Voltage vector stabilizer based on phase-locked loop and control method of voltage vector stabilizer

Abstract

The invention discloses a voltage vector stabilizer based on a phase-locked loop and a control method of the voltage vector stabilizer. Power exchange between the voltage vector stabilizer and a connected grid site is controlled through control over the change speed of an internal electric potential vector of the voltage vector stabilizer along with a voltage vector of the connected grid site for the purpose of lowering the change rate of the voltage vector of a new energy power plant in a weak power grid or the change rate of the voltage vector of the connected grid site with a sensitive load, helping the voltage vector of the connected grid site to be stable, and helping an electric power system to run stably. When phase disturbance or frequency disturbance happens to voltage, the voltage vector stabilizer provides active power support so as to lower the change speed of a phase or frequency of the voltage. When amplitude disturbance happens to the voltage, the voltage vector stabilizer provides reactive power support so as to lower the change speed of an amplitude value of the voltage. By means of the voltage vector stabilizer based on the phase-locked loop and the control method of the voltage vector stabilizer, the stability of grid-connected operation of new energy power generation can be improved, and the power supply quality of the sensitive load can be improved.

Description

technical field [0001] The invention belongs to the field of new energy grid-connected stability control, and more specifically relates to a voltage vector stabilizer based on a phase-locked loop and a control method thereof. Background technique [0002] When the grid strength is weak, the grid voltage vector (including amplitude and phase) is easily disturbed and changes rapidly. In recent years, with the rapid development of new energy power plants (mainly including wind power plants and photovoltaic power plants), their installed capacity has been rising steadily, which has changed the pattern that the power source in the traditional power system is only composed of a single synchronous generator. New energy power generation The stability of the grid is directly related to the security and stability of the power grid. Due to the characteristics of China's resources and the reverse distribution of loads, China's new energy power plants mainly adopt a development model of...

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Problems solved by technology

[0004] In view of the defects of the prior art, the purpose of the present invention is to suppress the voltage vector change rate of the power grid, especially the weak grid, and to solve the problem that the phase and amplitude of the voltage vector of the grid-connected point (or sensitive load) of the new energy power plant are easy to fluctuate, resulting in Its output (input) power is unstable, which in turn causes the problem of unstable power system

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