47results about How to "Achieve zero current shutdown" patented technology

The disclosed phase-shift full bridge circuit for flexible switch comprises: a transformer, a lead/lag bridge arm connected with one/another end of the primary side of transformer, an auxiliary bridge arm connected with power end, a break capacitor between primary side of transformer and the lead arm, and an output circuit set on secondary side of the transformer. This invention makes both the lead and lag arm fit to zero voltage switch, and turns off the rectifying diode with zero voltage.

The invention relates to direct current (DC) step-up power conversion technology and discloses a current-type multi-resonance DC converter. The current-type multi-resonance DC converter comprises a square-wave current source generator, a multi-resonance network and a rectification filtering output unit which are sequentially connected in series, and is characterized in that: the multi-resonance network comprises a transformer, a parallel resonant inductor, a parallel resonant capacitor and a serial resonant inductor, wherein the serial resonant inductor is connected with a primary side of the transformer; the rectification filtering output unit comprises a diode rectifying circuit and a filtering capacitor which is connected with an output end of the diode rectifying circuit in parallel.

The invention discloses a control method for an aging power supply device, and belongs to the field of power electronic system control. The method comprises a control method of a single-phase AC/DC converter circuit, an open-loop control method adopted by an LLC resonant converter, and a control method of a bidirectional BUCK-BOOST converter circuit. Through the control method of the single-phaseAC/DC converter circuit, the DC bus voltage is kept constant, fluctuation of the power grid frequency and distortion of the grid connection current at the non-fundamental frequency are suppressed, andharmonic pollution to the power grid is reduced. Through the adoption of the open-loop control method, the series LLC resonant converter can work in an intermittent mode, the switching loss of the circuit is reduced, and meanwhile, the requirement of boosting between a direct-current bus and the input of the BUCK-BOOST converter circuit is also met. Through the control method of the bidirectionalBUCK-BOOST converter circuit, power sharing by a host and a slave in a constant-current mode is realized, switching tube driving signals of two BUCK-BOOST converters are subjected to phase shifting by 180 degrees to realize interleaved parallel connection, ripples of the current on the output side are reduced, and the quality of the output current is improved.

The invention relates to a high-frequency high-transformation-ratio bidirectional DC/DC converter based on coupled inductors, belongs to the technical field of power electronics and solves the problems that an existing non-isolated bidirectional DC/DC converter is high in switching stress and low in system efficiency. The DC/DC converter comprises a first filter unit, a boost-buck unit and a second filter unit. The first filter unit and the second filter unit are used for input filtering and output filtering of the boost-buck unit. The boost-buck unit comprises a coupled inductor L1, a coupledinductor L2, a resonant capacitor Cr, a switching tube S1, a switching tube S2 and a switching tube S3, and the switching tube S1, the switching tube S2 and the switching tube S3 are respectively provided with a body diode. The coupled inductor L1, the coupled inductor L2, the switching tube S1 and the switching tube S3 form a coupled inductor type boost circuit. The resonant capacitor Cr and leakage inductances of the two coupled inductors form an LC series resonant unit, and the LC series resonant unit, the switching tube S2 and the switching tube S3 form a half-bridge converter topology structure.

The invention relates to an inductor built-in boost unit converter, belonging to the technical field of power electronic converters. The inductor built-in boost unit converter comprises an inductor built-in boost unit, a direct-current voltage source, a power switch tube, an output power diode and a filter capacitor, wherein the inductor built-in boost unit comprises a coupling inductor, an energystorage capacitor and a freewheel diode. By the invention, the voltage gain can be increased to a relatively high level, the defect that a conventional Boost circuit is insufficient in boost capacityis overcome, and the inductor built-in boost unit converter has the advantages of high gain, simple structure and high conversion efficiency. Compared with an existing coupling inductor boost circuit, it is unnecessary to add extra leakage inductance energy absorption and switch tube clamping circuits, the inductor built-in boost unit converter has the simplest circuit structure and the minimum components, and the conversion efficiency and the reliability are higher.

The invention provides a vehicle-mounted charger control circuit and method, a charger and an electric vehicle. The vehicle-mounted charger control circuit comprises a filtering and rectification module, a power factor correction module, a half-bridge LLC resonant conversion module and a main control module, wherein the filtering and rectification module is used for converting an input alternating-current electric signal into a direct-current signal after filtering out an electromagnetic interference signal; the half-bridge LLC resonant conversion module is used for enabling switching tubes tooperate in a zero-voltage state so as to realize zero-voltage switching when the charger is charged; and the main control module is used for acquiring a resonant current zero-crossing point of the half-bridge LLC resonant conversion module and a voltage zero-crossing point of mid-point voltage of the half-bridge LLC resonant conversion module in real time. By comparing the potential difference between the two zero-crossing points, resonant network input impedance of the half-bridge LLC resonant conversion module is detected to ensure that the half-bridge LLC resonant conversion module works in an inductive area, and it is ensured that the charger works in a zero-voltage working area no matter load changes or the input voltage changes, thereby reducing harmonic pollution during charging ofthe charger.

The invention discloses an LCCL resonant structure for compensating a higher harmonic current by a basic wave current. The structure comprises a resonant inductor, an inductive contact-less power transfer (ICPT) system electric energy emission end coil, a parallel resonant capacitor and a series resonant capacitor, wherein the ICPT system electric energy emission end coil is connected in parallel with the parallel resonant capacitor and then is connected with the resonant inductor after being connected with the series resonant capacitor. The method for compensating the harmonic current of an input end of the LCCL resonant structure by the basic wave current of the input end of the LCCL resonant structure is employed, a parameter design relation of the structure is given, and the purpose that a full-bridge inverter of the ICPT system connected with the LCCL resonant structure works in a zero-current switch-off state is achieved.

Characters of the method for controlling current regulator of charging and discharging superconducting magnet are as following: through relative phase shift between leading and lag bridge arms, unit of voltage (UV) in full bridge phase shift control mode adjusts charging and discharging power; through UV, auxiliary electric potential is supplied for unit of current; in time of phase change, switch tubes on two branches of converter in current source gives trigger signal to switch tube to be turned on first, and then, to switch tube of controlling converter of UV; thus, commutation voltage is generated at primary side of transformer, and converted into secondary side; the related current is opposite to current of switch tube to be turned off so as to turn off the switch tube when current is reduced to zero; and the related current is same to current of switch tube to be turned on so as to increase current. Features are: reducing loss of switch tube, and increasing stability of system.

The invention discloses a double-lamp indicating solid-state relay, which comprises a control signal input module, an input indication module, an optocoupler triggering control circuit and an output indication module, wherein the optocoupler triggering control circuit and the output indication module are connected with a load circuit; the load circuit comprises a load power supply, a load and two parallelly connected diodes; one diode is directly connected with the optocoupler triggering control circuit; and the output indication module is arranged between the other diode and the optocoupler triggering control circuit. The double-lamp indicating solid-state relay has a simple structure; by the double-lamp indicating solid-state relay, the operating state of a product can be clearly judged; and in addition, due to a resistance-capacitance (RC) absorption protection circuit and the photoelectric isolation of input and output, a circuit can safely and reliably work, and can be switched on/off for hundreds of millions of times, and zero-current switching-off and non-contact switching-on/off can be realized.

The invention provides a current source type bidirectional multipulse converter based on a polarity-variable direct current bus, which comprises a direct current side circuit (1), a three-phase alternating current power supply (5), a one-way three-phase bridge set (3), a multipulse transformer (4) and a control circuit (8), wherein the direct current side circuit (1), the one-way three-phase bridge set (3), the multipulse transformer (4) and the three-phase alternating current power supply (5) are sequentially connected with one another; the signal input end of the control circuit (8) is connected between the multipulse transformer (4) and the three-phase alternating current power supply (5); and the control end of the control circuit (8) is connected with the one-way three-phase bridge set (3). The circuit topology, provided by the invention, can realize two-way energy flow of a current source type multipulse inverter, and directly controls current on the three-phase alternating current side; a controller and a filter are independent of each other; the converter has a simple design and high reliability, and is suitable for various locations needing the multipulse converter to realize two-way energy transmission.

The invention relates to a novel compound switch for high-voltage capacitor switching and a working method of the novel compound switch. The compound switch comprises a compound switch control system, diode strings and mechanical switches, wherein each of A and C two phases is provided with two mechanical switches, namely a primary switch and an auxiliary switch; each primary switch is connected with one diode string in parallel; only one auxiliary mechanical switch is arranged on a B phase for playing an isolating role; and the compound switch control system comprises a voltage and current detection circuit, mechanical switch drive circuits, an operating mechanism energy-storage capacitor charging control circuit, a compound switch state display circuit and a digital control system. By the novel compound switch, voltage zero point turn-on and current zero point turn-off of the compound switch can be achieved; switching inrush current and breaking overvoltage in the switching process are eliminated; and non-arc operation of the mechanical switches can also be achieved. Meanwhile, a thyristor string is replaced with the diode strings; and compared with a traditional compound switch, the novel compound switch has the advantages that complicated trigger circuit is not needed and the problem of the damage caused by over-voltage conduction by mistake of a lightning stroke and the like is solved.

The invention discloses a quasi-resonant staggered switched capacitor battery equalization circuit and a control method thereof. The equalization circuit comprises a battery pack 1, a battery pack 2,an equalization subcircuit 1, an equalization subcircuit 2 and an equalization subcircuit 3; the battery packs composed of 2n batteries in series connection are divided into the battery pack 1 and thebattery pack 3; the equalization subcircuit 1 is connected with the battery pack 1, the equalization subcircuit 2 is connected with the battery pack 2, and the equalization subcircuit 3 is connectedwith the battery pack 1 and the battery pack 2. A pair of drive signals with fixed frequency, supplementary duty ratio and dead time are used for controlling the connection and disconnection of switchtubes inside the equalization subcircuit 2 and the equalization subcircuit 3 in the equalization subcircuit 1, the energy of high-voltage batteries is transmitted to low-voltage batteries through equalization capacitors, and automatic equalization for the voltage of each battery is realized. The equalization path between any two batteries is shortened, and two equalization passages are provided for any two batteries incapable of direct equalization, so that the influence of battery quantity on equalization speed is eliminated.

The invention provides a soft switching isolation DC-DC converter for train auxiliary power supply. The converter comprises a boost module used for carrying out boost processing on a power supply voltage accessed to the converter to obtain a predetermined high voltage, a resonance module used for realizing the zero-current turn-off based on a circuit state at a current moment, and an inversion module used for inverting the predetermined voltage into a predetermined low voltage according to a turn-off state of the current boost module, and the boost module, the resonance module and the inversion module are sequentially connected in series. According to the technical scheme, the total size and weight of a circuit can be reduced, meanwhile, higher accuracy can be guaranteed for the operationwithin the whole range of the output power, and the control manner of the converter does not need to be changed even under the no-load condition.

The invention discloses a soft switch resonance DC converter reducing the voltage stress of a diode. The soft switch resonance DC converter absorbs a part of leakage inductance of a transformer and takes the part as a resonance inductance, and absorbs a junction capacitance of a switch tube and a junction capacitance of the diode and takes the absorbed junction capacitance as part of the resonanceinductance. The related converter can realize zero-voltage switching ON/OFF of a switch tube and the diode and zero-current switching OFF of the diode, the switching loss of the converter is almost 0, the efficiency of the converter is improved, the voltage stress of the diode is clamped to two times of the output voltage, and the voltage stress is reduced.

The invention provides a high-voltage double-pulse superposed power supply for an electrostatic dust collector. The high-voltage double-pulse superposed power supply for the electrostatic dust collector adopts three-phase input, and adopts a series resonant mode through a resonant circuit to realize zero current shutdowns; and the highest output pulse frequency is designed to be 40KHZ. The high-voltage double-pulse superposed power supply for the electrostatic dust collector effectively solves the problem of insufficient power of the high-frequency pulse power supply in the prior art, and hasthe advantages of the high-frequency pulse power supply of three-phase balance, small ripple factor, high flashover voltage and constant current characteristics; the generation of anti-corona can be avoided for high specific resistance dust; and meanwhile, the double pulse is superposed, therefore, the ultra-fine dust collection is improved, and the dust removal efficiency and power application range are improved.

The invention provides a bidirectional isolation type resonant power converter control method based on a virtual synchronous motor to solve the problems of lack of rotational inertia in the charging and discharging process of an electric vehicle, low voltage stability of a power electronic converter, efficiency reduction caused by large reactive power in the operation process and the like. The bidirectional power converter is composed of a DC/DC stage and a DC/AC stage. According to the structural similarity of a three-phase synchronous motor model and a three-phase converter, the DC/AC-levelthree-phase converter can be equivalent to a synchronous motor, the whole electric vehicle charging pile is equivalent to a synchronous motor at the grid-connected point, and the motor can respond tovoltage and frequency disturbance of a power grid in a self-adaptive mode and provide necessary inertia and damping for the power grid. In order to overcome the defect of power loss caused by large reactive current of a traditional DAB converter, a resonance module is added, zero-voltage connection and zero-current disconnection of an interface converter switching device are achieved, and the overall operation efficiency of the converter is improved.

The invention provides an uninterruptible power supply, an on-off control module, a control method and a system, and relates to the technical field of electronic power supply. Wherein the input end of the uninterruptible power supply is connected with a power supply through a first on-off control module, and a controller of the uninterruptible power supply is used for controlling the current in a line, connected with a first on-off control module, of the uninterruptible power supply to be zero after receiving a first control signal sent by the first on-off control module. The output end of the uninterruptible power supply is connected with the load through the second on-off control module, and the controller of the uninterruptible power supply is used for controlling the uninterruptible power supply to be shut down after receiving a second control signal sent by a second on-off control module. According to the technical scheme of the invention, the arc discharge problem can be avoided, so that the cost of using the on-off control module can be reduced.

The invention discloses a modulation system and method for a cycle conversion type high-frequency link inverter. The system comprises a main circuit topology, a double-closed-loop controller and a switch modulation strategy module. The method comprises the following steps of: analyzing a relationship between voltage stress and a switching time sequence by taking the voltage stress of a switching tube as a starting point, obtaining switching combinations under different modulation strategies through states of leakage inductance current of a transformer under different modulation strategies, and realizing energy transmission between the primary side and the secondary side of the converter; establishing a converter dynamic mathematical model to obtain a transfer function of the system; and designing a discrete controller to obtain a reference modulation wave, and finally, designing a logic relationship between corresponding switching tubes to realize the safe soft commutation of the cycloconverter and the converter function. According to the invention, an effective modulation strategy is provided for the high-frequency link inverter, the leakage inductance current of the transformer is naturally reduced to zero, the voltage stress generated by the interruption of the inductive current during the commutation of the switching tube can be reduced, the soft switching of the converter can be realized, and the method has very high practicability.

The invention discloses a DCDC converter, and the converter comprises a step-down circuit and a resonant unit, which are connected in series. The converter also comprises a controller for controlling the step-down circuit and the resonant unit. The step-down circuit is used for the step-down of an input voltage so as to input the voltage to the input end of the resonant unit. The controller is used for obtaining the output end voltage of the resonant unit, and controls the output voltage of the step-down circuit according to a target value of the output end voltage, controls the switching frequency of the resonant unit till the output end voltage reaches the target value, and controls the switching frequency of the resonant unit to be less than or equal to the resonant frequency after the output end voltage reaches the target value. Because the step-down range of the step-down circuit is wider, the switching frequency of the resonant unit can be guaranteed to be less than the resonant frequency in a longer time period. Therefore, the converter solves a problem that the switching frequency increases with the decrease of the target value in the prior art, thereby reducing the loss of a rectification diode. In addition, the invention also discloses a control method for the DCDC converter, and the beneficial effects are shown as above.

The invention provides a commutation driving circuit of a ring winding permanent magnet brushless DC motor. A power switch in the next state is conducted and a power switch in the previous state is disconnected simultaneously, or the two power switches are simultaneously conducted within a quite short period of time; diodes provide a freewheeling path in commutation; commutation windings quickly change direction under the effect of DC side voltage; and the commutation moment is the moment when the induced electromotive force of the windings is zero, and then the output torque of the motor is the maximum output torque. The commutation driving circuit is high in commutation speed and suitable for the situations of relatively high frequency of commutation, such as a multipolar motor or a high-speed motor.