System and method for ground fault detection of static starter circuitry

A system, comprising:

• a turbine;
• an electrical generator or a motor;
• a static starter system configured to provide a variable frequency AC signal to drive the electrical generator or the motor during a starting sequence of the turbine;
• and
• a ground fault detection system configured to:
• receive one or more signals from the static starter system during operations of the static starter system;
• linearly filter the one or more signals via a linear filter to produce a linear filter output, wherein the linear filter comprises a recursive linear filter having poles and zeroes tuned to allow a selected frequency component from the input, the selected frequency component is between 2 to 5 times a load frequency, the input comprises a false neutral voltage (FNV) signal, and the linear filter comprises a biquad filter;
• rectify the linear filter output to produce a rectified output;
• apply a gain to the rectified output to produce a gain output;
• derive a mean value and/or an integrated value from the gain output to produce a mean value output and/or an integrated value output;
• and
• detect a ground fault based on the mean value output and/or the integrated value output, wherein the ground fault detection system is configured to command an action based on the ground fault.

A method, comprising:

• receiving one or more signals from a static starter system during operations of the static starter system;
• linearly filtering the one or more signals via a linear filter to produce a linear filter output, wherein the linear filter comprises a recursive linear filter having poles and zeroes tuned to allow a selected frequency component from the input, the selected frequency component is between 2 to 5 times a load frequency, the input comprises a false neutral voltage (FNV) signal, and the linear filter comprises a biquad filter;
• rectifying the linear filter output to produce a rectified output;
• applying a gain to the rectified output to produce a gain output;
• detecting a ground fault based on the gain output, and
• tripping a system based on the detection of the ground fault.