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

The invention discloses an auxiliary resonant converter pole inverter with minimized phase-associated ZVT magnetizing current. The auxiliary resonant converter pole inverter comprises a main circuit and an auxiliary circuit, a phase-shifted full-bridge network charges an auxiliary resonance electrode inductor through an isolation transformer to realize ZVS of a main switch, and ZVS of an auxiliaryswitch is realized through energy storage in the excitation inductor. The commutation charging phase and the reset phase are locked and inversely associated, so that magnetization current bidirectional reset is realized, and the volume of the magnetic core is reduced. The improved time sequence modulation effectively reduces the follow current loss of the magnetizing current and the turn-off lossof the auxiliary switch. A phase correlation method is used for keeping the existing technology, the advantage of zero-voltage switching of a main switch tube is achieved, the switching loss of the main switch is reduced, in addition, zero-voltage switching of the auxiliary switch in an auxiliary loop is achieved through energy storage in the excitation inductor, and the withstand voltage value of the auxiliary switch is far smaller than that of the main switch. Magnetizing current reset is reliably realized in each switching period, and the problem of overvoltage of auxiliary converter diodes Dc1 and Dc2 is solved through coupling of a secondary winding of the transformer.

The invention relates to an inductance energy storage pulse power source utilizing a superconductive pulse transformer and belongs to the technical field of pulse power. The inductance energy storage pulse power source is characterized by comprising the superconductive pulse transformer, a primary side of the superconductive pulse transformer is provided with a primary power source, an output end of the primary power source is separately connected with a conversion branch, a freewheeling branch and two ends of a superconductive pulse transformer primary winding through a controllable switch S1, an energy recuperation branch is connected between the conversion branch and the primary power source, for a secondary side of the superconductive pulse transformer, one end of a secondary side winding is connected with one end of a load control branch, the other end of the secondary side winding is separately connected with at least one set of superconductive energy storage inductance charging branches and one end of a switching branch, and the load control branch, the superconductive energy storage inductance charging branches and the other end of the switching branch are connected at one portion. According to the inductance energy storage pulse power source utilizing the superconductive pulse transformer, multi-modular superconductive energy storage inductors are employed, more energy is released to the load, and an instant overvoltage problem during switch switching is further solved.

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 embodiment of the present invention provides a driving circuit for a switch bridge arm, including: a driving chip, a double-winding driving transformer and a driving module; The two ends of the primary side are connected; the two ends of the secondary side of the double-winding drive transformer are respectively connected to the first input end and the second input end of the drive module; the first output end of the drive module is used to connect with the upper tube of the switch bridge arm The gate connection of the drive module, the second output terminal of the driving module is used to connect with the source of the upper tube of the switch bridge arm; the second output terminal of the driver chip is used to connect with the gate of the lower tube of the switch bridge arm; wherein, the drive The module is used to make only the voltage higher than the preset threshold value act on the gate and source of the upper transistor of the switch bridge arm. The drive circuit can solve the overvoltage problem of the power supply pin and the ground terminal pin of the upper tube floating drive circuit, and can improve the reliability of the upper tube drive of the switch bridge arm.

The invention discloses a method for preventing overvoltage of the neutral point of a main transformer in high-permeability photovoltaic access. The method is based on a traditional photovoltaic grid-connected decoupling double closed-loop control method, and can be divided into 3 states: in a state 1, the voltage of the neutral point of the main transformer is over the rated voltage but the overvoltage is within an allowable range, and a traditional grid-connected control method is adopted; in a state 2, the voltage of the neutral point of the main transformer rises to the phase voltage and does not reach the breakdown condition, the voltage and current of the grid connection point and the voltage of the neutral point of the main transformer are collected, the photovoltaic grid connectionphase angle is adjusted to limit the voltage of the neutral point of the main transformer within a safety range, and active power output of photovoltaic grid connection is ensured; and in a state 3,the voltage of the neutral point of the main transformer is broken down, the photovoltaic power supply operates in an off-grid mode, the voltage of the neutral point of the main transformer decreasessubstantially, and the photovoltaic system is connected with an energy storage device through a DC converter. By changing the photovoltaic grid-connected control strategy and adding a supporting energy storage device, the problem that transformer damage is caused due to too high voltage of the neutral point of the main transformer during operation of a high-permeability photovoltaic access grid infault can be solved.

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 a step-up DC / DC converter, which includes a step-up output circuit, a feedback control circuit and an overvoltage protection circuit. The boost output circuit includes an inductor, a first switch device, a second switch device and a capacitor; the connection node between the second switch device and the capacitor serves as the output terminal VOUT of the boost output circuit. The first input terminal of the feedback control circuit is connected to the output terminal VOUT, the first output terminal is connected to the control terminal of the first switching device, and the second output terminal is connected to the control terminal of the second switching device. The overvoltage protection circuit includes a third switching device and an overvoltage detection circuit, the third switching device is connected in parallel with the inductor; the overvoltage detection circuit is used to detect whether the output voltage of the output terminal VOUT is overvoltage, and when it is detected that the output voltage is not overvoltage, The overvoltage detection circuit controls the third switch device to be turned off; when the output voltage overvoltage is detected, the overvoltage detection circuit controls the third switch device to be turned on. Compared with the prior art, the step-up DC / DC converter in the present invention can prevent the output voltage from overvoltage.

The invention discloses an auxiliary resonant commutation pole inverter with bidirectional reset of the phase-related magnetizing current, which realizes the advantages of zero-voltage turn-on of the main switching tube and reduces the switching loss of the main switch. In addition, the auxiliary switch in the auxiliary circuit, The zero-voltage turn-on is also realized through the energy storage in the magnetizing 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, which effectively reduces the volume of the transformer; the secondary side of the transformer Winding coupling solves the auxiliary commutation diode D c1 and D c2 overvoltage problem. The zero-voltage turn-on of the main switch and the auxiliary switch can be realized; the efficiency and power density can be effectively improved, and the cost and EMI can be reduced.

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 clamped by a phase-correlated voltage regulator tube, 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. Zener tube clamp effectively protects the auxiliary commutation diode. The circuit of the present invention maintains the prior art by using the phase correlation method, realizes the zero-voltage turn-on of the main switch and the auxiliary switch, reduces the switching loss of the main switch, effectively improves efficiency and power density, and reduces cost and EMI. In addition, in the auxiliary circuit The auxiliary switch of the auxiliary switch also realizes zero-voltage turn-on through the energy storage in the exciting inductance, and its withstand voltage value is much lower than that of the main switch; the coupling of the secondary winding of the transformer solves the problem of the auxiliary commutation diode D c1 and D c2 overvoltage problem.

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.

The invention discloses an auxiliary resonant commutation pole inverter in which the phase-correlated magnetization current is symmetrically reset. The circuit of the invention maintains the prior art by using the phase-correlation method, realizes the advantages of zero-voltage turn-on of the main switching tube, and reduces the 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 , which effectively reduces the volume of the transformer; the secondary winding coupling of the transformer solves the problem of the auxiliary commutation diode D N1 and D N2 overvoltage problem.

The invention provides a voltage control method and device for a distributed optical storage system in a power distribution network, and relates to the technical field of power system analysis control. The method comprises the steps of acquiring the actual output of each distributed optical storage system at the current moment; constructing an objective function based on the output reduction amount of each distributed optical storage system, wherein the output reduction amount is the difference between the predicted output at the next moment and the actual output at the current moment; under the constraint condition of the objective function, solving the optimal value, which enables the objective function to be the minimum, of the output reduction amount of each distributed optical storage system so as to obtain the optimal predicted output at the next moment; and according to the relationship between the maximum actual output of each distributed optical storage system and the maximum predicted output of the distributed optical storage system, correcting the optimal predicted output of each distributed optical storage system at the next moment to obtain the actual control output of each distributed optical storage system at the next moment. According to the invention, the stability of the voltage of the power distribution network comprising a plurality of distributed optical storage systems can be improved.