to 0, but the inverter is always driven. For this reason, by setting the phase of the system and the phase of the inverter in advance, the power supply from the preliminary power supply means is in continuous phase immediately after the occurrence of the accident.

(5) The high speed switch is a pair of thyristors, the single-phase rectifier bridge circuit is a pair of thyristors connected to one of the two AC terminals, the two AC terminals of the single-phase rectifier bridge circuit It is characterized in that connected to the commercial power supply and the load, respectively.

In this configuration, by using a pair of thyristors as the high-speed switch of the rectifier circuit, it is possible to shut off the circuit for supplying electric power from the commercial power supply at a time of about 10 msec after an accident occurs in the commercial power supply. In addition, when the circuit between the commercial power supply and the load is interrupted by the thyristor in the event of a power failure, the induced electromotive force generated in the DC reactor can be short-circuited to the semiconductor rectifier element.

(6) accident detection means for detecting an accident of commercial power at a predetermined accident confirmation cycle, active power supplied to the load until the commercial power is sound and the accident detection means detects an accident of the commercial power; As the control to set the reactive power to 0, PQ control is set whose response time is longer than the accident confirmation period of the commercial power supply in the accident detection means, and the accident detection means detects the accident immediately after the occurrence of the commercial power supply accident. Until the fast current blocking means detects and cuts off the converter supplying power to the load from the commercial power supply, the electric power is supplied to the load and the accident point without interruption momentarily, and the accident detection means detects the accident of the commercial power supply. When detecting, the PQ control is stopped, and the fast current limiting means is disconnected from the commercial power supply. Blocking the converter for supplying electric power and for under the UPS having the reserve power source means for supplying power only to the load,

An emergency generator for blocking the electric current supplying power from the commercial power supply to the load from the commercial current supply and starting before the preliminary power supply means cannot supply power to the load;

And a switch capable of connecting the load to the commercial power supply or the emergency generator and switching the connection.

Incident detection means for detecting instantaneous voltage drop accidents and power failure accidents in a commercial power supply in a predetermined accident confirmation cycle,

A single phase rectifying bridge circuit including a high speed switch for opening and closing a converter for supplying power to the load from the commercial power supply, and a DC reactor connected between two DC terminals of the single phase rectifying bridge circuit. The power is supplied from the commercial power supply to the load through the direct current reactor until it is healthy and the accident detection means detects the accident of the commercial power. When the accident detection means detects the accident from the commercial power, A fast current interrupting means for disconnecting a converter for supplying power to a load from a commercial power supply with said high speed switch;

And a filter circuit connected in series, an inverter, and a direct current power source. The filter circuit includes an alternating current reactor. The filter circuit includes the alternating current reactor until the sound source of the commercial power source and the accident detecting unit detect the accident of the commercial power source. PQ control is performed to zero the active power and the reactive power supplied to the load, and the accident detection means detects the accident immediately after the occurrence of the accident, and the fast current interrupting means supplies power to the load from the commercial power supply. Until the circuit is cut off, power is supplied to the load and the accident point without interruption momentarily, and when the accident detection means detects an accident of the commercial power supply, the PQ control is stopped, and the high speed current limiting means If you disconnect the power supply from the power source to the load, only the power needed for that load It includes a backup power supply means,

An uninterruptible power supply in which the responsiveness of the PQ control is set longer than an accident confirmation period of commercial power in the accident detection means;

An emergency generator for blocking the electric current supplying power from the commercial power supply to the load from the commercial current supply and starting before the preliminary power supply means cannot supply power to the load;

And a switch capable of connecting the load to the commercial power supply or the emergency generator and switching the connection.

When an accident occurs in the commercial power supply, the power supply for the load can be supplied from the backup power supply for a while, but after a certain period of time, the DC power supply voltage of the backup power supply decreases, so that the required power supply to the load is reduced. It cannot be supplied. In the above configuration, before the voltage of the DC power supply decreases so that sufficient power cannot be supplied to the load from the preliminary power supply means, the emergency generator is started and the switch is switched to supply power to the load from the emergency generator so that the load is continued. It is possible to supply power stably.

According to the uninterruptible power supply device according to claim 1, power is usually supplied from a commercial power supply to a load, and when an accident occurs in the commercial power supply, power is supplied from the backup power supply means to the load from that time. Unlike the uninterruptible power supply, in the event of an accident of commercial power supply, power can be supplied without interruption from the standby power supply.

According to the uninterruptible power supply device according to claim 2, when the commercial power source is healthy, power can be supplied to the load only from the commercial power source without supplying power to the load from the preliminary power supply means. Further, after the fast current interrupting means cuts off the converter, it is possible to supply the necessary power from the preliminary power supply means so that the voltage does not fall with respect to the load.

According to the uninterruptible power supply of claim 3, even when a ground fault or short circuit occurs in the commercial power supply, the voltage of the preliminary power supply means is divided by the DC reactor and the AC reactor so that the voltage of the load does not lower than the allowable voltage drop rate. Can supply power

According to the uninterruptible power supply of claim 4, the voltage of the commercial power supply and the voltage of the backup power supply are controlled so that the phase and amplitude are almost the same, so that power is immediately supplied from the backup power supply to the load immediately when an accident occurs in the commercial power supply. Can supply

According to the uninterruptible power supply device according to claim 5, the converter supplying electric power from the commercial power supply can be cut off at a time of about 10 msec after an accident occurs in the commercial power supply. In addition, when the circuit between the commercial power supply and the load is interrupted by the thyristor in the event of a power failure, the induced electromotive force generated in the reactor can be shorted to the semiconductor rectifier element.

According to the electrostatic compensation system according to claim 6 or 7, it is possible to continuously supply power to the load from the emergency generator before the voltage of the DC power supply decreases so that sufficient power cannot be supplied to the load from the preliminary power supply means.

1 is a schematic configuration diagram of an uninterruptible power supply apparatus according to an embodiment of the present invention.

2 is a graph showing the relationship between the constant and the equivalent impedance during current attenuation for the AC power cycle.

3 is a block diagram of a controller of an uninterruptible power supply.

4 is a schematic view for explaining the operation of the uninterruptible power supply.

5 is an equivalent circuit and a vector diagram of an uninterruptible power supply.

6 is an output voltage waveform and a control timing chart of an uninterruptible power supply.

7 is a schematic diagram of connecting an emergency generator to an uninterruptible power supply.

8 is a configuration diagram in which a commercial power supply and a load are connected to a conventional uninterruptible power supply device of a conventional commercial power supply system.

1 is a schematic configuration diagram of an uninterruptible power supply apparatus according to an embodiment of the present invention. The uninterruptible power supply apparatus according to the embodiment of the present invention supplies power to a load in a commercial power supply system at all times, but is configured to compensate without an instantaneous interruption in the event of a power failure or a sudden low.

The uninterruptible power supply 1 includes an accident detection unit 2, a high speed current limiting unit 3, a backup power supply unit 4, and a bypass unit 5, and an input terminal 6 is connected to a commercial power source 8. The output terminal 7 is connected to the load 9. The accident detection unit 2 includes a measurement transformer 11 and a control unit 12. The fast current interrupting block 3 is composed of a bridge circuit 13 and a direct current reactor 14, which are single phase rectifying bridge circuits. The preliminary power supply unit 4 includes a battery 15 which is a DC power supply, a battery output measurement unit 16, a conversion unit 17, a filter circuit 18, a transformer 19, and a power output measurement unit 20. The bypass part 5 consists of the breaker 21.

The accident detection unit 2 detects that a power accident occurs in the commercial power supply 8 and that a net power failure or power failure occurs. The fast current interrupting block 3 interrupts the electric circuit between the commercial power source 8 and the load 9 when a power accident occurs in the commercial power source 8. The preliminary power supply unit 4 supplies electric power to the load 9 when a power accident occurs in the commercial power supply 8. The bypass section 5 bypasses the high speed current blocking section 3 and the reserve power supply section 4 to directly connect the commercial power supply 8 and the load 9.

The measuring transformer 11 measures the AC voltage of the commercial power source 8 and outputs the result to the control unit 12.

The control unit 12 controls the opening / closing operation of the bridge circuit 13 and the charging or output operation of the conversion unit 17 based on the voltage measurement result of the commercial power source output from the measuring transformer 11. In addition, the control unit 12 controls the charging operation of the converter 17 based on the measurement result of the battery output measuring unit 16. Furthermore, the controller 12 controls the output power of the converter 17 based on the measurement result of the power output measurer 20.

On the other hand, the control unit 12 is supplied with electric power from the spare power supply unit 4, and operates without being affected even when a power accident occurs in the commercial power supply 8. Moreover, the control part 12 detects the signal output from the measuring transformer 11, the battery output measuring part 16, and the power output measuring part 20 every quarter cycle.

The bridge circuit 13 consists of two (pair) thyristors 13a and 13b, two (pair) diodes 13c and 13d, two AC terminals 13a1 and 13a2 and two direct currents. Terminals 13d1 and 13d2 are provided. The anode of the thyristor 13a and the cathode of the thyristor 13b are connected to the AC terminal 13a1, and the cathode of the diode 13c and the anode of the diode 13d are connected to the AC terminal 13a2. The cathode of the thyristor 13a and the cathode of the diode 13d are connected to the DC terminal 13d1, and the anode of the thyristor 13b and the anode of the diode 13c are connected to the DC terminal 13d2. Furthermore, the DC reactor 14 is connected between the DC terminal 13d1 and the DC terminal 13d2. In addition, an input terminal 6 for connecting a commercial power supply 8 is connected to the AC terminal 13a1, and an output terminal 7 for connecting a load 9 is connected to the AC terminal 13a2.

On the other hand, in the bridge circuit 13, the AC terminal 13a1 may be connected to the output terminal 7 and the AC terminal 13a2 may be connected to the input terminal 6.

The DC reactor 14 limits the current flowing from the preliminary power supply unit 4 to the commercial power source 8 in the event of a power accident in the commercial power source 8.

The battery 15 accumulates electric power (electrical energy) to be supplied to the load 9 when a power failure or sudden low occurs in the commercial power source 8.

The battery output measuring unit 16 includes a DC measuring current transformer and a DC measuring transformer (not shown) to measure the DC voltage and the DC current of the battery, and output the result to the controller 12.

The conversion unit 17 includes a charging unit (capacitor) 17a and an inverter 17b (not shown), and the charging unit 17a outputs a control signal output from the control unit 12 to float charge the battery 15. Convert AC power to DC power based on In addition, the inverter 17b converts the DC power accumulated in the battery 15 into AC power based on the control signal output from the control unit 12 to supply power to the load 9.

On the other hand, the battery 15 may be configured to be charged by a charger disconnection method (direct current switch method). In this case, the converter 17 may be configured to be an inverter 17b alone, and the charger may be designed independently.

The filter circuit 18 includes a reactor 18L and a capacitor 18C and is a high frequency filter that absorbs noise generated when the power device switches inside the inverter.

The transformer 19 lowers the voltage of the commercial power supply 8 to a predetermined voltage, and boosts the output voltage of the inverter 17b to a voltage substantially equal to that of the commercial power supply.

The power output measuring unit 20 includes an AC measuring current transformer 20a and an AC measuring transformer 20v to measure inverter current and load voltage, and output the result to the controller 12.

The circuit breaker 21 switches the circuit break state at the time of maintenance or failure of the uninterruptible power supply 1, bypasses the uninterruptible power supply 1, and directly supplies power to the load 9 from the commercial power supply 8. It is to supply.

Here, the uninterruptible power supply 1 sets the relationship between the constant at the time of current attenuation and the system frequency cycle so that the impedance seen from the AC side becomes almost zero during normal operation and shows a large impedance only when an accident occurs. 2 is a graph showing the relationship between the constant and the equivalent impedance during current attenuation for the AC power cycle. In the uninterruptible power supply 1 configured as described above, a bridge circuit 13 composed of a reactance component, a resistance component, a pair of thyristors 13a and 13b, and a pair of diodes 13c and 13d of the reactor 14. As shown in Fig. 2, the equivalent impedance as determined by the current and the equivalent impedance seen from the grid side have a relationship in which the equivalent impedance decreases as the constant increases as the current decays. On the other hand, the circuit impedance in normal operation is preferably very small. In general, the DC reactance is selected so as to suppress the magnetic current in the event of a system short circuit to about three times the static current. That is, the bridge circuit 13 has an impedance of 33% of the rated current base. On the other hand, in the normal operation state as described above, it is preferable to make the equivalent impedance very small, and practically 3% of the rated current base, that is, the equivalent impedance shown in FIG. 2 is 0.09 pu (= 3%) represented by the DC reactor L. / 33%) or less to meet that need. Therefore, the current decay constant of the uninterruptible power supply 1 is set to 2.5 times or more of the system frequency period based on FIG.

Next, the detailed structure of the control part 12 is demonstrated. 3 is a block diagram of a controller of an uninterruptible power supply. The control unit 12 includes a voltage judging unit 31, a thyristor control unit 32, a synchronization signal generator 33, a self-driving phase signal generator 34, a switching switch 35, a PQ operation unit 36, and a PQ. The control part 37, the switch 38, the battery state determination part 39, the output voltage reference sine wave creation part 40, and the inverter output control part 41 are provided.

The voltage judging unit 31 has a signal corresponding to the AC voltage value of the commercial power source 8 output from the measuring transformer 11, and the voltage of the commercial power source 8 is a predetermined set voltage based on a predetermined setting value. It is determined whether the value is lower than the value, the predetermined set voltage value, or recovered to the predetermined set voltage value. The signal corresponding to the determination result is then output to the thyristor control unit 32. In the case where a sudden power failure or a power failure occurs in the commercial power supply 8, the voltage judging unit 31 outputs a signal to the voltage battery state determination unit 39 informing the effect thereof.

The thyristor control unit 32 outputs the thyristor lighting signal to the thyristors 13a and 13b of the bridge circuit 13 on the basis of the signal output from the voltage determining unit 31, and controls the opening / closing (lighting-off, turning-off) of these thyristors. do.

The synchronization signal generator 33 generates a signal for synchronizing the output voltage of the spare power supply unit 4 with the output voltage of the commercial power source 8, and outputs the reference voltage sine wave generator 40 through the switch 35. Output this signal. On the other hand, the synchronization signal generator 33 outputs this signal to the phase signal generator 34 for driving frequently.

The self-operating phase signal generator 34 is for generating a phase signal of a voltage to be output when the uninterruptible power supply 1 cuts off the path between the commercial power source 8 and the load 9 and operates frequently. On the other hand, the autonomous driving phase signal generator 34 controls the phase with the output voltage of the commercial power source 8 based on the signal output from the synchronization signal generator 33 when the commercial power source 8 is healthy. Doing.

The changeover switch 35 is switched in accordance with the switch control signal output from the voltage determiner 31. That is, when the commercial power source 8 is in a healthy state or when the AC voltage of the commercial power source 8 recovers, the switch 35 outputs a signal from the synchronization signal generator 33 to the output voltage reference sine wave generator 40. Is switched. On the other hand, when the AC voltage of the commercial power source 8 is lower than the predetermined set voltage, the switch 35 is switched so that a signal is output from the phase signal generator 34 for operation to the output voltage reference sine wave generator 40 indefinitely. .

The PQ calculating section 36 prepares phase information and amplitude information of the AC voltage (sine wave) output from the inverter 17b based on the calculation result of the power output measuring section 36, and converts these into these via the switching switch 38. Information is output to the output voltage reference sine wave generator 40.

The switching switch 38 is switched in accordance with the switch control signal output from the voltage determiner 31. That is, when the commercial power source 8 is in a healthy state or when the AC voltage of the commercial power source 8 is restored, the switch 38 is output so that a signal is output from the PQ control unit 37 to the output voltage reference sine wave generator 40. It is switched. On the other hand, when the voltage of the commercial power supply 8 is lower than the predetermined set voltage, the switch 38 is switched so that a signal is not output to the output voltage reference sine wave generator 40. Here, in the operation description to be described later, the switching switches 35 and 38 are described as latch switches.

The battery state determination unit 39 determines whether the battery 15 needs to be charged or fully charged based on the measurement results of the DC voltage and the DC current of the battery 15 output from the battery output measurement unit 16. do. The output voltage reference sine wave generator 40 generates phase information according to the determination result and outputs the phase information to the inverter output controller 41. The battery state determining unit 39 stops output of the phase signal and stops charging of the battery 15 when a signal is output from the voltage determining unit 31 due to a sudden power failure or power failure in the commercial power supply 8. .

The output voltage reference sine wave generator 40 outputs signals from the synchronization signal generator 33, the PQ controller 37 and the battery state determination unit 39, or the phase signal generator 34 for self-driving operation. Based on the signal, the phase and amplitude information of the sine wave voltage output from the inverter 17b is prepared, and this information is output to the inverter output control unit 41.

The inverter output controller 41 controls a signal output from the inverter 17b of the converter 17 on the basis of the signal output from the output voltage reference sine wave generator 40 or the battery 17 to the charger 17a. 15) outputs a control signal for charging.

Next, the operation of the uninterruptible power supply 1 will be described based on FIGS. 3 and 4. 4 is a schematic view for explaining the operation of the uninterruptible power supply. The uninterruptible power supply 1 supplies power to the load in a commercial power supply at all times, but can compensate without an instantaneous interruption in the event of power failure or net low.

(A) Healthy (commercial dispatch)

The uninterruptible power supply 1 does not supply power to the load from the preliminary power supply unit 4 when the commercial power supply 8 is healthy, that is, when no power accident occurs in the commercial power supply 8 and no step or power failure occurs. Instead, power is supplied only from the commercial power source 8.

In the uninterruptible power supply 1, as shown in Fig. 4A, the thyristor 13a and the thyristor 13b of the fast current interrupting block 3 are both turned on and controlled in a closed state, and are controlled from the commercial power source 8. Power is supplied to the load 9 via the fast current interrupting block 3.

Since the current flows in the DC reactor 14 at the same time in the high-speed current blocking section 3, the impedance of the DC reactor 14 is apparently zero, and the impedance seen from the AC terminals 13a1 and 13a2 is also shown. It becomes zero.

The spare power supply unit 4 is controlled so that electric power is not supplied to the load 9 when the commercial power source 8 is sound. That is, the control of the preliminary power supply unit 4 to make both of the active power P and the reactive power Q to be supplied to the load 9 to be 0 (hereinafter referred to as PQ control) is performed. In the conversion unit 17 of the preliminary power supply unit 4, direct voltage control for floating charge of the battery 15 and output voltage control for outputting a voltage having substantially the same phase and the same amplitude as the commercial power supply 8 are performed.

The operation of each part of the control part 12 in a healthy state is demonstrated. The control part 123 detects the signal output from the measuring transformer 11 every 1/4 cycle as mentioned above. The voltage determiner 31 outputs a signal for switching the switching switch 35 so that the signal output from the synchronization signal generator 33 is output to the output voltage reference sine wave generator 40 in a normal voltage. The voltage judging unit 31 also outputs a signal for switching the switching switch 38 in order to output the signal from the PQ control unit 37. Further, the voltage judging unit 31 outputs a signal to the battery state determining unit 39 to charge the battery when the battery 15 is not in a fully charged state. In addition, the voltage determining unit 31 outputs a signal to the thyristor control unit 32 to turn on the thyristors 13a and 13b of the bridge circuit 13. The thyristor control part 32 outputs a thyristor lighting signal when it detects this signal. On the other hand, in the health of the commercial power source 8, the thyristors 13a and 13b are always in the lit state (on state).

(PQ control)

In the control part 12, when performing the above-mentioned PQ control, in order to set both the active power P and the reactive power Q to be supplied to the load 9 to 0, the control part 12 is transferred from the preliminary power supply part 4 to the load 9. Control to set the output current to zero is performed. 5 is an equivalent circuit and a vector diagram of an uninterruptible power supply. In Fig. 5A, the output voltage of the commercial power supply 8 is V1, the voltage of the spare power supply unit 4 is V2, the voltage of the load 9 is VL, and the reactance on the commercial power source 8 side is X1, which is preliminary. The reactance of the power supply unit 4 is referred to as X2. In addition, the current I1 flows from the commercial power supply 8 to the preliminary power supply section 4, the current I2 flows from the preliminary power supply section 4 to the load 9, and the current I3 flows from the commercial power supply 8 to the load 9. Shall be. Incidentally, in the following description, V∠θv is referred to as the voltage vector V, and I∠θi is referred to as the current vector I.

When the voltage vector V2 of the preliminary power supply unit 4 and the voltage vector VL of the load voltage are the same, no current flows from the preliminary power supply unit 4 to the load 9. In this case, the directions of the current vectors I1 and I2 may be opposite to each other in the same magnitude. When these relationships are satisfied, the relationship of each vector becomes as shown in Fig. 5B. Meanwhile, in the drawing, the voltage vector V (x1 + x2) is obtained by adding the voltage vector Vx1 of the reactance x1 and the voltage vector Vx2 of the reactance x2.

The PQ calculator 36 calculates the active power P and the reactive power Q based on the inverter current and the load voltage measured by the power output measuring unit 20 to satisfy the above relationship. Subsequently, the PQ control unit 37 calculates a predetermined value [Delta] [theta] that corrects the phase of the sine wave voltage output from the inverter 17b so as to make the effective power P = O. Further, in order to make reactive power Q = O, a predetermined value? A for correcting the amplitude of the sine wave voltage output from the inverter 17b is calculated. The PQ control unit 37 then outputs the calculated? Θ and? A information to the output voltage reference sine wave generator 40.

The output voltage reference sine wave generator 40 creates a reference sine wave based on the signal output from the PQ control unit 37 or the like. When the sine wave is generated based only on the signal output from the PQ control unit 37, the sine wave voltage output by the inverter 17b is

V2 = (A + ΔA) sin (ωt + Δθ) ----- (Equation 1)

Becomes Therefore, by setting the output voltage V2 of the inverter 17b as described above, the power supplied from the preliminary power supply unit 4 to the load 9 can be zero.

On the other hand, the relationship between the phase (Δθ) for correcting the voltage V2 output from the spare power supply unit 4 and the effective power P and the amplitude (Δ) for correcting the voltage V2 output from the reserve power supply unit 4. The relationship between A) and reactive power Q can be easily calculated based on the impedance of the commercial power source 8 to which the uninterruptible power supply 1 is to be connected or the impedance of the uninterruptible power supply 1. You can get it.

(Charge control)

Moreover, the control part 12 performs charge control of the battery 15 as mentioned above. That is, the battery state determination unit 39 determines whether or not the battery 15 needs to be charged or fully charged based on the measurement results of the DC voltage and the DC current of the battery 15 output from the battery output measurement unit 16. To judge. When the battery 15 needs to be charged, the battery state determination unit 39 phases so that current flows from the charger 17a of the converter 17 to the battery 15 so that the battery 15 is charged. Fill out the information. The information of the phase signal generated by the battery state determination unit 39 is used as information for correcting the phase of the sine wave voltage output to the output voltage reference sine wave generator 40 and output from the inverter 17b. On the other hand, when the battery 15 is fully charged, the battery state determination unit 39 does not generate the phase signal, and does not output the phase signal information to the output voltage reference sine wave generator 40.

On the other hand, this control is not used when the battery 15 is charged by the charger detachment method.

(Spare Power Output Balance Control)

In addition, the control unit 12 outputs a voltage having no difference in phase and amplitude of the voltage waveform output from the preliminary power supply unit 4 when a step or power failure occurs, so that the phase and amplitude of the output voltage of the preliminary power supply unit 4 are output. Is controlled in synchronization with the phase and amplitude of the output voltage of the commercial power supply 8. The synchronization signal generator 33 switches the phase and amplitude information at the output voltage of the commercial power source 8 based on the AC voltage measurement result of the commercial power source 8 output from the measuring transformer 11. It outputs to the output voltage reference sine wave creation part 40 via switch 35. The output voltage reference sine wave generator 40 corrects the phase of the sine wave voltage output from the inverter 17b based on the information output from the synchronization signal generator 33.

In this way, when the commercial power supply 8 is healthy, the control unit 12 performs the same control as described above, so that the output voltage reference sine wave generator 40 has a synchronization signal generator 33, a PQ controller 37, and a battery. Based on the amplitude and phase correction information from the state determining unit 39, information on the phase and amplitude of the sine wave voltage output from the inverter 17b is generated, and the information is output to the inverter output control unit 41. In addition, the conversion unit 17 performs an operation based on the signal output from the inverter output control unit 41.

(B) In case of accident

The uninterruptible power supply 1 supplies power without a momentary disconnection from the reserve power supply unit 4 when a power accident occurs in the commercial power supply 8 and a sudden power failure or a power failure occurs. That is, as shown in Fig. 4B, the preliminary power supply unit 4 immediately supplies the current (output voltage control) to the accident point as a voltage source and supplies the electric power accumulated in the battery 15 to the load 9. do. When a low or power failure is detected by the accident detection unit 2, a cutoff signal is output to the thyristors 13a and 13b of the high speed current limiting unit 3. At this time, the PQ control is stopped in the preliminary power supply unit 4 to stop the charging of the battery 15.

The load voltage VL is a voltage determined by the partial pressure of the DC reactor 14 and the AC reactor 18L. That is, when the battery voltage is Vs, the impedance of the DC reactor 14 is Z1 and the impedance of the AC reactor 18L is Z2, the load voltage VL is

VL = Z1 / (Z1 + Z2) × Vs ------ (Equation 2)

It becomes

(Incident)

The uninterruptible power supply 1 detects a power failure such as an instantaneous voltage drop or a power failure every 1/4 cycle in a commercial power supply. Moreover, PQ control is performed so that electric power may not be supplied from the spare power supply part 4 when the commercial power supply is sound. On the other hand, when a power supply accident occurs, the following control is performed in order to supply electric power from the preliminary power supply unit 4 to the load 9 and the accident point without interruption.

The operation of each part of the control part 12 at the time of an accident will be described. 6 is an output voltage waveform and a control timing chart of an uninterruptible power supply. The sine wave voltage as shown in FIG. 6 is output from the commercial power supply 8. The control part 12 detects the signal output from the measuring transformer 11 every 1/4 cycle as mentioned above. As shown in Fig. 6, the voltage judging unit 31 performs the net low or power failure from the occurrence of the net low or power failure ((1) shown in Fig. 6) up to a quarter cycle (5 msec at 50 Hz) (within the t1 period). (2) shown in FIG.

In the uninterruptible power supply 1, when a sudden power failure or a power failure occurs, the PQ control responds to start supplying power immediately from the preliminary power supply unit 4 to the accident point of the commercial power supply 8 and the load 9 to supply the power continuously. The sex is set to 10 msec to several 100 msec, which is longer than the period in which the control unit 12 detects a power supply accident of the commercial power source. Therefore, even if a voltage drop accident or a power failure accident occurs in a commercial power supply, the response of the PQ control is not immediately followed, so that PQ control is continuously performed under the same system conditions as before the accident occurred. At this time, while an accident occurs on the system side (commercial power supply side), the PQ control is performed under the system condition before the accident occurs, so that the PQ control is not performed accurately. That is, PQ control is not performed correctly so that load current does not flow, and current flows from the preliminary power supply part 4 to the system. In the present invention, power supply is continued to the load 9 by the partial pressure action between the DC reactor 14 and the AC reactor 18L using the current at this time.

Thus, even if a power failure occurs, the spare power supply unit 4 performs the same control as that of the power supply for a while, so that the active power P and the reactive power Q supplied to the load 9 are set to zero. The power supply is immediately started from the spare power supply to the accident point of the power supply commercial power supply 8 and the load 9.

At this time, since a current flows from the preliminary power supply unit 4 to the accident point of the commercial power supply 8 and the load 9, the load voltage VL is determined by the partial pressure of the DC reactor 14 and the AC reactor 18L. It becomes a voltage. Therefore, when the allowable voltage drop rate with respect to the load 9 is A% and the impedance of the AC reactor 18L is Z2, the impedance Z1 of the DC reactor 14 is set to (100Z2) / A or more, and is preliminary. The voltage output from the power supply unit 4 to the load 9 can be made larger than the allowable voltage drop rate.

For example, when the allowable voltage drop rate for the load 9 is 10%, the ratio of the impedance Z2 of the AC reactor 18L to the impedance Z1 of the DC reactor 14 is Z1: Z2 = 10: By setting it to 1, the fall rate of the voltage output from the preliminary power supply part 4 to the load 9 can be made into less than 10%.

(Detection of accidents)

The uninterruptible power supply 1 stops PQ control at the accident detection timing ((3) shown in FIG. 6). After the PQ control is stopped, power is supplied from the spare power supply unit 4.

When the voltage judging unit 31 of the control unit 12 detects a power failure, the switching switch 35 is output such that the signal of the phase signal generator 34 for operation is output to the output voltage reference sine wave generator 40. Outputs a switching signal.

In addition, the voltage judging unit 31 stops PQ control of the preliminary power supply unit 4 and outputs a signal for switching the switching switch 38 to supply power to the load from the preliminary power supply unit 4. As a result, the output from the PQ control unit 37 is stopped by the output voltage reference sine wave generator 40.

Further, the voltage judging unit 31 outputs a signal to the battery state determining unit 39 to stop charging of the battery 15 to the battery state determining unit 39. In addition, the output voltage reference sine wave generator 40 generates a waveform of the sine wave voltage based on a signal (phase information) output from the phase signal generator 34 for driving frequently and outputs a signal to the inverter output controller 41. do. Therefore, electric power is continuously supplied from the spare power supply unit 4 to the accident point of the commercial power source 8 and the load 9.

The voltage judging unit 31 outputs a signal for turning off (turning off) the thyristors 13a and 13b of the bridge circuit 13 to the thyristor control unit 32 in addition to the above operation when detecting the low or power failure. do. When the thyristor control unit 32 detects this signal, the thyristor control unit 32 stops outputting the thyristor lighting signal. However, since the thyristors 13a and 13b do not turn off unless the load current becomes zero, the thyristor control unit 32 turns off several msec after stopping the thyristor control unit 32 from outputting the lighting signal of the thyristor (shown in FIG. 4)). Therefore, as shown in Fig. 6, a maximum half cycle (10 msec for 50 Hz) is required between the time when the low or power failure occurs until the thyristor turns off (= t1 + t2), but an accident occurs. From the timing to the incident detection timing, power is supplied from the preliminary power supply means to the load and the accident point without interruption.

On the other hand, in the PQ control, the load current is controlled to 0, but the inverter 17b is always driven. For this reason, as described above, the voltage phase of the system (commercial power source 8) and the voltage phase of the inverter 17b are previously set so that the output voltage from the spare power supply unit 4 is continuous in phase immediately after a power failure occurs. It becomes one.

(C) reward

When the thyristors 13a and 13b of the fast current interrupting block 3 are turned off and the converter between the commercial power source 8 and the load 9 is cut off, as shown in FIG. The power is supplied only to the load 9 at a voltage of 100%, thereby compensating for net low and power failure.

The operation of each part of the control part 12 at the time of compensation is demonstrated. The control part 12 performs control like an accident occurrence. In other words, the control unit 12 detects the signal output from the measuring transformer 11 every 1/4 cycle as described above. The voltage judging unit 31 detects the net low or the blackout while the net power or the power failure is occurring in the commercial power supply 8, and switches the switches 35 and 38, the battery state determining unit 39 and the thyristor control unit 32. No signal is output for. Therefore, the switching switch 35 is maintained in such a state that the signal of the operation phase signal generator 34 for frequent operation is output to the output voltage reference sine wave generator 40, and the switching switch 38 is a PQ controller ( The state is maintained so that the signal from 37) is not output. In addition, since the battery state determination unit 39 stops charging the battery 15 continuously, the battery state determination unit 39 does not output a signal, and the thyristor control unit 32 also does not output the ignition signal of the thyristor. Therefore, the output voltage reference sine wave generator 40 generates a waveform of the sine wave voltage based on the signal (phase information) output from the phase signal generator 34 for driving frequently and outputs the signal to the inverter output controller 41. Then, electric power is supplied only from the spare power supply unit 4 to the load 9.

(D) Restoration

When the power supply accident is eliminated in the commercial power supply 8 and the power is recovered, the uninterruptible power supply 1 has the thyristor 13a and the thyristor of the fast current interrupting block 3 as described with reference to Fig. 4A. 13b) lights together and is controlled in a closed state, power is supplied from the commercial power supply 8 to the load 9 via the high speed current interrupting block 3, and the power supply from the preliminary power supply unit 4 is stopped. .

Here, when an accident occurs in the commercial power supply, the necessary power can be supplied to the load from the spare power supply means for a while. However, the state in which power is supplied to the load 9 only from the uninterruptible power supply 1 continues, and when a certain time elapses, the voltage of the DC power supply of the preliminary power supply means decreases, so that necessary power can be supplied to the load. There will be no. Therefore, what is necessary is just to set it as the system structure which connects an emergency generator to a load as a backup power supply of the uninterruptible power supply 1. As shown in FIG. 7 is a schematic diagram of connecting an emergency generator to an uninterruptible power supply. As shown in FIG. 7, the uninterruptible power supply 1 is connected to the load 9, and a power supply system switching switch 52 is provided at the input terminal 6 of the uninterruptible power supply 1 to provide a commercial power supply. It is comprised so that the connection of (8) and the emergency generator 51 may be changed.

This power failure compensation system operates as follows. First, when a power supply accident occurs on the grid side, power is supplied from the preliminary power supply unit 4 of the uninterruptible power supply 1 to the load 9 as described above. In addition, the emergency generator 51 is started at a predetermined timing after the occurrence of an accident on the system side before the electric power supply unit 4 cannot supply sufficient power to the load 9. Then, the control unit 12 outputs a control signal to the power system switching switch 52, starts the emergency generator 51, and switches the power system switching switch 52 to the emergency generator 51 side when the operation is stable. .

The control unit 12 of the uninterruptible power supply 1 monitors the output phase of the emergency generator 51 with the measuring transformer 11 so that the output of the spare power supply unit 4 is synchronized with the output of the emergency generator 51. The converter 17 is controlled. When the output of the preliminary power supply unit 4 and the output of the emergency generator 51 are synchronized, the control unit 12 turns on the thyristor 13a and the thyristor 13b of the high speed current limiting block 3 to interpose the high speed current limiting unit 3. To supply power to the load 9 from the emergency generator 51. At this time, the control unit 12 switches the operation of the conversion unit 17 to stop the power supply from the preliminary power supply unit 4 to the load 9 and starts charging the battery 15. On the other hand, the electric power is supplied from the emergency generator 51 to the load 9, so that the battery 15 of the spare power supply unit 4 may be set to be charged.

When the power supply accident is eliminated in the commercial power supply 8 and the power is restored, the control unit 12 turns off the thyristor 13a and the thyristor 13b and switches the operation of the conversion unit 17 to transfer the load from the preliminary power supply unit 4 to the load. Supply power. On the other hand, at this time, the output of the spare power supply unit 4 is controlled to synchronize with the output of the emergency generator 51. Subsequently, the control unit 12 outputs a control signal to the power system switching switch 52, and switches the switch to the commercial power source 8 side. The control unit 12 monitors the output phase of the commercial power source 8 with the measuring transformer 11, and controls the conversion unit 17 so that the output of the spare power source unit 4 is synchronized with the output of the commercial power source 8. do. When the output of the preliminary power supply unit 4 and the output of the commercial power supply 8 are synchronized, the control unit 12 turns on the thyristor 13a and the thyristor 13b of the high speed current limiting block 3, and interposes the high speed current limiting block 3. Power is supplied from the commercial power source 8 to the load 9. At this time, the control unit 12 switches the operation of the conversion unit 17 to stop the power supply from the preliminary power supply unit 4 to the load 9, starts charging the battery 15, and is in a healthy state. It becomes

In this way, before the voltage of the battery 15 decreases so that sufficient power cannot be supplied from the preliminary power supply unit 4 to the load 9, the emergency generator 51 is started to supply power. It is stable and can supply power.

In addition, if the emergency generator 51 is provided with a time circuit such that the fast current interrupting block 3 of the uninterruptible power supply 1 cuts off the electric path between the commercial power source 8 and the load 9 and starts after a predetermined time. good. Thereby, electric power can be supplied from the emergency generator 51 before supply power of the spare power supply part 4 becomes below a predetermined value, and it becomes impossible to supply necessary electric power to the load 9.

In the above description, the case where the direct current power source and the battery (storage battery) of the preliminary power supply unit 4 is used in the uninterruptible power supply 1 is described. However, the present invention is not limited to this, and another one may be used. For example, an electric double layer capacitor, a capacitor, or the like is suitable as a direct current power source. Moreover, the structure which employ | adopted a flywheel as a power supply may be sufficient.

Claims (7)

An accident detection means for detecting an accident of commercial power at a predetermined accident confirmation cycle, When the commercial power supply is healthy, high-speed current-limiting current is supplied to the load from the commercial power supply, and when the accident detection means detects an accident in the commercial power supply, the electric current supplying power to the load is cut off from the commercial power supply. Blocking means, When the commercial power is sound and the accident detecting means detects the accident of the commercial power, the active power and reactive power supplied to the load are all set to 0. The response time is determined by the accident detecting means. PQ control is set longer than an accident confirmation period of the commercial power supply, and the accident detection means detects the accident immediately after the occurrence of the commercial power supply accident, and the fast current blocking means supplies a power supply to the load from the commercial power supply. Until disconnection, power is supplied to the load and the accident point without interruption momentarily. When the accident detection means detects an accident of the commercial power supply, the PQ control is stopped, and the fast current interrupting means loads from the commercial power supply. If you cut off the converter supplying power to the The uninterruptible power supply comprising: a standby power unit. Incident detection means for detecting the instantaneous voltage drop accident and power failure accident in a commercial power supply with a predetermined accident confirmation cycle, A single phase rectifying bridge circuit including a high speed switch for opening and closing a converter for supplying power to the load from the commercial power supply, and a DC reactor connected between two DC terminals of the single phase rectifying bridge circuit. The power is supplied from the commercial power supply to the load through the direct current reactor until it is healthy and the accident detection means detects the accident of the commercial power. When the accident detection means detects the accident from the commercial power, A fast current interrupting means for disconnecting a converter for supplying power to a load from a commercial power supply with said high speed switch; A filter circuit including an AC reactor, an inverter, and a DC power supply are connected in series, and are supplied to the load until the commercial power is sound and the accident detection means detects the accident of the commercial power. PQ control to set both the active power and the reactive power to 0 together, and the accident detection means detects the accident immediately after the occurrence of the accident, so that the fast current interrupting means cuts off the converter supplying power to the load from the commercial power supply. Until the moment, the power is supplied to the load and the accident point without interruption, and when the accident detection means detects the accident of the commercial power supply, the PQ control is stopped, and the fast current limiting means stops the load from the commercial power supply. When a circuit for supplying power to the circuit is cut off, a reserve for supplying the necessary power to the load only Including power means, Uninterruptible power supply, characterized in that the response of the PQ control is set longer than the accident confirmation period of the commercial power in the accident detection means. The method of claim 2, And the impedance of the DC reactor is set to (100Z) / A when the allowable voltage drop rate for the load is A% and the impedance of the AC reactor is Z. The method of claim 2 or 3, And a control means for controlling the output voltage of the preliminary power supply means and the output voltage of the commercial power supply with the same phase and amplitude. The method of claim 2 or 3, The high-speed switch is a pair of thyristors, the single-phase rectifier bridge circuit is a pair of thyristors are connected to one of the two AC terminals, the two AC terminals of the single-phase rectifier bridge circuit is the commercial power supply Uninterruptible power supply, characterized in that connected to the overload respectively. Accident detection means for detecting an accident of commercial power at a predetermined accident confirmation cycle; High speed current blocking means for supplying electric power from the commercial power supply to the load when the commercial power supply is healthy, and disconnecting the electric current supplying power to the load from the commercial power supply when the accident detecting means detects an accident in the commercial power supply. and; When the commercial power is sound and the accident detecting means detects the accident of the commercial power, the active power and reactive power supplied to the load are all set to 0. The response time is determined by the accident detecting means. PQ control is set longer than an accident confirmation period of the commercial power supply, and the accident detection means detects the accident immediately after the occurrence of the commercial power supply accident, and the fast current blocking means supplies a power supply to the load from the commercial power supply. Until disconnection, power is supplied to the load and the accident point without interruption momentarily. When the accident detection means detects an accident of the commercial power supply, the PQ control is stopped, and the fast current interrupting means loads from the commercial power supply. If you cut off the converter supplying power to the And an uninterruptible power supply apparatus having a,; the spare power source means An emergency generator for blocking the electric current supplying power from the commercial power supply to the load from the commercial current supply and starting before the preliminary power supply means cannot supply power to the load; And a switch capable of switching the connection by connecting the load to the commercial power supply or the emergency generator. Incident detection means for detecting the instantaneous voltage drop accident and power failure accident in a commercial power supply with a predetermined accident confirmation cycle, A single phase rectifying bridge circuit including a high speed switch for opening and closing a converter for supplying power to the load from the commercial power supply, and a DC reactor connected between two DC terminals of the single phase rectifying bridge circuit. The power is supplied from the commercial power supply to the load through the direct current reactor until it is healthy and the accident detection means detects the accident of the commercial power. When the accident detection means detects the accident from the commercial power, A fast current interrupting means for disconnecting a converter for supplying power to a load from a commercial power supply with said high speed switch; And a filter circuit connected in series, an inverter, and a direct current power source. The filter circuit includes an alternating current reactor. The filter circuit includes the alternating current reactor until the sound source of the commercial power source and the accident detecting unit detect the accident of the commercial power source. PQ control is performed to zero the active power and the reactive power supplied to the load, and the accident detection means detects the accident immediately after the occurrence of the accident, and the fast current interrupting means supplies power to the load from the commercial power supply. Until the circuit is cut off, power is supplied to the load and the accident point without interruption momentarily, and when the accident detection means detects an accident of the commercial power supply, the PQ control is stopped, and the high speed current limiting means If you disconnect the power supply from the power source to the load, only the power needed for that load It includes a backup power supply means, An uninterruptible power supply in which the responsiveness of the PQ control is set longer than an accident confirmation period of commercial power in the accident detection means; An emergency generator for blocking the electric current supplying power from the commercial power supply to the load from the commercial current supply and starting before the preliminary power supply means cannot supply power to the load; And a switch capable of switching the connection by connecting the load to the commercial power supply or the emergency generator.

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