A control panel includes power supply circuits for supplying power supply voltages to loads and a connection part for connecting wiring. The control panel comprises a system current detection unit that is for detecting a sudden increase in system current that is from a power system and flows through the control panel and includes a second current transformer, and individual current detection units that are for detecting a sudden increase in the individual current of one of the power supply circuits and include first current transformers. An arc discharge detection unit identifies an arc discharge occurring within the control panel separately from a surge flowing into the system based on a system current detection signal and individual current detection signals.

An insulation resistance detection circuit is coupled to a positive end and a negative end of a DC power source, and is used to detect a positive insulation resistance between the positive end and a ground point and detect a negative insulation resistance between the negative end and the ground point. A detection unit sets a first estimated resistance and a second estimated resistance, and acquires a first voltage based on turning on the switch and acquires a second voltage based on turning off the switch. The detection unit calculates a third voltage and a fourth voltage according to the first estimated resistance and the second estimated resistance so as to detect the positive insulation resistance and the negative insulation resistance when the third voltage is equal to the first voltage and the fourth voltage is equal to the second voltage.

An insulation resistance detection circuit is coupled to a positive end and a negative end of a DC power source, and is used to detect a positive insulation resistance between the positive end and a ground point and detect a negative insulation resistance between the negative end and the ground point. A detection unit sets a first estimated resistance and a second estimated resistance, and acquires a first voltage based on turning on the switch and acquires a second voltage based on turning off the switch. The detection unit calculates a third voltage and a fourth voltage according to the first estimated resistance and the second estimated resistance so as to detect the positive insulation resistance and the negative insulation resistance when the third voltage is equal to the first voltage and the fourth voltage is equal to the second voltage.

A circuit includes a dynamic core data register (DCDR) cell that includes a data register, a shift register and an output circuit to route the output state of the data register or the shift register to an output of the DCDR in response to an output control input. A clock gate having a gate control input controls clocking of the shift register in response to a first scan enable signal. An output control gate controls the output control input of the output circuit and controls which outputs from the data register or the shift register are transferred to the output of the output circuit in response to a second scan enable signal. The first scan enable signal and the second scan enable signal to enable a state transition of the shift register at the output of the DCDR.

A circuit includes a dynamic core data register (DCDR) cell that includes a data register, a shift register and an output circuit to route the output state of the data register or the shift register to an output of the DCDR in response to an output control input. A clock gate having a gate control input controls clocking of the shift register in response to a first scan enable signal. An output control gate controls the output control input of the output circuit and controls which outputs from the data register or the shift register are transferred to the output of the output circuit in response to a second scan enable signal. The first scan enable signal and the second scan enable signal to enable a state transition of the shift register at the output of the DCDR.

An arc fault detection device includes: a first electric line; at least one sensor for monitoring an electric current or voltage spectrum in the first electric line and outputting an analogue HF measurement signal; and an input section connected to the at least one sensor, the input section including: an input bandpass filter connected to the at least one sensor so as to filter the analogue HF measurement signal, a passband of the input bandpass filter having a predeterminable arc-frequency range so as to detect arcing effects; and a sampling mixer connected to the input bandpass filter, the sampling mixer having a sampling frequency lower than twice an upper threshold frequency of the arc-frequency range.

An arc fault detection device includes: a first electric line; at least one sensor for monitoring an electric current or voltage spectrum in the first electric line and outputting an analogue HF measurement signal; and an input section connected to the at least one sensor, the input section including: an input bandpass filter connected to the at least one sensor so as to filter the analogue HF measurement signal, a passband of the input bandpass filter having a predeterminable arc-frequency range so as to detect arcing effects; and a sampling mixer connected to the input bandpass filter, the sampling mixer having a sampling frequency lower than twice an upper threshold frequency of the arc-frequency range.

A time dependent dielectric breakdown test structure includes a plurality of test units connected in parallel between a constant voltage and a ground. Each of the plurality of test units includes a dielectric test sample connected to the constant voltage; and a current restraint unit connected between the dielectric test sample and the ground, for restraining a breakdown current from flowing on the dielectric test sample after the constant voltage has broken the dielectric test sample.

A time dependent dielectric breakdown test structure includes a plurality of test units connected in parallel between a constant voltage and a ground. Each of the plurality of test units includes a dielectric test sample connected to the constant voltage; and a current restraint unit connected between the dielectric test sample and the ground, for restraining a breakdown current from flowing on the dielectric test sample after the constant voltage has broken the dielectric test sample.

An apparatus for generating electrical discharge includes a component that generates an electrical discharge, a measurement circuit configured to measure a magnitude of the electrical discharge, and a controller configured to control the magnitudes of the electrical discharge. A method for controlling a reference partial discharge signal in an electric power system includes generating a partial discharge for built in self test, controlling an expected discharge magnitude of the partial discharge, and includes measuring an actual discharge magnitude of the partial discharge.