A method for starting a high-voltage svg and ice-melting device with low inrush current

Abstract

The invention relates to a starting method of a high-voltage SVG and ice-melting device with low impact current. It is characterized in that it includes three stages: 1) uncontrolled rectification charging stage, 2) active constant power charging stage with a starting resistor, and 3) entering the active charging stage after bypassing the soft-starting resistor. Without changing the original hardware equipment, the present invention makes full use of the current-limiting function of the starting resistor of the soft-start switchgear, reduces the impact of the starting current of the high-voltage SVG and ice-melting device, reduces the starting time, and improves the stability of the power grid .

Description

technical field [0001] The invention relates to the field of circuit devices for AC power transmission and distribution networks, in particular to a starting method for 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 operation, increase the line voltage, and perform timely reactive power adjustment in the event of a system failure to improve the stability of the transmission system. Maintain the voltage at the user end and strengthen the voltage stability of the equipment. Dynamically compensate system reactive power, improve power factor, reduce line loss, save energy and reduce consumption. Suppresses voltage fluctuations and flicker. [0003] The SVG and ice-melting device can be directly connected to the power grid on the 6 / 10 / 35kV bus, and is widely used in various application places such as substations, wind farms, solar powe...

AI Technical Summary

Problems solved by technology

[0009] The above-mentioned method mainly has the following defects: in the above-mentioned start-up process, the maximum voltage value (1.414×grid line voltage / (2N)) that can be charged by each module in the stage of uncontrolled rectification and charging, 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. Devices on the network adversely affect

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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