Current sharing control method for synchronously driving parallel-connection power module converter and current sharing controller

Abstract

The invention discloses a current sharing control method for synchronously driving a parallel-connection power module converter and a current sharing controller and relates to the field of power electronic power conversion. A software current sharing method is used for overcoming shortages in an existing parallel-connection converter hardware current sharing method. According to the technical scheme, the method comprises the steps that the step 11, average currents output by the converter and currents output by a power module are collected; the step 12, inductive current control processing is conducted on the average currents output by the converter and the current output by the power module, and therefore drive correction parameters are obtained; the step 13, time correction processing is conducted on the drive correction parameters and the currents output by the power module, and therefore drive correction time is obtained; the step 14, the duty ratio of a synchronous PWM drive signal of a master controller of the power module is corrected according to the drive correction time, and therefore a module drive signal of the power module is obtained; the step 15, the module drive signal is used for controlling a power unit of the power module, and therefore the currents output by the power module are adjusted.

Description

technical field [0001] The invention relates to the field of power electronic power conversion, in particular to a current sharing control method for MW-level parallel power module converters. Background technique [0002] Restricted by the withstand voltage, switching frequency and power level of power electronic devices, high-power converters mainly use the parallel connection of power modules to expand the power capacity. [0003] At present, there are two control modes for parallel connection of power modules: asynchronous drive type and synchronous drive type. MW level converters generally adopt synchronous drive. [0004] like figure 1 As mentioned above, the parallel converter includes a plurality of power modules connected in parallel, the current input terminals of each power module are connected together at the DC bus side, and the current output terminals of each power module are connected together at the load side. Each power module also has a signal connectio...

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Problems solved by technology

Those skilled in the art should know that if the hardware parameters of each power module are absolutely consistent, then the effect of automatic current sharing through the hardware system is very good, however, the stray characteristics of the electronic components inside the system will affect the current sharing effect of the power module , so that the output current of each power module is not the same. With the increase of the number of parallel power modules, the effect of hardware current sharing will become worse and worse, and even cause current sharing failure

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