High frequency isolation cascade AC excitation device for variable-speed pumped storage power generation system

Abstract

The invention relates to the pumped storage power generation field, and specifically relates to a high frequency isolation cascade AC excitation device for a variable-speed pumped storage power generation system. The high frequency isolation cascade AC excitation device comprises a rotor side grid connected switch module, a transformer module and a three phase cascade type isolation double back-to-back H bridge module, wherein the rotor side grid connected switch module is connected with the transformer module; and the transformer module is connected with the three phase cascade type isolation double back-to-back H bridge module. The high frequency isolation cascade AC excitation device for a variable-speed pumped storage power generation system has a frequency conversion operation capability and can satisfy the excitation requirement for speed change operation of a pumped storage generator set. The high frequency isolation cascade AC excitation device for a variable-speed pumped storage power generation system has a bidirectional energy flowing capability, and can satisfy the excitation requirement for generating condition and electric condition operation for the pumped storage generator set. The high frequency isolation cascade AC excitation device for a variable-speed pumped storage power generation system has a cascade feature, and can realize access of the high voltage grade of an AC excitation current transformer while avoid using a special high overpressure resistant semiconductor switch device.

Description

technical field [0001] The invention relates to the field of pumped storage power generation, in particular to a high-frequency isolated cascaded AC excitation device for a variable-speed pumped storage power generation system. Background technique [0002] The pumped storage power station has the characteristics of fast start-up and flexible operation, and can undertake tasks such as valley filling, peak regulation, frequency regulation, phase regulation and emergency backup in the system. The traditional motor-generator set adopts the traditional synchronous generator with DC excitation, which is difficult to adjust the speed and has poor operating characteristics. In addition, it is difficult to start when this type of unit is running in the electric state. The use of AC excitation generators powered by AC excitation devices to replace traditional motor-generator sets can effectively solve the problems of speed regulation or variable speed operation of hydro-generators in...

AI Technical Summary

Problems solved by technology

In the traditional cascaded H-bridge topology, special multi-winding power frequency transformers are mostly used to realize bus isolation and circulation simulation, but the high cost and bulky multi-winding power frequency transformers with large capacity are the disadvantages of this solution

In addition, traditional frequency conversion speed regulation applications generally require energy to flow in one direction, that is, to realize motor dragging, and energy feedback cannot be realized, which determines that the current cascaded H-bridge topology mostly adopts an uncontrolled rectification topology at the grid-connected end

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