Topology and control method of cascaded full-bridge multilevel converter with self-balancing characteristics

Abstract

The invention discloses a cascaded full-bridge multilevel converter topology with self-balancing characteristics. By adding a pair of auxiliary switching devices between two adjacent full-bridge modules, two adjacent full-bridge modules can be realized. The parallel operation of the bridge modules realizes the automatic equalization of the capacitor voltage between the parallel full bridge modules. Compared with the traditional cascaded full-bridge multi-level converter topology, the cascaded full-bridge multi-level converter topology with self-balancing characteristics connects the originally removed modules in parallel with other input modules to achieve Realize the automatic balance of all sub-module capacitor voltages. This topology does not need to add an additional voltage equalization control strategy, so it saves a large number of sub-module capacitive voltage sensors, and also reduces the complexity of the controller algorithm.

Description

Technical field [0001] The present invention relates to a grade bridge multi-substrate transformer topology, and more particularly to a cascaded full bridge multi-substantifier topology and a control method having self-pressure characteristics. Background technique [0002] The sub-module capacitance of the existing grade line bridge multi-electricity converter topology is independent, in order to ensure the same electrical stress in the waveform quality and module of the AC side voltage output, the sub-module capacitive voltage needs to be on the bridge arm Keeping a balance under the periodic action of the current. At present, the balance of capacitive voltage is mainly based on the agency control, and the complexity of the actions control algorithm is directly affected by the number of sub-modules. As the number of sub-modules increases, the amount of pressure control pair the controller, data acquisition speed And accuracy and other requirements become very high. Although man...

AI Technical Summary

Problems solved by technology

Although many literatures have optimized and improved the voltage equalization control algorithm, as the system voltage level and capacity increase, the voltage equalization control algorithm is still limited by the controller.

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