JP2010252574A - Uninterruptible power supply device, program for uninterruptible power supply device, and method of controlling uninterruptible power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an uninterruptible power supply device that is reduced in entire size and cost by suppressing the capacity of a capacitor between a step-up chopper circuit and a DC-AC inverter as small as possible. <P>SOLUTION: An uninterruptible power supply device includes a step-up chopper circuit, a DC power circuit, a DC-AC inverter, a capacitor between the step-up chopper circuit and the DC-AC inverter, and a switch control circuit. The control circuit controls a restart of the step-up chopper circuit wherein a voltage higher than the output voltage of the DC power circuit is set as an output level by a signal for recovering an AC power supply based on an input detection signal of an input voltage detection circuit and also controls a continuous operation of the DC power circuit until the voltage of the capacitor of the DC-AC inverter is stabilized after the step-up chopper circuit is restarted. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention reduces the capacity of an internal capacitor as much as possible by controlling the timing of turning off a DC power supply circuit that has supplied a DC voltage when the AC power supply voltage is restored within a normal range. The present invention relates to an uninterruptible power supply, a program for the uninterruptible power supply, and a control method for the uninterruptible power supply.

The present applicant has already proposed the uninterruptible stabilized power supply device shown in FIG. 7 (Patent Document 1).
In FIG. 7, the AC input terminals 2, 3 and the AC output terminals 8, 9 are coupled to one terminal 3, 9 to form a common line 16, and the common line 16 and the other input terminal 2 are connected to each other. The boost chopper circuit 32 performs boost chopping under the control of the control circuit 43 with respect to the AC voltage input therebetween, thereby obtaining a DC voltage boosted to the positive side and the negative side of the common line 16. A power supply circuit is shown in which the DC voltage stabilized on the negative side and the negative voltage are further converted into an AC voltage by a subsequent half-bridge DC-AC inverter 37 and output.

In this power supply circuit, the boost chopper circuit 32 includes switching elements 23 and 24 provided between the reactor 11 connected to the other input terminal 2 and the common line 16, and a rectifier diode 27 provided on the positive line. A rectifier diode 28 provided on the negative line, a capacitor 29 provided between the positive line and the common line 16, and a capacitor 30 provided between the negative line and the common line 16. Is. The step-up chopper circuit 32 is used as a power factor improving filter by making the input current into a sine wave similar to the input voltage by a signal obtained by adjusting the phase of the DC output voltage.

In addition, a DC power supply circuit in which a battery 38 and a backflow prevention switch element 39 are connected in series is provided between the AC input terminals 2 and 3 to supply power when the commercial power supply is out of the normal range due to a power failure or the like. That is, when the AC input voltage becomes low and a power failure is determined, the backflow prevention switch 39 is turned on, the voltage of the battery 38 is applied to the switch element 40, and the switch element 40, the reactor 11, and the diodes 27 and 28 form the boost chopper circuit 32. Thus, the boosted voltage is stored in the capacitors 29 and 30 even during a power failure, and is converted into an alternating current by the DC-AC inverter 37 and output.

JP 2006-158100 A.

  In the conventional circuit shown in FIG. 7, as shown in FIG. 6, when the reduced AC voltage recovers at t1, a recovery detection signal is output at t2 when the effective value is calculated, and DC power to the inverter circuit 37 is output. Is switched from the battery 38 to the step-up chopper circuit 32 connected to the AC power supply 10. However, since a certain amount of time is required until the output of the boost chopper circuit 32 reaches a desired level, if the battery 38 is stopped and the boost chopper circuit 32 is started at the same time, the boost chopper circuit 32 is connected to the inverter circuit. A period during which the voltage required for 37 is not supplied occurs. Meanwhile, the electric charge stored in the capacitors 29 and 30 needs to be supplied to the inverter circuit 37. If the capacitances of the capacitors 29 and 30 are small, the final target value will be greatly below the characteristic line n after t2 in FIG. 6, which may cause malfunction of the circuit. For this reason, the capacitors 29 and 30 have to be provided with a large capacity enough to supply the inverter circuit 37 with a voltage that does not decrease to the final target value as shown by the characteristic line m.

  An object of the present invention is to provide a capacitor whose capacity is as small as possible and whose entire device is small and inexpensive.

An uninterruptible power supply according to the present invention includes a step-up chopper circuit that converts an AC voltage input from an AC power source into a DC voltage having a preset output level, a reduction in the AC power source connected to the output terminal of the boost chopper circuit, and the like. A DC power supply circuit that outputs a DC voltage at an abnormal voltage, a DC-AC inverter that outputs a stabilized voltage by interposing a capacitor in series at the output terminal of the boost chopper circuit, and an input voltage detection circuit An uninterruptible power supply comprising a control circuit for switching and controlling a boost chopper circuit and a DC power supply circuit according to a detection signal as to whether or not the AC voltage of the detected AC power supply is abnormal, the control circuit includes the input voltage detection circuit The voltage higher than the output voltage of the DC power supply circuit is set as the output level by a signal for restoring the AC power supply based on the input detection signal of And restarting pressure chopper circuit, the voltage of the capacitor of the DC-AC inverter from restarting the boost chopper circuit is characterized in that so as to control the continued operation of the DC power supply circuit to stabilize.

The control circuit includes an effective value calculation circuit that calculates an effective value of the AC power supply voltage based on an input detection signal of the input voltage detection circuit, and an AC power supply when the effective value of the effective value calculation circuit is restored within the set value. A comparison circuit that outputs a restart signal of the boost chopper circuit for recovering the voltage and outputs a signal for continuously operating the DC power supply circuit until the voltage of the capacitor of the DC-AC inverter is stabilized after the restart of the boost chopper circuit And a step-up chopper control circuit for controlling restart of the step-up chopper circuit in which a voltage higher than the output voltage of the DC power supply circuit is set as an output level by the recovery signal of the comparison circuit.

The signal input to the comparison circuit and compared with the effective value of the AC power supply is set to a predetermined constant voltage for stopping the operation of the boost chopper circuit and starting the operation of the DC power supply circuit.
Moreover, it can also be set as the voltage which changes for every time based on a condition based on the output electric power from an output voltage detection circuit and an output current detection circuit.

  According to the first aspect of the present invention, in the uninterruptible power supply, the control circuit outputs a voltage higher than the output voltage of the DC power supply circuit by a signal for restoring the AC power supply based on the input detection signal of the input voltage detection circuit. Since the boost chopper circuit set as is restarted, the voltage of the capacitor does not fall below the value required by the inverter and the voltage of the capacitor is raised, so that the boost chopper circuit can be operated reliably. Since the continuous operation of the DC power supply circuit is controlled from the restart of the step-up chopper circuit until the voltage of the capacitor of the DC-AC inverter is stabilized, the power to the inverter is maintained even if the DC power supply circuit is stopped. The supply continues without being cut off, and the capacity and volume of the capacitor can be reduced to 1/2 or less of the conventional one. One can entire device to provide an inexpensive compact.

  According to the second aspect of the present invention, the control circuit has an effective value calculation circuit for calculating an effective value of the AC power supply based on an input detection signal of the input voltage detection circuit, and an effective value of the effective value calculation circuit is set. Outputs the boost chopper circuit restart signal to restore the AC power supply when it recovers within the set value, and continues the DC power supply circuit from the restart of the boost chopper circuit until the voltage of the DC-AC inverter capacitor stabilizes A comparison circuit that outputs a signal to be operated, and a boost chopper control circuit that controls restart of the boost chopper circuit in which a voltage higher than the output voltage of the DC power supply circuit is set as an output level by a recovery signal of the comparison circuit Since it is provided, it can be accurately controlled with a simple circuit configuration.

  According to the third aspect of the present invention, it is possible to reduce the ratings of the parts constituting the step-up chopper circuit, and to reduce the size and cost of the circuit.

  According to the fourth aspect of the present invention, the operation of the boost chopper circuit can be stopped and the operation of the DC power supply circuit can be started faster than the calculation of the effective value (minimum half cycle) after the occurrence of a power failure. The interruption time of the power supply to the capacitor can be minimized, and the capacitance of the capacitor can be made as small as possible. In addition, the circuit can be protected from an abnormality of the AC power source such as overvoltage.

  According to the fifth aspect of the present invention, in the uninterruptible power supply program for causing a computer to function as a step-up chopper means, a DC power supply switching means, a DC-AC inverter means, and a switching control means, the switching control means is effective. It is possible to obtain an uninterruptible power supply program that functions as value calculation means, comparison means, and boost chopper control means.

According to the sixth aspect of the present invention, in the control method for an uninterruptible power supply comprising a step-up chopper circuit, a DC power supply circuit, a DC-AC inverter, and a switching control circuit, an AC power supply is provided by an effective value arithmetic circuit. A step of calculating an effective value of the boost chopper, a step of outputting a restart signal of the boost chopper circuit for recovering the AC power supply when the effective value by the effective value calculation step is restored within the set value, and a boost chopper A step of outputting a signal for continuously operating the DC power supply circuit from the restart of the circuit until the voltage of the capacitor of the DC-AC inverter is stabilized, and a voltage higher than the output voltage of the DC power supply circuit by the recovery signal as an output level The switching of the uninterruptible power supply can be controlled by the set step of controlling the restart of the boost chopper circuit.

It is an electric circuit diagram which shows one Example of the uninterruptible power supply device by this invention. FIG. 2 is an electric circuit diagram of a DC power supply circuit 61 in FIG. 1. FIG. 2 is an electric circuit diagram of a control circuit 62 in FIG. 1. It is an operation | movement timing diagram of the uninterruptible power supply by this invention. It is an output waveform diagram of the uninterruptible power supply according to the present invention. It is an output waveform diagram of a conventional uninterruptible power supply. It is an electric circuit diagram of the conventional uninterruptible power supply.

The present invention relates to a boost chopper circuit that converts an AC voltage input from an AC power source into a DC voltage of a preset output level, and is connected to the output terminal of the boost chopper circuit to detect abnormalities such as a decrease or an increase in the AC power source. Detected by a DC power supply circuit that outputs a DC voltage at the time of voltage, a DC-AC inverter that outputs a stabilized voltage by interposing a capacitor in series at the output terminal of the boost chopper circuit, and an input voltage detection circuit The present invention is applied to an uninterruptible power supply apparatus including a boost chopper circuit and a control circuit that switches and controls a DC power supply circuit based on a detection signal indicating whether or not the AC voltage of the AC power supply is abnormal.
In this uninterruptible power supply, the control circuit includes the boost chopper in which a voltage higher than an output voltage of the DC power supply circuit is set as an output level by a signal for recovering an AC power supply based on an input detection signal of the input voltage detection circuit. The restart of the circuit and the continuous operation of the DC power supply circuit from the restart of the step-up chopper circuit until the voltage of the capacitor of the DC-AC inverter is stabilized are controlled.

More specifically, the control circuit includes an effective value calculation circuit for calculating an effective value of the AC power source based on an input detection signal of the input voltage detection circuit, and a set value in which the effective value of the effective value calculation circuit is set. A signal for outputting a restart signal for the boost chopper circuit for recovering the AC power supply when the power is restored to a level, and a signal for continuously operating the DC power supply circuit from the restart of the boost chopper circuit until the voltage of the capacitor of the DC-AC inverter is stabilized. And a boost chopper control circuit that controls restart of the boost chopper circuit in which a voltage higher than the output voltage of the DC power supply circuit is set as an output level by a recovery signal of the comparison circuit. Constitute.

The signal input to the comparison circuit for comparison with the effective value of the AC power supply may be a predetermined constant voltage for stopping the operation of the boost chopper circuit and starting the operation of the DC power supply circuit. Also, the voltage can be changed every time based on the output power from the output voltage detection circuit and the output current detection circuit.

Embodiment 1 of the present invention will be described below with reference to the drawings. The same parts as those in the conventional circuit are denoted by the same reference numerals.
In FIG. 1, 2 and 3 are AC input terminals of the AC power source 10, respectively, and 8 and 9 are AC output terminals after stabilization. Of these input / output terminals, one AC input terminal 3 and one AC output terminal 9 are connected by a common line 16, and the other AC input terminal 2 and the other AC output terminal 9 are connected. A direct transmission circuit is configured by connecting the direct transmission line 1 via the switching circuit 14.

An input voltage detection circuit 15 for detecting an input voltage of the AC power supply 10 is connected between the AC input terminals 2 and 3, and an abnormality of the AC power supply 10 is input to the AC input terminal 2 side. A switch circuit 60 for cutting off the AC power supply 10 in accordance with a command from a control circuit 62 described later when detected by the voltage detection circuit 15 is inserted, and a power factor improvement composed of a current transformer or a resistor is provided on the AC input terminal 3 side. An input current detection circuit 17 is inserted.
The input voltage detection circuit 15, the switch circuit 60, and the current transformer 17 are followed by a step-up chopper circuit (a power factor correction filter) 32, a DC-AC inverter 37, a filter circuit 96, an output voltage detection circuit 12, a current transformer. Are sequentially connected.

Among these, the boost chopper circuit 32, the DC-AC inverter 37, the filter circuit 96, and the output current detection circuit 13 have the same circuit configuration as the conventional circuit in which the switching element 40 in FIG. 7 is omitted. More specifically, the step-up chopper circuit 32 includes a reactor 11 connected to the input terminal 2 and fly units connected in series in opposite directions provided between the output side of the reactor 11 and the common line 16. Switching elements 23 and 24 composed of MOSFETs with wheel diodes, a rectifier diode 27 provided on a positive line branched from the output side of the reactor 11, and a rectifier provided on a negative line branched from the output side of the reactor 11. The diode 28 includes a capacitor 29 provided between the positive line and the common line 16 and a capacitor 30 provided between the negative line and the common line 16.

The step-up chopper circuit 32 is a component that is used in common on both the positive side and the negative side with respect to the common line 16 and performs boosting on each of the positive side and the negative side. Among these, the gates of the switching elements 23 and 24 are connected to a control circuit 62 described later. The positive and negative detection circuits 19 and 20 are connected to the capacitors 29 and 30, respectively. The detection results of these detection circuits 19 and 20 are obtained from a control circuit 62 described later. Is input. The output level of the step-up chopper circuit 32 is set to a value proportional to the input voltage in a steady state without increasing the step-up rate unnecessarily in order to increase efficiency.

  The DC-AC inverter 37 is configured as a half-bridge type including switching elements 33 and 34 made of IGBT and capacitors 29 and 30. The capacitors 29 and 30 are shared with the components of the boost chopper circuit 32. Among these, the gates of the switching elements 33 and 34 are connected to a control circuit 62 described later. The DC-AC inverter 37 converts the direct current into alternating current, and further compresses and outputs the harmonic component of the converted alternating voltage by the filter circuit 96 including the reactor 35 and the capacitor 36 at the subsequent stage. .

As shown in FIG. 2, the DC power supply circuit 61 includes a battery 38, a transformer 63, and switching elements 64, 65 such as MOSFETs connected to the primary side of the transformer 63. , Rectifier diodes 66, 67, 68, 69 as switching elements connected to the secondary side of the transformer 63, and reactors 70, 71, and an output terminal 72 is a cathode of the rectifier diode 27 on the positive side line. The output terminal 73 is connected to the anode side of the rectifier diode 28 on the negative side line, and the ground terminal 74 is connected to the common line 16.
These elements constitute a DC-DC converter.

As shown in FIG. 3, the control circuit 62 includes an effective value calculation circuit 76 that calculates an effective value a during AC recovery based on at least one cycle of the input voltage of the AC power supply 10 detected by the input voltage detection circuit 15; The switch circuit 60 and the direct current are compared with each other by a comparison signal between the effective value a at the time of AC recovery from the effective value arithmetic circuit 76, the instantaneous value b at the time of AC abnormality from the input voltage detection circuit 15, and the set value of the set value input terminal 80. A comparison circuit 75 that controls the power supply control circuit 81, a power factor improvement circuit 79 that outputs a power factor improvement signal based on the output from the current transformer 17, and a boosting step based on the signals of the comparison circuit 75 and the power factor improvement circuit 79. A step-up chopper control circuit 77 that outputs control signals for the switching elements 23 and 24 of the chopper circuit 32, an output voltage detection circuit 12, an output current detection circuit 13, and a positive-side detection circuit 1 It is provided with an inverter control circuit 78 for outputting a control signal of the switching elements 33, 34 of the negative side of the detection circuit 20 DC-AC inverter 37 based on a signal with. The DC power supply control circuit 81 controls opening and closing of the switching elements 64 and 65 of the DC power supply circuit 61 by its output.
Note that the value to be compared with the effective value by the comparison circuit 75 is a value that is changed for each time from the power of the output voltage detection circuit 12 and the output current detection circuit 13 in place of the setting value of the setting value input terminal 80. be able to.

Next, the operation of the uninterruptible power supply configured as described above will be described.
(1) When the AC power supply 10 is at a normal voltage, the step-up chopper circuit 32 operates in common on the positive side and the negative side, and the elements that operate depending on whether the AC input from the AC power supply 10 is positive or negative are slightly different. Since it is basically based on the same principle, the case where the AC input is positive will be mainly described.
The set value input terminal 80 connected to the comparison circuit 75 of the control circuit 62 stops the operation of the step-up chopper circuit 32 in order to detect whether or not the effective value input from the AC power supply 10 is abnormal. A constant set signal is input as a voltage lower limit value for starting the operation of the circuit 61.

In FIG. 1, when the AC power supply 10 is applied between the AC input terminals 2 and 3, the input voltage is detected by the input voltage detection circuit 15, and the detection result is sent to the effective value calculation circuit 76 of the control circuit 62. The effective value a is calculated and sent to the comparison circuit 75. Further, the instantaneous value b from the input voltage detection circuit 15 is also sent to the comparison circuit 75. The comparison circuit 75 compares the set value with the set value at the set value input terminal 80. If the set value is within the set value range (normal range), the switch circuit 60 is turned on and the switching element is connected via the step-up chopper control circuit 77. The gates 23 and 24 are turned on and off. A high frequency of 20 kHz is used for opening and closing the gate here.
Here, when the AC input is on the positive side, when the switching elements 23 and 24 are turned on, the current is passed from the AC power supply 10 through the loop of the switch circuit 60, the reactor 11, the switching elements 23 and 24, and the AC power supply 10. As a result, energy is stored in the reactor 11.
If the comparison circuit 75 is within the set value range, there is no output from the DC power supply control circuit 81, and no signal is sent to the switching elements 64 and 65 of the DC power supply circuit 61.

  Next, when the switching elements 23 and 24 are turned off, the energy stored in the reactor 11 is released, and current is passed from the AC power source 10 through the path of the switch circuit 60, the reactor 11, the diode 27, the capacitor 29, and the AC power source 10. Then, the boosted voltage is stored in the capacitor 29. The DC voltage stored in the capacitor 29 in this way is subjected to pulse width modulation by the switching operation of the switching element 33 of the DC-AC inverter 37, and the harmonic component is compressed by the filter circuit 96. , And output from the AC output terminals 8 and 9 as a positive AC voltage.

Similarly, when the AC input from the AC power supply 10 is on the negative side, when the switching elements 23 and 24 are turned on, a loop of the AC power supply 10, the switching elements 24 and 23, the reactor 11, the switch circuit 60, and the AC power supply 10 is used. Current flows, the energy is stored in the reactor 11, and when the switching elements 23, 24 are turned off, the energy stored in the reactor 11 is released, and the AC power source 10, the capacitor 30, the diode 28, the reactor 11, the switch circuit 60, a current flows through the path of the AC power source 10, and the boosted voltage is stored in the capacitor 30, and the DC voltage stored in the capacitor 30 is the switching operation of the switching element 34 of the DC-AC inverter 37, and By compression of harmonic components of the filter circuit 96 Is output from the AC output terminals 8 and 9 as an AC voltage of the negative side.
By repeating the above operation, a desired AC voltage is output from the AC output terminals 8 and 9 based on the power from the AC power source 10.

(2) When the instantaneous value b from the input voltage detection circuit 15 falls below the lower limit when the voltage of the AC power supply 10 falls outside the normal range, such as below the lower limit, the switch circuit 60 is turned off by a signal from the comparison circuit 75. In addition, the switching elements 23 and 24 are turned off via the step-up chopper control circuit 77.
At the same time, the DC power supply control circuit 81 is operated by a signal from the comparison circuit 75, and the switching elements 64 and 65 of the DC power supply circuit 61 are alternately turned on and off by the output of the DC power supply control circuit 81. Then, a positive-negative AC output is generated between the output terminal 72 and the ground terminal 74 and between the ground terminal 74 and the output terminal 73 by the DC-DC converter including the transformer 63, the rectifier diodes 66 to 69, and the reactors 70 and 71, and the boost chopper circuit. Charges are alternately stored in the positive side capacitor 29 and the negative side capacitor 30.

On the positive side, the DC voltage stored in the capacitor 29 is pulse-width modulated by the switching operation of the switching element 33 of the DC-AC inverter 37, and the harmonic component is compressed by the filter circuit 96. It is output from AC output terminals 8 and 9 as an AC voltage.
On the negative side, the DC voltage stored in the capacitor 30 is converted into a negative AC voltage by the switching operation of the switching element 34 of the DC-AC inverter 37 and the harmonic component compression of the filter circuit 96 as an AC output terminal 8. , 9 are output.

  In the above embodiment, the case where the instantaneous value b of the voltage of the AC power supply 10 has fallen below the lower limit value has been described, but the same control is performed when the instantaneous value b of the voltage of the AC power supply 10 exceeds the upper limit value. Can do.

(3) As the most characteristic action of the present invention, when the voltage of the AC power supply 10 falls outside the normal range depending on whether the voltage is lower than the lower limit value or higher than the upper limit value, the AC power supply 10 is disconnected and the DC power supply circuit 61 The operation when the AC power supply 10 is restored in place of the power supply state will be described.
It is assumed that the voltage of the AC power supply 10 is always detected by the input voltage detection circuit 15 and the voltage of the AC power supply 10 is actually recovered at t1 in FIG. However, in the comparison circuit 75 of the control circuit 62, the effective value of the effective value calculation circuit 76 is higher than the set value of the set value input terminal 80 at t2 after at least one cycle for effective value calculation after the actual recovery. Then, it is determined that the voltage of the AC power supply 10 has been recovered, and a recovery detection signal is output from the comparison circuit 75 as shown in FIG.

The switch circuit 60 is turned on by this recovery detection signal, and a signal is sent to the switching elements 23 and 24 of the boost chopper circuit 32 via the boost chopper control circuit 77, and the boost chopper circuit 32 starts a switching operation. At this time t2, in the uninterruptible power supply device of the present invention, the DC power supply circuit 61 does not immediately shut off, and as shown in FIG. 4 (d), the DC power supply is set for a predetermined time that is considered to be stable. The operation of the circuit 61 is continued and power is continuously supplied.
At this time, the target value of the output voltage of the DC power supply circuit 61 is set higher than the voltages of the capacitors 29 and 30 immediately before the recovery of the AC power supply 10 is detected (at time t2). Then, since the electric power begins to be supplied from the AC power supply 10 while continuing to supply the electric power to the capacitors 29 and 30 from the DC power supply circuit 61, as shown in FIG. 5, between the AC output terminals 8 and 9 from t2 to t3. Is slightly higher than the output voltage value of the DC power supply circuit 61. At t3 after the operation of the boost chopper circuit 32 is stabilized as shown in FIG. 4C at t3, the output of the DC power supply control circuit 81 disappears in response to a command from the comparison circuit 75 as shown in FIG. 4D. Then, the switching control operation of the switching elements 64 and 65 of the DC power supply circuit 61 is stopped, and the target value of the DC output voltage is gradually decreased from the time t4 to the normal value as shown in FIG. The switching process is completed while the circuit 32 is stably operated.

  As described above, the uninterruptible power supply device of the present invention receives recovery from the abnormality of the AC voltage input from the AC power supply 10 and operates the boost chopper circuit 32 at the same time while operating the DC power supply circuit 61. 29 and 30 can be reduced in capacity, and the apparatus can be downsized.

  In the comparison circuit 75, the set value set at the set value input terminal 80 is compared with the effective value / instantaneous value. Instead, the output power from the output voltage detection circuit 12 and the output current detection circuit 13 is compared. Based on the above, switching may be controlled by comparing a value that changes with time depending on the situation and an effective value / instantaneous value.

  In the above embodiment, the switching elements 23 and 24 are constituted by MOSFETs with built-in flywheel diodes, but the present invention is not limited to this. For example, it may be composed of only a MOSFET that does not incorporate a flywheel diode, or may be composed of a switching element such as a bipolar transistor or IGBT as another element. In some cases, a built-in flywheel diode is desirable. Further, the switching elements 33 and 34 are not limited to IGBTs, and switching elements such as bipolar transistors may be used.

DESCRIPTION OF SYMBOLS 1 ... Direct transmission line, 2, 3 ... AC input terminal, 8, 9 ... AC output terminal, 10 ... AC power supply, 11 ... Reactor, 12 ... Output voltage detection circuit, 13 ... Output current detection circuit, 14 ... Switching circuit, 15 ... Input voltage detection circuit, 16 ... Common line, 17 ... Current transformer, 19 ... Positive side detection circuit, 20 ... Negative side detection circuit, 23, 24 ... Switching element, 27,28 ... Rectifier diode, 29,30 ... Capacitor, 32 ... Boost chopper circuit (filter for improving power factor), 33, 34 ... Switching element, 35 ... Reactor, 36 ... Capacitor, 37 ... DC-AC inverter, 38 ... Battery, 39 ... Backflow prevention switch element, 40 ... switching element, 43 ... control circuit, 60 ... switch circuit, 61 ... DC power supply circuit, 62 ... control circuit, 63 ... transformer, 64, 65 ... switch , Rectifier diode, 70, 71 ... Reactor, 72 ..., 73 ... Output terminal, 74 ... Earth terminal, 75 ... Comparison circuit, 76 ... RMS value calculation circuit, 77 ... Boost chopper control Reference numeral 78: Inverter control circuit, 79: Power factor correction circuit, 80: Set value input terminal, 81: DC power supply control circuit, 96: Filter circuit

Claims (6)

A boost chopper circuit that converts an AC voltage input from an AC power source into a DC voltage of a preset output level, and is connected to the output terminal of this boost chopper circuit and outputs a DC voltage when the AC power source has an abnormal voltage Whether or not the AC voltage of the AC power source detected by the input voltage detection circuit is abnormal, a DC power supply circuit, a DC-AC inverter that outputs a stabilized voltage by interposing a capacitor in series at the output terminal of the boost chopper circuit In the uninterruptible power supply comprising a control circuit for switching and controlling the step-up chopper circuit and the DC power supply circuit according to the detection signal, the control circuit recovers the AC power supply based on the input detection signal of the input voltage detection circuit And restarting the boost chopper circuit in which a voltage higher than the output voltage of the DC power supply circuit is set as an output level. Uninterruptible power supply, wherein the restart of the circuit that the voltage of the capacitor of the DC-AC inverter is adapted to control the continuity operation of the DC power supply circuit to stabilize. The control circuit includes an effective value calculation circuit that calculates an effective value of the AC power supply voltage based on an input detection signal of the input voltage detection circuit, and an AC power supply when the effective value of the effective value calculation circuit is restored within the set value. A comparison circuit that outputs a restart signal of the boost chopper circuit for recovering the voltage and outputs a signal for continuously operating the DC power supply circuit until the voltage of the capacitor of the DC-AC inverter is stabilized after the restart of the boost chopper circuit And a step-up chopper control circuit for controlling restart of the step-up chopper circuit in which a voltage higher than the output voltage of the DC power supply circuit is set as an output level by a recovery signal of the comparison circuit. The uninterruptible power supply according to 1. The signal input to the comparison circuit for comparison with the effective value of the AC power supply is the output voltage from the output detection circuit and the output current detection circuit for starting the operation of the boost chopper circuit while continuing the operation of the DC power supply circuit. The uninterruptible power supply according to claim 2, wherein the voltage varies with time depending on the situation. An output voltage detection circuit and an output current detection circuit for stopping the operation of the step-up chopper circuit and starting the operation of the DC power supply circuit as a signal input to the comparison circuit for comparison with the instantaneous value of the AC power supply voltage The uninterruptible power supply according to claim 2, wherein the voltage varies with time based on the output power from the power supply. A boost chopper means for converting an AC voltage input from an AC power source into a DC voltage of a preset output level, and a DC power source connected to the output terminal of the boost chopper means when the AC power supply has an abnormal voltage DC power source switching means for switching to DC voltage supply, DC-AC inverter means for outputting a stabilized voltage by interposing a capacitor in series at the output terminal of the boost chopper means, the boost chopper means and DC power supply In the program for an uninterruptible power supply functioning as a control means for controlling switching of the power supply, the control means includes an effective value calculating means for calculating an effective value based on an input detection signal of an AC power supply, and an effective value of the effective value calculating means. A boost chopper means outputs a restart signal of the boost chopper means when the value recovers within a preset set value. A comparison means for outputting a signal for continuously operating the DC power supply switching means from the restart until the capacitor voltage of the DC-AC inverter means becomes stable, and a higher voltage than the output voltage of the DC power supply is output by a recovery signal of the comparison means. 2. The program for an uninterruptible power supply according to claim 1, wherein the program is made to function as a boost chopper control means for controlling restart of the boost chopper means set as a level. A boost chopper circuit that converts an AC voltage input from an AC power source into a DC voltage of a preset output level, and is connected to the output terminal of this boost chopper circuit and outputs a DC voltage when the AC power source has an abnormal voltage Whether or not the AC voltage of the AC power source detected by the input voltage detection circuit is abnormal, a DC power supply circuit, a DC-AC inverter that outputs a stabilized voltage by interposing a capacitor in series at the output terminal of the boost chopper circuit In a control method for an uninterruptible power supply device comprising a control circuit for switching and controlling a step-up chopper circuit and a DC power supply circuit according to any detection signal, a step of calculating an effective value of the AC power supply by an effective value calculation circuit, and this effective A step of outputting a boost chopper circuit restart signal for restoring the AC power supply when the effective value in the value calculation step is restored within the set value; A step of outputting a signal for continuously operating the DC power supply circuit from the restart of the chopper circuit until the voltage of the capacitor of the DC-AC inverter is stabilized, and a voltage higher than the output voltage of the DC power supply circuit is output by the recovery signal. And controlling the restart of the step-up chopper circuit set as: a method for controlling an uninterruptible power supply.

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