Method and device for eliminating generator neutral point circuit resonance during start-up of gas turbine power plant

Abstract

The invention relates to a method of eliminating generator neutral point circuit resonance and a device of eliminating the generator neutral point circuit resonance in the process of gas turbine power plant starting. The method of eliminating the generator neutral point circuit resonance and the device of eliminating the generator neutral point circuit resonance in the process of the gas turbine power plant starting is characterized in that a circuit resistance is added in a generator neutral point circuit, and particularly a resonance eliminating device is in serial connection with an LC serial resonance circuit of a generator neutral point to prevent the resonance from occurring in an energy absorbing mode; the device of eliminating the generator neutral point circuit resonance in the process of the gas turbine power plant starting comprises a vacuum contactor (1-2) and two resonance eliminating devices (1-1), one input end of one of the two resonance eliminating devices is connected with a neutral point of one generator to form a first resonance eliminating circuit, and one input end of the other one of the two resonance eliminating devices is connected with a neutral point of the other generator to form a second resonance eliminating circuit; and a normally open contact of the vacuum contactor (1-2) is connected to the two ends of the two resonance eliminating devices, and a normally closed contact of the vacuum contactor (1-2) is connected to a generator neutral point circuit knife switch to form a generator neutral point circuit knife switch linkage structure. The method of eliminating the generator neutral point circuit resonance and the device of eliminating the generator neutral point circuit resonance in the process of the gas turbine power plant starting have the advantages of being capable of eliminating or damping ferromagnetic resonance caused by a voltage transformer, avoided in internal and external insulation breakdown of the voltage transformer and discharge, simple in structure, capable of automatic switching, and safe and reliable.

Description

technical field [0001] The invention relates to a method and a device for eliminating the resonance of a neutral point circuit of a generator during the start-up process of a gas turbine power plant. It belongs to the technical field of power generation industrial equipment. Background technique [0002] Large-scale gas-fired power plants are new enterprises in my country, and there is no mature experience in their design and installation in my country. The design and installation of many auxiliary equipment are carried out with reference to traditional coal-fired power plants. Among them, the design of the coal-fired power plant is directly adopted in the neutral point circuit of the generator. In a traditional coal-fired power plant, the frequency of the generator is a constant 50Hz. In the LNG peak-shaving power plant, since the SFC is a static frequency conversion device, the gas turbine starts by using a variable frequency motor to run steplessly variable speed. When...

AI Technical Summary

Problems solved by technology

Due to the strong penetrating ability of high-order harmonics, it is very destructive, causing periodic speed changes and vibrations of the motor, affecting output efficiency and emitting noise

In addition, the copper loss and iron loss of the engine will increase, and even overheating will occur, shortening the service life

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