Characteristics of Alternating Current Induced Discharges with Live Working Robot

When a live working robot enters/leaves a high-voltage conductor, the induced discharge will cause violent electromagnetic field changes, which may cause the robot to refuse to move, misuse or even damage. In order to clarify the AC induction discharge characteristics of live working robots, an AC induction discharge test system and a pulse current measurement system conforming to the IEC 61000-4-2 standard are established. The induction discharge test of the robot is carried out in an anechoic chamber. The robot’s arcing current was measured using a broadband pulse current sensor and a floating oscilloscope. The measurement results show that the rise time of a single current pulse is 0.2-10ns, the duration is about 800ns, the frequency is within 1.3GHz, and the main energy is concentrated within 100MHz. As the gap between the robot and the conductor decreases, the number of induced discharge current pulses increases, the pulse amplitude increases first, and then decreases when it reaches a certain value. As the voltage increases, the AC induced discharge current of the robot also increases. The magnitude of the robot’s AC induced discharge current is related to the robot’s capacitance to ground. The larger the capacitance to ground, the larger the discharge current. Through the statistical analysis of 2000 sets of measurement data, the regression formulas of the induced discharge current and voltage, capacitance and the gap between the robot and the wire are obtained. The results show that the AC induced discharge of the robot is different from the electrostatic discharge. According to the test results and the current regression formula, the electromagnetic interference protection design of the robot and the electromagnetic compatibility standard of the robot can be formulated.