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KR-20260065913-A - Uninterruptible Power Supply

KR20260065913AKR 20260065913 AKR20260065913 AKR 20260065913AKR-20260065913-A

Abstract

An uninterruptible power supply (10) is connected between an AC power source (1) and a DC transmission line (4). The uninterruptible power supply (10) is equipped with a converter (12), a DC bus (14), and a bidirectional chopper (18). The converter (12) converts AC power supplied from the AC power source (1) into DC power. The DC bus (14) supplies DC power received from the converter (12) to the DC transmission line (4). The bidirectional chopper (18) receives DC power between the DC bus (14) and the power storage device (3). The converter (12) includes a plurality of power converters that convert AC power input to an AC terminal into DC power and output it from the DC terminal. The plurality of power converters have an AC terminal connected in series to the AC power source (1), and a DC terminal connected in parallel to the DC bus (14).

Inventors

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

Assignees

  • 가부시키가이샤 티마이크

Dates

Publication Date
20260511
Application Date
20240913

Claims (4)

  1. As an uninterruptible power supply connected between an AC power source and a DC transmission line, A converter that converts AC power supplied from the above AC power source into DC power, and A DC busbar that supplies DC power received from the above converter to the above DC transmission line, and A bidirectional chopper is provided for transmitting and receiving DC power between the above-mentioned DC bus and the power storage device, and The above converter includes a plurality of power converters that convert AC power input to an AC terminal into DC power and output it from a DC terminal. The plurality of power converters above have the AC terminal connected in series with the AC power source, and also have the DC terminal connected in parallel with the DC busbar. Uninterruptible Power Supply
  2. In paragraph 1, Each of the above plurality of power converters is, An AC/DC converter that converts AC power input to the above AC terminal into DC power, and An isolated DC/DC converter comprising transmitting DC power from the AC/DC converter to the DC terminal. Uninterruptible Power Supply
  3. In paragraph 2, The above isolated DC/DC converter is a DAB (Dual Active Bridge) converter Uninterruptible Power Supply
  4. In any one of paragraphs 1 through 3, The above AC power source is a power system or generator that supplies medium-voltage AC power, and The above power storage device is configured to store medium-voltage direct current power, and When the above AC power source is healthy, the converter converts the medium-voltage AC power supplied from the above AC power source into medium-voltage DC power and supplies it to the DC busbar, and In the event of a power outage of the above AC power source, the converter stops operation, and the bidirectional chopper supplies medium-voltage DC power of the power storage device to the DC busbar. Uninterruptible Power Supply

Description

Uninterruptible Power Supply The present disclosure relates to an uninterruptible power supply. For example, International Publication No. 2014/132452 (Patent Document 1) discloses an uninterruptible power supply for supplying power to multiple servers installed in a data center, etc. This uninterruptible power supply is connected to a low-voltage (400V) AC power source. The uninterruptible power supply is configured to include a converter that converts low-voltage AC power (AC 400V) from an AC power source into DC power, and an inverter that converts DC power from the converter or DC power stored in a battery into low-voltage AC power (AC 400V). FIG. 1 is a circuit block diagram showing the configuration of an uninterruptible power supply according to the present embodiment. Figure 2 is a block diagram showing the main circuit configuration of the converter. Figure 3 is a circuit diagram showing the main circuit configuration of the power converter shown in Figure 2. Figure 4 is a circuit diagram showing the main circuit configuration of a bidirectional chopper. FIG. 5 is a drawing illustrating an application example of an uninterruptible power supply device according to the present embodiment. Figure 6 is a diagram illustrating an application example of an uninterruptible power supply according to a comparative example. FIG. 7 is a drawing showing an example of the configuration of a power system using an uninterruptible power supply according to the present embodiment. Figure 8 is a circuit diagram showing the main circuit configuration of the converter shown in Figure 7. 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. FIG. 1 is a circuit block diagram showing the configuration of an uninterruptible power supply according to the present embodiment. As shown in FIG. 1, the uninterruptible power supply (10) is connected between an AC power source (1) and a DC transmission line (4). The uninterruptible power supply (10) receives a three-phase AC voltage from the AC power source (1) and supplies a DC voltage to the DC transmission line (4), but for the sake of simplicity of drawings and descriptions, only a circuit for one phase is shown in FIG. 1. In this specification, in accordance with the standards of the IEC (International Electrotechnical Commission), for alternating current, voltage classes of 230 kV or higher are classified as extra-high voltage (EHVAC), voltage classes of 35 kV to 230 kV as high voltage (HVAC), voltage classes of 1 kV to 35 kV as medium voltage (MVAC), and voltage classes of less than 1 kV as low voltage (LVAC). In addition, for direct current, voltage classes exceeding 100kV are classified as high voltage direct current (HVDC), voltage classes between 1.5kV and 100kV as medium voltage direct current (MVDC), and voltage classes below 1.5kV as low voltage direct current (LVDC). In addition, in Japan, currently, for AC, voltage classes of 7kV or higher are classified as extra-high voltage (EHVAC), voltage classes of 600V to 7kV as high voltage (HVAC), and voltage classes of less than 600V as low voltage (LVAC). For DC, voltage classes exceeding 7kV are classified as extra-high voltage (EHVDC), voltage classes of 750V to 7kV as high voltage (HVDC), and voltage classes of less than 1.5kV as low voltage (LVDC). The AC power source (1) is a power system that supplies medium-voltage AC power, or a generator that generates medium-voltage AC power. The DC transmission line (4) transmits medium-voltage DC power. The uninterruptible power supply (10) is equipped with an input terminal T1, a DC terminal T2, an output terminal T3, switches S1 to S3, a converter (12), current detectors CD1 to CD3, a DC busbar (14), a capacitor (16), a bidirectional chopper (18), and a control device (20). Input terminal T1 receives AC power of a predetermined frequency from an AC power source (1) through a transformer (2). The AC input voltage VI is a medium-voltage AC voltage, and its instantaneous value is detected by a control device (20). Based on the instantaneous value of the AC input voltage VI, the presence or absence of a power outage is determined. Current detector CD1 detects the AC input current Ii flowing through input terminal T1 and provides a signal Iif, which indicates the detected value, to the control device (20). The output terminal T3 is connected to a DC transmission line (4). The DC transmission line (4) transmits medium-voltage DC power. A plurality of loads (6) are electrically connected to the DC transmission line (4). A switch S4 and an inverter (5) are connected in series between the DC transmission line (4) and each load (6). By turning the switch S4 connected to each load (6) on or off, the load capacity of the uninterruptible power supply (10) changes. The i