31results about How to "Solve the problem of overvoltage" patented technology

The invention provides an in-station single-phase grounding fault control protection method for a bipolar flexible direct current power transmission system. After a voltage source transverter in which an in-station single-phase grounding fault occurs is locked, a lower bridge arm submodule of a non-single phase grounding fault phase is triggered to be a cutoff state again, alternating current direct current bias can be rapidly reduced, and the problem of submodule overvoltage caused by non-fault phase alternating voltage is avoided, thereby reducing fault removing time and overvoltage strain of a transient submodule; and closing a high-speed bypass switch of the lower bridge arm submodule of the non-single phase grounding fault phase can effectively solve the problem of alternating current direct current bias and the problem of submodule overvoltage, thereby guaranteeing normal switching-off of an alternating current circuit breaker, and protecting the transverter to the greatest extent.

The invention relates to an inductance energy storage pulse power supply utilizing a superconducting pulse transformer, which belongs to the technical field of pulse power. It is characterized in that it includes a superconducting pulse transformer, a primary power supply is arranged on the primary side of the superconducting pulse transformer, and the output terminal of the primary power supply is simultaneously connected to the conversion branch, the freewheeling branch and the primary side of the superconducting pulse transformer through a controllable switch S1 At both ends of the winding, there is also an energy recovery branch connected between the conversion branch and the primary power supply; on the secondary side of the superconducting pulse transformer, one end of the secondary winding is connected to one end of the load control branch, and the other end of the secondary winding One end is connected to at least one set of superconducting energy storage inductance charging branch and one end of the switching branch at the same time, and the load control branch, the superconducting energy storage inductance charging branch and the other end of the switching branch are connected at one place. The inductive energy storage pulse power supply using superconducting pulse transformer adopts multi-module superconducting energy storage inductance to release more energy to the load, and at the same time solves the problem of overvoltage at the moment of switching.

The invention discloses a non-contact power transmission device and a power transmission method. The rectification and filtering circuit receives the high-frequency alternating current output by the receiving coil, and obtains a direct current voltage signal after being rectified and filtered by the full bridge. When the rectified and filtered When the DC voltage exceeds the predetermined value, a current loop is formed by using the switch protection circuit, the impedance matching circuit and the receiving coil, so that the energy of the receiving coil is transferred until the current voltage drops to no more than the predetermined voltage value. Wherein, the switch protection circuit is connected between the impedance matching network and the ground. When the power transmission device works normally, the switch protection circuit does not work. When an overvoltage occurs, the switch protection circuit performs a switching action to reduce the DC voltage. value.

The invention provides an output port overvoltage protection circuit of battery testing equipment, which includes a power conversion circuit, a relay, an output port, a battery, a detection circuit, a logic circuit, a host computer and a drive circuit; the control input end of the power conversion circuit is connected to the host computer. The power output end of the power conversion circuit is electrically connected to the output port through the switch of the relay, and the output port is electrically connected to the battery; the coil of the relay is electrically connected to the output end of the drive circuit, and the input end of the overvoltage detection circuit is electrically connected to The output port is electrically connected, the output end of the overvoltage detection circuit is electrically connected with the input end of the logic circuit, and the output end of the logic circuit is electrically connected with the upper computer and the input end of the driving circuit respectively. The invention ensures the safety and reliability of real-time alarm and protection after the output port of the device is over-voltage.

The invention discloses a fault protection method for a hybrid cascaded multi-terminal direct current power transmission system. The faulty modular multi-level converter jumps off its connected AC switch, and at the same time sends a phase-shift command to the rectifier-converter station through inter-station communication; the rectifier-converter station immediately executes the phase-shift after receiving the command; After waiting for a first preset time, the station blocks other non-faulty modular multilevel converters connected in parallel. The invention can effectively solve the problem of sub-module overvoltage caused by the simultaneous blocking of modular multi-level converters in the hybrid cascade multi-terminal direct current transmission system, can effectively reduce the energy demand of the direct current energy consumption device, and better protect each equipment security.

The invention discloses an auxiliary resonant commutation pole inverter with phase-correlated ZVT magnetization current minimization, which includes a main circuit and an auxiliary circuit; the phase-shifting full-bridge network charges the auxiliary resonant pole inductance through an isolation transformer to realize the main switch. ZVS; the energy storage in the magnetizing inductance realizes the ZVS of the auxiliary switch. The commutation charging phase is anti-correlated with the reset phase locking, which realizes the bidirectional reset of the magnetizing current and reduces the volume of the magnetic core. The improved timing modulation effectively reduces the freewheeling loss of the magnetizing current and the turn-off loss of the auxiliary switch. Using the phase correlation method to maintain the existing technology, realize the advantages of zero-voltage turn-on of the main switch tube, reduce the switching loss of the main switch, in addition, the auxiliary switch in the auxiliary circuit also realizes zero-voltage turn-on through the energy storage in the excitation inductance And its withstand voltage value is much smaller than that of the main switch; and the magnetizing current reset is reliably realized in each switching cycle, and the secondary winding coupling of the transformer solves the problem of the auxiliary commutation diode D c1 and D c2 overvoltage problem.