A partial discharge (PD) transducer that includes a PD sensor configured to sense a PD event of an electrical system. At least one light emitting device (LED) is arranged in series with the PD sensor. The LED is configured to receive the electrical sensor signal from the PD sensor and to generate a light signal in response to the electrical sensor signal.

A partial discharge (PD) detection system includes a PD sensor configured to sense a PD event of an electrical system and to generate a sensor signal in response to the PD event. An envelope generator is coupled to receive the sensor signal from the PD sensor. The envelope generator extracts an envelope signal from the sensor signal. A digitizer is configured to convert the envelope signal to a digital representation of the PD event.

A partial discharge (PD) detection system includes a PD sensor configured to sense a PD event of an electrical system and to generate a sensor signal in response to the PD event. An envelope generator is coupled to receive the sensor signal from the PD sensor. The envelope generator extracts an envelope signal from the sensor signal. A digitizer is configured to convert the envelope signal to a digital representation of the PD event.

The invention relates to an apparatus for monitoring the cell voltage of an individual cell (3), formed by a membrane electrode assembly (4) and bipolar plates (6), of a fuel cell stack (1), the apparatus having a measuring device (7) for each of the individual cells (3), which measuring device comprises an optical signal generator (9) which is controllable by the measuring device. The apparatus according to the invention is characterized in that the measuring device (7) is formed on a flexible circuit board that is connected to a frame (5) of a framed membrane electrode assembly (4, 5) or is formed as part of the frame.

The invention relates to an apparatus for monitoring the cell voltage of an individual cell (3), formed by a membrane electrode assembly (4) and bipolar plates (6), of a fuel cell stack (1), the apparatus having a measuring device (7) for each of the individual cells (3), which measuring device comprises an optical signal generator (9) which is controllable by the measuring device. The apparatus according to the invention is characterized in that the measuring device (7) is formed on a flexible circuit board that is connected to a frame (5) of a framed membrane electrode assembly (4, 5) or is formed as part of the frame.

The present invention provides an electrically isolated acquisition of a measurement signal by means of a measurement probe. For this purpose, a probe arrangement is provided with a probe head for electrically measuring a signal. The probe head is coupled to a probe coupler via optical links. In particular, optical links are used for power supply of the probe head and for forwarding optical signals corresponding to the measured electrical signal.

The present invention provides an electrically isolated acquisition of a measurement signal by means of a measurement probe. For this purpose, a probe arrangement is provided with a probe head for electrically measuring a signal. The probe head is coupled to a probe coupler via optical links. In particular, optical links are used for power supply of the probe head and for forwarding optical signals corresponding to the measured electrical signal.

A ground conductor monitoring device, having: at least one ground conductor connection which is designed to connect a ground conductor potential, at least one first potential connection which is designed to connect a first electrical potential which differs from the ground conductor potential, at least one second potential connection which is designed to connect a second electrical potential which differs from the first potential and the ground conductor potential, at least one electrical switching device which is designed to establish an electrical connection, optionally in accordance with an electrical control signal, between the first potential connection and the ground conductor connection (connection state) or to interrupt same (interruption state), at least one control unit which is designed to automatically output control signals to the electrical switching device.

A ground conductor monitoring device, having: at least one ground conductor connection which is designed to connect a ground conductor potential, at least one first potential connection which is designed to connect a first electrical potential which differs from the ground conductor potential, at least one second potential connection which is designed to connect a second electrical potential which differs from the first potential and the ground conductor potential, at least one electrical switching device which is designed to establish an electrical connection, optionally in accordance with an electrical control signal, between the first potential connection and the ground conductor connection (connection state) or to interrupt same (interruption state), at least one control unit which is designed to automatically output control signals to the electrical switching device.

A leakage detection device includes at least one optical coupler, a voltage divider, an analog-to-digital converter and a processing unit. Wherein, the at least one optical coupler is adapted to output an electrical signal according to a leakage degree of a DC power supply. The electrical signal is divided by the voltage divider to be output to the analog-to-digital converter and converted into a digital signal. The processing is adapted to compare a digital value corresponding to the digital signal with a reference value and output a leak signal when a difference between the digital value and the reference value is greater than a predetermined difference. A battery pack includes a battery cell assembly, a switch element, and a control unit, wherein the control unit controls the switch element to switch off an electrical connection between the battery cell assembly and the load to block electric power to the load.