The Design Of Communication-Modulation Unit In PEBB And Its Realization

The distributed conversion system based on PEBB not only simplifies the system design,reduce the design difficulty,but also solve the inherent weakness of traditional inverter.New control system communicate each module by high speed network,each module complete fault,protection,sampling and power unit drivers by itself.Communication network and modulation are the core function of PEBB,PEBB scatter bridge arms to each module and coordinate with others by communication network,cause converter is real-time control system so the converter communication network should be fast and high-capacity which traditional industrial control bus can't fit all the requirement;In the study of two-level PEBB the modulation algorithm is finish by MCU(Master Control Unit)only transport duty-ratio to PEBB but in high-power invertor which adopts multilevel inverter output technology and space vector pulse width modulation(SVPWM)algorithm to obtain better performance,still using two-level's modulation method for PEBB system will spend many CPU resource during real-time control and difficult to modulate multiple unit in multilevel drive system.In order to make PEBB suitable for three level(or more)converter and multilevel drive system,this article design an integrated unit with high-speed communication network and three-level SVPWM modulation based on FPGA,which can be a standard interface between the MCU and the main circuit of PEBB,with g-h coordinate three-level SVPWM make it easy to calculate and modulate.Three experiment shows that the unit work correct.