A Chain Statcom DC Total Voltage Control Method with Voltage Ride Through Capability

Abstract

The invention discloses a chain-type STATCOM DC total voltage control method having voltage ride-through capability. The chain-type STATCOM DC total voltage control method comprises the steps of calculating a current system linear voltage value according to a voltage instantaneous value of a three-phase system; adjusting a DC total voltage control target given value U<dc><*> and a reference dispatching value M<base> in real time according to the system linear voltage value; performing control by employing an automatic regulator and combining the DC total voltage of each phase power unit to obtain three phase control adjustment quantity dMa, dMb and dMc; acquiring three phase DC total voltage control instantaneous instruction values iMa, iMb and iMc by combining the reference dispatching value M<base> and a lock phase angle; and finally, obtaining a switch control signal of the unit power by employing a modulation technology so as to achieve voltage ride-through and DC total voltage control. By the method, the problem of voltage ride-through of STATCOM equipment is solved, meanwhile, the response time of the equipment can be further increased, the reliability of the whole machine isfavorably improved, and the application range is expanded.

Description

technical field [0001] The invention relates to a chained STATCOM direct current total voltage control method. Background technique [0002] Static synchronous compensator (STATCOM) is a dynamic compensation and treatment device for power quality problems based on power electronic switching devices. As a fourth-generation compensation device, it represents the development direction of dynamic compensation for power quality problems. Static synchronous compensator (STATCOM) is mainly used in power system transmission and distribution substations, new energy industries (photovoltaic power stations, wind farms), iron and steel metallurgy industry, coal industry, submerged arc furnace industry, electrolysis industry, petrochemical industry, port, shipbuilding industry , rail transit industry, electric vehicle charging industry, etc. [0003] High-voltage STATCOM usually adopts a chain topology. The DC capacitors of this structure are independent of each other, and the control o...

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Problems solved by technology

[0005] For photovoltaic farms, wind farms, steel mills and other occasions where the voltage is prone to sudden changes, when the control of the compensation equipment is difficult to respond to voltage changes in a timely manner and adjust the control strategy, it will cause STATCOM overcurrent, tripping, etc., and cannot fully utilize STATCOM to provide continuous wireless The role of power to support voltage, such occasions require equipment to have high and low voltage ride-through capabilities, especially low voltage ride-through capabilities

There is a fuzzy PI control outer loop voltage through parameter self-tuning to deal with the voltage drop problem and improve equipment stability and anti-disturbance performance. This method only enhances the stability of the control, and does not improve the fast tracking of voltage changes and fast response control. Does not enable the compensation equipment to have voltage ride-through capability

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