A precharge system and method are provided. The precharge system comprises a load circuit, a precharge circuit and a control circuit. The load circuit comprises an input terminal, an input switch and a bus capacitor. The precharge circuit comprises a precharge resistor and a precharge switch. The precharge method comprises: during the load circuit being in a precharge mode, controlling the input switch to be in an off state, and controlling the precharge switch to switch between the on and off state for multiple times; and during the load circuit being in a work mode, controlling the input switch to be in an on state. During the load circuit being in the precharge mode, when the precharge switch is in the on state, a consuming power of the precharge resistor is larger than a threshold power and is smaller than or equal to a limit power of the precharge resistor.

According to one aspect of the present disclosure, an energy storage system includes one or more power sources, one or more energy storage components, and one or more solid state circuit breakers disposed between the one or more power sources and the one or more energy storage components such that electrical power is exchanged between the one or more power sources to the one or more energy storage components through the one or more solid state circuit breakers. The energy storage system also includes a controller configured to operate the one or more solid state circuit breakers to control current exchanged with the one or more energy storage components and protect the one or more energy storage components from the one or more power sources during a fault condition.

Examples described herein provide a method for overspeed protection of a motor of a gate crossing mechanism. The method includes monitoring, by an overspeed protection circuit, a voltage across a first Zener diode and a second Zener diode. An anode of the first Zener diode is connected to an anode of the second Zener diode. The method further includes, responsive to determining that a Zener voltage threshold is exceeded, allowing a current to flow into a gate pin of a triac. The triac controls the motor of the gate crossing mechanism.

A current detecting device includes a sense resistor through which a sense current corresponding to a consumption current supplied to a load flows, and an A/D converter configured to perform A/D conversion on a voltage drop generated by the sense current flowing through the sense resistor to detect the consumption current. A resistance value of the sense resistor is variably provided.

A forced discharge test apparatus includes a heating circuit; a discharge circuit; a temperature sensor; and a controller. When the controller receives a test command indicating a test resistance and a test temperature, the controller outputs a first control signal to the heating circuit to increase the temperature of a battery cell. The controller outputs a second control signal to the discharge circuit to discharge the battery cell when the temperature of the battery cell reaches the set test temperature. The controller determines that the test temperature is valid with respect to the test resistance when the temperature of the battery cell is equal to or lower than the upper temperature limit at a time point at which a predetermined heating time has passed from a time point when the first control signal is outputted.

A thermal management system is provided. The system includes a temperature sensor, a fan, an electronic circuit breaker (ECB) coupled to the fan to provide electric power to the fan. The system includes a controller coupled to the temperature sensor and the ECB, to direct the ECB to turn off the electric power to the fan responsive to detecting a temperature, from the temperature sensor less than a temperature threshold based on a temperature rating of the fan.

A thermal management system is provided. The system includes a temperature sensor, a fan, an electronic circuit breaker (ECB) coupled to the fan to provide electric power to the fan. The system includes a controller coupled to the temperature sensor and the ECB, to direct the ECB to turn off the electric power to the fan responsive to detecting a temperature, from the temperature sensor less than a temperature threshold based on a temperature rating of the fan.

Provided is a protection circuit capable of reliably preventing an overcurrent or a sneak current after cutoff to improve safety, implementing cost reduction with a device configuration simpler than conventional device configurations, and further reducing a failure rate of a device. In a protection circuit, after one of two fuse elements provided in each of a plurality of protection elements is blown due to an overcurrent flowing along a current-carrying path, a heater provided in at least one of the plurality of protection elements generates heat due to a sneak current flowing via the plurality of protection elements on the current-carrying path which is remained and the current-carrying path which is remained is cut off due to destruction of the heater.

A surge protection device with a high breaking capacity includes a housing with at least two lead-out electrodes, and a voltage limiting device and a thermal tripping mechanism that are installed in the housing. The voltage limiting device includes a voltage limiter, a first electrode and a second electrode that are positioned and installed in an insulating cover. The thermal tripping mechanism includes a fixed assembly, a movable assembly and a thermal trigger device. The fixed assembly and the movable assembly form a plurality of displacement switches arranged in series. The thermal trigger device is disposed in linkage with the movable assembly and includes a metal trigger sheet, a fusible alloy and an energy storage member. One end of the metal trigger sheet is fixed on the movable assembly, and the other end of the metal trigger sheet is fixed on the second electrode through welding by the fusible alloy.

A power supply control system and a vehicle includes: a plurality of supplying branches; a voltage conversion module, connected between an output end of a low-voltage direct current (DC) power supply and an input end of each of the supplying branches, configured to convert a voltage of output DC of the low-voltage DC power supply to a preset voltage; an information acquisition module, configured to collect temperature information of a preset area and/or load information; and a control module, communicating with the information acquisition module, configured to generate control signals for the supplying branches based on the temperature information of the preset area and/or load information.