高压电力线路相位无线检测仪的设计

为了检测高压电力线路不同相间的电压相位差,设计了一种根据法拉第电磁感应定律利用限幅电路实现电力线路电压相位信号采集的新检测仪,该检测仪由两个发送装置和一个接收装置组成,发送装置将采集的电压相位信号通过ASK调制电路调制后发送到接收装置,接收装置将接收到的两路电压相位信号解调后分别送到FP-GA,从而实现高压电力线路不同相间电压的相位差和相序的采集。实践证明,该方法使高压电力线路电压的相位差和相序的检测更为方便、安全。

Design of Wireless Phase Detector for High Voltage Transmission Lines

In order to detect the phase difference of high voltage transmission lines, this paper presents a new method for wireless detection of high voltage phase based on the law of electromagnetic induction. Using the new method, a wireless phase detector is designed and consists of two transmit devices and a receive device. In the transmit devices the phase signals of high voltage transmission lines are collected by electromagnetic coupling circuit and cut-ridge circuit. Then the phase signals are modulated by ASK modulate circuit and sent to the receive device in different frequencies. The receive device is portable and equipped with LCD. In the receive device, the phase signals of high voltage from the transmit devices are demodulated and sent to FPGA circuit. In the FPGA circuit the collection of phase difference and phase sequence for high voltage transmission lines is achieved. Then the measurement results are sent to the display circuit. The value of phase difference and wave graph of phase sequence can be directly displayed in the LCD. At the same time, the transmit devices can generate power frequency voltage signals which can be controlled by hand buttons. The power frequency voltage signals are mainly used to simulate the voltage signals of electric power lines when the detector is self inspecting. Only after successful self inspection which indicates the normal communication between the transmit devices and the receive device, the detector can measure the phases accurately. In the design of the detector, the disturbance of magnetic field can be successfully avoided through several kinds of measures such as electromagnetic screen, the adjustment of coupling capacitance, the reduction of ground circumfluent areas and high frequency transmission to avoid the high noise voltage. This method can result in reliable, convenient and secure detection of phase difference and phase sequence for high voltage transmission lines.