Isolated high-voltage DC/AC converter and wide-range voltage modulation control method thereof

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 is suitable for application occasions of high-voltage direct current to high-voltage alternating current conversion. Background technique [0002] In the occasion 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 facing researchers. 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 a bottleneck, the problem can only be solved by optimizing the topology and control methods. Ther...

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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