A test signal is applied from a continuity test source to a photovoltaic (PV) panel string, to test electrical continuity in the PV panel string and between the PV panel string and an inverter that is coupled to the PV panel string. If the test signal is detected at a PV panel disconnect switch that is separate from the continuity test source and switchably couples one or more Direct Current (DC) PV panels in the PV panel string, then the PV panel disconnect switch is controlled to connect the one or more DC PV panels in the PV panel string. Otherwise, the PV panel disconnect switch is controlled to disconnect the one or more DC PV panels from the PV panel string. The test signal could be, for example, an Alternating Current (AC) signal tuned to a PV installation that includes the PV panel string and the inverter.

Embodiments include a technique for eliminating secondary fuses in high power solid state power controllers, the technique includes controlling gate power provided to a field effect transistor array, and detecting a failure mode. The technique also includes disabling the gate power based at least in part on detecting the failure mode, and restoring the gate power responsive to resolving the failure mode.

A power converter includes an input voltage detection section, a power factor correction (PFC) section, a DC-DC conversion section, and a control section that stops power conversion operation in a case where an input voltage value is greater than or equal to a predetermined value. The control section resumes power conversion operation such that a second input current value lower than a first input current value corresponding to the input voltage value is input into the PFC section after stopping the power conversion operation.

A system and method of protecting the input components of a power supply. An input overcurrent protection module is provided, which may be implemented in firmware, which monitors the input current through an input interface of the power supply. When the input current exceeds a threshold current (i.e., a current above the maximum rating of an input component, such as an input cable), the input current protection module determines whether an input overcurrent event is occurring. When it is determined that an input overcurrent event has occurred, the input current protection module disables the output circuitry of the power supply and triggers a few timers. The input overcurrent protection module continues to monitor the input and, if the input current continues to exceed the threshold current, is configured to shut down the power supply. In this way, input components may be protected from overcurrent issues in high-power systems.

A DC power switching assembly includes a plurality of series connected power switching units. Each power switching unit has a first terminal of the unit and a second terminal of the unit, the terminals having the same polarity. A power switching sub-unit is electrically coupled between the first terminal and the second terminal of the unit to control current flow between the first terminal and the second terminal. The sub-unit has at least one semiconductor device, a current limiter and a pair of series connected diodes in parallel with the current limiter. The series connected diodes and current limiter are connected to one terminal of the semiconductor device; and a capacitor is connected to the other terminal of the semiconductor device.

A circuit breaker includes a control circuit capable of generating and transmitting a test pulse through its attached circuit and any connected load while its contacts are open, with the breaker in the OFF, or TRIPPED, state, to determine if detrimental anomalies exist, such as a short circuit. In certain configurations, the control circuit can measure and store a circuit's parameters for a properly operating load when the breaker is in the OFF state, and subsequently with the breaker in the OFF, or TRIPPED, state, compare the stored parameters to determine if an alarm condition exists and thereby initiate appropriate alerts and actions. In an alternate configuration, the breaker can be commanded to the OFF position by the load sending a signal through the power connection, with the breaker then being able to store the load's reason for shut-down and report such information to a remote location.

A method of clearing a fault in a high voltage DC electrical network, including power converters interconnected by a DC power transmission, comprising: detecting a fault in the DC power transmission and reconfiguring each power converter to a fault blocking mode driving the DC fault current towards zero; locating the fault and isolating a faulty portion from a healthy remaining portion; reconfiguring one of the power converters designated as a re-energising power converter from the fault blocking to re-energise the healthy remaining portion; and detecting a rise in the voltage level in the healthy remaining portion above a threshold level and reconfiguring the remaining power converter connected with the healthy remaining portion from the fault blocking to the normal power transmission.

An electronic circuit and a method are disclosed. The electronic circuit includes an LED circuit, wherein the LED circuit (1) includes: an input (11, 12) configured to receive an input voltage (V.sub.IN); a drive circuit (2A) connected to the input (11, 12); and an LED module (3A) connected to the drive circuit (2A) and comprising an LED string (4.sub.1) with at least one LED. The drive circuit (2A) is configured to monitor the LED module (3A) for the occurrence of an LED short in the LED string (4.sub.1) and to change from a normal mode to a defect mode upon detection of the LED short, and the drive circuit (2A) is configured, in the defect mode, to operate the LED string (4.sub.1) in at least one defect cycle that includes deactivating the LED string (4.sub.1) for a deactivation period, activating the LED string for an activation period, and checking for the persistence of the LED short in the activation period.

A disconnect component coupled between a lighting load and a main power line. The disconnect component includes an input coupled to the main power line and a neutral line input to the disconnect component from the 277 volt circuit and an output coupled to the lighting load. The disconnect component includes a monitor that monitors a voltage on the main power line and a coupling component that couples the main power line to the output. The coupling component is configured to decouple the main power line from the output when the monitor senses a voltage on the main power line is higher than an upper limit voltage and re-couple the main power line to the output when the monitor senses that the voltage on the main power line is below the upper limit voltage.

A monitor circuit that monitors power delivered by an electrical utility or other source to a consumer. The device may be located at or near an entry point, such as near an electrical meter. The device senses a material change in voltage, and terminates power to the consumer until normal voltage is restored. The device automatically resets when normal voltage is restored, without need for a service call.