Active modular converter test system and control method

Abstract

The invention provides an active modular converter test system, which comprises an electric reactor, an external AC power supply and two converter chains. One end of the first converter chain is connected with one end of the second converter chain through the electric reactor, the connection point is defined as a first connection point, the other ends of the two converter chains are directly connected, and the connection point is defined as a second connection point; the first connection point and the second connection point are respectively connected to two ends of the external AC power supply; each of the first converter chain and the second converter chain comprises at least one sub-module; each sub-module comprises an energy storage unit, a power unit and a sub-module control unit; the power unit comprises a full-bridge circuit consisting of a direct-current capacitor and four power semiconductor switching devices; the direct current side of the power unit is connected with the energy storage unit, and the alternating current side of the power unit is connected with a bypass switch in parallel; and the sub-module control unit takes energy from the direct-current capacitor. The scheme can simulate real working conditions on site, and is low in required power, low in scheme cost and high in reliability.

Description

technical field [0001] The application relates to the technical field of high-power power electronic conversion, and in particular to an active modular converter test system and a control method. Background technique [0002] In the field of large-capacity and high-power power electronic conversion technology, multi-level converters use modular cascade technology to integrate energy storage units into sub-modules, which have high modularity, good harmonic characteristics, and equivalent switching frequency. Low-level advantages, it has become the standard topology in the field of high-voltage power electronics. By integrating the energy storage unit as a sub-module in a modular multilevel converter, AC-DC power conversion and energy storage can be realized simultaneously. [0003] The resulting active modular converter is a feasible solution that can effectively meet the access requirements of energy storage systems and alleviate or isolate fault propagation between AC and ...

AI Technical Summary

Problems solved by technology

Since the active modular converter integrates the energy storage unit, when testing it, not only the power unit but also the energy storage unit must be able to verify whether it can work normally, and the energy storage unit needs to be charged and discharged. And it has a continuous energy source or energy release path; on the other hand, before the start of the test, the premise for the device to start is that the control unit of the sub-module can obtain energy. When it is applied to the actual system, it can be charged through the grid power supply The circuit supplies energy for the DC capacitor of the sub-module. This method is expensive to obtain energy, and it is not easy to construct the circuit during in-factory tests; low-cost test plan

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