Small-impact-current low-voltage current converter soft-starting control method

Abstract

The invention discloses a small-impact-current low-voltage current converter soft-starting control method. The method is suitable for a small-impact-current low-voltage current converter soft-starting circuit, which is formed by a DC side soft-starting resistor; a switch device IGBT connected in series with the soft-starting resistor; and a single-pole DC circuit breaker connected in parallel with a series branch formed by the soft-starting resistor and the IGBT to serve as a by-pass switch. The circuit is connected between a DC bus and a DC capacitor to form a small-impact-current soft-starting loop of the device. Through the method above, the three-phase current converter can finish the soft-starting process quickly, and meanwhile, impact of the current converter to an AC system and the device of the current converter itself in the soft-starting process can be further reduced; and operation safety of the device is protected, and meanwhile, influence of the device on the system in the soft-starting is reduced.

Description

technical field [0001] The invention relates to the technical field of application of low-voltage converters based on electric power technology, in particular to a soft-start control method for low-voltage converters with small inrush currents. Background technique [0002] In recent years, with the rapid development of power electronics technology, power electronic equipment based on switching devices such as insulated gate bipolar transistors (IGBTs) are widely used in uninterruptible power supplies, frequency conversion speed regulation, dynamic reactive power compensation, power quality management, Electric vehicles, new energy access and other fields. In the low-voltage three-phase power distribution system, the three-phase two-level voltage source converter topology, as the most typical circuit topology, has been widely used in various power electronic technology applications. For example, three-phase inverters applied to motor speed regulation, static var generator...

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Problems solved by technology

[0005] Based on the above circuit, if the conventional soft-start method of the common three-phase two-level converter is still adopted, the soft-start circuit of the low-impact current and low-voltage converter proposed by the present invention still cannot achieve the design goal, and the soft-start circuit of the converter can be reduced. The current impact on the system and the components of the equipment itself during the start-up process will even cause the inverter to fail to reach the DC voltage required for work, directly affecting the normal operation of the inverter

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