Research On Cascade SVG Controller Simulation Modeling And Performance Test

SVG has become the development direction of modern reactive power compensation devices as a novel reactive power regulation device. Cascade structure SVG has many advantages:such as it has the advantage of small size and low cost without multiplex transformer; It can be easily modularized and has faster respond speed and low harmonics, it can implement individual phase control and so on.Firstly, this paper introduces the working principle of SVG briefly, established the mathematical model of cascade SVG under synchronous rotating coordinate system and completed the design work of lOkV/lOMvar cascade SVG. Secondly cascade SVG control strategy is researched and designed.component level control analyses in detail single pole double frequency carrier phase shifted sinusoidal pulse width modulation (CPS-SPWM) and bipolar CPS-SPWM, Comparative analysis concludes that the use of single pole double frequency CPS-SPWM modulation waveform is closer to a sine wave output with better characteristics to eliminate harmonics; device-level control uses direct current decoupling control strategy and three level control of voltage sharing; system-level control uses the constant reactive power control and constant voltage control. This paper analyzes the device features under capacitive and inductive conditions based on PSCAD/EMTDC simulation software, It concludes three-phase converter chain voltage is balanced, device side output voltage and current waveforms are good, dynamic response is faster, the transient process is relatively short, and it is error-free after becoming stable. Finally, based on real-time simulation software RTDS, this paper presents network testing technical solutions of a dynamic reactive power compensation device, develops detection platform for SVG dynamic reactive power compensation device and carrys out functional tests.