Pre-charge circuit and photovoltaic inverter

Patent metadata

Field	Value
Publication number	US-2016352252-A1
Application number	US-201615164069-A
Country	US
Kind code	A1
Filing date	May 25, 2016
Priority date	May 27, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

Provided is a pre-charge circuit and a photovoltaic inverter. The pre-charge circuit includes an alternating current power source, a half-bridge rectifier, an auxiliary charging capacitor, a current limiting device and a controllable switch. The pre-charge circuit is connected to a target charging capacitor to form a voltage doubling rectifier circuit. A direct current side of the half-bridge rectifier is connected in parallel to the target charging capacitor, and an alternating current side of the half-bridge rectifier is connected to one end of the alternating current power source. One end of the auxiliary charging capacitor is connected to any one end of the target charging capacitor, and the other end of the auxiliary charging capacitor is connected to the other end of the alternating current power source.

First claim

1 . A pre-charge circuit, comprising an alternating current power source, a half-bridge rectifier, an auxiliary charging capacitor, a current limiting device and a controllable switch, and the pre-charge circuit being connected to a target charging capacitor to form a voltage doubling rectifier circuit; wherein a direct current side of the half-bridge rectifier is connected in parallel to the target charging capacitor, and an alternating current side of the half-bridge rectifier is connected to one end of the alternating current power source;
one end of the auxiliary charging capacitor is connected to any one end of the target charging capacitor, and the other end of the auxiliary charging capacitor is connected to the other end of the alternating current power source; the current limiting device is connected in series on each charging path of the pre-charge circuit; and the controllable switch is connected in series on each charging path of the pre-charge circuit.

2 . The pre-charge circuit according to claim 1 , wherein the alternating current power source is a phase voltage of an electrical grid or a line voltage of an electrical grid.

3 . The pre-charge circuit according to claim 1 , wherein a semiconductor device in the half-bridge rectifier is a diode, a thyristor, a Metallic Oxide Semiconductor Field Effect Transistor (MOSFET) or an Insulated Gate Bipolar Transistor (IGBT) with anti-parallel diode.

4 . The pre-charge circuit according to claim 1 , wherein the current limiting device is a resistor, an electrical-inductor, a choke coil, or any combination thereof

5 . The pre-charge circuit according to claim 1 , wherein the controllable switch is a relay, a Metallic Oxide Semiconductor Field Effect Transistor (MOSFET) or an Insulated Gate Bipolar Transistor (IGBT).

6 . The pre-charge circuit according to claim 1 , wherein a semiconductor device in the half-bridge rectifier is an anti-parallel diode in an inverting circuit of a photovoltaic inverter.

7 . The pre-charge circuit according to claim 1 , wherein the auxiliary charging capacitor is a positive bus capacitor and/or a negative bus capacitor on a direct current side of a photovoltaic inverter.

8 . The pre-charge circuit according to claim 1 , wherein the current limiting device is an alternating current reactor of a photovoltaic inverter.

9 . The pre-charge circuit according to claim 1 , wherein the controllable switch is a grid-connected switch of a photovoltaic inverter.

10 . A photovoltaic inverter, comprising a pre-charge circuit, the pre-charge circuit comprising an alternating current power source, a half-bridge rectifier, an auxiliary charging capacitor, a current limiting device and a controllable switch, and the pre-charge circuit being connected to a target charging capacitor to form a voltage doubling rectifier circuit; wherein
a direct current side of the half-bridge rectifier is connected in parallel to the target charging capacitor, and an alternating current side of the half-bridge rectifier is connected to one end of the alternating current power source; one end of the auxiliary charging capacitor is connected to any one end of the target charging capacitor, and the other end of the auxiliary charging capacitor is connected to the other end of the alternating current power source; the current limiting device is connected in series on each charging path of the pre-charge circuit; and the controllable switch is connected in series on each charging path of the pre-charge circuit.

11 . The photovoltaic inverter according to claim 10 , wherein the alternating current power source is a phase voltage of an electrical grid or a line voltage of an electrical grid.

12 . The photovoltaic inverter according to claim 10 , wherein a semiconductor device in the half-bridge rectifier is a diode, a thyristor, a Metallic Oxide Semiconductor Field Effect Transistor (MOSFET) or an Insulated Gate Bipolar Transistor (IGBT) with anti-parallel diode.

13 . The photovoltaic inverter according to claim 10 , wherein the current limiting device is a resistor, an electrical-inductor, a choke coil, or any combination thereof.

14 . The photovoltaic inverter according to claim 10 , wherein the controllable switch is a relay, a Metallic Oxide Semiconductor Field Effect Transistor (MOSFET) or an Insulated Gate Bipolar Transistor (IGBT).

15 . The photovoltaic inverter according to claim 10 , wherein a semiconductor device in the half-bridge rectifier is an anti-parallel diode in an inverting circuit of a photovoltaic inverter.

16 . The photovoltaic inverter according to claim 10 , wherein the auxiliary charging capacitor is a positive bus capacitor and/or a negative bus capacitor on a direct current side of a photovoltaic inverter.

17 . The photovoltaic inverter according to claim 10 , wherein the current limiting device is an alternating current reactor of a photovoltaic inverter.

18 . The photovoltaic inverter according to claim 10 , wherein the controllable switch is a grid-connected switch of a photovoltaic inverter.

Assignees

• Sungrow Power Supply Co Ltd

Inventors

• Yu Yanfei
• Ni Hua
• Yang Zongjun
• Dai Shangfang
• Huang Pengcheng

Classifications

• H02M7/537 Primary

  using semiconductor devices only, e.g. single switched pulse inverters · CPC title

• H02J3/383

  Electricity · mapped topic

• H02M1/36 Primary

  Means for starting or stopping converters · CPC title

• H02M7/05

  Capacitor coupled rectifiers · CPC title

• H02M7/5387

  in a bridge configuration · CPC title