M and delta comprehensive optimization control method applicable to SVG

Abstract

The invention discloses an M and delta comprehensive optimization control method applicable to an SVG. The M and delta comprehensive optimization control method comprises the steps of obtaining a function relationship form among a current output by the SVG, the delta and the M on the premise of maintaining udc to be constant, obtaining the current which should be output by the SVG according to real-time extraction of a three-phase power grid phase current, and using the current output by the SVG as a control target current reference value; selecting the M and the delta corresponding to the control target current reference value in the function relationship form to adjust and control the current output by the SVG; when the current output by the SVG reaches the reserved proportion of the control target current reference value, conducting fine tuning on the delta and the M according to u*cd and u*cq. According to the M and delta comprehensive optimization control method, the dynamic performance of the SVG is remarkably improved, the step response time of the SVG is greatly shortened, the overshoot of an offset current obtained when an idle jumping is output is greatly reduced, the stabilization response time of the SVG is shortened, the margin of a device and a power device can be reduced, the cost of the device is reduced, and the comprehensive performance of the SVG is remarkably improved.

Description

technical field [0001] The invention relates to the technical field of high-voltage power electronic conversion, and more specifically relates to an M and δ comprehensive optimization control method suitable for SVG, which is suitable for implementing high-performance harmonic suppression and reactive power compensation for power grids. Background technique [0002] With the rapid development of modern industry, nonlinear impact loads such as high-power power electronic devices, metallurgical arc furnaces and rolling mills have been widely used, and the rapid development of grid-connected renewable energy power generation has brought more and more power to the grid. The more serious the problem of reactive power and harmonic pollution, the voltage fluctuation and waveform distortion of the power grid will lead to the degradation of power quality and threaten the safety of the power grid. Therefore, the Flexible AC Transmission System (FACTS) is of great significance to the d...

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Problems solved by technology

[0013] a). Large-capacity impact loads often cause grid voltage flicker, which requires SVG to have good dynamic performance, and because the existing control methods need to adjust the output reactive power of SVG at the same time. The capacitor voltage udc on the DC side of each link unit, because the capacitor voltage cannot be mutated, the dynamic performance of the SVG is poor, the step response time of the device is too long, and the dynamic compensation performance becomes poor; it affects the dynamic compensation capability of the SVG

[0014] b). Also due to the defects and deficiencies of the existing control methods, when the output reactive power jumps, the compensation current will overshoot, and the stabilization time of the device will be too long, which will reduce its reliability, and it is necessary to increase the residual power of power devices and devices amount, increase the cost of the device, and impact the power grid at the same time

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