An energy storage system can include a battery, a power converter comprising a first plurality of switching devices coupled to the battery and a second plurality of switching devices coupled between the first plurality of switching devices and an AC power system, and control circuitry that determines whether the AC power system is a single/split phase system or a three phase system and operates the first and second pluralities of switching devices accordingly. The control circuitry can include a microcontroller and a plurality of voltage sensors each configured to monitor a magnitude and a phase of a voltage to allow the control circuitry to determine whether the AC power system is a single/split phase system or a three phase system and whether the AC power system is connected with a line to line or line to neutral fault condition

A short-circuit protection apparatus includes a first detection branch, a second detection branch, and a controller. The first detection branch includes a first sampling resistor and a first sampling capacitor that is connected in parallel to the first sampling resistor. A difference between an absolute value of a second sampling voltage and an absolute value of a first sampling voltage is a first difference. The controller obtains a comparison result between an absolute value of a first sampling voltage at two terminals of the first sampling resistor and an absolute value of a second sampling voltage at two terminals of the second sampling resistor, and if a difference between the absolute value of the second sampling voltage and the absolute value of the first sampling voltage is a second difference and the second difference is less than the first difference, controls the target circuit to stop working.

A photovoltaic system, an inverter, and a direct current electric arc detection method. The system includes an inverter, a controller, and at least two converters. When detecting an electric arc, the controller controls an input current of the inverter to decrease to extinguish the arc. After the arc is extinguished, the controller controls an output voltage of at least one photovoltaic string to decrease to a first preset voltage, where the first preset voltage is less than an input voltage of the inverter when the electric arc is detected, or controls a maximum value of an output current of the at least one photovoltaic string to be a second preset current, where the second preset current is less than the input current of the inverter when the electric arc is detected. In the foregoing two recovery manners, no electric arc recurs.

Methods, systems, and devices for protecting a wireless power transfer system. One aspect features a sensor network for a wireless power transfer system. The sensor network includes a differential voltage sensing circuit and a current sensing circuit. The differential voltage sensing circuit is arranged within a wireless power transfer system to measure a rate of change of a voltage difference between portions of an impedance matching network and generate a first signal representing the rate of change of the voltage difference. The current sensing circuit is coupled to the differential voltage sensing circuit and configured to calculate, based on the first signal, a current through a resonator coil coupled to the wireless power transfer system.

A circuit for minimizing energy provided to a ground fault includes a source, a multiple switches, an output filter, and a controller. The switches include a first side pair of switches and a second side pair of switches configured to provide an output signal based on the source. The output filter includes one or more energy storage elements coupled to the first side pair of switches or the second side pair of switches. The controller is configured to receive a ground fault signal that indicates a fault has occurred and configured to generate a switch signal for the switches for a minimum energy state of the output filter and in response to the ground fault signal.

A power module for driving a motor includes: a positive bus input voltage terminal; a phase terminal for each motor phase; an inverter including a half bridge for each motor phase, each half bridge including a high-side power switch electrically coupled between the positive bus input voltage terminal and respective phase terminal, and a low-side power switch electrically coupled between the respective phase terminal and ground; a first driver circuit for driving a gate terminal of each power switch; a protection switch electrically coupled in series between the positive bus input voltage terminal and each high-side power switch, and having a greater short-circuit withstand time and a lower short-circuit current level compared to each inverter power switch; and a second driver circuit for turning on the protection switch during normal operation and turning off the protection switch in response to a detected short circuit condition.

A protective device intended to protect a power converter, the protective device includes a set of at least one sensor, each sensor in the set of at least one sensor making it possible to deliver a measurement representative of the instantaneous current delivered at the output of a power converter on a phase in the set of at least one phase, a protective device receiving the measurement representative of the instantaneous current delivered by the set of at least one sensor and connected to a control device and to the power converter such that the commands delivered by the control device are transmitted to the power converter via the protective device, the protective device being configured to inhibit the commands delivered by the control device when the absolute value of the measurement representative of the instantaneous current and delivered by at least one sensor in the set of at least one sensor exceeds a predetermined first threshold S1 such that the power switches of the power converter are kept in the off state.

A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

A method is provided for operating an inverter of an inverter-based power resource providing electric power to a grid through one or more transformers. The method includes measuring voltages associated with terminals on a selected primary winding and/or measuring voltages associated with terminals on a selected secondary winding; and injecting currents into the primary terminals of the selected primary winding during a fault condition based on the measured voltages being indicative of the type of fault occurring. Preferably the inverter is operated to emulate at least some characteristics of fault currents provided by a generator having rotating magnets or electrical windings. An apparatus is configured to operate in accordance with the method and includes an electrical switching device circuit having input terminals for an inverter-based power resource and output terminals for providing AC electric power to an electric power grid. An inverter controller operates the electrical switching device circuit.

A power module for driving a motor includes: a positive bus input voltage terminal; a phase terminal for each motor phase; an inverter including a half bridge for each motor phase, each half bridge including a high-side power switch electrically coupled between the positive bus input voltage terminal and respective phase terminal, and a low-side power switch electrically coupled between the respective phase terminal and ground; a first driver circuit for driving a gate terminal of each power switch; a protection switch electrically coupled in series between the positive bus input voltage terminal and each high-side power switch, and having a greater short-circuit withstand time and a lower short-circuit current level compared to each inverter power switch; and a second driver circuit for turning on the protection switch during normal operation and turning off the protection switch in response to a detected short circuit condition.