Synchronous condenser start-up grid-connected circuit and control method based on sequential hybrid excitation control

Abstract

The invention discloses a synchronous condenser start-up grid-connected circuit and a control method based on time-sequence hybrid excitation control. , excitation system and static inverter, where the AC outlet of the synchronous condenser is connected to a three-phase AC transformer, the other side of the three-phase AC transformer is connected to the main AC circuit breaker at the machine end, and the other side of the main AC circuit breaker at the machine end is connected to the AC power grid , the static inverter is connected in parallel with the main AC circuit breaker at the machine end through the auxiliary AC circuit breaker at the machine end. The method adopts the subsection control method to optimize the voltage rise curve of the synchronous condenser in the grid-connected deceleration stage, eliminate the voltage impact, reduce the excitation inrush current, and realize the smooth start-up and grid-connection of the synchronous condenser. The control method of the invention has low complexity and is easy to implement, and is also applicable to the starting control of synchronous motors and asynchronous motors.

Description

technical field [0001] The invention relates to a start-up control technology of a synchronous condenser, in particular to a start-up grid-connected circuit and a control method for a synchronous condenser based on sequential hybrid excitation control. Background technique [0002] Synchronous condenser is a common reactive power compensation equipment. As a rotating motor, the synchronous condenser can increase the inertia of the power system after being connected, so it is widely used in the field of high-voltage direct current transmission. However, the operation and maintenance of the synchronous condenser is more complicated than that of the static var compensation equipment. It is likely that a large excitation inrush current and surge voltage will occur during the start-up grid connection process. If the start-up control method is improper, it will cause an impact on the power grid. Therefore, it is meaningful to design a suitable start-up grid-connection circuit and...

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Problems solved by technology

[0003] Aiming at the start-up grid connection control problem of synchronous condensers, the existing schemes mainly have the following problems: 1) The voltage setting value of the excitation system is always kept at the rated value or changes from zero to the rated value when the start-up command is issued, and the excitation system is not clearly defined. The specific calculation method of the voltage setting value, which will cause obvious impulse voltage and excitation inrush current during the start-up process; 2) At the moment when the AC circuit breaker at the synchronous camera terminal is closed, there will be obvious impulse voltage and excitation inrush current at the grid connection point; 3) There is no specific method to clearly limit the surge voltage and excitation inrush current at the grid-connected point

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