Method for realizing insulation coordination of basic functional units of voltage source converter (VSC) based on half bridge circuit

Abstract

The invention relates to a method for realizing the insulation coordination of basic functional units of a voltage source converter (VSC) based on a half bridge circuit, which comprises the following steps of: 1) determining the insulation strength and properties of each component according to the steady-state over-voltage level, transient-state over-voltage level and transient over-voltage level of a sub-module under various operation conditions; 2) making equal the ground potential of a metal shell and a secondary control protection board of primary equipment and the potential of the cathode of the sub-module according to the potential distribution characteristics of the sub-module, and connecting the secondary control protection board and a primary circuit by using an isolation transformer to isolate the influence of the high voltage of the primary circuit on a secondary circuit; 3) shielding the electromagnetic interference of an insulated gate bipolar translator (IGBT) high speed switch in the secondary control protection board by using a metal shielding box according to the electromagnetic field distribution of the sub-module; 4) making equipotential an operating mechanism of a bypass switch and the cathode of the sub-module; and 5) selecting a high voltage wire as a wire crossing a high potential and a low potential to reduce the local discharge capacity of the sub-module. By the insulation coordination method, the insulation requirements of a system can be met, and high security and high economy are achieved.

Description

technical field [0001] The invention relates to a power electronic device, in particular to a basic functional unit for AC / DC conversion and power control based on an IGBT device for a power system. Background technique [0002] With the rapid development of power electronic devices, the voltage source converter technology (Voltage Source Converter, referred to as VSC) low-voltage system with fully controlled devices and pulse width modulation (Pulse Width Modulation, referred to as PWM) as the core technology has been widely used. However, the existing VSC technology is affected by devices and systems, and has no engineering applications in high-voltage and high-power fields such as island power supply, offshore drilling platform power supply, weak AC system interconnection, and wind power grid connection. The new VSC topology and modulation technology is to solve this problem. The key to the bottleneck. [0003] The present invention relates to the insulation coordination...

AI Technical Summary

Problems solved by technology

However, VSC based on multi-level technology is in the theoretical research stage at home and abroad, and has no experience in power system operation.

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