Research On Autonomous Triggering System For STATCOM

According to the requirements of Static Compensator (STATCOM) to triggering pulse generator, an autonomous triggering system for STATCOM was developed based on complex programmable logic device (CPLD).By analyzing the equivalent circuit of STATCOM, the basic requirements to the triggering system was pointed out, and the CPLD-based functional structure for triggering pulse generator was established. The system is composed of parallel microprocessor interface, SPWM generator, deadtime compensation module and pulse blocking module. The PWM pulse signal is automatically generated as soon as the control variables(S, X )input from microprocessor.The digital logic units of SPWM generator was designed with VHDL language and graphic editor under the developing environment of Max+PlusII. SPWM signal is produced by comparing sine waveform with triangular carrier waveform. The standard sine waveform is generated by looking up the sine table, and the triangular carrier waveform is produced by a reversible counter. Due to the symmetry of sine waveform, the logic resource of CPLD is saved greatly by a particular searching way of the sine table. Each logic module was verified by simulation.The logic design was realized in EPF10K30RC208 chip and a testing system for triggering pulse generator was developed. The experiment results indicated that the logic design is correct and the autonomous triggering system satisfiedthe requirements of STATCOM.