A partial discharge detection apparatus includes low-speed and high-speed AD converters. The low-speed AD converter converts an analog signal of an AC waveform flowing through a power cable into a digital signal. The high-speed AD converter converts an analog signal of a partial discharge current into a digital signal. The analog signal is in a plurality of Nyquist frequency domains defined for each of two different types of sampling frequencies. The partial discharge is detected by a partial-discharge-detection digital signal processing unit based on the maximum value or the sum of a current value obtained from the digital signal of the partial discharge current obtained by the conversion of the high-speed AD converter, for each phase of the AC waveform, which is obtained from the digital signal of the AC waveform flowing in the power cable. The digital signal is obtained by the conversion of the low-speed AD converter.

A partial discharge detection apparatus includes low-speed and high-speed AD converters. The low-speed AD converter converts an analog signal of an AC waveform flowing through a power cable into a digital signal. The high-speed AD converter converts an analog signal of a partial discharge current into a digital signal. The analog signal is in a plurality of Nyquist frequency domains defined for each of two different types of sampling frequencies. The partial discharge is detected by a partial-discharge-detection digital signal processing unit based on the maximum value or the sum of a current value obtained from the digital signal of the partial discharge current obtained by the conversion of the high-speed AD converter, for each phase of the AC waveform, which is obtained from the digital signal of the AC waveform flowing in the power cable. The digital signal is obtained by the conversion of the low-speed AD converter.

An arc detector for a RF power supply system, where the RF power supply incudes a first RF power supply and a second RF power supply. A signal applied to a non-linear load varies in accordance with an output from one of the first RF power supply or the second RF power supply. The signal has a frequency. During an arc or arc condition in the non-linear load, the frequency of the signal changes, and if the frequency is outside of a selected range, an arc or arc condition is indicated. The frequency can be determined by digitizing the signal into a series of pulses and measuring a time or period between pulses.

A drive circuit for driving an electronically commutated motor contains a DC voltage intermediate circuit, and an inverter which is connected to the latter and has a bridge circuit containing a plurality of transistors, to which the motor phases of a motor configuration containing the motor can be connected. For detecting an insulation fault in the motor configuration, a positive or negative transistor of the inverter is switched on, while all other transistors of the inverter are switched off before all transistors of the inverter are switched off. A motor phase voltage of a selected motor phase of the motor phases with respect to a reference potential is then captured, while all transistors of the inverter remain switched off in order to determine whether there is an insulation fault on the motor phase on a basis of a voltage profile of the motor phase voltage.

A drive circuit for driving an electronically commutated motor contains a DC voltage intermediate circuit, and an inverter which is connected to the latter and has a bridge circuit containing a plurality of transistors, to which the motor phases of a motor configuration containing the motor can be connected. For detecting an insulation fault in the motor configuration, a positive or negative transistor of the inverter is switched on, while all other transistors of the inverter are switched off before all transistors of the inverter are switched off. A motor phase voltage of a selected motor phase of the motor phases with respect to a reference potential is then captured, while all transistors of the inverter remain switched off in order to determine whether there is an insulation fault on the motor phase on a basis of a voltage profile of the motor phase voltage.

An arc fault detector includes slew-rate-detection, envelope-step-detection, and first and second controller units. The slew-rate-detection-unit determines a slew rate of the electric current in the first electric line, comparing the slew rate with a threshold, and outputting a slew-rate-detection-signal on a second output when the determined slew rate is higher than the threshold. The envelope-step-detection-unit determines change of an envelope-value of a predefined frequency band of the broadband measurement signal within a predefined timespan, and outputs an envelope-step-detection-signal on a third output when the change is higher than a threshold change. The first controller-unit, connected to second and third outputs, outputs a second arc-detection-signal on a fourth output when it receives slew-rate and frequency-detection signals within a first detection-window. The second controller-unit, connected to first and fourth outputs, outputs a trigger signal when it receives first and second arc-detection-signals for at least a defined total time within a second detection-window.

An arc fault detector includes slew-rate-detection, envelope-step-detection, and first and second controller units. The slew-rate-detection-unit determines a slew rate of the electric current in the first electric line, comparing the slew rate with a threshold, and outputting a slew-rate-detection-signal on a second output when the determined slew rate is higher than the threshold. The envelope-step-detection-unit determines change of an envelope-value of a predefined frequency band of the broadband measurement signal within a predefined timespan, and outputs an envelope-step-detection-signal on a third output when the change is higher than a threshold change. The first controller-unit, connected to second and third outputs, outputs a second arc-detection-signal on a fourth output when it receives slew-rate and frequency-detection signals within a first detection-window. The second controller-unit, connected to first and fourth outputs, outputs a trigger signal when it receives first and second arc-detection-signals for at least a defined total time within a second detection-window.

Disclosed in the present disclosure are an insulation resistance detection circuit, a resistance detection method, a converter and a photovoltaic centrifuge. The insulation resistance detection circuit includes a resistance detection module connected between a positive electrode and a negative electrode of a direct-current bus to be detected. The resistance detection module includes a first resistance bridge and a second resistance bridge arranged in parallel. The first resistance bridge is connected to the positive electrode of the direct-current bus by means of a first sampling resistor R1. The second resistance bridge is connected to the negative electrode of the direct-current bus by means of a second sampling resistor R2, and both the first sampling resistor R1 and the second sampling resistor R2 are equipped with voltage sampling chips. The resistance detection module is configured to calculate an insulation resistance value of the direct-current bus according to voltage values of the two sampling resistors before and after a first switch S is switched.

Disclosed in the present disclosure are an insulation resistance detection circuit, a resistance detection method, a converter and a photovoltaic centrifuge. The insulation resistance detection circuit includes a resistance detection module connected between a positive electrode and a negative electrode of a direct-current bus to be detected. The resistance detection module includes a first resistance bridge and a second resistance bridge arranged in parallel. The first resistance bridge is connected to the positive electrode of the direct-current bus by means of a first sampling resistor R1. The second resistance bridge is connected to the negative electrode of the direct-current bus by means of a second sampling resistor R2, and both the first sampling resistor R1 and the second sampling resistor R2 are equipped with voltage sampling chips. The resistance detection module is configured to calculate an insulation resistance value of the direct-current bus according to voltage values of the two sampling resistors before and after a first switch S is switched.

Some aspects of this disclosure are directed to an automated method to check electrostatic discharge (ESD) effect on a victim device. For example, some aspects of this disclosure relate to a method, including determining a probe point, in a circuit design, for determining effective resistance between the probe point and ground, where the probe point is on an ESD path of in the circuit design. The method includes determining voltage between the probe point and the ground. The method further includes comparing, by a processing device, a resistance value of the ESD path determined based a predefined electric current value at a source point and the measured voltage with a target resistance value range. The method further includes reporting a violation upon determining that the determined resistance value of the ESD path is outside the target resistance value range.