DC-link charging arrangement and method for charging a DC-link capacitor

Patent metadata

Field	Value
Publication number	US-11569732-B2
Application number	US-202016924864-A
Country	US
Kind code	B2
Filing date	Jul 9, 2020
Priority date	Jul 12, 2019
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A DC-link charging arrangement is described having a DC-link capacitor, rectifier means, and contactor means arranged between supply voltage ports and the rectifier means and having at least one contactor. Such a charging arrangement should enable charging of a DC-link capacitor in a simple way with low losses. To this end a charging capacitor is arranged bridging the at least one contactor.

First claim

What is claimed is:

1. A DC-link charging arrangement having a DC-link capacitor, rectifier means, and contactor means arranged between supply voltage ports and the rectifier means and having at least one contactor, wherein a charging capacitor is arranged bridging the at least one contactor, wherein the rectifier means is an active rectifier having a plurality of switches which are controlled by control means, the control means being configured to adjust a power angle between a voltage at the supply voltage ports and a charging voltage at active rectifier ports to be close to 90°, wherein the control means are configured to reduce the power angle to zero and voltage amplitude to be the same as grid voltage before the at least one contactor is closed, and wherein an auxiliary power unit is connected to a point between the charging capacitor and a supply voltage port of the supply voltage ports that is connected to the charging capacitor.

2. The DC-link charging arrangement according to claim 1 , wherein a filter arrangement having at least one filter capacitor connected between a phase and a mid-point of at least two phases is arranged between the at least one contactor and the rectifier means.

3. The DC-link charging arrangement according to claim 2 , wherein the charging capacitor has a capacitance value at least 25% of a capacitance value of the at least one filter capacitor.

4. The DC-link charging arrangement according to claim 3 , wherein an additional contactor is arranged in series with the charging capacitor.

5. The DC-link charging arrangement according to claim 2 , wherein an additional contactor is arranged in series with the charging capacitor.

6. The DC-link charging arrangement according to claim 1 , wherein an additional contactor is arranged in series with the charging capacitor.

7. The DC-link charging arrangement according to claim 1 , wherein the charging capacitor is arranged within an LCL filter arrangement.

8. The DC-link charging arrangement according to claim 7 , wherein the charging capacitor is arranged between a filter inductor and at least one filter capacitor.

9. A method for charging a DC-link capacitor connected to rectifier means, the method comprising supplying the rectifier means from supply voltage ports by means of a charging capacitor bridging an open contactor, controlling the rectifier means with control means, the rectifier means being an active rectifier having a plurality of switches, adjusting, by the control means, a power angle between a voltage at the supply voltage ports and a charging voltage at active rectifier ports to be close to 90°, and reducing, by the control means, the power angle to zero and voltage amplitude to be the same as grid voltage before the open contactor is closed, wherein an auxiliary power unit is connected to a point between the charging capacitor and a supply voltage port of the supply voltage ports that is connected to the charging capacitor.

10. The method according to claim 9 , wherein a voltage supplied to the rectifier means is filtered by means of an LCL filter.

Assignees

• Vacon Oy

Inventors

• Strandberg Stefan
• Södö Nicklas

Classifications

• H02M1/322

  Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock · CPC title

• H02M7/219 Primary

  in a bridge configuration · CPC title

• H02J7/345

  using capacitors as storage or buffering devices · CPC title

• H02M7/217

  using semiconductor devices only · CPC title

• H02M1/143 Primary

  using compensating arrangements (for reducing noise from the supply in transmission systems H04B15/005) · CPC title