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KR-20260065914-A - Uninterruptible Power Supply

KR20260065914AKR 20260065914 AKR20260065914 AKR 20260065914AKR-20260065914-A

Abstract

An uninterruptible power supply device according to the present disclosure comprises a converter (1), capacitors (C1, C2), an inverter (3), a first current detector (CD1), a second current detector (CD3), and a control device (5). The control device (5) controls the converter (1) such that the phase of the input voltage and the input current of the converter (1) match, and the DC voltage of the DC lines (L1, L3) becomes a first reference voltage. The control device (5) controls the converter (1) such that the input current, which includes a feedback component based on the deviation between the DC voltage of the DC lines (L1, L3) and the first reference voltage, and a feedforward component based on the load current detected by the second current detector (CD2), flows from the AC power source to the converter (1).

Inventors

  • 이마니시 료고
  • 야마모토 유신
  • 기노시타 마사히로
  • 나가노 히로타카

Assignees

  • 가부시키가이샤 티마이크

Dates

Publication Date
20260511
Application Date
20240913

Claims (5)

  1. A converter that converts AC power supplied from an AC power source into DC power and supplies it to a DC line, and A capacitor connected to the above DC line, and An inverter that converts DC power received from the above DC line into AC power and supplies it to a load, and A first current detector for detecting the input current of the above converter, and A second current detector for detecting the load current flowing from the inverter to the load, and A control device is provided to control the converter such that the phase of the input voltage of the converter and the phase of the input current match, and the DC voltage of the DC line becomes a first reference voltage. The control device controls the converter such that the input current, comprising a feedback component based on the deviation between the DC voltage of the DC line and the first reference voltage, and a feedforward component based on the load current detected by the second current detector, flows from the AC power source to the converter. Uninterruptible Power Supply
  2. In paragraph 1, The above control device is, The feedback component is calculated by a control operation that takes as input the difference between the DC voltage of the above DC line and the first reference voltage, and The feedforward component is calculated by determining the moving average value of one cycle of the AC power source with respect to the detection value of the second current detector, and Based on the sum of the feedback component and the feedforward component and the input voltage of the converter, a current command value is generated, and Controlling the converter so that the deviation between the above current command value and the input current detected by the first current detector becomes zero Uninterruptible Power Supply
  3. In paragraph 1 or 2, The above control device is, In the case where the above AC power source is an AC system, the feedforward component according to the load current detected by the second current detector is calculated, and In the case where the above AC power source is a generator, the above feedforward component is set to zero. Uninterruptible Power Supply
  4. In paragraph 1 or 2, A switch further provided for connecting either the AC system or the generator to the AC terminal of the converter, and The above control device is, When the AC system is connected to the AC terminal by the above switch, the feedforward component is calculated from the load current detected by the second current detector, and When the generator is connected to the AC terminal by the above switch, the feedforward component is set to zero. Uninterruptible Power Supply
  5. In paragraph 4, Further equipped with a bidirectional chopper that transmits and receives DC power between the above-mentioned DC line and the power storage device, When the above AC system is healthy, the control device, The AC system is connected to the AC terminal by the above switch, and The converter is controlled such that the phases of the input voltage and the input current of the converter match, and the DC voltage of the DC line becomes the first reference voltage. The bidirectional chopper is controlled so that the voltage between the terminals of the power storage device becomes the second reference voltage, and In the event of a power outage in the above AC system, the control device, If the stored amount of the power storage device is greater than or equal to a reference value, the AC system is connected to the AC terminal by the switch, while if the stored amount of the power storage device is less than a lower limit value, the generator is connected to the AC terminal by the switch. Uninterruptible Power Supply

Description

Uninterruptible Power Supply The present disclosure relates to an uninterruptible power supply. For example, International Publication No. 2020/026430 (Patent Document 1) discloses an uninterruptible power supply comprising a converter, a capacitor, an inverter, and a control device. When the AC power supply is healthy, the converter converts AC power supplied from the AC power supply into DC power and supplies it to a DC line. The capacitor is connected to the DC line. The inverter converts DC power received from the DC line into AC power and supplies it to a load. When the AC power supply is healthy, the control device controls the converter so that the DC voltage of the DC line becomes a reference voltage. FIG. 1 is a circuit block diagram showing the configuration of an uninterruptible power supply according to embodiment 1. Figure 2 is a block diagram showing an example of the hardware configuration of a control device. Figure 3 is a block diagram showing the configuration of the part related to the control of the converter in the control device. Figure 4 is a block diagram showing the configuration of the control circuit shown in Figure 3. FIG. 5 is a circuit block diagram showing the configuration of an uninterruptible power supply according to embodiment 2. FIG. 6 is a block diagram showing the configuration of the part related to the control of the converter among the control devices shown in FIG. 5. Figure 7 is a block diagram showing the configuration of the control circuit shown in Figure 6. Figure 8 is a flowchart illustrating the control of a switch by a switch control unit. Figure 9 is a flowchart illustrating the control of the load current FF section. FIG. 10 is a circuit block diagram showing the configuration of an uninterruptible power supply according to embodiment 1. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, identical or substantial parts in the drawings are given the same reference numerals below, and their descriptions will, in principle, not be repeated. [Form of Embodiment 1] FIG. 1 is a circuit block diagram showing the configuration of an uninterruptible power supply according to embodiment 1. As shown in FIG. 1, the uninterruptible power supply comprises an input terminal T1, a DC terminal T2, an output terminal T3, a converter (1), current detectors CD1 to CD3, DC lines L1 to L3, capacitors C1 to C4, a bidirectional chopper (2), an inverter (3), an operating unit (4), and a control device (5). Input terminal T1 receives an AC voltage VI from an AC power source (6). The instantaneous value of the AC voltage VI (hereinafter also referred to as 'AC input voltage VI') is detected by a control device (5). Based on the instantaneous value of the AC input voltage VI, the occurrence of a power outage of the AC power source (6) is determined. The DC terminal T2 is connected to a battery (7) (power storage device). The battery (7) stores DC power. It does not matter if a capacitor is connected instead of the battery (7). The instantaneous value of the DC voltage VB of the DC terminal T2 (i.e., the terminal-to-terminal voltage VB of the battery (7)) is detected by the control device (5). The output terminal T3 is connected to a load (8). The load (8) is driven by AC power supplied from an uninterruptible power supply. The instantaneous value of the AC voltage VO (hereinafter also referred to as 'AC output voltage VO') appearing at the output terminal T3 is detected by a control device (5). Additionally, the uninterruptible power supply receives a three-phase AC voltage from an AC power source (6) and supplies a three-phase AC voltage to a load (8), but for the sake of simplicity of drawings and descriptions, only one phase circuit is shown in FIG. 1. The converter (1) has an AC terminal (1a), a positive voltage terminal (1b), a neutral voltage terminal (1c), and a negative voltage terminal (1d). The bidirectional chopper (2) has a DC terminal (2a), a positive voltage terminal (2b), a neutral voltage terminal (2c), and a negative voltage terminal (2d). The inverter (3) has an AC terminal (3a), a positive voltage terminal (3b), a neutral voltage terminal (3c), and a negative voltage terminal (3d). The AC terminal (1a) of the converter (1) is connected to the input terminal T1. The current detector CD1 detects the instantaneous value of the current Ii (hereinafter also referred to as 'AC input current Ii') flowing between the input terminal T1 and the AC terminal (1a) of the converter (1), and gives a signal Iif representing the detected value to the control device (5). The DC terminal (2a) of the bidirectional chopper (2) is connected to the DC terminal T2. The current detector CD2 detects the instantaneous value of the DC current IB flowing between the DC terminal T2 and the DC terminal (2a), and provides a signal IBf representing the detected value to the control device (5). The AC terminal (3a) of the inver