Power factor correction circuit, power factor correction assembly and on-line uninterruptible power supply comprising same

Patent metadata

Field	Value
Publication number	US-2022021298-A1
Application number	US-201917299730-A
Country	US
Kind code	A1
Filing date	Dec 3, 2019
Priority date	Dec 4, 2018
Publication date	Jan 20, 2022
Grant date	—

Abstract

The present invention provides a power factor correction circuit (21, 22), a power factor correction assembly (2) and an on-line uninterruptible power supply including the same. The power factor correction circuit (21) comprises a pulse width modulated rectifier (211, 221) and an isolated DC-DC converter (212, 222), wherein an output of the pulse width modulated rectifier (211, 221) is connected to an input of the isolated DC-DC converter (212, 222). The power factor correction assembly (2) comprises a plurality of power factor correction circuits (21, 22) described above, wherein inputs of pulse width modulated rectifiers (211, 221) in the plurality of power factor correction circuits (21, 22) are connected in series, and outputs of isolated DC-DC converters (212, 222) in the plurality of power factor correction circuits (21, 22) are connected in parallel. The power factor correction assembly (2) of the present invention needs no line-frequency transformer and has the advantages of small size, low cost and improved operation reliability.

First claim

1 . A power factor correction circuit, comprising a pulse width modulated rectifier and an isolated DC-DC converter, wherein an output of the pulse width modulated rectifier is connected to an input of the isolated DC-DC converter.

2 . The power factor correction circuit according to claim 1 , wherein the pulse width modulated rectifier is a full-bridge pulse width modulated rectifier or a half-bridge pulse width modulated rectifier.

3 . The power factor correction circuit according to claim 1 , wherein the isolated DC-DC converter comprises:
an inverter having an input connected to the output of the pulse width modulated rectifier; a transformer having a primary side of the transformer connected to an output of the inverter; and a rectifying device having an input connected to a secondary side of the transformer and an output that serves as an output of the isolated DC-DC converter.

4 . The power factor correction circuit according to claim 3 , wherein the inverter is a full-bridge inverter or a half-bridge inverter, the transformer is a high-frequency transformer having a working frequency greater than 10 kHz, and the rectifying device is a full-bridge pulse width modulated rectifier, a half-bridge pulse width modulated rectifier, or a bridge rectifying circuit.

5 . The power factor correction circuit according to claim 1 , further comprising a first fuse and a second fuse connected to an input of the pulse width modulated rectifier, and a third fuse and a fourth fuse connected to an output of the isolated DC-DC converter.

6 . The power factor correction circuit according to claim 5 , wherein the power factor correction circuit further comprises a first switch, a second switch, a third switch, and a fourth switch connected in series with the first fuse, the second fuse, the third fuse, and the fourth fuse, respectively.

7 . A power factor correction assembly, comprising a plurality of power factor correction circuits according to claim 1 , wherein inputs of pulse width modulated rectifiers of the plurality of power factor correction circuits are connected in series, and outputs of isolated DC-DC converters of the plurality of power factor correction circuits are connected in parallel.

8 . The power factor correction assembly according to claim 7 :
wherein each of the power factor correction circuits further comprises a first fuse and a second fuse connected to the input of the pulse width modulated rectifier, a third fuse and a fourth fuse connected to the output of the isolated DC-DC converter, and a first switch, a second switch, a third switch, and a fourth switch connected in series with the first fuse, the second fuse, the third fuse, and the fourth fuse, respectively; and wherein the power factor correction assembly further comprises fifth switches connected between inputs of the power factor correction circuits.

9 . The power factor correction assembly according to claim 8 , wherein the power factor correction assembly further comprises a first control device, wherein:
when the plurality of power factor correction circuits are all operational, the control device turns on the first switch, the second switch, the third switch, and the fourth switch in each of the power factor correction circuits and turns off the fifth switches in the power factor correction; and when at least one of the plurality of power factor correction has failed, the control device turns on the fifth switch connected to the input of the at least one failed power factor correction circuit turns off the first switch, the second switch, the third switch, and the fourth switch in the at least one failed power factor correction circuit, and turns on the first switches, second switches, third switches, and fourth switches in operational ones of the plurality of power factor correction circuits and turns off the fifth switches connected to the inputs of the operational ones of the plurality of power factor correction circuits.

10 . An on-line uninterruptible power supply, comprising:
the power factor correction assembly according to claim 8 , wherein an output of the power factor correction assembly is connected to positive and negative direct-current (DC) buses; a bi-directional DC-DC converter connected between a battery and the positive and negative DC buses; and an inverter assembly having an input connected to the positive and negative DC buses and an output that provides an alternating current.

11 . The on-line uninterruptible power supply according to claim 10 , wherein the bi-directional DC-DC converter assembly comprises a plurality of bi-directional DC-DC converters connected in parallel.

12 . The on-line uninterruptible power supply according to claim 11 , wherein each of the plurality of bi-directional DC-DC converters comprises:
a bi-directional DC-DC conversion circuit having a first connection end and a second connection end; a sixth fuse and a seventh fuse respectively connected to a positive terminal and a negative terminal of the first connection end of the bi-directional DC-DC conversion circuit and a sixth switch and a seventh switch respectively connected in series with the sixth fuse and the seventh fuse; and an eighth switch and a ninth switch respectively connected to a positive terminal and a negative terminal of the second connection end of the bi-directional DC-DC conversion circuit.

13 . The on-line uninterruptible power supply according to claim 12 , wherein the on-line uninterruptible power supply further comprises a control device,
wherein, when the plurality of bi-directional DC-DC converters are all operational, the control device turns on the sixth switch, the seventh switch, the eighth switch, and the ninth switch in each of the plurality of bi-directional DC-DC converters, and wherein, when the plurality of bi-directional DC-DC converters include a failed bi-directional DC-DC converter, the control device turns off the sixth switch, the seventh switch, the eighth switch, and the ninth switch in the failed bi-directional DC-DC converter and turns on the sixth switches, seventh switches, eighth switches, and ninth switches in other operational bi-directional DC-DC converters.

14 . The on-line uninterruptible power supply according to claim 12 , wherein the inverter assembly comprises a plurality of inverters connected in parallel.

15 . The on-line uninterruptible power supply according to claim 14 , wherein each of the plurality of inverters comprises:
an inversion circuit; a tenth fuse and an eleventh fuse respectively connected to a positive input terminal and a negative input terminal of the inversion circuit; a tenth switch and an eleventh switch respectively connected in series to the tenth fuse and the eleventh fuse; and an output switch connected to an output terminal of the inversion circuit.

16 . The on-line uninterruptible power supply according to claim 15 , wherein the on-line uninterruptible power supply further comprises a control device
wherein, when the plurality of inverters are all operational, the control device turns on the tenth switch, the eleventh switch, and the output switch in each of the plurality of inverters; and wherein, when the plurality of inverters include a failed inverter, the control device turns off the tenth switch, the eleventh switch, and the output switch of the failed inverter and turns on the tenth switches, eleventh switches and output switches of other operational ones of the inverters.

17 . An uninterruptible power supply comprising:
a plurality of power factor correction circuits, each

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Luo Cheng
• Xin Huiting
• Li Han
• Zheng Dawei
• Li Hualiang

Classifications

• H02J9/062 Primary

  for AC powered loads · CPC title

• H02M1/4233 Primary

  using a bridge converter comprising active switches · CPC title

• H02M3/33584

  Bidirectional converters · CPC title

• H02M3/33573

  Full-bridge at primary side of an isolation transformer · CPC title

• H02M3/33571

  Half-bridge at primary side of an isolation transformer · CPC title