US 6,603,647 B2 · Method for controlling freewheeling paths in a matrix converter

Abstract

A method for controlling positive or negative freewheeling paths of the phases of a matrix converter with nine bidirectional power switches arranged in a 3×3 switch matrix is described. Each power switch has two back-to-back series-connected semiconductor switches. Those semiconductor switches are actuated that have the most positive/negative line voltage to provide a negative/positive freewheeling path capable of carrying a negative/positive load current. The matrix converter can be immediately disconnected if an error is detected or if the matrix converter is inadvertently switched off, without damaging the matrix converter.

Claims6

Dependent claims

A method for controlling a positive or negative freewheeling path in a phase of a matrix converter having nine bidirectional power switches arranged in a 3×3 switch matrix, with each power switch associated with a matrix converter phase and having two back-to-back series-connected semiconductor switches, comprising the steps of:

a) identifying a bidirectional power switch of a matrix converter phase having a most negative line voltage;
b) identifying a bidirectional power switch of a matrix converter phase having a most positive line voltage;
c) actuating the semiconductor switch of the identified bidirectional power switch having the most negative line voltage to provide a positive freewheeling path capable of carrying a positive load current, and
d) actuating the semiconductor switch of the identified bidirectional power switch having the most positive line voltage to provide a negative freewheeling path capable of carrying a negative load current.

1 more element

a) determining a phase-to-phase input voltage of at least two matrix converter phases;
b) determining one of a positive and a negative zero crossing of the phase-to-phase input voltage and the two bidirectional power switches associated with the zero crossing;
c) selecting from each of the two bidirectional power switches a semiconductor switch to provide corresponding positive and negative freewheeling paths in a region of the zero crossing;
d) actuating the selected semiconductor switch if the selected semiconductor switch is identical to a semiconductor switch determined with a commutation method, and
e) actuating both selected semiconductor switches if none of the selected semiconductor switches is identical to a semiconductor switch determined with the commutation method.

2 more elements

Dependencies are inferred from the claim text.

Method for controlling freewheeling paths in a matrix converter

Life of this patent

Method for controlling freewheeling paths in a matrix converter

Life of this patent

Abstract

Claims6