On/off and FSK model transmitter-receiver for power system protection based on microprocessor

The authors present a new type of transmitter-receiver used in high-frequency protection, which is based on the micro digital signal processor MTS32020. The problems existing in the conventional transmitter-receiver are basically solved by taking advantage of the TMS32020´s strong function in digital signal processing in demodulating the medium frequency signal of the transmitter-receiver. The fast speed and the large quantity of information in digital processing of TMS32020 are utilized so that several new functions such as automatic diagnosis, digital display, timed transmitting and phase comparison in phase differential protection, etc. are incorporated into the new type transmitter-receiver. FSK mode (key-controlled frequency-shift mode) transmitter-receiver is implemented without any hardware change. The demodulating algorithms such as the FFT transform are discussed