Abstract: A system, in one embodiment, may include a system includes a ground fault detection system. The ground fault detection system includes a linear filter configured to receive one or more signals from a static starter system during operations of the static starter system and to produce a linear filter output. The ground fault detection system further includes a rectifier configured to rectify the linear filter output and to produce a rectifier output, and a gain system configured to multiply the rectifier output by a factor to produce a gain output. The ground fault detection system additionally includes a fault indicator system configured to indicate a ground fault based on the gain output, wherein the ground fault detection system is configured to command an action based on the ground fault.

Abstract: A system, in one embodiment, may include a system includes a ground fault detection system. The ground fault detection system includes a linear filter configured to receive one or more signals from a static starter system during operations of the static starter system and to produce a linear filter output. The ground fault detection system further includes a rectifier configured to rectify the linear filter output and to produce a rectifier output, and a gain system configured to multiply the rectifier output by a factor to produce a gain output. The ground fault detection system additionally includes a fault indicator system configured to indicate a ground fault based on the gain output, wherein the ground fault detection system is configured to command an action based on the ground fault.

Abstract: A reference-free direct digital lock-in system (RDDL 10) has a first input coupled to a periodic electrical signal and an output for outputting an indication of a magnitude of a desired periodic signal component. The RDDL also has a second input for receiving a signal (9) that specifies a reference period value, and operates to autonomously generate a lock-in reference signal having a specified period and a phase that is adjusted to maximize a magnitude of the outputted desired periodic signal component. In an embodiment of a measurement system that includes the RDDL 10 an optical source provides a chopped light beam having wavelengths within a predetermined range of wavelengths, and the periodic electrical signal is generated by at least one photodetector that is illuminated by the chopped light beam. In this embodiment the measurement system characterizes, for at least one wavelength of light that is generated by the optical source, a spectral response of the at least one photodetector.

Abstract: Motor-load inertia of a drive system is determined from motor friction current and the time required to accelerate and decelerate to a predetermined speed in response to a current command. A desired response time provided by the operator is checked to determine if the response time is achievable with the motor-load inertia previously determined. The maximum achievable response time based on motor-load inertia is determined if the desired response time is not achievable. The speed loop parameters based on the achievable response time and motor-load inertia.