Application of virtual instrument to SVC control system

ZHANG Shu， WANG Yi-fan， CHEN Guo-zhu
（College of Electrical Engineering， Zhejiang University， Hangzhou 310007， China）

Abstract： In order to solve the problems that the traditional static var compensator（SVC） control system is complicated in structure，lack of agility，and highly dependent on hardware，the virtual instrument technology was applied to the SVC control system. The thyristor control reactor（TCR）mathematical model was analyzed and established. Based on LabWindows/CVI development platform and made use of interactive development technology and ANSI C programming language，the TCR control system was designed and realized， which was used for the 90 kvar/380 V TCR reactive power compensation device. Load current and voltage was sampled，and the reactive power for compensation was calculated by FFT algorithm. The corresponding thyristor conduction angle was calculated by industrial personal computer（IPC），and the corresponding trigger impulse was output to adjust TCR reactive power compensation quantity. The operation results indicate that TCR controller based on the virtual instrument technology can detect power grid parameters in real time，and accurately compensate for the reactive power in a period with high agility and reliability，which fully reflects the advantages of the virtual instrument technology.
Key words： transmission systems； virtual instrument（VI）； static var compensator（SVC）； LabWindows/CVI； interpolated FFT； harmonic measurement