The Intelligent Measurement Device Of Insulating Parameter For Underground Low-Voltage Electrical Network

A new intelligent measuring device for underground low-voltage electrical network, no neutral-earth, is designed. It uses the 50 Hz AC directly as the auxiliary power supply, not the directive-current auxiliary source as before. With the known resistance as sample signal resistance and based on the micro-controller 8031, the device is developed. The insulance and distributive capacitance of underground electrical network of a coal mine can be measured and calculated accurately, and displayed quickly with LED. The insulance is the alternating current insulating resistance, not the direct current insulating resistance as the past. It conforms reality for elecrical network in alternating current state. The measured distributive capacitance of electrical network is convenient to be compensated with inductance to improve human body safety in coal mines. This compensation is difficult to realize in the past. When the variation of measured values of insulance is recorded and analyzed, the service life of the network cables may be predicted. As to increase the reliability of the device, some steps of protection and anti-interference are adopted.