The current regulation system, providing fine dimming control, has an under-voltage circuit, an over-temperature control circuit, and sometimes a variable resistor (VR) control circuit. The under-voltage and over-temperature controls (first and second control signals) pass through voltage limiters such that the lowest level voltage control signal is applied to the voltage reference signal IREF input of LED IC driver. IC driver has a voltage reference input IREF which controls an IC output current for an load demand. The VR control generates a third control signal at the junction to reduce the voltage reference signal under control of the VR. The lowest level control signal dims the LED lamps. Since low level voltage control signals are used, a low voltage turn OFF circuit applies an IC disablement signal to the LED IC driver input control based upon sensing a. very low voltage at the junction.

A circuit protection method comprises operating a range extender in a normal mode, wherein the range extender comprises at least one DC-to-DC converter having an input side and an output side and at least one bypass device coupled between the input side and the output side. The operating of the range extender in the normal mode comprises converting an input voltage at the input side into an output voltage at the output side by the DC-to-DC converter, wherein the output voltage is higher than a critical voltage. The method further comprises operating the range extender in a safety mode when the output voltage is lower than the critical voltage. The operating of the range extender in the safety mode comprises bypassing the DC-to-DC converter by the bypass device, wherein the critical voltage is lower than or equal to the input voltage.

The present invention is directed towards a serially connected micro-inverter (SCMI) system comprising a plurality of power sources for producing DC power, a plurality of micro-inverters, where each micro-inverter is coupled to at least one power source of the plurality of power sources, for converting the DC power into AC power, an AC bus for coupling the plurality of micro-inverters in series to form a string and for coupling the AC power an AC line; and a controller, coupled to the string, for measuring an output signal of one or more strings of series coupled micro-inverters, comparing the measured output signal to a desired signal for the string; and adjusting a phase angle of an output from each micro-inverter in the one or more strings until a difference between the measured output signal and the desired signal is less than a predetermined threshold value.

The present invention is directed towards a serially connected micro-inverter (SCMI) system comprising a plurality of power sources for producing DC power, a plurality of micro-inverters, where each micro-inverter is coupled to at least one power source of the plurality of power sources, for converting the DC power into AC power, an AC bus for coupling the plurality of micro-inverters in series to form a string and for coupling the AC power an AC line; and a controller, coupled to the string, for measuring an output signal of one or more strings of series coupled micro-inverters, comparing the measured output signal to a desired signal for the string; and adjusting a phase angle of an output from each micro-inverter in the one or more strings until a difference between the measured output signal and the desired signal is less than a predetermined threshold value.

An electric motor system having substantially independent hardware-based and software-based pathways for detecting and initiating responses to fault conditions, such as over-current conditions, in an electric motor which is powered by a power inverter which is controlled by a power module and a microprocessor. Each pathway involves comparing a voltage, which is representative of an electric current flowing to the motor, to a predetermined maximum voltage, and if the former exceeds the latter using hardware or software to initiate shutting off the motor, such as by shutting off the power inverter. When one pathway detects a fault condition it may notify the other pathway, and the notified pathway may also initiate shutting off the motor.

A power transmission apparatus with over-loading protection and power-saving mechanism is provided. The power transmission apparatus includes a switch module and a control module. The switch module includes a first switch circuit, a second switch circuit and a protection circuit. The first switch circuit is coupled between a power input module and a power supply port. The second switch circuit is coupled to the power input module. The protection circuit is coupled between the second switch circuit and the power supply port and detects a load power of the power supply port when the second switch circuit is turned-on. When the load power is greater than a predetermined over-loading threshold, the protection circuit enables the first switch circuit. After the control module determines that the first switch circuit is enabled, the control module controls the first switch circuit keeps enabling and disables the second switch circuit and the protection circuit.

There is disclosed a method comprising providing a first signal to an apparatus comprising a protection circuit and an output for providing electric power. The protection circuit comprises at least an overdischarge detection element and a discharging control output. The first signal is used to change a voltage level at an input of the overdischarge detection element of the protection circuit. The change of the voltage level at the input of overdischarge detection element is detected, and a second signal is provided at the discharging control output to switch off the output of the apparatus. There is also disclosed an apparatus comprising a protection circuit comprising at least an overdischarge detection element and a discharging control output. The apparatus also comprises an output for providing electric power; the protection circuit; and a first signal input adapted to receive a first signal to change a voltage level at an input of the overdischarge detection element of the protection circuit. The overdischarge detection element is configured for detecting the change of the voltage level at the input of the overdischarge detection element, and for providing a second signal at the discharging control output to switch off the output of the apparatus.

A circuit includes a protection circuit and a gate driver coupled to a power supply voltage node configured to have a power supply voltage level. The protection circuit generates a first signal having a first logical voltage level when the power supply voltage level is equal to or greater than a threshold voltage level, and having a second logical voltage level when the power supply voltage level is less than the threshold voltage level. The gate driver receives the first signal and a second signal, and, when the first signal has the first logical voltage level, outputs a third signal based on the second signal, and when the first signal has the second logical voltage level, outputs the third signal having a predetermined one of the first or second logical voltage levels.

An undervoltage detection circuit includes a voltage divider, a voltage-to-current (V-to-I) converter and a current comparator. The voltage divider divides a supply voltage to generate a divided voltage. The V-to-I converter converts the divided voltage into a first current based on a first V-to-I transfer function, and converts the divided voltage into a second current based on a second V-to-I transfer function different from the first V-to-I transfer function. The current comparator compares the first and second currents to generate a comparison signal that indicates whether the supply voltage is sufficiently large.

A method for analyzing power quality events in an electrical system includes processing electrical measurement data from or derived from energy-related signals captured by at least one metering device in the electrical system to generate at least one dynamic tolerance curve. Each dynamic tolerance curve of the at least one dynamic tolerance curve characterizes a response characteristic of the electrical system at a respective metering point in the electrical system. The method also includes analyzing the at least one dynamic tolerance curve to identify special cases which require further evaluation(s)/clarification to be discernable and/or actionable. The at least one dynamic tolerance curve may be regenerated or updated, and/or new or additional dynamic tolerance curves may be generated, to provide the further clarification. One or more actions affecting at least one component in the electrical system may be performed in response to an analysis of the curve(s).