Controller for power converter

Patent metadata

Field	Value
Publication number	US-2016308459-A1
Application number	US-201615063097-A
Country	US
Kind code	A1
Filing date	Mar 7, 2016
Priority date	Apr 15, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

The present disclosure provides a controller for a power converter that converts input power to a prescribed form and outputs the power by switching a semiconductor switching device ON and OFF and that has an output circuit including a filtering reactor on an output side, the controller including: a carrier calculating unit that generates a carrier having prescribed frequencies for generating a control signal that switches the semiconductor switching device ON and OFF, wherein the carrier calculating unit generates the carrier such that a carrier frequency at phase angles where ripple components in a current flowing through the reactor are relatively high in magnitude, which is defined as a high ripple carrier frequency, is higher than a carrier frequency at phase angles where the ripple components are relatively low in magnitude, which is defined as a low ripple carrier frequency.

First claim

What is claimed is:

1 . A controller for a power converter that converts input power to a prescribed form and outputs the power by switching a semiconductor switching device ON and OFF and that has an output circuit including a filtering reactor on an output side, the controller comprising:
a carrier calculating unit that generates a carrier having prescribed frequencies for generating a control signal that switches the semiconductor switching device ON and OFF, wherein the carrier calculating unit generates the carrier such that a carrier frequency at phase angles where ripple components in a current flowing through the reactor are relatively high in magnitude, which is defined as a high ripple carrier frequency, is higher than a carrier frequency at phase angles where the ripple components are relatively low in magnitude, which is defined as a low ripple carrier frequency.

2 . The power converter controller according to claim 1 , wherein the carrier calculating unit sets an upper limit and a lower limit of the carrier frequency according to a number of phases in an output voltage of the power converter and calculates the high ripple carrier frequency and the low ripple carrier frequency within a range between the upper limit and the lower limit.

3 . An uninterruptible power supply, comprising:
said controller as set forth in claim 1 ; and said power converter as set forth in claim 1 , said converter including:
a rectifier configured to be connected to a power supply system on an alternative current side;
a rechargeable battery connected to a direct current side of the rectifier; and
an inverter connected to the rechargeable battery on a direct current side, the inverter being configured to be connected to a load on an alternating current side and including said semiconductor switching device and said filtering reactor on the output side.

4 . The uninterruptible power supply according to claim 3 , wherein the carrier calculating unit sets an upper limit and a lower limit of the carrier frequency according to a number of phases in an output voltage of the power converter and calculates the high ripple carrier frequency and the low ripple carrier frequency within a range between the upper limit and the lower limit.

5 . A power converter system comprising:
said controller as set forth in claim 1 ; and said power converter as set forth in claim 1 in a plurality, connected in parallel, wherein the carrier calculating unit in said controller generates carriers for the respective power converters such that carrier frequencies of all of the power converters are synchronized.

6 . The power converter system according to claim 4 , wherein the carrier calculating unit sets an upper limit and a lower limit of the carrier frequency according to a number of phases in an output voltage of the power converter and calculates the high ripple carrier frequency and the low ripple carrier frequency within a range between the upper limit and the lower limit.

Assignees

• Fuji Electric Co Ltd

Inventors

• Fujii Kansuke

Classifications

• H02M2005/2932

  Electricity · mapped topic

• H02M7/2173 Primary

  in a biphase or polyphase circuit arrangement (H02M7/2176 takes precedence; voltage multipliers H02M7/25) · CPC title

• H02M1/12

  Arrangements for reducing harmonics from AC input or output · CPC title

• H02M1/126

  using passive filters · CPC title

• H02M5/4585 Primary

  having a rectifier with controlled elements · CPC title