78results about How to "Achieve zero voltage turn-on" patented technology

The invention discloses a super-wide output voltage range charger based on LLC topology and a control method. The super-wide output voltage range charger comprises an LLC resonant converter and a control circuit. The LLC resonant converter comprises a switch network composed of an MOSFET full-bridge conversion circuit, the input end of the switch network is connected with the input end of a power source, the output end of the switch network is connected with the input end of a resonant network, the output end of the resonant network is connected with a leakage inductor of a transformer, and a secondary side coil of the transformer is connected with a rectifying and filtering network; the control circuit comprises a control unit, the control unit controls MOS tubes of the MOSFET full-bridge conversion circuit to be connected or disconnected according to received signals at the input end and the output end of the LLC resonant converter, and therefore the LLC resonant converter can achieve no-voltage connection of a primary side switch tube and no-current disconnection of a secondary side rectifying diode within a full voltage range. The super-wide output voltage range charger is wide in output voltage, free of limitation of the input voltage range of a charged object and capable of charging various new energy electric vehicles.

The present invention provides a zero-voltage switching synchronous rectification Boost circuit, a zero-voltage switching Boost circuit and a control method thereof. An auxiliary resonance circuit isconnected in series with a rectifying circuit of a main power circuit, when a main power switch tube is switched off, the current of a Boost inductor is employed to achieve zero-voltage conduction ofan auxiliary switch tube, resonances of a resonance capacitor and a resonance inductor are employed to achieve rapid increasing of the current of the resonance inductor and prompt the current of the resonance inductor to be larger than the current of the Boost inductor, a diode connected in parallel with the resonance capacitor is employed to perform follow current of the current of the resonanceinductor to ensure that the voltage of the resonance capacitor cannot be inversed and the current of the resonance inductor cannot be rapidly reduced after reaching the maximum value. After the auxiliary switch tube is switched off, the difference of the resonance current and the Boost inductor current is employed to achieve zero-voltage opening of the main switch tube.

The invention discloses a resonance boost DC/DC converter and a control method thereof suitable for high-voltage and high-power occasions. The converter is connected with a direct-current input power source and a load and comprises two primary-side diodes, a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a resonance unit, a first rectifier diode, a second rectifier diode and two filter capacitors. The resonance boost DC/DC converter is characterized in that the resonance unit is connected with a bridge arm composed of the four switching tubes and a rectifier unit composed of the two rectifier diodes and the two filter capacitors. According to the resonance boost DC/DC converter and the control method thereof, approximate zero voltage switching-off of the switching tubes and zero current switching-off of the rectifier diodes can be achieved, losses can be greatly reduced, and meanwhile the voltage stress of all switching devices is not larger than one second of the output voltage. A resonance circuit can be used for the high-power boost occasions.

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 provides a high-gain Boost converter based on a three-winding coupled inductor and a working method of the high-gain Boost converter. The high-gain Boost converter comprises a Boost unit, an auxiliary Boost unit, a voltage doubling unit and a low ripple unit; the Boost unit comprises a primary winding, a first switching tube, a second switching tube and a fourth capacitor and a fifthcapacitor which are connected in series; the positive electrode of a power supply is connected with the non-dotted terminal of the first winding; the dotted terminal of the primary winding is connected with the drain electrode of the first switching tube and the source electrode of the second switching tube; the source electrode of the first switching tube and the source electrode of the second switching tube are connected to the two ends of the fifth capacitor respectively; and the negative electrode of the power supply is connected with the source electrode of the first switching tube. Theproblem of low efficiency of the Boost converter in the prior art is solved.

The invention discloses an isolation three-port DC-DC converter. The isolation three-port DC-DC converter comprises a three-winding transformer, a DC-isolation capacitor, two full-bridge circuits, a full-wave rectification circuit and two LC resonant cavities, wherein the two LC resonant cavities respectively comprises a first resonant inductor, a first resonant capacitor, a second resonant inductor and a second resonant capacitor, a DC bus-side winding is connected with a DC bus port by the DC-isolation capacitor and a first full-bridge circuit, a high-voltage battery-side winding is connected with a high-voltage battery port by the first resonant inductor, the first resonant capacitor and a second full-bridge circuit, and a low-voltage battery-side winding is connected with a low-voltagebattery port by the second resonant inductor, the second resonant capacitor and the full-wave rectification circuit. The isolation three-port DC-DC converter employs a three-winding structure, the numbers of rectification diodes and transformers are reduced, the power loss is reduced, and the circuit conversion efficiency is improved.

The invention relates to a topological structure of an asymmetrical half-bridge converter. A PWM control chip generates two phase-complementary driving pulses, and generates two driving signals VGS1 and VGS2 through an isolated driving circuit. With dead time, VGS1 drives power transistor Q1, and VGS2 drives power transistor Q2; power transistors Q1 and Q2 are connected in series to form a half-bridge bridge arm, and the midpoint A of the bridge arm is connected to The primary side coil of the power transformer T1; the secondary side coil of the power transformer T1 is connected with a full-wave rectification filter circuit, followed by a filter capacitor Cf to output a stable DC voltage Vo. The asymmetrical half-bridge converter of the present invention can conveniently realize DC voltage conversion through the resonant inductance, the parasitic capacitance of the power device, and the leakage inductance of the power transformer, and realize the high-voltage and low-current output of the power device. Zero-voltage conduction improves power conversion efficiency, is convenient to control, and has remarkable effects.

The invention provides a half-bridge LLC resonant converter staggered parallel circuit and a current sharing control method thereof. Two phase half-bridge LLC resonant converters are staggered and connected in parallel. Two capacitors connected in series are on the direct current input side of each phase half-bridge LLC resonant converter, and a resonant cavity is connected through a T-switch network. The secondary side of a transformer is connected with a rectifier circuit, an output capacitor and a load. According to the invention, the insertion of the Vin/2 state in the input voltage of theresonant cavity is realized by adding an auxiliary path and MOS tubes, so as to reduce the effective value of the fundamental wave of the input voltage of the resonant cavity; the gain of the LLC resonant converters can be reduced while the switching frequency remains unchanged; in the case of parallel interleaving at the same frequency, the resonance current of each phase can be compared with the average value of the resonance current of a parallel system; the gain of each phase LLC resonant converter is adjusted to achieve current sharing control; and all MOS tubes on the primary side can achieve zero voltage turn-on.

The invention discloses an all-digital soft switching control circuit of a four-switch buck-boost bidirectional converter, and belongs to the technical field of control of power electronic converters. According to the invention, the converter works in a critical conduction mode, and zero-voltage conduction of the switch tube can be realized in a full-load range. During boost operation, a PI controller forming a current regulator and a voltage regulator calculates the turn-off time of a switch tube, and keeps the turn-on time constant; during step-down operation, the PI controller calculates the conduction time of the switch tube and keeps the conduction time constant for a short time; on the basis, the dead time is dynamically adjusted according to the input and output voltage of the converter, so that zero-voltage conduction of all switching tubes is realized. According to the invention, a high-cost zero-cross detection circuit is omitted, the control is simple and easy to realize, the power density of the converter is improved, and the method has a wide application prospect in the field of power electronic converters.

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.

Disclosed is an active clamping forward switching power supply circuit. On the basis of an LCL forward converter, the N<P1> dotted terminal of a transformer B is connected with a power supply, and the N<P2> dotted terminal is grounded; the N<P1> and N<P2> are in double-wire parallel winding; one end of a capacitor C1 is connected with the non-dotted terminal of the N<P1> while the other end is connected with the non-dotted terminal of the N<P2>; the dotted terminal of the N<P2> and a clamping network 400 which is connected with a C3 in series are connected with the power supply through a field effect transistor Q2, so that the conditions are realized as follows: when a Q1 is in a saturation switch-on state, N<P1> and N<P2> both can be excited, and a secondary side NS outputs energy; when the Q1 is switched off, an L1 outputs energy based on follow current, a D2 is synchronously switched off, the energy generated by exciting is clamped through the N<P2> via 400, the primary side is in an inductive state, the Q2 is switched on, the C3 and the primary side inductor are in resonance, and zero-voltage switching on of the Q1 is realized; in a light load state, the Q2 is switched on after several periods, and during the period, the end voltage of the C3 is increased in a step manner; when the Q2 is re-switched-on, the C3 and the primary side inductor are in resonance, and the zero-voltage switching on of the Q1 is realized, so that power consumption in driving the Q2 in the light load state is lowered; and consequently, the duty ratio can be greater than 0.5, demagnetized energy recycling can be realized, and the efficiency is improved in the light load state.

The invention provides a dual-motor drive inverter. The dual-motor drive inverter comprises a direct-current power supply, six switching tube bridge arms and two motors; each switching tube bridge arm is connected between the positive pole and negative pole of the direct-current power supply; each switching tube bridge arm is compose of a transistor and a diode which are in series connection; and the first center line of the first motor is connected with the positive bus of the direct-current power supply, the second center line of the second motor is connected with the negative bus of the direct-current power supply, and the three phases of each motor are connected with the middle points of the switching tube bridge arms, and therefore, control on the three-phase voltage of the two motors can be realized. The dual-motor drive inverter of the invention has the advantages of simple structure and few used electronic components. According to the dual-motor drive inverter adopted, the zero-voltage switching on of the switching devices can be realized, and the efficiency of the dual-motor drive inverter can be improved.

The invention discloses an active clamping LED driving power supply without an electrolytic capacitor. The active clamping LED driving power supply comprises an AC input power supply, an input filtering part, a rectification part, a clamping circuit, a flyback converter, an output filtering capacitor Co, a parallel absorption loop and an LED load. The input filtering part is composed of an input filtering inductor and an input filtering capacitor. The rectification part is composed of four switch tubes. The clamping circuit is composed of a switching tube S2 and a clamping capacitor Caux; theflyback converter is composed of a flyback transformer, a switching tube S1 and a diode Ds. The flyback transformer comprises a primary side winding and a secondary side winding, the primary side winding comprises a main inductor Lm and a leakage inductor Lr, the primary side winding is connected with the input, and the secondary side winding is connected with the output; the parallel absorption circuit comprises a boost inductor Lb, a switching tube S3, a switching tube S4 and an energy storage capacitor Cds. According to the invention, the active clamping circuit is introduced, so that the switching stress of the switching tube S1 is reduced; both the switching tube S1 and the switching tube S2 realize soft switching, so that the switching loss is reduced; meanwhile, leakage inductance energy can be fed back.

The invention discloses an efficiency optimization control method for a wireless power transmission system. The efficiency optimization control method comprises the following steps: step 1, a control system is accessed to the wireless power transmission system based on a bilateral LCC compensation network; 2, according to the detected voltage and current values of the secondary side direct current side and a duty ratio value beta s obtained by sampling an input voltage vcd duty ratio detection circuit, a phase update value in a main control PWM module is obtained, and phase locking and output voltage and current control are achieved; the input current irs is ahead of the input voltage vcd through a phase-locked link, so that the input impedance of the rectifier is capacitive, and zero-voltage switching-on of the secondary side rectifier is realized; and the duty ratio beta s of the input voltage vcd is controlled through the voltage loop controlled rectifier, so that the output voltage V2 and the current I2 are controlled; and step 3, the working mode of an inverter is adjusted according to the adjustable range of the input voltage of the inverter. According to the invention, the output voltage and current control of the system is simplified without depending on communication and control.

The invention discloses a soft switching control circuit of a coupled inductor interleaved four-switch buck-boost bidirectional converter, belongs to the technical field of control of power electronic converters, and can enable the converter to work in a critical state under the condition of considering nonlinearity of coupled inductors. Zero-voltage conduction of the switch tube can be realized under the conditions of different loads and input and output voltages; according to the invention, a method for calculating the turn-off time and the dead time by considering the influence of the coupling inductance is provided, so that zero-voltage conduction of all switching tubes is realized; by adopting the interleaving parallel structure, the inductive current flowing through each switching tube can be effectively reduced, the on-state loss is reduced, the control is simple and easy to realize, the high power density of the converter is facilitated, and the interleaving parallel structure has a wide application prospect in the field of low-voltage large-current lithium battery charging and discharging.

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 discloses an inverter power source device used for converting a direct current output by a direct-current power source into an alternating current. The inverter power source device comprises a preceding-stage current feed circuit and a posterior-stage inverter circuit. The current feed circuit comprises a full-bridge converter, an isolation transformer and a rectifying circuit, wherein the full-bridge converter, the isolation transformer and the rectifying circuit are connected in series in sequence. The posterior-stage inverter circuit comprises a tank circuit and a bipolar full-bridge high-frequency inverter circuit, wherein the tank circuit is connected between two output ends of the current feed circuit, and the bipolar full-bridge high-frequency inverter circuit is used for converting direct voltage output by the current feed circuit into alternating voltage. Due to the inverter power source device, under the condition that energy conversion efficiency is ensured, complexity of control can be reduced, and reactive power adjusting and power expansion are convenient.