43results about How to "Reduce voltage and current stress" patented technology

The invention relates to an energy system suitable for an LEO satellite and a control method of the energy system. The energy system comprises a solar cell array, an MPPT circuit unit, a storage battery, a capacitor array, a satellite platform load and a remote measuring and controlling unit, wherein the MPPT circuit unit carries out peak power tracking on the solar cell array by three DC-DC conversion modules which are connected in parallel according to a triple redundancecy hot backup mode, the MPPT circuit unit carries out closed-loop control by a majority voting control circuit, and each control circuit generates a driving signal to carry out closed-loop control on the corresponding MPPT circuit according to output voltage signals and output current signals of the solar cell array module and voltage signals and current signals of the storage battery to implement maximum power tracking on the solar cell array module and charging management on the storage battery. The solar cell array is high in utilization rate, high in reliability and low in system cost.

The invention discloses an electric automobile wireless charging method and system based on a double transmission-double picking mode. The electric automobile wireless charging method based on the double transmission-double picking mode comprises the steps of inputting direct current voltage into two inverter circuits; enabling an output end of the first inverter circuit to load high frequency alternating current to a first primary side transmitting coil through a first primary side resonance circuit so as to generate a high frequency magnetic field; generating electric energy after sensing the high frequency magnetic field through a first secondary side picking coil; inputting the electric energy into a first buck-boost converter through a first secondary side resonance circuit and a first rectification filter circuit; enabling an output end of the second inverter circuit to load high frequency alternating current to a second primary side transmitting coil through a second primary side resonance circuit to generate a high frequency magnetic field; generating electric energy after sensing the high frequency magnetic field through a second secondary side picking coil; inputting theelectric energy into a second buck-boost converter through a second secondary side resonance circuit and a second rectification filter circuit; converting the electric energy into load electric energyby using the two buck-boost converters; and outputting the load electric energy to a series-connected load.

The invention discloses an asymmetrical half-bridge zero-voltage soft switching inverter type welding and cutting machine, which comprises an input filtering circuit, a primary side rectifier filtering circuit, an asymmetrical half-bridge soft switching inverter circuit, an isolation transformer circuit, a secondary side rectifier filtering circuit and a master control board circuit, wherein the asymmetrical half-bridge soft switching inverter circuit comprises a main inverter circuit half-bridge consisting of a first insulated gate field effect power switch device and a second insulated gate field effect power switch device, as well as a first driving resistor, a second driving resistor, a first resonant capacitor, a second resonant capacitor, a saturated inductor and a stopping condenser; the central point of a bridge arm of the main inverter circuit is connected with an intermediate-frequency transformer through the stopping condenser; the saturated inductor, the first and the second resonant capacitors and a leakage inductor of the intermediate-frequency transformer form a soft switching resonant circuit. The asymmetrical half-bridge zero-voltage soft switching inverter type welding and cutting machine is simple in structure and low in implementation cost, and the switching voltage stress and current stress are reduced considerably.

The invention provides a wide-voltage-range output current feed converter, which comprises a primary side power circuit, a first secondary side rectification circuit, a second secondary side rectification circuit and a change-over switch circuit, wherein the primary side power circuit is connected to the first secondary side rectification circuit and the second secondary side rectification circuitthrough a main power transformer; the first secondary side rectification circuit and the second secondary side rectification circuit are respectively connected with the change-over switch circuit; and the change-over switch circuit adjusts the output ends to be connected in series or in parallel by controlling the on-off state. According to the change-over switch circuit, the output ends are adjusted to be connected in series or in parallel by controlling the on-off state, high-voltage small current is output during series connection, low-voltage large current is output during parallel connection, the wide-voltage-range output requirement of the converter is further met, voltage and current stress of components such as a main power switch tube, a transformer and an alternating-current inductor in the circuit design is small, and therefore the power density and the efficiency of the power source can be effectively improved.

The invention relates to an energy system suitable for an LEO satellite and a control method of the energy system. The energy system comprises a solar cell array, an MPPT circuit unit, a storage battery, a capacitor array, a satellite platform load and a remote measuring and controlling unit, wherein the MPPT circuit unit carries out peak power tracking on the solar cell array by three DC-DC conversion modules which are connected in parallel according to a triple redundancecy hot backup mode, the MPPT circuit unit carries out closed-loop control by a majority voting control circuit, and each control circuit generates a driving signal to carry out closed-loop control on the corresponding MPPT circuit according to output voltage signals and output current signals of the solar cell array module and voltage signals and current signals of the storage battery to implement maximum power tracking on the solar cell array module and charging management on the storage battery. The solar cell array is high in utilization rate, high in reliability and low in system cost.

The invention relates to a current path reconstruction type single-phase five-level rectifier. The rectifier comprises an alternating current power source VS, an inductor L, switching tubes S1, S2 andS3, diodes D1-D8, capacitors C1 and C2 and a load RL. According to the current path reconstruction type single-phase five-level rectifier of the invention, a plug-in diode uncontrolled rectifier bridge rectifying unit exists in the topological structure of the rectifier, the number of needed switches can be increased or decreased to a certain extent, switching tubes are applied to power factor correction, and therefore, on one hand, a circuit structure is simpler, and on the other hand, circuit control difficulty can be reduced. The rectifier can be widely applied to the field of single-phasesmall and medium-power rectifiers.

The invention relates to an expandable gain unit type high-capacity DC / DC converter, which comprises an input module and a gain module, and is characterized in that the input module comprises a plurality of input end ports, and the gain module comprises a plurality of gain units; the output end of the input module is electrically connected with the input end of the gain module, and different numbers of input end ports and gain units are adjusted to adapt to different voltage and current stresses. The invention provides an expandable gain unit type high-capacity DC / DC converter. High boosting capacity is realized by the aid of the voltage-multiplying unit capacitor with gradually increased voltage, basic gain can be increased by more than multiple times on the original basis when one inputphase number or one gain unit number is increased, and lower voltage and current stress of the active device is obtained by adjusting the input phase number and the gain unit number.

The invention relates to a SiC MOSFETE open-loop active driving circuit, and belongs to the technical field of circuit control. The circuit comprises a traditional driving circuit and an auxiliary circuit, the auxiliary circuit comprises a di / dt detection circuit and a shunting circuit, the di / dt detection circuit is used to determine ON and OFF states of a SiC MOSFETE, and transmits the signal obtained by determining to the shunting circuit, and the shunting circuit is used to shunt gate current of the SiC MOSFET via the signal of the di / dt detection circuit. According to the provided SiC MOSFETE open-loop active driving circuit, the shunting circuit and the di / dt detection circuit are added to the traditional SiC MOSFET driving circuit, the ON / OFF delay time is shortened, the switching loss is reduced, the active driving circuit is of open-loop operation, and the system cost and complexity are reduced.

The invention discloses a wireless charging receiving end load modulation switch zero-voltage asynchronous control method and a wireless charging receiving end load modulation switch zero-voltage asynchronous control circuit. The wireless charging receiving end load modulation switch zero-voltage asynchronous control method comprises the steps of: designing an asynchronous control circuit based onalternating voltage characteristics of a positive input end and a negative input end of a wireless charging receiving end; and using the asynchronous control circuit to drive and control two load modulation switches for asynchronously output, so that switching tubes connected with the load modulation switches are conducted when the corresponding alternating voltage is low. According to the wireless charging receiving end load modulation switch zero-voltage asynchronous control method, the asynchronous control circuit is designed based on the alternating voltage characteristics of the positiveinput end and the negative input end of the wireless charging receiving end, when the load modulation switches are driven to be switched on, the corresponding alternating voltage is low, namely zerovoltage is turned on, the corresponding switch tubes are further turned on when the corresponding alternating voltage is low instead of being turned on immediately after a load modulation signal is ready, and the voltage and current stress of the load modulation switch tube can be effectively reduced.

The invention discloses a coordination and protection method and device of DC grid having a resistive type superconductive current limiter. The resistive type superconductive current limiter is put into a fault discharging loop. The method comprises the steps of obtaining a first impedance scope of the resistive type superconductive current limiter when the fault discharging loop reaches to the over-damping state; obtaining a second impedance scope of the resistive type superconductive current limiter when the fault current of the fault discharging loop begins to be attenuated; obtaining a third impedance scope of the resistive type superconductive current limiter based on the movement time of a master breaker in a DC breaker; obtaining the impedance value of the resistive type superconductive current limiter based on the first impedance scope, the second impedance scope, and the third impedance scope. The invention is advantageous in that through selecting the impedance value of the superconductive current limiter, the fault current can be effectively inhibited; it can be guaranteed that the DC breaker can reliably turn off the fault current, and the voltage and current stress ofa switch member can be reduced.

The invention provides a multi-condition high-gain multi-port DC / DC converter which comprises an input unit A, an interleaving and voltage doubling unit B and a load unit C. The input unit A includesat least one new energy micro power supply upv, a storage battery energy storage unit ub, diodes VD2, VD3 and switch tubes S3, S4 and S5. The interleaving and voltage doubling unit B comprises two inductors L1 and L2, two main circuit power switch tubes S1 and S2 and one voltage doubling unit formed by a diode VD2 and a capacitor C1. The load unit comprises an output diode VDo, an output filteringcapacitor Co and a load R. Compared with an existing scheme, the scheme of the converter has the advantages that number of times of power conversions among the micro power supply, a storage battery and the load can be significantly reduced, the power conversion efficiency is improved, and N-channel input expansion can be achieved at the same time.

The invention discloses a dynamic wireless electric energy constant power output system and an equivalent resistance control method thereof and relates to the technical field of dynamic wireless electric energy transmission. The system comprises a transmitting end and a receiving end, wherein the transmitting end comprises a transmitting coil Lp; the receiving end comprises a secondary side assembly 1 and a secondary side assembly 2 which are connected with a load R; the secondary side assembly 1 comprises a receiving coil Ls1 parallel to the transmitting coil Lp; the secondary side assembly 2comprises a receiving coil Ls2 parallel to the transmitting coil Lp; the receiving coil Ls1 and the receiving coil Ls2 each comprise a square coil with a side length of L; the transmitting coil Lp comprises a plurality of square coils with the side length of L in cascade connection; the receiving coil Ls1 and the receiving coil Ls2 are overlapped to form a secondary side coil assembly, and the length of the overlapped part is L / 2. According to the system disclosed by the invention, the total power is averagely distributed in the receiving end of the secondary side assembly 1 and the receivingend of the secondary side assembly 2 in a moving process, voltage-current stress of a switching tube can be decreased, and constant output power of the system is ensured.

The invention discloses an electric vehicle range extender and a control method, and belongs to the technical field of electric vehicles. According to the electric vehicle range extender , the range extender brushless direct current motor is controlled to be used as a starting / power generation integrated motor; when the brushless direct current motor operates electrically, the three-phase inverterworks, and the three-phase rectifier performs current following; when the brushless direct current motor generates power and operates, the three-phase inverter does not work, the three-phase rectifier and a body diode of the three-phase inverter jointly form a rectifying circuit, and three-phase alternating current generated by the brushless direct current motor is rectified into direct current;when the brushless direct current motor generates power and operates, the voltage and rotating speed dual PI regulator regulates the rotating speed and the output voltage of the engine to keep the stability of the output voltage. The method is simple in control structure, small in calculation workload and rapid in response.

The invention discloses a power electronic transformer circuit, a power electronic transformer and a control method of the power electronic transformer; a multi-winding transformer is arranged among acascade H bridge and an inversion H bridge connected with a three-phase alternating current power grid, and a rectifying H bridge arranged at the input end of a direct current power grid; the input end of the multi-winding transformer is connected with H bridge modules connected from a three-phase alternating-current power grid; the input power of each H bridge module comprises a direct-current component and a secondary pulsation component, and the secondary pulsation power is in a rule of three-phase symmetry and negative sequence; after the multi-winding transformer is input from the threeH bridge modules, the output power of the multi-winding transformer is equal to the synthesis of input power of three ports according to the power balance relation, the secondary pulsation power is counteracted, and only the direct current component is transmitted to the direct current output end. A direct-current capacitor in the cascaded H bridge does not need to store pulse power, and the volume of the direct-current capacitor can be remarkably reduced, so that the size of the power electronic transformer is reduced, and the voltage and current stress of the power device is reduced.

The present discloses a control method of a LCC resonant DC-DC converter and a device thereof, used for controlling the LCC resonant DC-DC converter to realize zero-voltage soft switching operation in a wide input voltage range and a wide load range. According to the control method, by circuits controlling turn-on time and turn-off time of switch tubes of the LCC resonant DC-DC converter, the turn-on time and the turn-off time of the switch tubes vary with an input voltage and a load. The turn-on time and the turn-off time of the switch tubes are determined by an error value between an output voltage and a reference signal. Because a resonant current can not have an abrupt change, when any switch tube turns off, a body diode of the other switch tube immediately turns on, so that the switch tubes all work in a zero-voltage soft switching state. The control method of the LCC resonant DC-DC converter and the device thereof can reduce a switching frequency variation range of the conventional LCC resonant DC-DC converter and maintain the zero-voltage soft switching operation condition of the LCC resonant DC-DC converter in the wide input voltage range and the wide load range.

The invention discloses a gradient amplifier and a modulation method thereof. The gradient amplifier comprises a plurality of service half-bridge groups, every service half-bridge group consists of two service half-bridges, every service half-bridge is composed of two IGBTs (insulated gate bipolar transistors), and an emitting electrode of one IGBT in every service half-bridge is connected with a collecting electrode of the other IGBT in the service half-bridge. In every service half-bridge group, a gradient coil is connected between connection points of the two IGBTs in every service half-bridge, so that output current of a power supply flows through one IGBT of one service half-bridge in every service half-bridge group and the gradient coil and then the other IGBT of the other service half-bridge in the service half-bridge group. The gradient amplifier has the advantages that the service half-bridges serve as main power devices, the current flowing through the gradient coils is superimposed N-channel current, and accordingly operation frequencies of the gradient coils are superimposed and ripple waves of the current flowing through the gradient coils are reduced.

A simplified multilevel DC converter circuit structure comprises a dual input DC power supply, a power control module and an AC side low-pass filter, wherein each of the dual input DC power supply supplies half of the rated DC voltage to the power control module, and the power control module is composed of six power switches, and different switching combinations of each power switch are controlled to convert a DC voltage to an output of an AC voltage, and two of the power switches of the power control module perform a low-frequency switching twice every cycle of the output voltage, and the withstand voltage is equal to the input voltage, and the remaining power switches perform the switching by a high frequency, and the withstand voltage is only half of the input voltage, such that a multilevel voltage can be outputted, and a low harmonic AC waveform can be outputted from the AC side low-pass filter.

The invention discloses a lithium battery system with the self-repair function and a self-repair method thereof and belongs to the battery fault repairing field. The system includes a bidirectional DC / DC converter, a super capacitor bank, a processor, a battery detection module and a battery pack composed of multiple lithium batteries and multiple switches, wherein the super capacitor bank is usedfor providing power for the bidirectional DC / DC converter, the battery detection module is used for detecting status data of each lithium battery in the battery pack, the status data is faulty or normal, when the status data is faulty, the faulty lithium battery is replaced by the bidirectional DC / DC converter by controlling turn-on and turn-off of the multiple switches in the battery pack by theprocessor. The system is advantaged in that when a lithium battery fault occurs in the system, the external power supply of the system is abnormal, the self-repair function is for self-repairing external power supply abnormality of the system, after detecting the faulty lithium battery, the faulty lithium battery is replaced by the bidirectional DC / DC converter, so that the external power supplyof the system returns to normal, and the self-repair feature is achieved.

The invention discloses a method for eliminating the cross-coupling coefficient of a multi-transmission-multi-pick-up-multi-load IPT system. The method includes determining the resonance compensation circuits on the primary side and the secondary side; determining all circuit parameters satisfying the system output performance index; Current equation; determine each cross-coupling coefficient existing in the circuit, and solve the current equation of each branch; make the difference of each branch current equation without considering the cross-coupling coefficient and considering the condition of the cross-coupling coefficient, and obtain the difference equation of each branch current ; Add the compensation impedance where there is a cross-coupling coefficient in the difference equation; bring the solved current equation of each branch into the difference equation containing the impedance to be compensated, and solve it in reverse to obtain the impedance value to be compensated for each branch; The circuit angle eliminates the cross-coupling coefficient between multiple coils, and is universal to any multi-transmission-picked-multi-load IPT system, which is beneficial to the guidance of the elimination of the cross-coupling coefficient of the actual system and improves the system output performance.

The invention discloses a parallel resonant zero-voltage switch push-pull forward converter. The main circuit of the converter includes a primary circuit and a secondary circuit; the primary circuit is provided with a resonant inductor and a parallel resonant capacitor. Through the resonance of the resonant inductance and the parallel resonant capacitor, the zero-voltage switch of the main power transistor in the primary side circuit is realized. The converter can eliminate the voltage peak of the main power tube, improve the EMC effect, increase the boosting capability and conversion efficiency. The circuit of the invention has the advantages of simple structure, convenient control and reliable operation.

The invention discloses an interleaved parallel LED drive circuit based on a quadratic Buck and its working method, belonging to the field of power electronics, including an AC input, a rectifier bridge D1, a filter inductor Lf, a filter capacitor Cf, and two switch tubes Q1 and Q2 , diodes D2, D3, D4, D5, D6, inductors L1, L2, L3 and energy storage capacitors C1, C2, output capacitor Co and LED load. Based on the existing secondary buck converter circuit topology, a switch network composed of switch tube Q2, inductor L3, capacitor C2 and diode D6 is added to form an interleaved parallel structure, which effectively reduces the output current ripple and reduces The filter inductor design reduces the volume of the converter, improves system stability and power density, and realizes high efficiency and high power factor operation.

The invention relates to a three-level pseudo totem pole type converter suitable for a single-phase AC / DC hybrid micro-grid. The three-level pseudo totem pole type converter comprises a pseudo totem pole structure consisting of a diode, switching tubes S1 and S2 and inductors L1 and L2, the diode clamping type three-level structure is composed of switching tubes S3-S6 and diodes D3 and D4, and the direct-current bus structure is composed of capacitors C1 and C2 which are connected in series. One side of the alternating current power supply ug is connected with the inductors L1 and L2, and the inductor L1, the drain electrode of the switching tube S1 and the anode of the D1 are connected; the inductor L2 is connected with the cathode of the diode D2 and the source electrode of S2; the other side of the alternating current power supply ug is connected with a source electrode of a switch tube S4 and a drain electrode of a switch tube S5; the cathode of the diode D1, the drain electrodes of the switching tubes S2 and S3, the anode of the capacitor C1 and the anode of the direct-current power supply Udc are connected; the anode of the diode D2, the source electrodes of the switching tubes S1 and S6, the cathode of the capacitor C2 and the cathode of the direct-current power supply Udc are connected; and the anode of the diode D3 and the cathode of the diode D4 are connected with the split capacitors C1 and C2. The invention can realize the advantages of bidirectional energy flow, small alternating current harmonic wave, low voltage and current stress of the switch tube and the like.

A novel high-gain double-input DC-DC converter comprises an input unit, a first boosting unit, a second boosting unit and a load unit, wherein the input unit comprises three inductors L1, L3 and L4, four capacitors C3, C5, C7 and C8, three power switches S1, S2 and S3 and four diodes D1, D2, D3 and D4; the first boosting unit comprises an inductor L2, a capacitor C4 and a diode D5, and the second boosting unit comprises an inductor L5, a capacitor C6 and a diode D6. Compared with an existing scheme, the converter can remarkably reduce the number of times of electric energy conversion among the micro power source, the storage battery and the load, improves the electric energy conversion efficiency, has the advantages of being wide in input and output voltage adjusting range, low in switching device voltage stress and the like, and can achieve N-path boost expansion.

The invention provides an SCDAB-CLLLC composite direct-current transformer with a wide voltage regulation range and a control method thereof. A main circuit comprises a switched capacitor type bidirectional full-bridge DC / DC converter and a CLLLC type resonant converter which are cascaded in an input-series output-parallel manner, so the requirement on the transformation ratio of a high-frequency transformer is reduced, the voltage and current stress of an input side power device is reduced, and the voltage regulation range is wide. The controller takes a DSP as a core device and has the functions of overvoltage and overcurrent protection, phase shift control and frequency modulation control; the phase shift control is applied to the switched capacitor type bidirectional full-bridge DC / DC converter, and the frequency modulation control is applied to the CLLLC type resonant converter.

The invention belongs to the technical field of circuit control, in particular to a SiC MOSFET open-loop active drive circuit. The circuit includes a traditional drive circuit, and also includes an auxiliary circuit, the auxiliary circuit includes a di / dt detection circuit and a shunt circuit; the di / dt detection circuit is used to judge the turn-on and turn-off phases of the SiC MOSFET, and judge the obtained The signal is transmitted to the shunt circuit; the shunt circuit shunts the gate current of the SiC MOSFET through the signal of the di / dt detection circuit. The present invention provides a SiC MOSFET open-loop active drive circuit, which adds a shunt circuit and a di / dt detection circuit after the traditional SiC MOSFET drive circuit, shortens the switching delay time, reduces the switching loss, and the active drive circuit is Open-loop operation reduces system cost and complexity.

The invention relates to the field of inverters. The invention relates to a step-down and step-down control method for a Z-source inverter of an electric vehicle. By collecting information, the required reference value of the motor line voltage is determined, and it is determined whether the system has added a through signal, and the corresponding modulation coefficient reference value and the through signal are obtained. Duty cycle reference value, and then adjust the modulation coefficient and direct duty cycle step by step until the optimal modulation signal is reached to make the system optimal. The solution is that the power supply voltage of the electric vehicle battery is unstable and the energy conversion of the existing boost solution The efficiency is low, which affects the performance of the motor drive system, or the voltage demand is not adjusted according to the different working conditions of the electric vehicle, and the inverter loss is large. According to the different operating conditions of the vehicle, the demand for the AC output voltage of the drive system is different. The Z-source inverter can step up and down, and provide an optimal control method that meets the voltage requirements of the operating conditions, so that the performance and efficiency of the drive system can be optimally regulated.

The invention belongs to the field of electric energy transmission, and discloses a maximum efficiency tracking DC-DC converter and its control method for inductive electric energy transmission systems, including LCL-S compensation topology, uncontrolled rectifier bridge and double-tube Buck-Boost circuit; LCL The output of the ‑S compensation topology is connected to the input of the uncontrolled rectifier bridge, and the output of the uncontrolled rectifier bridge is connected to the input of the dual-tube Buck‑Boost circuit. The present invention realizes the constant voltage control of induction electric energy transmission by adjusting the phase shift angle between the leading and lagging bridge arms of the full-bridge inverter circuit, and realizes impedance matching by controlling the DSBB switch tube by adopting an interleaved duty cycle bias modulation strategy. Keep the equivalent load on the output side of the rectifier bridge always at the maximum efficiency load point; the double-tube structure of the present invention can effectively reduce the voltage and current stress of the switch tube, so that the system output has a wider voltage range and a higher power level; The adjustment of the pressure mode can make the load adjustable range wider when the system realizes the maximum efficiency tracking, which greatly improves the applicability of the system.