Compensating for drift in a switch gear voltage sensor

A method for compensating for drift in a switch gear voltage sensor, the method comprising:

• receiving, at a circuit including a compensation capacitor and a voltage divider including a measurement resistor and a divider resistor, the compensation capacitor being in parallel with the voltage divider, a first signal (Input 1) from a first capacitor of the voltage sensor (C1_2) formed by an electrode and an inner electrically conductive sheet of the switch gear voltage sensor, the first signal (Input 1) being received at the measurement resistor,
• receiving, via the circuit, a second signal (Input 2) from a second capacitor of the voltage sensor (C1_1) formed by the electrode and the inner electrically conductive sheet of the switch gear voltage sensor, the second capacitor being in parallel to the first capacitor, the second signal (Input 2) at the compensation capacitor, the second capacitor being in parallel to the first capacitor,
• generating, via the circuit, a third signal (V1) at an output of the measurement resistor based on the first signal,
• generating, via the circuit, a fourth signal (V2) at an input of the compensation capacitor based on the second signal;
• receiving, via an electronic processor, the third signal and the fourth signal,
• determining, via the electronic processor, an angular frequency of the third signal (V1),
• determining, via the electronic processor, a phase difference between the third signal (V1) and the fourth signal (V2),
• determining, via the electronic processor, a resistance value based on the angular frequency and the phase difference,
• determining, via the electronic processor, a capacitor voltage across a compensation capacitor,
• determining, via the electronic processor, an initial gain based on a line voltage, a capacitance of the second capacitor, a capacitance of the compensation capacitor, and the capacitor voltage,
• determining, via the electronic processor, a final gain based on the resistance value, the angular frequency, and the phase difference, and
• determining, via the electronic processor, a drift value of the fourth signal based on the final gain.

A system for compensating for drift in a switch gear voltage sensor, the system comprising:

• an electronic processor configured to
• receive a first signal (V1) from a first capacitor of the switch gear voltage sensor (C1_2) formed by an electrode and an inner electrically conductive sheet of the switch gear voltage sensor,
• receive a second signal (V2) from a second capacitor of the switch gear voltage sensor formed by the electrode and the inner electrically conductive sheet of the switch gear voltage sensor, the second capacitor being in parallel to the first capacitor,
• determine an angular frequency of the first signal (V1),
• determine a phase difference between the first signal (V1) and the second signal (V2),
• determine a resistance value based on the angular frequency and the phase difference,
• determine a capacitor voltage across a compensation capacitor,
• determine an initial gain based on a line voltage, a capacitance of a second capacitor, a capacitance of the compensation capacitor, and the capacitor voltage,
• determine a final gain based on the resistance value, the angular frequency, and the phase difference,
• determine a drift value of the second signal based on the final gain, and
• apply a determined gain compensating for the drift value of the second signal.