Apparatus and method for generating a defined charge pulse for carrying out a partial discharge measurement

A measurement system for performing a partial discharge measurement at an electrical component, comprising

• at least one partial discharge measurement device for performing a partial discharge measurement at the electrical component, and
• an apparatus for generating a defined calibration charge pulse for calibrating the performance of the partial discharge measurement by the at least one partial discharge measurement device, wherein the apparatus comprises:
• a housing,
• an external electrode to be mounted at on an exterior surface of the housing, and
• a control unit that determines a stray capacitance of the external electrode and to that generates a charge pulse in dependence on the determined stray capacitance such that a defined charge pulse is output by the external electrode at a predefined charge level for performing a partial discharge measurement at an electrical component.

An apparatus for generating a defined charge pulse for performing a partial discharge measurement at an electrical component, the apparatus comprising:

• a housing;
• an external electrode to be mounted at the housing;
• a control unit configured to generate the defined charge pulse in dependence on a stray capacitance of the external electrode;
• and
• a controllable voltage source configured and connected to the external electrode such that by applying a voltage jump a charge stored in the external electrode due to stray capacitance of the electrode can be output as a charge pulse via a terminal of the apparatus,
• wherein the apparatus is configured to automatically determine the stray capacitance of the external electrode and generate in response thereto the defined charge pulse by correspondingly controlling the voltage source, and
• wherein the control unit is configured such that, for determining the stray capacitance of the external electrode by correspondingly controlling the voltage source, the control unit applies a known voltage to a capacitive voltage divider comprising the stray capacitance of the external electrode and a known internal reference capacitance to subsequently determine the stray capacitance of the external electrode by evaluating the voltage drop at the known internal reference capacitance depending on the known voltage and depending on the known value of the internal reference capacitance.