Abstract: Disclosed are a device and method for detecting defects of a high-voltage cable cross-bonded grounding system. The method comprises: selecting a protective grounding box of a cross-bonded grounding system, respectively connecting a signal excitation coupler to A-phase, B-phase and C-phase coaxial cables of the protective grounding box, selecting a stable signal with a frequency different from a power frequency or a field interference frequency, and testing effective current values and phases responded by the A-phase, B-phase and C-phase coaxial cables when the stable signal with the frequency F1 is injected into the A-phase, B-phase and C-phase coaxial cables of the protective grounding box in a coupled manner; and obtaining resistances and inductances of branch circuits of the cable cross-bonded grounding system by calculation according to measurement data, and determining if the cable cross-bonded grounding system has a connection defect.

Abstract: Disclosed is a charging station capable of realizing mutual capacity aid, which comprises a plurality of charging units, a power bus and a mutual capacity aid bus. Each charging unit is powered by the power bus, and each charging unit provides mutual aid capacity for another charging unit through the mutual capacity aid bus or receives mutual aid capacity from other charging units through the mutual capacity aid bus. The charging station can realize rapid charging of electric vehicles, and can also realize mutual capacity aid.

Abstract: Disclosed is an electrical topology of an integrated DC charging station and an operation control method. The electrical topology comprises a supply side DC bus, K discrete charging pile units and a mutual aid total DC bus; each charging pile unit comprises an input DC bus, a mutual aid sub-DC bus, an output DC bus, N isolation branches, a non-isolation DC/DC module and an output terminal, the input DC bus is connected to the supply side DC bus, and the mutual aid sub-DC bus of each charging pile unit is connected to the mutual aid total DC bus; the isolation branch comprises an output branch and a mutual aid branch; and when all the output branches of one charging pile, unit are started and the output power cannot meet the required power, the mutual aid branches of other charging pile units are started to meet the required power.

Abstract: The present invention discloses a method and apparatus for photovoltaic DC direct-fed power generation based on controllable power supply. According to the present invention, the photovoltaic cells are directly connected to the DC microgrid, and the DC bus voltage is flexibly regulated by the controllable power supply in the DC microgrid to enable the photovoltaic cells to operate at the maximum power, thus eliminating the need for a DC interface converter when the photovoltaic cells are connected to the DC bus and reducing the cost and size of the distributed PV power generation system.

Abstract: A combined platform for testing fireproof materials for cables includes a main frame for providing operating space; an air circulation system including a fresh air supply unit for supplying fresh air into the operating space and an exhaust gas treatment unit for treating the gas in the operating space under set conditions; an open flame system for providing an open flame for testing cables; a water circulation system for supplying water at least to the exhaust gas treatment unit and the operating space; and a control system for collecting at least the temperature and gas concentration in the operating space, and performing process control based on the collected results. The actual working conditions of scenarios such as fire-resistant cable tunnels and fire-resistant cable trenches can be simulated, and multiple tests such as combustion performance test and physical and chemical performance test can be carried out under various working conditions.

Abstract: Disclosed is a low-voltage DC power distribution fast switching device. The device includes a positive output terminal electrically connected to a positive pole of a load, and no less than two switching circuits connected in parallel with each other; the switching circuit includes a positive input terminal electrically connected to a positive pole of common negative power supplies, a supplementary diode cluster composed of no less than one diode connected in series, and a thyristor connected between the positive input terminal and the positive output terminal; the positive input terminal is electrically connected to an anode of the supplementary diode cluster and an anode of the thyristor, and the positive output terminal is electrically connected to a cathode of the complementary diode cluster and a cathode of the thyristor.

Abstract: Disclosed is a low-voltage DC power distribution fast switching device. The device includes a positive output terminal electrically connected to a positive pole of a load, and no less than two switching circuits connected in parallel with each other; the switching circuit includes a positive input terminal electrically connected to a positive pole of common negative power supplies, a supplementary diode cluster composed of no less than one diode connected in series, and a thyristor connected between the positive input terminal and the positive output terminal; the positive input terminal is electrically connected to an anode of the supplementary diode cluster and an anode of the thyristor, and the positive output terminal is electrically connected to a cathode of the complementary diode cluster and a cathode of the thyristor.

Abstract: Disclosed is a fault current controller for a direct current power grid, which includes a primary circuit and a controller. The primary circuit includes an inductor, a filter capacitor, a resistor, an IGBT switch, a diode, a contactor and a Hall current sensor. The inductor, a first resistor and a second contactor are connected in series and are connected to a first contactor in parallel. A first branch including a second resistor and a first diode, a second branch including a third resistor and a second diode, and the inductor are connected in parallel; the filter capacitor, the IGBT switch and the first resistor are connected in parallel. The Hall current sensor is arranged in the series circuit. The controller controls the IGBT switch and the two contactors in the primary circuit to form different on-off combinations.

Abstract: Disclosed is a fault current controller for a direct current power grid, which includes a primary circuit and a controller. The primary circuit includes an inductor, a filter capacitor, a resistor, an IGBT switch, a diode, a contactor and a Hall current sensor. The inductor, a first resistor and a second contactor are connected in series and are connected to a first contactor in parallel. A first branch including a second resistor and a first diode, a second branch including a third resistor and a second diode, and the inductor are connected in parallel; the filter capacitor, the IGBT switch and the first resistor are connected in parallel. The Hall current sensor is arranged in the series circuit. The controller controls the IGBT switch and the two contactors in the primary circuit to form different on-off combinations.