JP2020018054A - Uninterruptible power system - Google Patents

Abstract

To provide an uninterruptible power supply for supplying power to a load even if abnormalities such as power failure or instantaneous voltage drop occur due to voltage phase adjustment.SOLUTION: The uninterruptible power system includes: a power supply switch 4, connected to a power supply line between an AC input and an AC output, that is turned on and off according to a voltage value of an AC input; a series power converter 6 having an AC side connected in series to the power supply switch 4; a parallel power converter 8 having an AC side connected in parallel with an AC output; a storage battery 9 connected to a DC side of the series power converter 6 and a DC side of the parallel power converter 8; and a reactor 10 connected in series between the series power converter 6 and the parallel power converter 8. The parallel power converter 8 synchronizes a phase of an AC output voltage with a phase of an AC input voltage, maintain a voltage value of the AC output at a predetermined value and output it. The series power converter 6 adjusts a phase and amplitude of the output voltage of the series power converter 6 so that a control voltage between the series power converter 6 and the reactor 10 becomes the predetermined value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an uninterruptible power supply that supplies stable power during normal operation and supplies power of a power storage unit to a load when an abnormality occurs.

  As a technique for maintaining power supply without interruption when an abnormality occurs in the input voltage, for example, techniques disclosed in Patent Documents 1 to 3 are disclosed. The technique disclosed in Patent Literature 1 is an operation mode in which the input commercial power supply voltage fluctuation range is within a predetermined value, and in a condition in which the voltage of the power storage means becomes higher than a preset value, the series for temporary series compensation is temporarily used. The operation of the converter (first DC / AC converter) is stopped, and power is supplied to the load from the power storage means via the parallel converter (second DC / AC converter).

In the technique disclosed in Patent Document 2, a disconnection switch is provided between an AC power supply and a load, a primary side of a transformer is connected between the disconnection switch and the load in parallel with the load, and an AC power supply is connected to a secondary side thereof. When the power supply is _normal , an AC correction voltage ΔV, which is the difference between the actual output voltage V _REL of the AC power supply and the specified voltage V ^* to be supplied to the load, is output from the input AC voltage. A converter that converts the storage voltage of the storage means into AC power and applies it to the secondary side of the transformer is connected, and the capacity of the converter may satisfy the output voltage fluctuation of the AC power supply. It is possible to reduce the loss of the converter at the time.

  According to the technique disclosed in Patent Document 3, a first converter for performing waveform improvement and power factor improvement and a second converter for voltage adjustment are connected between an AC power supply and a load 3, and a first converter is provided. A capacitor and a storage battery shared by the converter and the second converter are provided. When the power supply is normal, the first converter supplies a compensation current for waveform improvement and power factor improvement and charges the capacitor and the storage battery to a constant voltage. Then, when the power supply fails, the DC voltage of the capacitor and the storage battery is converted to AC by the first converter and supplied to the load, and the second converter converts the DC voltage of the capacitor and the storage battery to an AC voltage, It adjusts the load voltage.

Patent No. 4304519 Patent No. 4389387 Patent No. 3082849

  In the techniques disclosed in Patent Documents 1 and 3, when the voltage of the AC input is not in the normal range, the switch is turned off and the parallel power converter performs the backup operation. Since it takes time for the power converter to switch from the current control mode to the voltage control mode, an instantaneous interruption to the load may occur.

  In addition, the techniques described in Patent Documents 1 to 3 all have a circuit configuration using a transformer, so that the size of the device increases. Further, typically, the capacity of the transformer is about 15% of the rated output capacity, and if the transformer winding rating on the power converter side is 100 V, the transformer winding rating on the commercial line side is about 15 V. If a short circuit occurs on the AC input side during a period in which the polarity of the AC input voltage and the polarity of the current are different, the AC output voltage of the parallel power converter is applied to the 15 V winding of the transformer, and the output voltage becomes 100 V. In the case of, an overcurrent flows to the AC input side until the transformer is saturated and the switch is turned off, causing an instantaneous interruption of サ イ ク ル cycle at the maximum, and possibly stopping depending on the load.

  Further, a thyristor switch is generally used as a switch for turning on / off a commercial line because of its large instantaneous overcurrent withstandability and robustness. However, since it is a non-self-extinguishing element, it can be supplied with an off signal. If the current flowing through the thyristor main body does not become lower than the holding current, the thyristor does not turn off completely. That is, an overcurrent flows without switching off until the current becomes equal to or lower than the holding current, and there is a possibility that an instantaneous interruption occurs.

  In the cited document 1, the operation for improving the power factor is performed by the active filter operation. However, it is difficult to completely set the power factor to 1, and the vicinity of the zero crossing between the input voltage and the current is close to each other. There is always a period in which the polarities of are different.

  The present invention provides an uninterruptible power supply that supplies power to a load without an instantaneous interruption even when an abnormality such as a power failure or a sag occurs due to voltage phase adjustment without using a large device such as a transformer. provide.

  An uninterruptible power supply according to the present invention includes a power supply switch that is connected to a power supply line between an AC input and an AC output, and that uses a thyristor that switches on / off according to a voltage value of the AC input, and the power supply switch. A series power conversion unit in which the AC side is connected in series, a parallel power conversion unit in which the AC side is connected in parallel to the AC output, a series side of the series power conversion unit, and a series side of the parallel power conversion unit. Power storage means, and a reactor connected in series between the serial power conversion means and the parallel power conversion means, wherein the parallel power conversion means changes the phase of the AC output voltage to the AC input voltage. While synchronizing with the phase, the voltage value of the AC output is maintained and output at a predetermined value, and the serial power conversion means is provided between the serial power conversion means and the reactor. As the control voltage becomes the predetermined value, and adjusts the phase and amplitude of the output voltage of the series power conversion means.

  As described above, in the uninterruptible power supply according to the present invention, the power supply switch using the thyristor that is connected to the power supply line between the AC input and the AC output and that switches on / off in accordance with the voltage value of the AC input A series power converter in which an AC side is connected in series to the power supply switch; a parallel power converter in which an AC side is connected in parallel to the AC output; a series side of the series power converter, and a parallel power converter. Power storage means connected to the series side, and a reactor connected in series between the series power conversion means and the parallel power conversion means, the parallel power conversion means, the phase of the voltage of the AC output the While synchronizing with the phase of the voltage of the AC input, the voltage value of the AC output is maintained and output at a predetermined value, and the serial power converter is connected to the serial power converter. In order to adjust the phase and amplitude of the output voltage of the series power conversion means so that the control voltage between the reactor and the reactor becomes the predetermined value, the circuit configuration can be simplified without the need for a large component such as a transformer. In addition, there is an effect that a high-performance uninterruptible power supply that can reliably prevent instantaneous interruption even when an abnormality occurs can be realized.

  In particular, during a period in which the polarity of the voltage and the current of the AC input are different, if a short-circuit power failure occurs, the series power conversion means is connected in series to the AC input so that the voltages applied to both ends of the reactor are equal. Control by the series power converter means that almost no overcurrent occurs at the time of backup operation switching of the parallel power converter means, and the output voltage does not decrease due to this. This has the effect of switching to backup operation.

  Also, the value of the reactor may be within a range where the charging power of the power storage means can be controlled, and it is sufficient that an AC input and an AC output produce a phase difference. Therefore, the reactor can be reduced in size, loss can be reduced, and a highly efficient device can be obtained. Is achieved.

It is a functional block diagram showing the composition of the uninterruptible power supply concerning a 1st embodiment. FIG. 4 is a diagram illustrating a case where two power sources are coupled via a reactor. FIG. 3 is a diagram illustrating a power flow when the input AC voltage of the uninterruptible power supply according to the first embodiment is within a normal range. It is a vector relation diagram of each voltage, such as an AC input voltage. FIG. 4 is a diagram illustrating a power flow when the input AC voltage of the uninterruptible power supply according to the first embodiment is not in a normal range. FIG. 4 is a diagram illustrating an overcurrent generated from a parallel power converter to an AC input side. FIG. 2 is a control block diagram of the uninterruptible power supply according to the first embodiment. FIG. 3 is a control block diagram of a serial power converter control unit in the uninterruptible power supply according to the first embodiment. It is a control block diagram in a normal state of the parallel electric power converter control part in the uninterruptible power supply concerning a 1st embodiment. It is a control block diagram in the abnormal state of the parallel electric power converter control part in the uninterruptible power supply concerning a 1st embodiment. It is a figure showing other examples of a power converter in an uninterruptible power supply concerning a 1st embodiment.

  Hereinafter, embodiments of the present invention will be described. The same elements are denoted by the same reference numerals throughout the embodiment.

(First embodiment of the present invention)
The uninterruptible power supply according to the present embodiment will be described with reference to FIGS. FIG. 1 is a functional block diagram illustrating a configuration of the uninterruptible power supply according to the present embodiment. The uninterruptible power supply 1 includes an AC power supply 2 connected to the input terminals 2a and 2b on the AC input side, a load 3 connected to the output terminals 3a and 3b on the AC output side, and a connection between the AC power supply 2 and the load 3. A power supply switch 4 using a thyristor that switches on / off the connection according to the input voltage, a first filter circuit 5 connected in series to the power supply switch 4, and an AC side connected to the first filter circuit 5 A series power converter 6, a second filter circuit 7 connected in parallel to the load 3 on the AC output side, a parallel power converter 8 connected to the second filter circuit 7 on the AC side, A storage battery 9 connected to each of the series terminal of the unit 6 and the series terminal of the parallel power converter 8, and a reactor 10 connected in series between the first filter circuit 5 and the second filter circuit 7 are provided. .

  The AC input voltage (Vi) supplied by the AC power supply 2 as a commercial power supply is constantly detected by an AC input voltage detection unit (not shown in FIG. 1), and the voltage is in a normal range (for example, in a frequency of 50 Hz or 60 Hz). When the voltage is in the range of 90 V to 110 V), the power supply switch 4 is in the ON state, and the parallel power converter 8 has the same phase of the voltage of the AC output to the load 3 as that of the AC power supply 2. In such a manner, a constant output voltage (for example, 100 V) is controlled to be output to the load 3 (Vo).

  When the voltage of the AC power supply 2 fluctuates, the series power converter 6 makes the effective value of the phase voltage (Vst) between the first filter circuit 5 and the reactor 10 equal to the AC output voltage (Vo). As described above, the output voltage (Vc) of the first filter circuit 5 is added to or subtracted from the AC input voltage (Vi) in a vector manner. By making the values of Vst and Vo equal by the addition and subtraction, the circulating reactive current generated between the AC power supply 2 and the parallel power converter 8 is suppressed. In addition, in this vector calculation, the power of the AC input is reduced by adding or subtracting the phase of the output voltage Vc of the first filter circuit 5 so that the phase of the phase voltage Vst is ahead of the phase of the AC output voltage Vo. The storage battery 9 is converted into DC power via the two-filter circuit 7 and the parallel power converter 8 and charged by the constant current / constant voltage control. The processing operation by this vector operation will be described later in detail.

  When the AC input voltage Vi is not in the normal range (for example, when the voltage is lower than 90 V or higher than 110 V), the AC input voltage detection unit (not shown in FIG. 1) detects an abnormal state, and 4 is given an off signal. The uninterruptible power supply 1 operates to supply the power of the storage battery 9 to the load 3 in an abnormal state. At this time, the output of the parallel power converter 8 is controlled so that the AC output voltage Vo becomes a constant output voltage (for example, 100 V) in the same manner as described above. It is possible to continuously supply the same power.

  At the time of transition from the normal state to the abnormal state, an off signal is given to the power supply switch 4 as described above. However, a predetermined time is required until the main body of the power supply switch 4 using the thyristor is substantially turned off and becomes equal to or less than the holding current. Periods may occur. Conventionally, there has been a possibility that an overcurrent may flow during that period, causing an instantaneous interruption. However, in the present embodiment, during the period from when the OFF signal is supplied to the power supply switch 4 to when the main body of the power supply switch 4 is substantially turned off, the voltage value between both ends of the reactor 10 is 0, that is, Vst = The series power converter 6 controls the voltage Vc so as to be Vo, thereby suppressing an overcurrent flowing to the AC output and controlling the power of the storage battery 9 by the parallel power converter 8 so that the rated AC voltage is kept constant. It is possible to supply power to the load 3 without any instantaneous interruption.

  Here, the function of the serial power converter 6 and the processing operation by the vector operation will be described in detail. First, the active power and the reactive power between the two power supplies when the two power supplies are coupled via the reactor L will be described with reference to FIG. In the circuit of FIG. 2A, the active power P (W) can be expressed by the following equation, where θ is the phase difference between Vi and Vo.

  The reactive power P (var) can be expressed by the following equation.

  As shown in FIG. 2B, when the phases match, the phase difference θ is zero, and no active power flows between Vi and Vo according to equation (1). Further, when the voltage values also match, no reactive power flows according to the equation (2). As shown in FIG. 2C, when Vi is ahead of Vo in phase, active power flows from Vi to Vo according to equation (1). As shown in FIG. 2D, when Vi has a higher voltage value than Vo, reactive power flows from Vi to Vo according to equation (2). In FIG. 2 (C), when Vo has a phase ahead of Vi, on the contrary, active power flows from Vo to Vi according to equation (1). On the other hand, in FIG. 2D, when Vo has a higher voltage value than Vi, the reactive power flows from Vo to Vi according to the equation (2). Equations (1) and (2) are intertwined with each other, but since the maximum control value of the phase difference is about 10 degrees as an actual operation of the apparatus, in the present embodiment, the two equations are used. Are treated as independent.

  Based on the above equations (1) and (2), the calculation and processing operation when the AC input voltage Vi is in the normal range will be described. FIG. 3 is a diagram illustrating a power flow when the input AC voltage of the uninterruptible power supply according to the present embodiment is within a normal range. The parallel power converter 8 controls so that the AC output voltage Vo of the parallel power converter 8 is synchronized with the AC input voltage Vi, and the phase also matches. At this time, the circuit operates in the constant voltage control mode so that the value of Vo becomes a rated value (here, 100 V). On the other hand, even if the AC input voltage Vi fluctuates in the normal range (for example, 90 V to 110 V), the series power converter 6 sets the phase voltage Vst between the first filter circuit 5 and the reactor 10 to 100 V. The output voltage Vc of the serial power converter 6 is controlled so as to be constant. That is, the voltage is controlled so that Vi + Vc = Vst = 100 V. At this time, the serial power converter 6 performs a vector-like operation by shifting the phase, instead of simply adding the output voltage Vc to the AC input voltage Vi. In other words, by controlling Vc so that the phase of the phase voltage Vst is ahead of the phase of Vo, the power is forced to flow from the side where the phase is advanced to the side where it is delayed, and passes through the parallel power converter 8. The storage battery 9 is charged.

  FIG. 4 is a diagram showing the relationship between the vectors of Vo, Vi, Vst, and Vc. FIG. 4A shows the relationship between the vectors when the charging power to the storage battery 9 decreases, and FIG. 4B shows the relationship between the vectors when the charging power to the storage battery 9 increases. In FIG. 4, since the AC input voltage Vi and the AC output voltage Vo have the same phase, the directions of the vectors also match. The AC output voltage Vo is kept constant at 100 V by the parallel power converter 8, whereas the AC input voltage Vi fluctuates in a normal range. FIG. 4 shows a vector (as a scalar value) when the voltage becomes smaller than 100 V, for example.

  The DC power converter 6 controls Vc so that Vst is equal to Vo (constant at 100 V). At this time, θ, that is, the advance of the phase is controlled according to the setting of the charging power. The larger the θ is, the larger the charging power charged to the storage battery 9 is, and the amount of charging power can be adjusted by the value of θ. In addition, since Vo is applied to the load 3, the power of the storage battery 9 is used by the parallel power converter 8 and the amount of the storage battery decreases, but when the storage battery amount decreases, the charging power is supplied to the storage battery 9 from the AC input side. As a result, the power to the load 3 is supplied from the AC input side.

  Even if the AC input voltage Vi is constant at 100 V, the serial power converter 6 needs to add the voltage in a vector manner in order to charge the storage battery 9. If no phase difference occurs between Vst and Vo, no active power flows from the AC input side. From the above equation (1), if θ = 0, no active power P is generated. Therefore, in this case, the power to the load 3 is covered by the power of the storage battery 9 from the parallel power converter 8, and the storage battery 9 is discharged without being charged. That is, even when the AC input voltage Vi is 100 V and coincides with the AC output voltage Vo, it is necessary to perform the operation of charging the storage battery 9 by changing θ.

  If the AC power input voltage Vi is other than 100 V and the serial power converter 6 does not perform the vector operation by adjusting Vc, then Vi = Vst, and Vo is the output voltage of the parallel power converter 8. Since it is a certain 100 V, a potential difference occurs between Vi and Vst and Vo, a circulating reactive current flows through the circuit, and the circuit loss increases. Further, the output voltage Vo of the parallel power converter 8 is synchronized with the AC input voltage Vi and has the same phase (θ = 0), so that the power of the load 3 is not supplied from the AC input side. Is supplied from the parallel power converter 8 and the storage battery 9 is only discharged.

  Although FIG. 4 shows the vector operation (addition) of Vc in the state of Vi <Vo, in the state of Vi> Vo, the operation of making Vst and Vo equal by subtracting the vector of Vc. Is performed.

  As described above, the series power converter 6 controls the voltage Vst of the preceding stage of the reactor 10 with respect to the AC output voltage Vo in terms of the voltage value and the phase, thereby eliminating the circulating reactive current flowing through the circuit and reducing the circuit loss. At the same time, it is possible to reliably charge the storage battery 9.

  Next, calculation and processing operations when the AC input voltage Vi is not in the normal range will be described. FIG. 5 is a diagram showing a power flow when the input AC voltage of the uninterruptible power supply according to the present embodiment is not in the normal range. When the AC input voltage Vi is not within the normal range due to the occurrence of a short circuit accident or the like (for example, Vi <90 V or Vi> 110 V), the power supply switch 4 is turned off and the series power converter 6 is stopped. The parallel power converter 8 stops synchronizing with the AC input voltage Vi and operates at the free-running frequency (fixed at 60 Hz or 50 Hz). The power supply to the load 3 is performed by the parallel power converter 8 using the power of the storage battery 9. The voltage and current paths at this time are as shown in FIG.

  When switching from the normal state to the abnormal state, the power supply switch 4 is turned off as described above. However, since the power supply switch 4 using a thyristor is a non-self-extinguishing element, even if an off signal is given, the element is turned off. Unless the current flowing through the main body becomes zero, the conduction state is actually maintained. At this time, if the circuit does not include the above-described series power converter 6 or does not perform the control of Vst = Vo, if an input short-circuit power failure occurs, as shown in FIG. Then, an overcurrent is generated from the parallel power converter 8 to the AC input side through a short-circuit point. Then, when the overcurrent becomes zero (zero crossing), the thyristor is finally turned off, and the overcurrent does not flow, so that power can be supplied to the load 3. That is, power is not supplied to the load 3 while the overcurrent is occurring, and an instantaneous interruption occurs.

  In order to solve such a problem, in the present embodiment, the series power converter 6 always performs control such that | Vst | = | Vo |, and supplies power to the load 3 from an AC input. Since the control for advancing the phase of Vst is also performed, no overcurrent flows to the input side until the power supply switch 4 using the thyristor is turned off. Therefore, switching of the backup operation to the load 3 can be performed without any instantaneous interruption.

  Next, control of the uninterruptible power supply according to the present embodiment will be described in more detail. FIG. 7 is a control block diagram of the uninterruptible power supply according to the present embodiment. The uninterruptible power supply 1 has an AC input voltage detector 61 for detecting an AC input voltage Vi, a DC current detector 62 for detecting a DC current of the storage battery 9, and a storage battery 9 for the circuit configuration shown in FIG. , A control voltage detector 64 for detecting a phase voltage between the first filter circuit 5 and the reactor 10, and an AC output voltage detector 65 for detecting an AC output voltage Vo. A serial power converter control unit 66 that controls the serial power converter 6 based on the AC input voltage Vi, the charging current Idc of the storage battery 9, the charging voltage Vdc of the storage battery 9, the control voltage Vst, and the AC output voltage Vo; A parallel power converter control section 67 for controlling the parallel power converter 8 based on the input voltage Vi and the AC output voltage Vo.

  As described above, the serial power converter control unit 66 and the parallel power converter control unit 67 control the operations of the serial power converter 6 and the parallel power converter 8, respectively, so that the AC input voltage Vi falls within the normal range. It is possible to realize stable power supply to the load 3 according to the fluctuation of the AC input voltage Vi in a certain case and stable power supply to the load 3 when the AC input voltage Vi is not in a normal range. Has become. In addition, when the AC input voltage Vi transitions from the normal state to the abnormal state, the operation switching without instantaneous interruption is performed by the control operation of the serial power converter control unit 66 and the parallel power converter control unit 67. It is possible.

  FIG. 8 is a control block diagram of the serial power converter control unit in the uninterruptible power supply according to the present embodiment. The series power converter 6 performs constant current and constant voltage charging control on the storage battery 9 as described above. In the PLL, by giving a phase sliding instruction value corresponding to the amount of charge to the storage battery 9 to a reference sine wave synchronized with the AC input voltage Vi, the serial power converter 6 synchronizes with the AC input voltage Vi. By adjusting the phase of the control voltage Vst, the charging power to the storage battery 9 is controlled. By this phase adjustment, the power on the AC input side is converted into DC power via the reactor 10, the second filter circuit 7 and the parallel power converter 8, and the storage battery 9 is charged.

  The phase slide instruction value at the time of performing the phase adjustment is detected by the DC voltage detector 63 and a first value obtained by amplifying the difference between the DC current Idc detected by the DC current detector 62 and the charging current instruction value Idcref. The DC voltage Vdc of the storage battery 9 is lower than the charge voltage instruction value Vdcref, and the DC current flowing through the storage battery 9 is lower than the DC voltage Vdc of the storage battery 9. If it is larger, the first value is selected. If the DC voltage Vdc of the storage battery 9 is higher than the charging voltage instruction value Vdcref, and if the DC current flowing through the storage battery 9 is smaller, the second value is selected and the phase sliding instruction value is selected. Is determined.

  Next, the serial power converter 6 performs the AC operation with the effective value (1) of the AC output voltage Vo so that the effective value of the phase voltage Vst detected by the control voltage detector 64 becomes the effective value of the AC output voltage Vo. The difference between the waveform obtained by multiplying the reference sine wave (2) synchronized with the input voltage Vi by the multiplier and the control voltage Vst detected by the control voltage detector 64 is amplified, and the PWM control unit generates a pulse modulation signal. , The series power converter 6. That is, when the AC input voltage Vi is in the normal range, the control voltage Vst follows the fluctuation of the AC output voltage Vo, so that the parallel power generated due to the voltage difference between the AC input voltage Vi and the AC output voltage Vo. Overcurrent from the converter 8 to the AC input side can be prevented. Further, when the backup operation is performed due to the abnormality of the AC input voltage Vi, the series power converter 6 prevents the overcurrent from flowing until the power supply switch 4 is substantially stopped. It can be completely eliminated.

  FIG. 9 is a control block diagram in a normal state of the parallel power converter control unit in the uninterruptible power supply according to the present embodiment. When the AC input voltage Vi is in the normal range, the parallel power converter 8 multiplies the reference sine wave synchronized with the phase of the AC input voltage Vi by the output voltage amplitude instruction value (for example, the instruction value of 100 V) in the PLL. The AC output voltage Vo is feedback-controlled so that the value is constant.

  FIG. 10 is a control block diagram in an abnormal state of the parallel power converter control unit in the uninterruptible power supply according to the present embodiment. When the AC input voltage Vi falls within the abnormal range, the thyristor of the power supply switch 4 is turned off, and the parallel power converter 8 is switched from the charging operation to the backup operation. At this time, the AC output voltage Vo of the parallel power converter 8 is feedback-controlled so as to be a value obtained by multiplying the reference sine wave by the AC output voltage amplitude instruction value.

  In the present embodiment, the series power converter 6 and the parallel power converter 8 are described as full bridge circuits, but are not limited to full bridge circuits and may be half bridge circuits as shown in FIG.

  As described above, in the uninterruptible power supply according to the present embodiment, when a short-circuit power failure occurs during a period in which the polarity of the AC input voltage and the polarity of the current are different, and when switching to the backup operation, the serial power converter By controlling the voltage applied to both ends of the reactor to be zero, it is possible to prevent the overcurrent from flowing and eliminate the output voltage drop that accompanies this and perform the switching operation without any instantaneous interruption. Will be possible.

  Further, the value of the reactor may be in a range where the charging power of the storage battery can be controlled, that is, in a range in which a potential difference can be generated between the AC input voltage and the AC output voltage, so that the reactor is reduced in size and loss is reduced. Thus, the efficiency of the apparatus can be improved.

DESCRIPTION OF SYMBOLS 1 Uninterruptible power supply 2 AC power supply 2a, 2b input terminal 3 Load 3a, 3b output terminal 4 Power supply switch 5 First filter circuit 6 Series power converter 7 Second filter circuit 8 Parallel power converter 9 Storage battery 10 Reactor 61 AC input Voltage detector 62 DC current detector 63 DC voltage detector 64 Control voltage detector 65 AC output voltage detector 66 Series power converter controller 67 Parallel power converter controller

Claims (4)

A power supply switch that is connected to a power supply line between an AC input and an AC output and that uses a thyristor that switches on / off according to a voltage value of the AC input;
Series power conversion means in which the AC side is connected in series to the power supply switch,
A parallel power conversion unit in which an AC side is connected in parallel to the AC output,
A power storage unit connected to the series side of the series power conversion unit and the series side of the parallel power conversion unit,
A reactor connected in series between the series power conversion means and the parallel power conversion means,
The parallel power converter, while synchronizing the phase of the voltage of the AC output with the phase of the voltage of the AC input, outputs the AC output while maintaining the voltage value of the AC output at a predetermined value. An uninterruptible power supply, wherein the conversion means adjusts a phase and an amplitude of an output voltage of the series power conversion means so that a control voltage between the series power conversion means and the reactor has the predetermined value. apparatus. The uninterruptible power supply according to claim 1,
A first filter including an LC filter connected in series between the power supply switch and the series power conversion unit;
An uninterruptible power supply device comprising: a second filter including an LC filter connected in parallel between the AC output and the parallel power converter. The uninterruptible power supply according to claim 1 or 2,
An uninterruptible power supply device in which the serial power conversion means adjusts the phase of the control voltage in a direction that advances the phase of the voltage of the AC input to set the control voltage value to the predetermined value. The uninterruptible power supply according to claim 3,
An uninterruptible power supply device, wherein the serial power conversion means controls charging power to the power storage means by adjusting the advance of the phase of the control voltage.

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