System and method for safe switching in an AC-to-AC converter

摘要

A system and method for controlling switching in an AC-AC converter is disclosed. A controller for the AC-AC converter determines a direction of current flow on supply lines that provide AC power to the AC-AC converter and determines a switching pattern for each of a plurality of line-side switches and each of a plurality of floating-neutral side switches in the AC-AC converter based on the determined direction of current flow on each of the supply lines. The controller causes the line-side switches and the floating-neutral side switches to operate in an ON or OFF condition according to the determined switching pattern, such that a controlled current flow is output from the AC-AC converter. The controller also implements a safe-switching routine when transitioning from a first switching pattern to a second switching pattern that prevents a non-zero current from being interrupted during the transitioning between the first and second switching patterns.

主权项

1. A controller for an AC-AC converter to control current flows from an AC source to an AC load, the controller being programmed to:
determine a direction of current flow on each of one or more supply lines that provide AC power to the AC-AC converter, each supply line corresponding to a phase in the AC load; determine a switching pattern for each of a plurality of line-side switches and each of a plurality of floating-neutral side switches in the AC-AC converter based on the determined direction of current flow on each of the supply lines; cause each of the plurality of line-side switches and each of the plurality of floating-neutral side switches to operate in either an ON condition or an OFF condition according to the determined switching pattern, such that a controlled current flow is output from the AC-AC converter; and implement a safe-switching routine when transitioning from a first switching pattern to a second switching pattern, the safe-switching routine preventing a non-zero current from being interrupted during the transitioning from the first switching pattern to the second switching pattern.