Patent ID: 9614457
Date: 2017-04-04
CPC Classifications: H02M

Claim:
1. A power conversion apparatus for controllably converting alternating current (AC) to direct current (DC), the power conversion apparatus comprising: a plurality of AC sources galvanically isolated from one another; a plurality of bridge rectifier circuits, including one or more controllable bridge rectifier circuits, wherein each of the plurality of bridge rectifier circuits has respective AC-side terminals and DC-side terminals and each of the plurality of bridge rectifier circuits is connected to a corresponding one of the plurality of AC sources via each bridge rectifier circuit at respective AC-side terminals, and wherein the DC-side terminals are connected so that outputs of the plurality of bridge rectifier circuits are combined in series; and a control circuit configured to individually control each of the one or more controllable bridge rectifier circuits to selectively operate in (i) a regulator mode, whereby a non-zero voltage less than or equal to a maximum rectifier voltage is provided by the DC-side terminals of each of the one or more controllable bridge rectifier circuits, and (ii) a bypass mode, whereby each of the one or more controllable bridge rectifier circuits provides a nominally zero voltage to the DC-side terminals of the one or more controllable bridge rectifier circuits and draws a nominally zero current from the corresponding one of the plurality of AC sources connected to the controllable bridge rectifier circuits, even while one or more of the plurality of bridge rectifier circuits are operating in regulator mode; wherein the plurality of bridge rectifier circuits includes at least two controllable bridge rectifier circuits, wherein the regulator mode for each of the at least two controllable bridge rectifier circuits comprises a voltage regulating mode and a full output mode, and wherein the control circuit is configured to control the at least two controllable bridge rectifier circuits so that only one of the controllable bridge rectifier circuits is operating in voltage regulating mode at any given time, while each of the remaining controllable bridge rectifier circuits is operating in either bypass mode or full output mode.