55results about How to "Limit current" patented technology

The invention relates to a double-fed wind driven generator system and a low-voltage through control method. According to the double-fed wind driven generator and the low-voltage through control method on the basis of a Crowbar circuit and a battery energy storage device, the low-voltage through capability can be effectively improved under the condition of large-range voltage drop, the double-fed wind driven generator system can be still kept to be connected with a power grid, and the stability of a wind power system is improved.

The invention relates to a power fluctuation and malfunction control system and method of a direct-current-transmission double-fed wind turbine set, and belongs to the field of wind power. The system includes a double-fed power generator, a stator-side converter, a rotor-side converter, a net-side direct-current converter and an energy storage system. According to the method, firstly, the energy storage system supplies power to the rotator-side converter to achieve inverse conversion; secondly, after a draught fan is enabled, the stator-side converter conducts rectification boosting, the net-side direct-current converter conducts constant power control and controls the energy storage system to charge and discharge electricity to achieve power fluctuation suppression; if voltage drop occurs to a power network, the net-side direct-current converter conducts constant direct voltage control, and the rotator-side converter and the energy storage system run in a voltage drop malfunction control mode; if overvoltage occurs to the power network, the energy storage system conducts voltage clamp on the power network; if the network is disconnected, the net-side direct-current converter conducts constant direct voltage control, the rotator-side converter makes the output power of the power generator turn to zero; and finally, the net-side direct-current converter is switched off. The power fluctuation and malfunction control system and method of the direct-current-transmission double-fed wind turbine set are conducive to usage of the double-fed wind turbine set in a flexible direct current transmission system.

An actuator control system comprises an electric actuator, a driver, and a controller. The electric actuator is provided with a buffering mechanism which absorbs impact applied to a piston rod. The buffering mechanism includes piston dampers which absorb impact applied to a piston, a first end damper which is provided at an end of a housing facing the piston, and a second end damper which is provided on a rod cover separated from the housing by a predetermined distance.

The invention relates to a method for determining a thermal impedance of a semiconductor device, wherein the semiconductor device is energized with a warm-up current (101, 201), a power loss of the semiconductor device is determined, a voltage drop dependent on a temperature of the semiconductor device is detected on the semiconductor device (103, 205), the temperature of the semiconductor device over time is determined as a warm-up curve (104, 207), and the thermal impedance of the semiconductor device is determined as a quotient of the determined temperature and the determined power loss (106, 208).

The invention discloses a power distribution control circuit of a vehicle-mounted motor controller of an electric vehicle and a control method of the control circuit. The control circuit comprises a power battery, a complete vehicle logic unit, the vehicle-mounted motor controller, a drive motor controller, a power-on buffer circuit, a CAN bus and a vehicle-mounted electric control switch, wherein the complete vehicle logic unit is connected with the power battery, the vehicle-mounted motor controller and the drive motor controller, connected with a first electric control switch and a second electric control switch through low-tension control wires and then grounded; a negative electrode of the battery is connected to the vehicle-mounted motor controller and the drive motor controller; a positive electrode of the battery is connected with a parallel circuit formed by the power-on buffer circuit and the second electrical control switch and then connected to the drive motor controller and the vehicle-mounted motor controller. Multiple motor controllers share one power-on buffer circuit through specific control logic, a relay is used among the motor controllers for power distribution control, normal demands are met, and electrical safety can also be guaranteed.

The invention provides a current open circuit arc extinguishing device and method based on a nonlinear resistor. The problems that according to an existing arc extinguishing device of a circuit breaker, when high-current breaking happens, due to the low arc extinguishing capability, strong electric arcs are generated, and the service life of the circuit breaker is shortened, and even a contact is burnt out are solved. According to the direct-current circuit breaker arc extinguishing device designed based on the characteristics of the nonlinear resistor, the electric arc of the direct-current circuit breaker in the breaking process is reduced through shunting of the circuit and the current limiting capability of the nonlinear resistor. The aims of improving the breaking capacity of the circuit breaker and prolonging the service life of the circuit breaker are achieved.

The invention relates to a direct-current switch comprising a relay and a relay control module. The relay control module comprises an MCU which is in control connection with a coil of the relay and is sampling connection with a current sensor and a voltage sensor. The current sensor is used for measuring the current flowing through a contact loop of the relay, and the voltage sensor is used for measuring the input voltage of the direct-current switch. The current state and voltage state of the direct-current switch can be visually monitored in real time, so that the operating state of the direct-current switch can be known visually, and furthermore, the power consumption can be calculated based on the voltage and current values.

A simple low-cost vehicle-mounted low-power power supply protection circuit belongs to the field of automotive circuit control. The invention aims to solve the problems existing in the P5 test of automotive electronic devices. The present invention includes voltage stabilizing diode RD1, bidirectional voltage stabilizing diode RD2, resistors R1-R4, electrolytic capacitor C1 and capacitor C2; the anode of voltage stabilizing diode RD1 is used as the high voltage input end of P5; the cathode of voltage stabilizing diode RD1 is connected to one end of resistor R1 at the same time and one end of resistor R3, the other end of resistor R1 is simultaneously connected to one end of resistor R2, the other end of resistor R3 and one end of resistor R4; the other end of resistor R2 is connected to the other end of resistor R4, one end of bidirectional voltage regulator diode RD2, The anode of the electrolytic capacitor C1 and one end of the capacitor C2 serve as the output end of the protection circuit; the other end of the bidirectional voltage regulator diode RD2 is simultaneously connected to the negative electrode of the electrolytic capacitor C1 and the other end of the capacitor C2, and is grounded.

The invention discloses a frequency tracking circuit of a CMUT resonant biochemical sensor, and the circuit comprises a bias network, an impedance matching network, a CMUTs network, a load capacitancenetwork and a BJT amplification feedback network, wherein the bias network provides DC voltage for the CMUTs and avoids current overload; the impedance matching network tunes to make the CMUTs form aseries-parallel resonant region; and positive feedback of an oscillating signal is formed based on the BJT and the load capacitance network to realize real-time output of the oscillating signal of the CMUTs parallel resonance point. The frequency tracking circuit provided by the invention enables the CMUTs to form a series-parallel resonant region at a low voltage, and the resonant circuit is simple and convenient, the starting time is microsecond, and the CMUTs resonant frequency can be output in real time, which is of great significance for portable and real-time detection applications based on CMUTs resonant biochemical sensors.

The invention provides a surge protection device comprising a Y-shaped pressure-sensitive chip, and a distribution box. The surge protection device comprising the Y-shaped pressure-sensitive chip comprises an insulated fixing seat, the Y-shaped pressure-sensitive chip, a first electrode and a second electrode, wherein the first electrode and the second electrode are used for being connected with an external circuit, the Y-shaped pressure-sensitive chip is fixed on the fixing seat, the Y-shaped pressure-sensitive chip comprises an electrode A, an electrode B, an electrode C, a first piezoresistor chip and a second piezoresistor chip, the first piezoresistor chip is located between the electrode A and the electrode B, the second piezoresistor chip is located between the electrode A and the electrode C, the electrode B is electrically connected with the second electrode, and the electrode C is electrically connected with the first electrode. The surge protection device comprising the Y-shaped pressure-sensitive chip, and the distribution box can be used in a direct current system and an unconventional 690 VAC and above power system, and the safety performance is higher.

The invention relates to an electrical component and an electrical device therewith, wherein the electrical component includes a first coil 15, a second coil 20 and a switch element 80 includes, with the first coil 15 has a first input 30 and a first output 35, wherein the second coil 20 has a second input 45 and a second output 50, wherein the first input 30 to an electric power source is connectable, the second output 50 is connected to a consumer 70, wherein the second input 45 and second outputs 50 are connected one another via the switching element 80, wherein the first output 35 is connected to the second input 45, the first coil 15 is formed; increasing an electromagnetic tolerance of the load 70 and the second coil 20 is formed to limit a current to the load 70, the switching element 80 is formed, in the closed position substantially completely bridge the second coil 20 and in the open state a substantially to ensure full flow of electric current through the second coil 20.

A device is provided for intrinsically safe redundant current supply of field devices (3) with a common current-limiting resistor (21) in the mesh of the field device and with redundant current supply units (11, 12). In the system, a current sensor (22) can be provided in the mesh of the field device, the output signal of whichis connected to devices for controlling current or active current limiters (112,122) in the redundant current supply units.

The invention relates to a gas discharge comprehensive experiment platform, which comprises an induction voltage regulator, a corona-free test transformer, a protection impedance, a capacitive voltage divider, a voltmeter, a gas insulation performance test device and a constant current diode. Compared with a traditional gas discharge comprehensive test platform, constant-current diodes are additionally arranged on the voltage regulator side, the constant-current diodes are used for limiting current in a circuit, and meanwhile the overall withstand voltage value of the circuit is met in the mode that the constant-current diodes are connected in series.