An isolated high-voltage dc/ac converter and its wide-range voltage regulation control method

Abstract

The invention discloses an isolated high-voltage DC / AC converter and a wide-range voltage modulation control method thereof. The isolated high-voltage DC / AC converter comprises a plurality of series-connected modules, wherein each module comprises a half-bridge structure converter, an H-bridge inverter and an output isolation transformer which are sequentially connected, a high-voltage DC voltageis connected to input ends of the plurality of series-connected modules, an AC voltage is output to be connected to two ends of a single-phase load by an LC filter after all transformers of the plurality of modules are connected in series, each half-bridge structure converter comprises a capacitor, the capacitor is connected in parallel with a series branch formed by connecting two isolated gate bipolar transistors (IGBTs) in series, the H-bridge inverter comprises a first IGBT, a second IGBT, a third IGBT and a fourth IGBT, each IGBT is reversely connected in parallel with a diode, the firstIGBT and the second IGBT are connected in series, and the third IGBT and the fourth IGBT are connected in series. By the isolated high-voltage DC / AC converter, the voltage of each sub-module can be stabilized to be an expected voltage, and the voltage stabilization effect is good.

Description

technical field [0001] The invention relates to an isolated high-voltage DC / AC converter and a wide-range voltage regulation control method thereof, which are suitable for the application occasion of high-voltage direct current to high-voltage alternating current conversion. Background technique [0002] In the case of high-power DC / AC conversion, limited by the development level of a single switching device, how to choose a suitable high-voltage switching device is one of the challenges that researchers are currently facing. For example, in my country's ship power supply system, 850-1250V DC power supply is generally used, and the power supply DC bus in the high-speed electrified railway power supply system is as high as 2160-2600V. Such high-voltage applications make the selection of switching devices limited and expensive. Since the performance level of power electronic switching devices has reached the bottleneck, the problem can only be solved by optimizing the topology...

AI Technical Summary

Problems solved by technology

Among them, the full-bridge isolation topology used in DC-DC conversion requires 4 IGBT devices and 4 fast recovery diodes, a total of 8 devices, which increases the switching loss and device cost of DC-DC conversion.

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