A Method for Measurement of Step Voltage Rise Time of Partial Discharge Calibrators

The measurement methods of the step voltage risetime of Partial Discharge calibrators are discussed. A method using a capacitor is recommended in the latest edition of IEC standard(IEC 60270-2015). However, the influences by the capacitance of cables and the capacitive component of the input impedance of the oscilloscope should not be neglected in the former method, especially for the measurement of the low-quantity discharge. A method for the measurement of the rise time of the step voltage by connecting a resistor to PD calibrators is presented. This method is more suitable for the measurement of charge transfers less than hundreds of picocoulombs.