Method for starting high-voltage SVG and ice melting device with low impact current

Abstract

The invention relates to a method for starting a high-voltage SVG and ice melting device with low impact current. The method is characterized by comprising three stages of (1) an uncontrolled rectifying stage; (2) an active constant-power charging stage with a starting resistor; and (3) an active charging stage after bypassing a soft starting resistor. According to the method, the current limitingfunction of the starting resistor of a soft starting switch cabinet is fully utilized under the condition of not changing original hardware equipment, starting current impact of the high-voltage SVGand ice melting device is reduced, the starting time is shortened and the stability of a power grid is improved.

Description

Technical field [0001] The invention relates to the field of circuit devices of an AC power transmission and distribution network, in particular to a method for starting a high-voltage SVG and ice-melting device with low inrush current. Background technique [0002] The SVG and ice melting device can compensate the reactive power loss of the line under normal operating conditions, increase the line voltage, and perform timely reactive power adjustment in the case of system failures, thereby improving the stability of the transmission system. Maintain the user terminal voltage and strengthen the equipment voltage stability. Dynamically compensate system reactive power, improve power factor, reduce line loss, save energy and reduce consumption. Suppress voltage fluctuations and flicker. [0003] SVG and ice melting devices can currently be directly connected to the power grid on the 6 / 10 / 35kV bus, and are widely used in various applications such as substations, wind farms, solar po...

AI Technical Summary

Problems solved by technology

[0009] The above method mainly has the following defects: In the above startup process, the maximum voltage value (1.414×grid line voltage / (2N)) that can be charged by each module in the rectification stage is not controlled. At this time, the power module unit group can output The highest voltage is 0.866 times the grid voltage, and there is still a gap of {(1-0.866)×grid voltage} from the grid voltage. equipment adversely affected

For example, in a 10kV system, the resistance value of the reactor is 4mH. When the soft-start switch is closed, due to the existence of the pressure difference, the instantaneous impact current can reach 1000A, which will cause the switch protection to operate.

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