High-voltage DC synchronous condenser start-up grid-connected control system and its control method

Abstract

The invention discloses a starting grid-connected control system and control method of a high-voltage DC synchronous phase modifier. The system comprises a starting control system, a grid-connected control system, a master control selector, an output control system and a high-voltage DC synchronous phase modifier main circuit, wherein the starting control system is used for outputting a starting voltage reference value of the synchronous phase modifier according to a starting initial voltage of the synchronous phase modifier, the grid-connected control system is used for outputting a power grid voltage control compensation value according to a power grid voltage reference value and a measurement value, the mater control selector is used for selecting the starting control system or the grid-connected control system as an input of the output control system according to a running state of the synchronous phase modifier main circuit, and the output control system is used for determining the input of the high-voltage DC synchronous phase modifier main circuit according to an output of the starting control system or the grid-connected control system so as to achieve starting and grid connection of the synchronous phase modifier. By the system, an impact current and an excitation surge current which are generated by the starting process of the synchronous phase modifier are reduced, and smooth starting and grid connection of the synchronous phase modifier are achieved.

Description

technical field [0001] The invention belongs to the start-up grid-connection control technology of high-voltage direct current synchronous condensers, in particular to a high-voltage direct current synchronous condenser start-up grid-connection control system and a control method based on sequence control. Background technique [0002] As a special synchronous motor, the synchronous condenser can not only provide reactive power compensation to the grid, but also absorb the excess reactive power of the grid, and has high application value in the fields of high-voltage direct current and ultra-high voltage direct current transmission. The synchronous condenser is a rotary dynamic reactive power compensation device. Large excitation inrush current and surge voltage are likely to occur during the grid connection process. If the grid connection control method is not appropriate, it will cause shocks at the grid connection point and the grid. Therefore, it is meaningful to design ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the start-up and grid-connected control of synchronous condensers, the existing schemes mainly have the following problems: 1) The sequence between the start-up control of the excitation system on the rotor side of the synchronous condenser and the grid-connected control of the excitation system is not clear, and the main The coordination relationship between the circuit and the control system will cause confusion in the control sequence and unclear control relationship, and it is prone to controller oscillation or control imbalance; 2) The initial voltage value of the excitation system startup control and the voltage rising slope setting value during startup are not clear and its specific calculation method; 3) There is no voltage matcher in the start-up control of the synchronous condenser, which is used to match the start-up control voltage of the excitation system with the actual voltage of the excitation system, which will cause obvious impulse voltage and excitation inrush current during the start-up process; 4) There is no synchronous condenser rotor delay unlocking control link, and the grid-connected control logic circuit has no P-I control tracker

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