Method for achieving arc suppression coil function by using high-voltage cascading type SVG

Abstract

The invention discloses a method for achieving an arc suppression coil function by using a high-voltage cascading type SVG. The method includes the steps of 1) monitoring whether a system runs normally or not, 2) when the system runs normally, starting a reactive compensation mode and a harmonic suppression function mode, controlling a cascading type SVG converter to perform system reactive compensation and harmonic cancellation, meanwhile, monitoring bus voltage, judging whether a neutral point of the bus voltage deviates and generates zero-sequence voltage or not, if the neutral point of the bus voltage deviates and generates the zero-sequence voltage, executing the step 3), and otherwise, keeping the current operation state, 3) starting an arc suppression coil function mode, controlling the cascading type SVG converter to compensate ungrounded phase grounding capacitive current, and meanwhile monitoring the bus voltage, judging whether deviation and the zero-sequence voltage of the neutral point of the bus voltage disappear or not, if deviation and the zero-sequence voltage of the neutral point of the bus voltage disappear, executing the step 2), and otherwise keeping the current operation state. The method has the advantages of being simple to achieve and capable of adjusting automatically, having the dual function modes, and being flexible in mode conversion.

Description

technical field [0001] The invention mainly relates to the field of neutral point ungrounded systems, in particular to a method for realizing the function of an arc suppression coil by using a high-voltage cascaded SVG in a neutral point ungrounded system. Background technique [0002] Reactive power and harmonic current problems are common in 35kV and below neutral point non-directly grounded systems, which are generally equipped with various types of control devices, typically including active var generators (SVG) and dynamic var compensation devices (SVC), capacitance compensation device (FC), etc. With the development of technology, SVG devices in the small and medium capacity range have been widely used due to their superior performance and convenient construction. In addition, most of the power supply lines of systems below 35kV whose neutral point is not directly grounded are cables, and have a large ground capacitance. When a single-phase ground fault occurs, the gr...

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