500kV voltage class four-thirds wiring hydropower station black-start system and method

Abstract

The invention discloses a 500kV voltage class four-thirds wiring hydropower station black-start system and method. The system mainly comprises a diesel generator, a hydro-generator, a boosting transformer, a first 500kV line and a second 500kV line, wherein the first 500kV line and the second 500kV line are connected into a four-thirds wiring; a generator-transformer line self-excitation test is carried out, the hidden danger of starting self-excitation oscillation is eliminated, the overvoltage multiple of a line is determined by using a diesel generator, a reference is provided for the voltage limitation of the high-voltage side of a black-start boosting transformer,the hydro-generator is started by the diesel generator, the hydro-generator is provided with a boosting transformer to charge a circuit, and the operation of the factory 10kV bus load island of the water turbine is recovered. According to the method, the black start safety and controllability are improved from multiple aspects of setting a standby power supply of the diesel generator, modifying an overvoltage constant value, modifying a low excitation limit constant value, adopting automatic excitation AVR control, inputting a black start pressing plate, performing single-side non-voltage closing on a grid-connected switch, reasonably simplifying the switch and disconnecting link operation and the like, and the black start time is saved.

Description

technical field [0001] The invention belongs to the technical field of black start of hydropower stations, and in particular relates to a black start system and method of a 500kV voltage level four-thirds connection hydropower station. Background technique [0002] Black start means that after an extreme fault occurs in the grid and the entire grid loses power, power plants with self-starting capabilities take the lead in supplying power, and gradually expand the scope of power supply until the normal operation of the entire grid is restored. Black start, as the security guard of power grids in various countries, can reduce power outage losses caused by major natural disasters. Many black start cases at home and abroad show that black start is of great significance to power grid and national security. In order to ensure the safe and stable operation of the power grid and standardize the operation and management of black start equipment, the power grid has successively issued...

AI Technical Summary

Problems solved by technology

[0003] The following defects and deficiencies of the existing black start technology: (1) The self-excitation judgment of the black start of the generator and the step-up transformer with the line mostly adopts the theoretical analysis method, and the self-excitation judgment needs to be judged from the perspective of the actual test. The actual test can judge the self-excitation more accurately. Excitation phenomenon; (2) The overvoltage multiples at the first and last ends of the black start line are mostly calculated through the line distribution parameters, and then the voltage on the high voltage side of the step-up transformer is determined according to the maximum allowable operating voltage at the end of the line. , the actual measurement is more accurate than the theoretical calculation result; (3) the overvoltage setting value of the generator is not adjusted during the common hydropower black start, and the excitation system usually adopts a manual method when charging the line, and the voltage of the generator is built to the rated voltage. After the grid switch, a large amount of capacitive current in the line causes the voltage to exceed the rated value, and the grid-connected signal is manually released to the signal of the excitation system and the speed control system, and the grid-connected switch is closed by manual short circuit, which reduces the safety of black start

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