JP2019135898A - Uninterruptible power source equipment - Google Patents

Abstract

To provide uninterruptible power source equipment that can completely supply uninterrupted power to a load even when an AC input becomes abnormal and that is highly safe and efficient and inexpensive.SOLUTION: Power is supplied to a load through a first input winding and an output winding of a first transformer 11 when a voltage of an AC input falls within an allowable range. A series inverter 14 and a second transformer 13 stabilize the voltage applied to the load. A power storage device 16 is charged with a DC output of a parallel converter 15. A first switch 12 is turned off, and the power of the storage device 16 is supplied to the load through the parallel converter 15 and the second input winding and output winding of the first transformer 11 when the voltage of the AC input does not fall within the allowable range. The series inverter 14 and the second transformer 13 stabilize the voltage applied to the load and compensate for the shortage of power supplied to the load. The overcurrent flowing from the parallel converter 15 to the first switch 12 is suppressed by leakage inductances 1, 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an uninterruptible power supply, and in particular, even when an AC input fluctuates, a stable power is supplied to a load by a series inverter. The present invention relates to an uninterruptible power supply that supplies power to a load.

  An uninterruptible power supply that supplies power to the load from the AC power supply when the AC power supply is normal, and supplies the power stored in the storage battery to the load when an abnormality such as a power failure or instantaneous drop occurs in the AC power supply The device is known.

  FIG. 17 is a block diagram illustrating the uninterruptible power supply described in Patent Document 1.

  In this uninterruptible power supply 30, when the voltage of the AC input from the AC power source is within the allowable range (when the AC input is normal), the first switch (a pair of anti-parallel connected thyristors) 171 is turned on. The second switch (a pair of anti-parallel connected thyristors) 172 is turned off. As a result, AC input power is supplied to the load through the first switch 171, the first system input and output windings of the first transformer 173, and the primary winding of the second transformer 174. The series inverter 177 and the second transformer 174 stabilize the voltage applied to the load.

  At this time, the AC input power includes the first system input winding of the first transformer 173, the leakage inductance between the first system input winding and the second system input winding, and the second system. To the parallel inverter 175 through the input windings of The parallel inverter 175 operates in synchronization with the AC input to generate a DC output and charges the power storage device 176.

  When the AC input voltage is not within the allowable range (when the AC input becomes abnormal), the abnormality is detected, the first switch 171 is turned off, and the second switch 172 is turned on. At this time, parallel converter 175 switches from a synchronous operation with an AC input to a backup operation at a free-running frequency (a fixed frequency of 50 or 60 Hz), and converts the power of power storage device 176 into AC power. This AC power is supplied to the load through the input and output windings of the second system of the first transformer 173 and the primary winding of the second switch 172.

  At this time, the series inverter 177 is turned off to open the secondary winding of the second transformer 174. Since the primary winding of the second transformer 174 has impedance by opening the secondary winding of the second transformer 174, the second system of the first transformer 173, the second Short-circuit current flowing to the AC input side through the switch 172 and the power supply line is suppressed.

  At this time, an AC voltage is applied from the parallel inverter 175 to the first switch 171 through the second system input winding and the first system input winding of the first transformer 173. The short-circuit current flowing through the switch 171 is suppressed by the leakage inductance between the first system input winding and the second system input winding of the first transformer 173.

  As described above, according to the uninterruptible power supply of Patent Document 1, even when the AC input becomes abnormal, the uninterruptible power is supplied to the load while suppressing the overcurrent flowing through the first switch 171. Can do.

  FIG. 18 is a block diagram showing the uninterruptible power supply described in Patent Document 2.

  The uninterruptible power supply 40 includes an AC switch (a pair of thyristors connected in reverse parallel) 181, an input reactor 182, a transformer 183, a series inverter 184, a parallel converter 185, and a storage battery 186.

  In the uninterruptible power supply 40, when the AC input voltage is within the allowable range, the pair of thyristors of the AC switch 181 are alternately turned on according to the polarity of the input voltage. As a result, the AC input power is supplied to the load through the AC switch 181, the input reactor 182 and the primary winding of the transformer 183. At this time, the series inverter 184 generates a correction voltage in the primary winding of the transformer 183 and stabilizes the voltage applied to the load.

  At this time, the parallel converter 185 converts the AC input into the DC output and charges the storage battery 186. Parallel converter 185 controls input power factor, that is, power factor of input voltage and input current (current flowing through input reactor 182) to be 1. However, the power factor does not necessarily have to be 1, and may be a power factor that can prevent the thyristor from being automatically turned off when the current flowing through the thyristor that is on-controlled becomes zero. It is said that.

  When the voltage of the AC input decreases and the conducting thyristor is in a reverse bias state, the thyristor is automatically cut off. Thereby, since both thyristors will be in the interruption | blocking state, an alternating current input will be cut off from a feed line. At this time, the series inverter 184 generates AC power using the storage battery 186 as an energy source, and supplies the AC power to the load through the transformer 183.

  When the voltage of the AC input further decreases and falls outside the allowable range, parallel converter 185 converts the power of storage battery 186 into AC power and performs a backup operation. At this time, since the thyristor of the AC switch 181 is in the cut-off state, the short-circuit current flowing from the parallel converter 185 to the AC input side is suppressed. Further, since the input reactor 182 is inserted, the short circuit current until the thyristor of the AC switch 181 is automatically cut off is also suppressed. Since the thyristor of the AC switch 181 is automatically cut off due to a decrease in the voltage of the AC input, the value of the input reactor 182 is supposed to be small.

  As described above, according to the uninterruptible power supply described in Patent Document 2, when the AC input voltage decreases, AC power is supplied from the storage battery 186 through the series inverter 184 to the load, and the AC input voltage is further increased. When the voltage drops, AC power is supplied from the storage battery 186 through the parallel converter 145 to the load, so that uninterruptible power can be supplied to the load.

JP 2017-28789 A (Patent No. 6051274) JP 2003-259567 A

  In the uninterruptible power supply 30 described in Patent Document 1, when the AC input becomes abnormal, the abnormality is detected and the second switch 172 is turned on to start power supply to the load by the backup operation. Therefore, the time required for detecting the abnormality of the AC input and the time required for turning on the second switch 172 are required before the power supply is started. As a result, when the AC input becomes abnormal, a momentary interruption of several milliseconds occurs in power supply to the load, and depending on the load, the operation may be stopped due to the instantaneous interruption.

  Although the instantaneous interruption of power feeding can be shortened by detecting an abnormality in AC input at high speed, the instantaneous interruption cannot be completely eliminated. In addition, if an AC input abnormality is to be detected at high speed, the possibility of erroneous detection increases.

  In the uninterruptible power supply 40 described in Patent Document 2, since the short-circuit current flowing to the AC input side is suppressed by the input reactor 182 until the thyristor of the AC switch 181 is cut off, the reactance value is increased. There is a need to. Further, the input reactor 182 is inserted on the AC input power supply line, and when the AC input is normal, the AC input is supplied to the load through the input reactor 182. Therefore, the efficiency is reduced due to the loss caused thereby. There is a problem.

  In addition, when the voltage of the AC input decreases, the entire power is supplied from the storage battery 186 to the load through the series inverter 184. Therefore, the series inverter 184 needs to be enlarged. Further, when the voltage of the AC input decreases, the AC input is automatically disconnected from the power supply line, so that the energy stored in the storage battery 186 becomes zero, and power supply to the load may be stopped. . Furthermore, since the AC input side, AC output side, and DC side are not insulated, there is a risk of electric shock due to leakage current and equipment damage due to DC component outflow. These problems are specifically described in Patent Document 1.

  The object of the present invention is to solve the above-mentioned problems and to supply completely uninterrupted power to the load even when the AC input becomes abnormal. Also, the safety and efficiency are high and inexpensive uninterruptible power supply. It is to provide a power supply device.

  In order to solve the above problems, an uninterruptible power supply of the present invention has a first input winding, a second input winding, and an output winding arranged on the same iron core. A first transformer intentionally provided with a first leakage inductance and a second leakage inductance between the first and second output windings and between the second input and output windings; A first switch provided between a first input winding of the first transformer, a primary winding, and a secondary winding, and the primary winding is an output winding of the first transformer. A second transformer connected in series between the line and the load; a first power converter connected to a secondary winding of the second transformer; and a second input of the first transformer. A second power converter connected to the winding via an LC filter and controlling power in both directions; and the first power A power storage device connected to both the DC side of the converter and the DC side of the second power converter, and detecting means for detecting whether the voltage of the AC input is within an allowable range, When the voltage is within an allowable range, the first switch is turned on to supply AC input power to the first input and output windings of the first transformer and the primary of the second transformer. A voltage supplied to the load is stabilized by the first power converter and the second transformer, and the AC input power is supplied to the load through the winding and the first input winding of the first transformer. Supplying the second power converter through a line, an output winding and a second input winding, charging the power storage device with a DC output of the second power converter, and the voltage of the AC input is within an allowable range. Turn off the first switch when The power of the power storage device is loaded through the second power converter, the LC filter, the second input and output windings of the first transformer, and the primary winding of the second transformer. The first power converter and the second transformer stabilize the voltage applied to the load and compensate for the shortage of power supplied to the load. At this time, the second power The overcurrent that flows from the power converter to the first switch through the first transformer is suppressed by the first and second leakage inductances, thereby preventing the uninterrupted power while suppressing the overcurrent from flowing. It is characterized by being supplied to a load.

  The uninterruptible power supply of the present invention has a first input winding, a second input winding and an output winding arranged on the same iron core, and the first input winding and the output winding And a first transformer intentionally provided with a first leakage inductance and a second leakage inductance between the second input winding and the output winding, respectively, and an AC input and the first transformer. A first switch provided between the first input winding, a primary winding and a secondary winding, wherein the primary winding is connected to the output winding of the first transformer and the load. A second transformer connected in series between the first transformer, a first power converter connected to a secondary winding of the second transformer, and an LC filter connected to a second input winding of the first transformer. A second power converter that is connected via a power source and controls the power in one direction, and a DC side and a front side of the first power converter. Whether or not the power storage device connected to both the DC side of the second power converter, the charger connected between the AC input and the power storage device, and the voltage of the AC input is within an allowable range When the AC input voltage is within an allowable range, the first switch is turned on to convert the AC input power to the first input winding and the output winding of the first transformer. A line and a primary winding of the second transformer to the load, the first power converter and the second transformer stabilize the voltage applied to the load, and the charger When the power storage device is charged and the voltage of the AC input is not within the allowable range, the first switch is turned off, and the power of the power storage device is converted to the second power converter, the LC filter, the first Transformer second An input winding and an output winding and a primary winding of the second transformer are supplied to the load, and the voltage applied to the load is stabilized by the first power converter and the second transformer. In addition, the shortage of power supplied to the load is compensated, and at this time, the overcurrent flowing from the second power converter through the first transformer to the first switch is converted into the first and second leakage inductances. It is characterized by supplying non-instantaneous power to the load while suppressing overcurrent flow.

  Here, when the voltage of the AC input is within an allowable range, the second power converter has the same amplitude as the amplitude value of the voltage applied to the first input winding of the first transformer by the AC input. Preferably, an alternating voltage having a phase that is delayed from that phase is applied to the second input winding of the first transformer.

  It is also preferable that the reactance value of the first leakage inductance and the reactance value of the second leakage inductance of the first transformer are the same.

  The first transformer has a first input winding, an output winding, and a second input winding arranged one above the other, between the first input winding and the output winding, and between the output winding and the first winding. It is also preferable that a path core is inserted between each of the two input windings, and the first and second leakage inductances are realized by inserting the path core.

  Furthermore, it is also preferable to use three uninterruptible power supply devices described above, and to form a three-phase machine by connecting the first transformers with Δ-Y connection, Δ-Δ connection, Y-Δ connection or Y-Y connection.

  In the uninterruptible power supply of the present invention, since the operation is switched to the backup operation without using the second switch required by the uninterruptible power supply of Patent Document 1, power supply to the load is performed by the backup operation after the AC input becomes abnormal. The time required for the second switch to turn on is not required before the operation starts. Moreover, even if the AC input becomes abnormal, AC power from the power storage device can be continuously supplied to the load. As a result, completely uninterrupted power can be supplied to the load, so that it is possible to eliminate the possibility of the load being stopped due to instantaneous power supply interruption when the AC input becomes abnormal.

  The first transformer has a structure in which the first input winding, the second input winding, and the output winding are arranged on the same iron core. Since power is supplied to the load only through the transformer, the efficiency can be improved compared to the uninterruptible power supply apparatus (Patent Document 1) that supplies power to the load through the first and second system isolation transformers.

  Further, the first input winding side (AC input side), the output winding side (AC output side), and the second input winding side (DC side) are each insulated by the first transformer. The risk of equipment damage due to electric shock or DC component outflow can be eliminated. Therefore, safety and efficiency can be increased and the cost can be reduced.

  Further, if the reactance value of the first leakage inductance is the same as the reactance value of the second leakage inductance, the reactance value of the first leakage inductance inserted into the power supply line is the reactance value of the input reactor in Patent Document 2. Since 1/2 is sufficient, the efficiency of power supply from the AC input to the load can be increased. In addition, the series inverter does not need to supply the entire power from the power storage device to the load, and therefore does not need to be large.

  Furthermore, since the overcurrent flowing through the first switch when switching to the backup operation is suppressed by both the first leakage inductance and the second leakage inductance, the overcurrent can be effectively suppressed, The parallel converter need not be considered to withstand a large short-circuit current, and may be small.

It is a block diagram showing the 1st basic composition of the uninterruptible power supply concerning the present invention. It is a figure which shows a power flow when the voltage of alternating current input falls within an allowable range. It is a figure which shows a power flow when the voltage of alternating current input rises within an allowable range, when an electrical storage device is not a full charge state. It is a figure which shows a power flow when the voltage of alternating current input rises within an allowable range, when an electrical storage device is a full charge state. It is a figure which shows the voltage applied to the 1st input winding and 2nd input winding of a 1st trans | transformer in a 1st basic composition. It is a figure which shows the power flow before backup operation switching when the voltage of alternating current input becomes abnormal. It is a figure which shows the power flow immediately after backup operation switching when the voltage of alternating current input becomes abnormal. It is a block diagram which shows embodiment which actualized the uninterruptible power supply device of FIG. It is a block diagram which shows an example of the control by a series inverter control part when the voltage of alternating current input is normal. It is a block diagram which shows an example of the control by a parallel converter control part when the voltage of alternating current input is normal. It is a block diagram which shows an example of the control by a parallel converter control part when the voltage of alternating current input becomes abnormal. It is a block diagram which shows the 2nd basic composition of the uninterruptible power supply concerning the present invention. It is a figure which shows the voltage applied to the 1st input winding and 2nd input winding of a 1st trans | transformer in a 2nd basic composition. It is a block diagram which shows embodiment which actualized the uninterruptible power supply device of FIG. An embodiment in which the uninterruptible power supply of the present invention is a three-phase machine is shown. It is a figure which shows the example of a specific structure of a 1st transformer. It is a block diagram which shows the uninterruptible power supply described in patent document 1. It is a block diagram which shows the uninterruptible power supply described in patent document 1.

  The present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a first basic configuration of an uninterruptible power supply according to the present invention.

  The uninterruptible power supply 10 includes a first transformer 11, a first switch 12, a second transformer 13, a series inverter (first power converter) 14, a parallel converter (second power converter) 15, The power storage device 16, the LC filter 17, and detection means (not shown) for detecting whether the voltage of the AC input is normal or abnormal are provided.

  The first transformer 11 is configured by arranging a first input winding, a second input winding, and one output winding on the same iron core, and includes a first input winding and an output winding. Leakage inductances 1 and 2 are intentionally provided between and between the second input winding and the output winding. A specific configuration of the first transformer 11 will be described later.

  The first switch 12 includes a pair of thyristors connected in antiparallel, and is provided between the AC input and the first input winding of the first transformer 11. The first switch 12 is turned on when the AC input voltage is within the allowable range, i.e., when the AC input voltage is normal, and when the AC input voltage is not within the allowable range, i.e., It turns off when the AC input voltage becomes abnormal.

  The second transformer 13 has a primary winding and a secondary winding, and the primary winding is connected in series between the output winding of the first transformer 11 and the load (AC output side). The secondary winding is connected to the AC side of the series inverter.

  The series inverter 14 has the AC side connected to the secondary winding of the second transformer 14 and the DC side connected to the power storage device 16.

  The parallel converter 15 has an AC side connected to the second input winding of the first transformer 11 through the LC filter 17 and a DC side connected to the power storage device 16. The parallel converter 15 can control power in both directions.

  The power storage device 16 is connected to both the DC side of the series inverter 14 and the DC side of the parallel converter 15, and serves as an energy source during a backup operation.

  The LC filter 17 is connected between the AC side of the parallel converter 15 and the second input winding of the first transformer 11.

  The detecting means for detecting whether the AC input voltage is normal or abnormal detects whether the AC input voltage is abnormal.

  Next, the operation of the uninterruptible power supply of FIG. 1 will be described.

  When the voltage of the AC input is normal, the first switch 12 is turned on. Thereby, the AC input power is supplied to the load through the first switch 12, the first input and output windings of the first transformer 11, and the primary winding of the second transformer 13. At this time, the series inverter 14 controls the voltage generated in the primary winding of the second transformer 13 to stabilize the voltage applied to the load.

  At this time, AC input power is supplied to the parallel converter 15 through the first input winding, the output winding, the second input winding, and the LC filter 17 of the first transformer 11. The parallel converter 15 generates a direct current output and charges the power storage device 16.

  FIG. 2 is a diagram illustrating a power flow when the voltage of the AC input decreases within an allowable range.

  Even if the voltage of the AC input falls within an allowable range, the first switch 12 is turned on. Accordingly, AC input power is supplied to the load through the first switch 12, the first input and output windings of the first transformer 11, and the primary winding of the second transformer 13. At this time, the series inverter 14 uses the DC output of the parallel converter 15 as an energy source, adds a decrease in the voltage applied to the load through the second transformer 13, and stabilizes the voltage applied to the load. Compensates for a decrease in power supplied to the load.

  At this time, AC input power is supplied to the parallel converter 15 through the first input winding, the output winding, the second input winding, and the LC filter 17 of the first transformer 11. The parallel converter 15 generates a direct current output and charges the power storage device 16.

  3 and 4 are diagrams showing the power flow when the AC input voltage rises within an allowable range. 3 shows a case where the electricity storage device 16 is not fully charged, and FIG. 4 shows a case where the electricity storage device 16 is fully charged.

  Even if the voltage of the AC input rises within an allowable range, the first switch 12 is turned on. When the power storage device 16 is not fully charged, as shown in FIG. 3, the AC input power is supplied from the first switch 12, the first input and output windings of the first transformer 11, and the second It is supplied to the load through the primary winding of the transformer 13. At this time, the series inverter 14 absorbs the increase in the voltage of the AC input from the second transformer 13 to stabilize the voltage applied to the load, and converts the increase in the power supplied to the load to the DC output. Convert. The direct-current power generated thereby is used to charge the electricity storage device 16.

  At this time, AC input power is supplied to the parallel converter 15 through the first input winding, the output winding, the second input winding, and the LC filter 17 of the first transformer 11. The parallel converter 15 generates a direct current output and charges the power storage device 16.

  When the storage device 16 is in a fully charged state, as shown in FIG. 4, the series inverter 14 absorbs the increase in the voltage of the AC input from the second transformer 13 and stabilizes the voltage applied to the load. In addition, an increase in power supplied to the load is converted into a DC output. The DC output thus generated is converted into an AC output by the parallel converter 15 and regenerated to the AC input side.

  When the AC input is normal, the AC input voltage is applied to the first input winding of the first transformer 11. At this time, the parallel converter 15 controls the power in both directions, and controls the voltage so that the amplitude value of the voltage of the capacitor of the LC filter 17 is equal to the amplitude value of the voltage applied to the first input winding. Operate in mode. As a result, a voltage having an amplitude value equal to the amplitude value of the voltage applied to the first input winding is applied to the second input winding of the first transformer 11 from the parallel converter 15 through the LC filter 17. . When two voltage sources are combined in this way, active power flows from the advancing voltage side to the lagging voltage side, and if there is a difference between the amplitude values of both voltages, reactive power is generated between the two voltage sources. Flows.

  At this time, the parallel converter 15 is operated synchronously with the AC input, and the phase of the voltage applied from the parallel converter 15 to the second input winding of the first transformer 11 through the LC filter 17 as shown in FIG. The phase of the parallel converter 15 is controlled so as to be delayed from the phase of the voltage applied to the first input winding. Thereby, the electricity storage device 16 can be charged at a constant voltage and a constant current.

  6 and 7 are diagrams showing power flows before and after switching the backup operation when the AC input voltage becomes abnormal.

  FIG. 6 is a diagram showing a power flow before switching the backup operation when the AC input voltage becomes abnormal. FIG. 6 also shows voltages of the first input winding, the second input winding, and the output winding of the first transformer 11. Here, only the flow of power supply from the AC input to the load and charging of the power storage device 16 is shown.

  Before the AC input voltage becomes abnormal, the AC input power is supplied to the load through the first input winding, the output winding of the first transformer 11, and the primary winding of the second transformer 13. . The AC input power is supplied to the parallel converter 15 through the first input winding, the output winding, the second input winding, and the LC reactor 17 of the first transformer 11. The parallel converter 15 generates a DC output and charges the power storage device 16.

  At this time, the AC input voltage is applied to the first input winding of the first transformer 11, and the voltage applied from the parallel converter 15 to the first input winding of the first transformer 11. Since a voltage having a phase later than the first phase is applied to the second input winding, the power storage device 16 is charged with a constant voltage and a constant current.

  FIG. 7 is a diagram illustrating a power flow immediately after switching the backup operation when the AC input voltage becomes abnormal. FIG. 7 also shows the voltages of the second input winding and the output winding of the first transformer 11. Here, only the flow of power supply from the power storage device 16 to the load is shown.

  When a short circuit occurs in the AC input and the voltage of the AC input becomes abnormal, the abnormality is detected and the first switch 12 is turned off. At this time, the parallel converter 15 switches from a synchronous operation with an AC input to a backup operation at a free-running frequency (a fixed frequency of 50 or 60 Hz).

  At this time, it is applied from the parallel converter 15 to the second input winding of the first transformer 11 during the period from when the OFF signal is given to the first switch 12 until the first switch 12 is actually turned OFF. The voltage is apportioned by the reactance values of the leakage inductances 1 and 2, and if the reactance values of the leakage inductances 1 and 2 are equal, a voltage corresponding to half the voltage is generated in the output winding. At this time, the series inverter 14 is always operating and compensates for the remaining half voltage by the instantaneous operation, so that the voltage applied to the load is maintained at the rated voltage.

  Further, during this period, the overcurrent flowing from the parallel converter 15 to the first switch 12 through the second input winding, the output winding and the first input winding of the first transformer 11 has a leakage inductance of 1, 2 It is suppressed by.

  When the first switch 11 is actually turned off, a voltage corresponding to the voltage applied from the parallel converter 15 to the second input winding of the first transformer 11 is generated in the output winding.

  As described above, even if the AC input voltage becomes abnormal due to the above-described series of operations, an AC voltage is applied from the parallel converter 15 to the second input winding of the first transformer 11 throughout the operation. Further, even if the voltage applied to the load is reduced, the series inverter 14 compensates for this, so that it is possible to supply the load with uninterrupted power while maintaining the rated voltage.

  The overcurrent flowing from the parallel converter 15 to the first switch 12 through the second input winding, the output winding and the first input winding of the first transformer 11 is caused by the voltage of the first input winding. Even if it becomes zero, it is suppressed by the leakage inductances 1 and 2. Note that the period during which the overcurrent flows is from when the first switch 12 is supplied with the off signal to when it is actually turned off.

  In the first basic configuration of the present invention, when the AC input voltage is normal, the AC input power is supplied to the load through the first input winding and the output winding of the first transformer 11. In this case, the leakage inductance 1 is interposed in the power supply line, but the leakage inductance 2 is not interposed. On the other hand, when switching to the backup operation, the overcurrent that flows from the parallel converter 15 to the first switch 12 through the second input winding, the output winding, and the first input winding of the first transformer 11 causes leakage inductance. 1 and leakage inductance 2 are suppressed. When the reactance values of the leakage inductances 1 and 2 are the same, the reactance value may be ½ of the reactance value of the input reactor disclosed in Patent Document 2. Therefore, the voltage drop in the power supply line when the voltage of the AC input is normal can be reduced, and the power loss can be reduced.

  FIG. 8 is a block diagram showing an embodiment in which the uninterruptible power supply 10 of FIG. 1 is embodied. 8, the same reference numerals are given to the same or equivalent parts as in FIG. 1, and the description thereof is omitted.

  When the voltage of the AC input is normal, an ON signal is given to the thyristor gate of the first switch 12 to make it conductive. As a result, AC input power is supplied to the load through the first input and output windings of the first transformer 11 and the primary winding of the second transformer 13.

  The series inverter 14 is feedback-controlled by a series inverter control unit 81 that receives the load voltage detection value Vo of the load voltage detector 82 so that the load voltage detection value Vo becomes the series inverter output voltage instruction value.

  FIG. 9 is a block diagram illustrating an example of control by the series inverter control unit 81 when the voltage of the AC input is normal.

  When the AC input voltage is normal, the series inverter control unit 81 calculates the difference between the load voltage detection value Vo and the series inverter output voltage instruction value Voref, and controls the PWM control unit 91 based on the difference.

  When the load voltage detection value Vo is lower than the series inverter output voltage instruction value Voref, the PWM controller 91 adds the insufficient voltage to the second transformer 13 and the load voltage detection value from the series inverter output voltage instruction value Voref. When Vo is high, a pulse modulation signal is generated so that the second transformer 13 subtracts the excess voltage, and the series inverter 14 is driven. Thereby, the voltage applied to the load is stabilized.

  Returning to FIG. 8, the parallel converter control unit 83 includes the AC input 1 voltage detection value Vi 1 of the AC input 1 voltage detector 84, the AC input 2 voltage detection value Vi 2 of the AC input 2 voltage detector 85, and the DC current detector 86. The parallel converter 15 is controlled using the DC current detection value Idc, the DC voltage detection value Vdc of the DC voltage detector 87, and the parallel converter AC output voltage detection value Vac of the parallel converter AC output voltage detector 89 as inputs.

  FIG. 10 is a block diagram illustrating an example of control by the parallel converter control unit 83 when the AC input voltage is normal.

  Whether or not the voltage of the AC input is normal is detected by the AC input 1 voltage detection value Vi1 of the AC input 1 voltage detector 84. Therefore, the parallel converter control unit 83 also functions as a detection unit that detects whether the voltage of the AC input is normal or abnormal.

  When the AC input voltage is normal, the parallel converter 15 charges the power storage device 16 with a constant current and a constant voltage. In this constant current / constant voltage charging, an AC input voltage is detected, and the detected value is given to the PLL so that the reference sine wave in the PLL is synchronized with the AC input voltage. To control the phase of the reference sine wave.

  The parallel converter 15 controls the phase of the AC voltage output while synchronizing with the voltage of the AC input. At this time, the AC input voltage is applied to the first input winding of the first transformer 11, and the AC voltage is applied from the parallel converter 15 to the second input winding of the first transformer 11. . As a result, the power storage device 16 is charged with a constant voltage and a constant current.

  Specifically, the AC input 2 voltage detection value Vi2 is input to the PLL 101. The PLL 101 synchronizes the reference sine wave inside the PLL with the AC input 2 voltage Vi2. Further, a value obtained by amplifying the difference between the DC current detection value Idc and the charging current instruction value Idcref of the DC current detector 86 and a value obtained by amplifying the difference between the DC voltage detection value Vdc and the charging voltage instruction value Vdcfef of the DC voltage detector 87 And the smaller value is selected, and the selected value is given to the PLL 101 as the phase slide instruction value.

  For example, the logical sum (OR) of the value obtained by amplifying the difference between the detected value of the DC current and the charge current instruction value and the value obtained by amplifying the difference between the detected value of the DC voltage and the instruction value of the charging voltage is obtained. When the DC voltage is lower than the indicated value and the direct current flowing to the electricity storage device 16 is large, the difference between the detected value of the direct current and the indicated value of the charging current is selected as the phase slide indication value, and the charging voltage of the electricity storage device 16 is selected. Is higher than the instruction value and the current flowing to the power storage device 16 is small, the difference between the detected value of the DC voltage and the instruction value of the charging voltage is selected as the slide instruction value.

  The PLL 101 controls the phase of the reference sine wave synchronized with the voltage of the AC input by the slide instruction value. As a result, a reference sine wave having the phase instructed by the slide instruction value is output from the PLL 101 in synchronization with the AC input voltage.

  The parallel converter control unit 83 drives the parallel converter 15 so that the effective value of the output voltage of the parallel converter 15 becomes the effective value of the AC input voltage. For this driving, the AC input 2 voltage detection value Vi2 and the parallel converter output voltage detection value Vac are input to the execution value calculators 102 and 103, respectively, and their effective values are calculated. Then, the difference between the effective value of the AC input 2 voltage detection value Vi2 and the execution value of the parallel converter output voltage detection value Vac is amplified and input to the multiplier 104, and is multiplied by the reference sine wave output from the PLL101. The PWM control unit 105 receives the output of the multiplier 104 as an input, generates a pulse modulation signal, and drives the parallel converter 15.

  By applying the AC voltage from the parallel converter 15 driven by the pulse modulation signal generated as described above to the second input winding of the first transformer 11, the power storage device 16 is made to have a constant voltage / constant current. Can be charged. In addition, when the AC input voltage is normal, the effective value of the AC voltage of the parallel converter 15 follows the effective value of the AC input voltage. The short-circuit current flowing to is suppressed.

  FIG. 11 is a block diagram illustrating an example of control by the parallel converter control unit 83 when the AC input voltage becomes abnormal.

  When the AC input voltage becomes abnormal, the first switch 12 (FIG. 8) is turned off. As described above, parallel converter 15 switches from the operation of charging power storage device 16 to the backup operation.

  The parallel converter control unit 83 calculates a difference between the parallel converter AC voltage detection value Vac of the parallel converter AC output voltage detector 89 and the parallel converter AC output voltage instruction value Vacref, and controls the PWM control unit 105 based on the difference. The PWM control unit 105 generates a pulse modulation signal, and thereby drives the parallel converter 15. Thereby, the parallel converter 15 is feedback-controlled so that the parallel converter AC output voltage Vac becomes the parallel converter AC output voltage instruction value Vacref.

  The electric power of the power storage device 16 is supplied to the load through the parallel converter 15, the second input and output windings of the first transformer 11, and the primary winding of the second transformer 13. The voltage applied to the load is stabilized by the series inverter 14 and the second transformer 13.

  At this time, the short-circuit current flowing from the second input winding of the first transformer 11 to the first switch 12 through the output winding and the first input winding is the first input winding of the first transformer 11. And the leakage inductance 1 between the first and second output windings and the leakage inductance 2 between the second input and output windings.

  Through the series of operations described above, even when the AC input voltage becomes abnormal, it is possible to supply the load with completely uninterrupted power while maintaining the rated voltage.

  FIG. 12 is a block diagram showing a second basic configuration of the uninterruptible power supply according to the present invention.

  The uninterruptible power supply 20 in FIG. 12 is different from the uninterruptible power supply 10 in FIG. 1 in that the charger 28 charges the power storage device 16 and the parallel converter 25 controls the power in one direction to power the power storage device 16. Is supplied to the load.

  When the AC input voltage is normal, the AC input power is supplied to the first switch 22, the first input and output windings of the first transformer 21, and the primary winding of the second transformer 23. Through the load. At this time, the voltage applied to the load is stabilized by the series inverter 24 and the second transformer 23. At this time, the power storage device 26 is charged with a constant voltage and a constant current by the charger 28.

  At this time, an AC voltage is applied from the parallel converter 25 to the second input winding of the first transformer 21 through the LC filter 27. The parallel converter 25 operates synchronously with the AC input, and as shown in FIG. 13, the AC voltage value of the capacitor voltage of the LC filter 27 is supplied to the first input winding of the first transformer 21. It operates in the voltage control mode so as to be equal to the amplitude value of the input voltage.

  The parallel converter 25 controls electric power in one direction, and the phase and amplitude value of the voltage applied to the second input winding of the first transformer 21 are converted into the first transformer 21 by the AC input. It operates so as to match the phase and amplitude value of the voltage applied to one input winding. Therefore, parallel converter 25 does not charge power storage device 26.

  When the AC input voltage becomes abnormal, the first switch 22 is turned off to switch to the backup operation. Thereby, the electric power of the electricity storage device 26 is supplied to the load through the parallel converter 25, the second input and output windings of the first transformer 21, and the primary winding of the second transformer 23.

  Even when switched to the backup operation, the second input winding of the first transformer 21 has the phase and amplitude value of the voltage applied to the first input winding of the first transformer 21 by the AC input. Since an AC voltage matching the phase is applied in advance from the parallel converter 25, completely uninterrupted power with the rated voltage maintained is supplied to the load. At this time, the voltage applied to the load is stabilized by the series inverter 24 and the second transformer 23.

  Even if the voltage of the AC input becomes abnormal, it is possible to supply uninterrupted power to the load while maintaining the voltage applied to the load at the rated voltage by the above series of operations. Further, when switching to the back-up operation, the overcurrent flowing from the parallel converter 25 to the first switch 22 through the second input winding, the output winding and the first input winding of the first transformer 21 is The leakage inductances 1 and 2 between the second input winding and the first input winding of one transformer 21 are suppressed.

  FIG. 14 is a block diagram showing an embodiment in which the uninterruptible power supply 110 of FIG. 12 is embodied. In FIG. 14, the same or equivalent parts as in FIG.

  When the AC input voltage is normal, the parallel converter control unit 143 synchronizes the AC voltage of the parallel converter 25 with the AC input voltage, and the phase of the AC voltage of the parallel converter 25 matches the phase of the AC input voltage. Thus, the parallel converter 25 is controlled.

  The parallel converter control unit 143 controls the charger 28 based on the DC current detection value Idc of the DC current detector 146 and the DC voltage detection value Vdc of the DC voltage detector 147. The charger 28 charges the power storage device 26 with constant current / constant voltage. The series inverter 24 and the second transformer 23 stabilize the voltage applied to the load. The operation is the same as that of the embodiment of FIG.

  When the AC input voltage becomes abnormal, the parallel converter 25 performs a backup operation as in the embodiment of FIG. At this time, the charger 28 stops operating and does not charge the power storage device 26.

  Thus, the parallel converter 25 does not charge the power storage device 26 when the AC input is normal, and performs a backup operation when the voltage of the AC input becomes abnormal. Further, when switching to the backup operation, a short-circuit current flowing from the parallel converter 25 to the first switch 22 through the first transformer 21 is generated between the first input winding and the output winding of the first transformer 21. It is suppressed by the leakage inductance 1 and the leakage inductance 2 between the second input winding and the output winding.

  Although the said embodiment is an uninterruptible power supply device comprised as a single phase machine, the uninterruptible power supply device of this invention can also be comprised as a three phase machine.

  FIG. 15 shows an embodiment in which the uninterruptible power supply of the present invention is a three-phase machine.

  In this embodiment, three uninterruptible power supplies having the configuration shown in FIG. 12 are used, and the first transformers 21-1, 21-2, and 21-3 are connected in a Δ-Y connection. The connection of the first transformer may be Δ−Δ, Y−Δ, or YY. Also, a three-phase machine can be configured by using three uninterruptible power supply apparatuses having the configuration shown in FIG.

  FIG. 16 is a diagram illustrating an example of a specific configuration of the first transformer 11 (21, 21-1, 21-2, 21-3).

  In this example, the first transformer 11 (21, 21-1, 21-2, 21-3) includes a first input winding 162, a second input winding 163, and an output winding 164 in the same iron core 161. It has an arranged structure. The iron core 161 has an outer peripheral core and a central core, and the first input winding 162, the second input winding 163, and the output winding 164 are wound around the central core, and the outer peripheral core and the first input winding are wound around the central core. A spacer 165 is disposed between the second input winding and the second input winding.

  The first input winding 162 is disposed above the output winding 164, the second input winding 163 is disposed below the output winding 164, and the first input winding 162 and the output winding 164 are disposed. A “pass core” 166 in which magnetic materials, for example, silicon steel plates are stacked to form a block shape, is inserted between the first and second output windings 164 and 163, respectively. As a result, intentional leakage inductances 1 are provided between the first input winding 162 and the output winding 164 and between the output winding 164 and the second input winding 163, respectively.

  Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and includes various modifications within the scope of the technical idea of the invention described in the claims. .

10, 20, 30, 40 ... Uninterruptible power supply
11,21,21-1,21-2,21-3,173 ・ ・ ・ first transformer
12,22,22-1,22-2,22-3,171 ・ ・ ・ first switch (thyristor)
13,23,23-1,23-2,23-3,174,183 ... second transformer
14,24,24-1,24-2,24-3,177,184 ... Series inverter (first power converter)
15,25,25-1,25-2,25-3,175,185 ・ ・ ・ Parallel converter (second power converter)
16,26,26-1,26-2,26-3,176,186 ・ ・ ・ Power storage device (storage battery)
17,27,27-1,27-2,27-3 ・ ・ ・ LC filter
28,28-1,28-2,28-3 ・ ・ ・ Charger
81,141 ・ ・ ・ Series inverter control unit
82,142 ... Load voltage detector
83,143 ... Parallel converter controller
84,144 ・ ・ ・ AC input 1 voltage detector
8,1455 ・ ・ ・ AC input 2 voltage detector
86,146 ... DC current detector
87,147 ... DC voltage detector
89,149 ・ ・ ・ Parallel converter AC output voltage detector
91,105 ・ ・ ・ PWM controller
101 ... PLL
102,103 ・ ・ ・ RMS
104 ... Multiplier
92,93 ・ ・ ・ Running value calculator
161 ... iron core
162 ... first input winding
163 ... Second input winding
164 ... Output winding
165 ・ ・ ・ Spacer
166 ・ ・ ・ Passcore
172 ... Second switch (thyristor)
181 ... AC switch
182 ... Input reactor

In order to solve the above-described problem, an uninterruptible power supply according to the present invention has a first input winding, a second input winding, and a single output winding arranged on the same iron core, A first transformer intentionally provided with a first leakage inductance and a second leakage inductance between the input winding and the output winding and between the second input winding and the output winding, respectively; A first switch provided between an AC input and a first input winding of the first transformer, a primary winding, and a secondary winding are provided, and the primary winding is the first transformer. A second transformer connected in series between the output winding of the first transformer and a load; a first power converter connected to a secondary winding of the second transformer; and a second transformer of the first transformer. A second power converter connected to the two input windings via an LC filter and controlling power in both directions; A power storage device connected to both the direct current side of the power converter and the direct current side of the second power converter, and a detecting means for detecting whether or not the voltage of the alternating current input is within an allowable range; When the voltage of the first transformer is within an allowable range, the first switch is turned on, and the AC input power is supplied to the first input winding and the output winding of the first transformer, and 1 of the second transformer. The first power converter and the second transformer stabilize the voltage applied to the load, and the AC input power is supplied to the first input of the first transformer. The second power converter is supplied to the second power converter through a winding, an output winding, and a second input winding, and the power storage device is charged by a DC output of the second power converter. The first switch when no longer in Turn off the power of the electricity storage device through the second power converter, the LC filter, the second input and output windings of the first transformer, and the primary winding of the second transformer The voltage supplied to the load is stabilized by the first power converter and the second transformer, and the shortage of the power supplied to the load is compensated. At this time, the second power The overcurrent that flows from the power converter to the first switch through the first transformer is suppressed by the first and second leakage inductances, thereby preventing uninterrupted power while suppressing the overcurrent from flowing. Is supplied to the load.

The uninterruptible power supply of the present invention has a first input winding, a second input winding and a single output winding arranged on the same iron core, and the first input winding and the output A first transformer intentionally provided with a first leakage inductance and a second leakage inductance between the winding and between the second input winding and the output winding, respectively, an AC input and the first A first switch provided between the first input winding of one transformer, a primary winding and a secondary winding, wherein the primary winding is an output winding of the first transformer; A second transformer connected in series with a load; a first power converter connected to a secondary winding of the second transformer; and a second input winding of the first transformer A second power converter connected to the first power converter through a LC filter to control the power in one direction, and a direct current of the first power converter And the battery connected to the DC side of the second power converter, the charger connected between the AC input and the electricity storage device, and whether the voltage of the AC input is within an allowable range Detecting means for detecting whether or not, and when the voltage of the AC input is within an allowable range, the first switch is turned on, and the power of the AC input is connected to the first input winding of the first transformer. An output winding and a primary winding of the second transformer are supplied to the load, and the voltage applied to the load is stabilized by the first power converter and the second transformer, and the charger When the accumulator device is charged and the voltage of the AC input is not within the allowable range, the first switch is turned off, and the electric power of the accumulator device is converted to the second power converter, the LC filter, the first 1 transformer A second input winding and an output winding and a primary winding of the second transformer are supplied to the load, and a voltage applied to the load is supplied by the first power converter and the second transformer. In addition to stabilizing, the shortage of power supplied to the load is compensated, and at this time, the overcurrent flowing from the second power converter to the first switch through the first transformer is changed to the first and second It is characterized by supplying non-instantaneous power to the load while suppressing overcurrent flow by suppressing the leakage inductance.

Claims (10)

A first input winding, a second input winding, and an output winding arranged on the same iron core, between the first input winding and the output winding, and the second input winding and the output A first transformer intentionally provided with a first leakage inductance and a second leakage inductance, respectively, between the windings;
A first switch provided between an alternating current input and a first input winding of the first transformer;
A second transformer comprising a primary winding and a secondary winding, wherein the primary winding is connected in series between the output winding of the first transformer and a load;
A first power converter connected to the secondary winding of the second transformer;
A second power converter connected to the second input winding of the first transformer via an LC filter and controlling power bidirectionally;
An electricity storage device connected to both the DC side of the first power converter and the DC side of the second power converter;
A detecting means for detecting whether or not the voltage of the AC input is within an allowable range;
When the voltage of the AC input is within an allowable range, the first switch is turned on to supply the AC input power to the first input winding and the output winding of the first transformer, and to the second transformer. The first power converter and the second transformer stabilize the voltage applied to the load, and the AC input power is supplied to the first transformer of the first transformer. Supplying the second power converter through the input winding, the output winding, and the second input winding, and charging the power storage device with a DC output of the second power converter,
When the voltage of the AC input is not within the allowable range, the first switch is turned off, and the power of the electricity storage device is supplied to the second input of the second power converter, the LC filter, and the first transformer. The winding is supplied to the load through the output winding and the primary winding of the second transformer, and the voltage applied to the load is stabilized by the first power converter and the second transformer. Compensating for the shortage of power supplied to the load, and at this time, the overcurrent flowing from the second power converter through the first transformer to the first switch is caused by the first and second leakage inductances. Suppress,
An uninterruptible power supply, wherein uninterruptible power is supplied to a load while suppressing overcurrent flow.   When the voltage of the AC input is within an allowable range, the second power converter has the same amplitude value as the amplitude value of the voltage applied to the second input winding of the first transformer by the AC input. 2. The uninterruptible power supply according to claim 1, wherein an AC voltage having a phase delayed from the phase is applied to the second input winding of the first transformer.   The uninterruptible power supply according to claim 1 or 2, wherein a reactance value of the first leakage inductance of the first transformer and a reactance value of the second leakage inductance are the same.   The first transformer includes a first input winding, an output winding, and a second input winding arranged one above the other, between the first input winding and the output winding, and between the output winding and the second winding. 4. The structure according to claim 1, wherein a pass core is inserted between each of the first and second input windings, and the first and second leakage inductances are realized by inserting the pass core. Uninterruptible power supply as described in 1.   Three uninterruptible power supply units according to any one of claims 1 to 4 are used, and the first transformers thereof are Δ-Y connection, Δ-Δ connection, Y-Δ connection or Y-Y connection. An uninterruptible power supply comprising a three-phase machine. A first input winding, a second input winding, and an output winding arranged on the same iron core, between the first input winding and the output winding, and the second input winding and the output A first transformer intentionally provided with a first leakage inductance and a second leakage inductance, respectively, between the windings;
A first switch provided between an alternating current input and a first input winding of the first transformer;
A second transformer comprising a primary winding and a secondary winding, wherein the primary winding is connected in series between the output winding of the first transformer and a load;
A first power converter connected to the secondary winding of the second transformer;
A second power converter connected to the second input winding of the first transformer via an LC filter to control the power in one direction;
An electricity storage device connected to both the DC side of the first power converter and the DC side of the second power converter;
A charger connected between the AC input and the electricity storage device;
A detecting means for detecting whether or not the voltage of the AC input is within an allowable range;
When the voltage of the AC input is within an allowable range, the first switch is turned on to supply the AC input power to the first input winding and the output winding of the first transformer, and to the second transformer. The first power converter and the second transformer stabilize the voltage applied to the load, and the charger charges the power storage device.
When the voltage of the AC input is not within the allowable range, the first switch is turned off, and the power of the electricity storage device is supplied to the second input of the second power converter, the LC filter, and the first transformer. The winding is supplied to the load through the output winding and the primary winding of the second transformer, and the voltage applied to the load is stabilized by the first power converter and the second transformer. Compensating for the shortage of power supplied to the load, and at this time, the overcurrent flowing from the second power converter through the first transformer to the first switch is caused by the first and second leakage inductances. Suppress,
An uninterruptible power supply, wherein uninterruptible power is supplied to a load while suppressing overcurrent flow.   When the voltage of the AC input is within an allowable range, the second power converter has the same amplitude value as the amplitude value of the voltage applied to the second input winding of the first transformer by the AC input. The uninterruptible power supply according to claim 6, wherein an AC voltage having the same phase as that phase is applied to the second input winding of the first transformer.   The uninterruptible power supply according to claim 6 or 7, wherein a reactance value of the first leakage inductance of the first transformer and a reactance value of the second leakage inductance are the same.   The first transformer includes a first input winding, an output winding, and a second input winding arranged one above the other, between the first input winding and the output winding, and between the output winding and the second winding. 9. The structure according to claim 6, wherein a pass core is inserted between each of the input windings and the first and second leakage inductances are realized by inserting the pass core. Uninterruptible power supply as described in 1.   Three uninterruptible power supply units according to any one of claims 6 to 9 are used, and the first transformers thereof are Δ-Y connection, Δ-Δ connection, Y-Δ connection or Y-Y connection. An uninterruptible power supply comprising a three-phase machine.

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