USB Based Simulation And Measurement For Excitation System Of Synchronous Generator

The excitation regulator is one of the most important control devices in power system. Its performance not only directly influences the generator's operation, but also has effect on the stability of the electric power system. There isn't a convenient and economical instrument to test its performance for a long time.Based on digital signal processing technology, an instrument for simulation and measurement of the synchronous generator excitation system is proposed in this paper. It can test excitation regulator's performance easily, and can make a close loop to simulate the excitation system's running only by itself. The system uses USB interface substituting RS-232C to get a higher data transmit rate.The mathematic models for each excitation subsystem are presented first. Then USB communication protocol is expatiated. After that, USB based excitation simulation and measurement system is described in detail. The system consists of two parts: simulation and testing instrument and central maintenance platform. The instrument is based on 32 bits float digital signal processor TMS320C32.Its main functions include: data acquisition, real-time calculation and simulating outputs. The maintenance platform is based on a personal computer and Windows operating system, it displays waves,calculates performance indices, manages different types of testing and implements man-machine interfaces.The simulation and testing instrument expands communication interface with PDIUSBD12 which is provided by Philips Semiconductor Corporation. Combined with the simulation and measurement system design requirements, USB hardware, firmware, device's driver and communication application are presented.Test results demonstrate that a high transfer rate can be got with USB, the excitation system can be well simulated and measured with the proposed system, the cost of testing is reduced and the burden of engineers is freed.