63results about How to "Achieve feedback" patented technology

The invention discloses an automatic vehicle control method. The method comprises the following steps that 100, the vehicle state is detected, the vehicle is started after it is detected that the vehicle state is normal, and the vehicle is driven in a conventional driving mode; 200, a set driving mode is received, and whether the received set driving mode is an automatic driving mode or not is judged; 300, when it is determined that the received set driving mode is the automatic driving mode, the battery capacity is detected, the vehicle enters the automatic driving mode if the battery capacity is larger than a set threshold value, and the vehicle is driven in a conventional driving mode if not. The automatic vehicle control method is good in safety.

The invention relates to a DC motor control circuit, a braking method, an electricity generating method and a device thereof, in particular to the problems of the starting, the speed regulation, the braking and the reversal rotation of a series excitation DC motor. The control circuit comprises an excitation circuit (7), an armature circuit (8) and a DC voltage transforming circuit (9), and has the characteristics of reusing the braking energy and no mechanical contact point in reversal rotating control. The braking method reuses the braking energy, and the electricity generating method utilizes the rotation of the series excitation DC motor to generate electricity. The device of the invention realizes the stable starting, the stepless speed control, the stepless braking and the running of reversal rotation, the energy in braking is fed back or reused, and the energy in braking can be effectively controlled if the series excitation DC motor rotates when the electricity is cut off. No input electric source exists. If the series excitation DC motor continuously rotates under the action of external force, the device is an electricity generator of the series excitation DC motor and can provide an electric source for the outside.

The invention relates to a braking system (1) comprising an actuator unit (10), said actuator unit comprising a brake pedal (2), a pedal simulator (4), and a brake servo (12), and a main brake cylinder (20) by way of which at least one wheel brake (42, 44, 46, 48) may be actuated, said wheel brake having a braking pressure that may be predetermined, wherein the brake pedal (2) or the brake servo (12) acts on the main brake cylinder (20) to increase or decrease a braking force. According to the invention, during a first operating mode, preferably a brake-by-wire operating mode, the braking force amplifier (12), controlled by an analysis and control unit (11), generates an outside force that acts on a piston (21) of the main brake cylinder (20), wherein the actuator unit (10) comprises a first transmission device (5) that, controlled by the analysis and control unit (11), mechanically decouples the brake pedal (2) from the piston (21) of the main brake cylinder (20) as a function of predetermined criteria during the first operating mode, or couples the brake pedal (2) to the piston (21) of the main brake cylinder (20) such that the pedal force generated at the brake pedal (2) additionally acts at least partially on the piston (21) of the main brake cylinder (20).

A method of CQI feedback comprises: in a CoMP system, a terminal feeding back a CQI corresponding to a comprehensive channel formed between the terminal and all transmission nodes in a CATS or each CQI corresponding to each channel between the terminal and each transmission node. A system of CQI feedback; in the system is also disclosed, a feedback unit at the terminal side is used in the CoMP system to calculate and feed back the CQI corresponding to the comprehensive channel formed between the terminal and all the transmission nodes in the CATS or each CQI corresponding to each channel between the terminal and each transmission node. With the method and system of the present invention, not only the CQI feedback in the CoMP system can be realized, but also the difference between the CQI feedback in the control channel and that in the traffic channel can be avoided.

The invention discloses an energy feedback and harmonic passive power compensation system applicable to a rectifying device, comprising a power transistor, a controlling device, a three-phase power bridge and a filtering device, wherein, the anode of the power transistor is connected with the anode of a diode rectifying DC voltage, and the cathode of the power transistor is connected with the anode of a DC bus voltage of the three-phase power bridge; the cathode of a diode rectifying DC bus voltage is connected with the cathode of a DC voltage of the three-phase power bridge; the controlling device is used to control the opening and cutting of a power transistor of the three-phase power bridge; the three-phase power bridge is used to provide DC bus voltage to the controlling device and control the closing of the power transistor according to a command from the controlling device to generate a compensation current and provides the compensation current to the filtering device; the filtering device receives the compensation current from the three-phase power bridge, compensates the compensation current to the power grid after filtering high harmonics and provides the current signals to the controlling device. The energy feedback and harmonic reactive power compensation system can play the roles of active filtering and passive compensation, feed back energy to the power grid and realize energy saving.

The invention discloses an alternating current servo driver capable of realizing energy feedback, which comprises a power unit and a control unit, wherein the power unit comprises an overvoltage protection module, a noise filter, a three-phase input alternating current reactor, a PFC (Power Factor Correction) correction regenerative braking module and a servo driving module which are connected in sequence; a soft start module and an energy storage filter capacitor are also arranged between the PFC correction regenerative braking module and the servo driving module; the control unit comprises a digital signal processor, an interface circuit module, a direct current bus voltage detection module, a voltage sampling module and two current sampling modules, wherein the interface circuit module, the direct current bus voltage detection module, the voltage sampling module and the current sampling module are respectively connected between the digital signal processor and the power unit. The alternating current servo driver can realize the feedback of energy in a power grid, but also can be used for rectifying and filtering the three-phase alternating current of the power grid, effectively reduces the pollution generated by the power grid, saves the energy and protects the energy.

The invention discloses a bi-directional dual-input SEPIC direct-current converter and a power distribution method of the bi-directional dual-input SEPIC direct-current converter. The bi-directional dual-input SEPIC direct-current converter comprises a first SEPIC pulse current source unit, a second SEPIC pulse current source unit and an output filter circuit. The first SEPIC pulse current source unit comprises a first input direct current voltage source A, a first power switch tube M1, a second power switch tube M3, a first inductor L1, a second inductor L3 and a first capacitor C1. The second SEPIC pulse current source unit comprises a second input direct current voltage source B, a third power switch tube M2, a fourth power switch tube M4, a third inductor L2, a fourth inductor L4 and a second capacitor C2. The first SEPIC pulse current source unit and the second SEPIC pulse current source unit are connected in parallel, and the output filter circuit comprises an output filter capacitor C. The power distribution method includes power distribution and load feedback power control which are carried out on the two input direct current voltage sources. The bi-directional dual-input SEPIC direct-current converter and the power distribution method of the bi-directional dual-input SEPIC direct-current current have the advantages of being complex in circuit structure, capable of achieving boost and voltage reduction, wide in adjusting range of output voltage, capable of achieving energy feedback, small in loss, high in circuit efficiency, small in ripple in output voltage waveform and capable of being used on a large current occasion due to connection of two current sources in parallel, and an isolation transformer is not needed.

The invention discloses a magnetic refrigerating device based on a pulsed magnetic field. The device comprises a repetitive pulsed power supply without a continuous loop, a pulsed magnet, a magnetic refrigeration working medium, a hot end heat exchange unit and a cold end heat exchange unit, wherein the repetitive pulsed power supply discharges to the pulsed magnet, and part of electric energy flows back to the repetitive pulsed power supply to achieve energy recovery; during the discharge process, the pulsed magnet generates the pulsed magnetic field and causes the refrigeration working medium to magnetize and release heat, and the heat generated by the magnetic working medium is transferred to a high-temperature heat source through the hot end heat exchange unit; after the discharge is finished, the repetitive pulsed power supply is shut off, and the pulsed magnet stops generating the pulsed magnetic field, and the magnetic refrigeration working medium demagnetizes and absorbs the heat, and through heat absorption of a low-temperature heat source by the cold end heat exchange unit, the temperature of the low-temperature heat source is lowered, thus completing a discharge refrigeration cycle; and the discharge refrigeration cycle is circulated in a manner above to realize continuous refrigeration. According to the scheme disclosed by the invention, the controllable pulsed magnet generates the intermittent repetitive pulsed magnetic field to achieve the magnetic refrigeration, and the magnetic refrigerating device has the characteristics of high magnetic field intensity, no moving part, convenience and fastness of control, high efficiency and high refrigeration power.

The invention discloses a parallel type energy feedback elevator system comprising a variable frequency driving main loop of an elevator, an energy feedback device and a controller, wherein the variable frequency driving main loop consists of an uncontrollable rectifier bridge module, a direct current bus capacitor and an inverting power module; the energy feedback device consists of a boosting and filtering device, a PWM rectifier module, a direct current bus capacitor and a power diode module; the input end of a three-phase power supply is provided with two current sensors; a three-phase input power end of a motor is provided with two current sensors which are used for providing current feedback signals for the controller respectively; the controller is used for providing PWM control signals for the inverting power module and the PWM rectifier module and directly controlling the on and the off of a switch thereof; and the power diode module consists of two power diodes which are serially connected at the positive side and the negative side of a direct current bus. The energy feedback elevator system can reduce the capacity by half, simultaneously restrict the circulating current in the circuit well, and can realize the purposes of energy saving, environment production and cost reduction.

The invention relates to a three-phase synchronous rectification circuit, which is applied to a four-quadrant frequency converter and is provided with a direct current end and an alternating current end. The three-phase synchronous rectification circuit comprises at least three double-tube packaged insulated gate bipolar transistors and a diode, wherein the diode is connected in reverse parallel with each insulated gate bipolar transistor; the at least three double-tube packaged insulated gate bipolar transistors are connected in parallel to form a three-phase bridge circuit; a controller is also connected between the three-phase synchronous rectification circuit and a power system and is used for controlling the conduction of each insulated gate bipolar transistor according to a phase position of a three-phase alternating voltage input by the power system; when the input voltage in the four-quadrant frequency converter is greater than the voltage of a direct current bus, the three-phase synchronous rectification circuit is in a rectification state; and when the voltage of the direct current bus in the four-quadrant frequency converter is greater than the input voltage, the three-phase synchronous rectification circuit is in an energy feedback state. As the rectification circuit is controlled by the phase position, the three-phase synchronous rectification circuit has the advantages of low cost, low switching loss and anti-interference capacity. Besides, the invention also provides a control method for the synchronous rectification circuit.

The invention provides an energy feedback control method for a full electric vehicle. The energy feedback control method includes the following specific steps that on the premise that an accelerator pedal is released and the vehicle is in a forward gear, whether an ABS is started or not is judged, and if the ABS is not started, the vehicle enters a feedback mode; the feedback mode selection step includes the procedures that after the vehicle enters the feedback mode, whether a brake pedal is trodden or not is judged, if the brake pedal is trodden, the vehicle enters a brake feedback mode, if the brake pedal is not trodden, the vehicle enters a sliding feedback mode, a vehicle control unit calculates feedback torque, and recycled energy is stored in a power battery; when the vehicle enters the brake feedback mode or the sliding feedback mode, whether the ABS is started or not is monitored in real time, and if the ABS is started, the vehicle quits from the feedback mode. The feedback torque is determined through the maximal receiving capacity of the power battery, the actual deceleration working condition of the vehicle and the feedback capacity of a motor, and the driving range of the full electric vehicle is prolonged as much as possible on the premise that vehicle safety is guaranteed.

The present invention relates to a hydraulic drive, particularly of a digger, particularly for a rotation system having a hydraulic circuit comprising a pump (1) and a motor (2), wherein a high-pressure reservoir (3) connectable to the pump and / or motor via at least one valve (4) and a control unit (6) controlling the at least one valve are provided.

The invention discloses an energy feeding magnetorheological elastomer vehicle vibration reducing device. The device comprises a vibration reducing device body and a vibration reducing device controller; the vibration reducing device body includes a cylinder barrel, a piston rod, an upper spring clamping base, an upper spring pressing plate, an upper force transfer spring, a lower spring clamping base, a lower spring pressing plate and a lower force transfer spring; multiple piezoelectric modules and multiple magnetorheological elastomers coat the middle part of the piston rod; the adjacent piezoelectric modules and magnetorheological elastomers are bonded through double-surface adhesive thin iron plates; magnetic conducting brackets are bonded on the double-surface adhesive thin iron plates, and are wound with magnet exciting coils; piezoelectric vibrators are inlaid in the piezoelectric modules; the top of the upper spring clamping base is connected with a support frame; the top of the support frame is connected with an upper lifting ring; and the bottom of the cylinder barrel is fixedly connected with a lower lifting ring. The invention further discloses a control method of the energy feeding magnetorheological elastomer vehicle vibration reducing device. The energy feeding magnetorheological elastomer vehicle vibration reducing device is convenient to realize, low in cost, high in working stability and reliability, excellent in energy feeding effect, excellent in vibration reducing performance and strong in practicability.

The invention discloses a power supply circuit, a repeated flat-topped pulse high-intensity magnetic field generation device and a control method thereof, and belongs to the technical field of pulse power. A storage battery type circuit topology is adopted, and an energy storage capacitor is used for discharging an inductive load to generate a pulsed magnetic field; compared with the prior art, the external high-voltage charger is adopted to charge the energy storage capacitor, the storage battery can be externally connected with charging equipment according to the duration time of the flat-topped pulsed magnetic field, and the charging equipment can monitor the electric quantity of the storage battery on line; in a power supply circuit topology, an energy feedback branch is designed and is used for realizing energy feedback of an energy storage capacitor and reducing energy consumption of a system; a compensation branch is designed and used for outputting stable flat-top current, so that the stability of the flat-top part of the magnetic field is realized; and the discharge voltage of the energy storage capacitor is improved, a steep output current rising edge is generated to reduce heating of an inductive load, and meanwhile the repeatability and stability of a magnetic field are improved. The circuit has the advantages of simple structure, stability in control, high reliability, convenience in implementation and the like.

The invention relates to a middle-high voltage variable frequency speed control circuit based on a modular multilevel converter (MMC). The middle-high voltage variable frequency speed control circuit based on the MMC comprises a cascade rectifier circuit and a cascade inverter circuit, an input capacitor is connected with an output capacitor through a high-frequency isolated direct current / direct current (DC / DC) converter, the high-frequency isolated DC / DC converter comprises a primary side H bridge with four power switch devices, an output end of the primary side H bridge is connected with a primary side coil of a high-frequency transformer, a secondary side coil of the high-frequency transformer is connected with an input end of a secondary side H bridge, and an output end of the secondary side H bridge is in bridge joint with two ends of the output capacitor. According to the middle-high voltage variable frequency speed control circuit based on the MMC, a rectification section is isolated from an inversion end of an MMC variable-frequency speed control system by means of the high-frequency isolated DC / DC converter; energy transmission and feedback can be efficiently achieved without an industrial frequency transformer; the high-frequency isolated DC / DC converter is added so that a rectifier and an inverter can safely work without mutual influence, and safe and reliable work can be achieved while efficient energy transmission can be guaranteed.

The invention relates to a motor driving system for a vehicle bidirectional quasi-Z-source inverter. The motor driving system comprises a speed regulation control module, a sensor unit, and a power supply module, a bidirectional quasi-Z-source preceding-stage passive network, a three-phase bridge type inverter and a motor which are connected in sequence, wherein the bidirectional quasi-Z-source preceding-stage passive network and the three-phase bridge type inverter form the bidirectional quasi-Z-source inverter; the speed regulation control module is connected with the sensor unit and the bidirectional quasi-Z-source inverter separately; and the bidirectional quasi-Z-source preceding-stage passive network comprises inductors L1 and L2, capacitors C1 and C2, an IGBT switch tube S7 and a diode D7. Compared with the prior art, the bidirectional quasi-Z-source inverter system established by the invention, taken as the single-stage inverter system, can replace the two-stage conversion DC / DC and DC / AC conversion in the conventional electric driving field to avoid voltage fluctuation of the battery pack and maintain the stable and adjustable direct bus voltage; and in addition, the problem of dead time existing in the conventional inverter is prevented, so that the output voltage distortion can be lowered, and the torque pulsation and electromagnetic noises can be reduced.

The invention relates to a micro-grid energy storage topological inverter and a method for operating the same. The micro-grid energy storage topological inverter comprises a controller and an isolation transformer applicable to being connected with a three-phase power source. Three output phases of the isolation transformer are respectively connected with a first four-quadrant H-bridge converter, a second four-quadrant H-bridge converter and a third four-quadrant H-bridge converter, direct-current sides of the first four-quadrant H-bridge converter, the second four-quadrant H-bridge converter and the third four-quadrant H-bridge converter are connected with one another in parallel and then are connected with a first bidirectional DC / DC transducer and a second bidirectional DC / DC transducer, the first bidirectional DC / DC transducer is connected with a storage battery, and the second bidirectional DC / DC transducer is connected with a super capacitor. The micro-grid energy storage topological inverter and the method have the advantages that the storage battery and the super capacitor can be respectively charged and discharged by the three four-quadrant H-bridge converters and the two bidirectional DC / DC transducers under the control of the controller, so that micro-grid energy storage and feedback effects can be realized, and corresponding charge and discharge forms can be controlled according to charge and discharge characteristics of the storage battery and the super capacitor.

The invention discloses a two-way two-input CUK direct-current converter and a power distribution method thereof. The two-way two-input CUK direct current converter comprises a first CUK impulse voltage source unit, a second CUK impulse voltage source unit and an outputting filter circuit. The first CUK impulse voltage source unit comprises a first input direct-current voltage source A, a first power switch tube M1, a second power switch tube M3, a first inductor L1 and a first capacitor C1. The second CUK impulse voltage source unit comprises a second input direct-current voltage source B, a third power switch tube M2, a fourth power switch tube M4, a second inductor L2 and a second capacitor C2. The outputting filter circuit comprises an outputting filter inductor L and an outputting filter capacitor C. The power distribution method includes performing power distribution and load feedback power control on the two input direct-current voltage sources. The two-way two-input CUK direct-current converter and the power distribution method thereof have the advantages that the circuit structure is complex, output polarity is reversed, voltage increasing and decreasing can be realized, range of output voltage regulation is large, energy feedback can be realized, loss is low, the circuit is efficient, ripple wave in output voltage waveform is small, isolation transformers are not needed and the like.

The invention relates to a high-power energy feedback type power grid analog device which comprises a PWM rectification part and a power grid analog part, and the PWM rectification part and the power grid analog part share the same direct-current bus; the PWM rectification part comprises an input filtering unit and a three-phase bridge rectification unit; the power grid analog part comprises three single-phase inverters, an output filtering unit and an isolation unit. A control method adopted in the high-power energy feedback type power grid analog device comprises the steps that a double closed loop control device provided with a phase-locked loop and composed of a voltage outer ring and an inductive current inner ring is adopted in the PWM rectification part to control the amplitude and waveform of currents and the voltage of the direct-current bus; a digital-analog hybrid three-loop control device comprising the inductive current instantaneous value, the voltage instantaneous value and the voltage effective value is adopted in the power grid analog part to control the amplitude and waveform of the voltage of an analog power grid. The high-power energy feedback type power grid analog device has high net side power factors, can feed energy back to the power grid, and breaks through the limits of low switching frequency and bandwidths.

The invention relates to the technical field of motor control, and provides a PMSM (permanent magnet synchronous motor) grid-connected operation control method and system, and a quasi-synchronization controller. The method comprises the following steps: obtaining the frequency and voltage of a power grid; detecting the output frequency, output voltage and phase of a motor controller in a process that the motor controller drives a motor to operate; adjusting the rotating speed of the motor through the motor controller according to the frequency of the power grid, wherein the output frequency is the same as the frequency of the power grid; controlling the motor to carry out grid-connected operation when the output voltage of the motor controller and the voltage of the power grid are judged to meet conditions of grid-connected operation, enabling a PMSM to operate without the controller, and enabling the efficiency of an operation system to be improved. Moreover, the method achieves the feedback of energy when the motor is in a state of power generation. The energy saving of the system is achieved through employ less equipment cost.

Provided is a dual-direction dual-input ZETA / SEPIC direct-current converter and a power distribution method of the dual-direction dual-input ZETA / SEPIC direct-current converter. The direct-current converter comprises a ZETA impulse voltage source, an SEPIC impulse current source and an output filtering circuit. The SEPIC impulse current source comprises a first input direct voltage source A, a first power switching tube M1, a third power switching tube M3, a first inductor L1, a second inductor L2 and a first capacitor C1. The ZATA impulse voltage source comprises a second input direct voltage source B, a second power switching tube M2, a fourth power switching tube M4, a third inductor L3 and a second capacitor C2. The ZETA impulse voltage source is embedded into the SEPIC impulse current source. The output filtering circuit comprises an output filtering capacitor C. The power distribution method includes the steps of conducting power distribution and load feedback power control on the two input sources. The dual-direction dual-input ZETA / SEPIC direct-current converter and the power distribution method of the dual-direction dual-input ZETA / SEPIC direct-current converter can achieve voltage boosting, voltage reduction and energy feedback, are high in circuit efficiency, allow the converter not to be isolated, and are suitable for small and medium-size power new energy joint power supply systems.

The invention belongs to a field of mechanical structures and more specifically relates to a feed-back type capacity check discharge device for storage battery and an application method of said device. The feed-back type capacity check discharge device includes the storage battery, a DC chopping module and a rectification inversion module electrically connected in sequence. The capacity check discharge device includes a monitoring management module used for performing current and voltage monitoring on the device. The monitoring management module is connected with the storage battery, the DC chopping module and the rectification inversion module electrically. The capacity check discharge device is provided with a three-phase power source used for charging. The three-phase power source is connected with the rectification inversion module electrically. The capacity check discharge device includes a load connected with the storage battery and the rectification inversion module. According to the invention, through the arrangement of an energy feedback power grid, environment protection and energy conservation are achieved. At the same time, the device can automatically enable a single body that is unqualified in capacity check to be in short circuit and performs field activation on the storage battery that fails in capacity check discharge, so that the service life of the storage battery is prolonged, the maintenance cost is reduced and the safe operation of a power system is ensured.

The invention discloses a bidirectional double-input BUCK / BUCKBOOST dc converter and a power distribution method thereof. The dc converter is composed of a BUCK pulse voltage source, a BUCKBOOST pulse current source and an output filter circuit, wherein the BUCK pulse voltage source comprises a power supply and a half-bridge switch block, the BUCKBOOST pulse current source comprises a power supply, a power switch tube and an inductor, and after the BUCK pulse voltage source is embedded into the BUCKBOOST pulse current source, a load is supplied via a filter C. The power distribution method comprises power distribution and load feedback power control is carried out on two input sources, wherein when the required power of the load is greater than the power provided by the power source A, the power source B is discharged; and when the required power of the load is lower than the power provided by the power source A, the power source B is charged. The dc converter and the power distribution method of the invention are characterized by capability of stepping voltage up / down, inversion of output polarity, large adjusting range of output voltage, energy feedback, low loss and high circuit efficiency, etc.

The invention discloses an energy feeding magnetorheological elastomer vehicle vibration reducing device. The device comprises a vibration reducing device body and a vibration reducing device controller; the vibration reducing device body includes a cylinder barrel, a piston rod, an upper spring clamping base, an upper spring pressing plate, an upper force transfer spring, a lower spring clamping base, a lower spring pressing plate and a lower force transfer spring; multiple piezoelectric modules and multiple magnetorheological elastomers coat the middle part of the piston rod; the adjacent piezoelectric modules and magnetorheological elastomers are bonded through double-surface adhesive thin iron plates; magnetic conducting brackets are bonded on the double-surface adhesive thin iron plates, and are wound with magnet exciting coils; piezoelectric vibrators are inlaid in the piezoelectric modules; the top of the upper spring clamping base is connected with a support frame; the top of the support frame is connected with an upper lifting ring; and the bottom of the cylinder barrel is fixedly connected with a lower lifting ring. The invention further discloses a control method of the energy feeding magnetorheological elastomer vehicle vibration reducing device. The energy feeding magnetorheological elastomer vehicle vibration reducing device is convenient to realize, low in cost, high in working stability and reliability, excellent in energy feeding effect, excellent in vibration reducing performance and strong in practicability.

The invention relates to an energy feedback type linear motor testing and loading device, which belongs to the technical field of motor testing, and solves the problem that the existing linear electric motor thrust loading and testing device can only carry out unidirectional test without continuously adjusted loading force. A stand body of the device is of a U-shaped structure, supporting guide rails are symmetrically arranged on the upper surfaces of two vertical sections of the stand body, a sliding support of a motor to be tested and a sliding support of a loading motor are respectively arranged on the supporting guide rails, the sliding support of the motor to be tested is in sliding connection with the supporting guide rails through guide rail slide blocks, the sliding support of theloading motor is in sliding connection with the supporting guide rails through guide rail slide blocks, a stator of the linear motor to be tested is fixedly arranged on the inner side surface of a horizontal section of the stand body, a rotor of the linear motor to be tested is fixedly arranged on the bottom face of the sliding support of the motor to be tested, a pair of loading linear motor stators is symmetrically arranged on the inner side walls or the outer side walls of the two vertical sections of the stand body, and a pair of loading linear motor rotors is symmetrically arranged on the sliding support of the loading motor. The energy feedback type linear motor testing and loading device, provided by the invention, is applicable to loading and testing of the linear motor.

The invention discloses a bi-direction dual-input ZETA / BUCKBOOST direct current converter and a method for distributing power of the direct current converter. The bi-direction dual-input ZETA / BUCKBOOST direct current converter comprises a ZETA impulse voltage source unit, a BUCKBOOST impulse current source unit and an output filter circuit. The ZETA impulse voltage source unit comprises a first input direct current voltage source A, a first power switch tube M1, a second power switch tube M3, a first inductor L1 and a first capacitor C1. The BUCKBOOST impulse current source unit comprises a second input direct current voltage source B, a third power switch tube M2, a fourth power switch tube M4 and a second inductor L2. The output filter circuit comprises an output filter capacitor c. The method for distributing the power of the direct current converter comprises the step of distributing power and controlling load feedback power of the ZETA impulse voltage source unit and the BUCKBOOST impulse current source unit. The bi-direction dual-input ZETA / BUCKBOOST direct current converter and the method for distributing the power of the direct current converter have the advantages of being capable of achieving the purposes of increasing and reducing voltage, feeding back energy and inversing output polarity, large in output voltage adjusting range, small in loss, high in circuit efficiency, small in ripple waves in output voltage waveform and the like, and an isolation transformer is not needed.

The invention discloses a bidirectional two-input CUCK / SEPIC direct current converter and a power distribution method thereof. The direct current converter comprises a CUCK pulse voltage source, a SEPIC pulse current source and an output filter circuit, wherein the SEPIC pulse current source comprises a first input direct-current voltage source A, first and third power switch tubes M1 and M3, first and second inductors L1 and L2 and a first capacitor C1, the CUCK pulse voltage source comprises a second input direct-current voltage source B, second and fourth power switch tubes M2 and M4, a third inductor L3 and a second capacitor C2, the CUCK pulse voltage source is embedded in the SEPIC pulse current source, and the output filter circuit comprises an output filter capacitor C. The power distribution method of the direct current converter comprises that power distribution and load feedback power control are performed on the two input sources. According to the bidirectional two-input CUCK / SEPIC direct current converter and the power distribution method thereof, voltage boosting and reduction and energy feedback can be achieved, the circuit efficiency is high, no isolation transformer is required, and the bidirectional two-input CUCK / SEPIC direct current converter is applicable to middle-and-low-power new-energy joint power supply systems.

The invention relates to a low-voltage electrical appliance life test device based on an AC solid-state simulated load. The low-voltage electrical appliance life test device comprises a measuring andcontrolling cabinet and an AC solid-state load cabinet, wherein the measuring and controlling cabinet is composed of an industrial control computer, a data acquisition card, a control circuit, a sample voltage acquisition module and a loop current acquisition module; the industrial control computer is connected with a data acquisition card; the control circuit, the sample voltage acquisition module and the loop current acquisition module are connected with the data acquisition card respectively; an input end of the sample voltage acquisition module is connected with two ends of a contact of the sample, and the output end of the module is connected with an AD input end of the data acquisition card; the input of the loop current acquisition module is a sample test current, and an output endis connected with the AD input end of the data acquisition card; and the AC solid-state simulated load comprises a sample test current generating unit and an energy feedback unit. The low-voltage electrical appliance life test device can generate the test currents in any shape, is more suitable for controlling the actual load, and overcomes the shortcoming of limitations of the conventional test current.

The invention discloses a disengaging shaft type double-power hybrid engineering van. The disengaging shaft type double-power hybrid engineering van comprises a front wheel electric drive system providing power for front wheels through electric driving, a rear wheel mechanical drive system providing power for rear wheels through mechanical driving, and a whole vehicle controller electrically connected with the front wheel electric drive system and the rear wheel mechanical drive system; when the speed of the engineering van is smaller than a set threshold value, the whole vehicle controller controls the front wheel electric drive system to provide power for the front wheels, and the rear wheel mechanical drive system provides power for the rear wheels; when the speed of the engineering van is not smaller than the set threshold value, the front wheel electric drive system does not provide power for the front wheel, and the rear wheel mechanical drive system provides power for the rear wheels. The problem that the vehicle travels hard under the conditions of loaded starting and climbing is solved, and environment pollution caused by insufficient burning of fuel of the rear wheel mechanical drive system is avoided.

The invention provides an energy-saving device capable of feeding back electric energy to a power grid from parallel connection. The device adopts double closed-loop control of a direct current bus voltage control loop and a feedback current control loop, and adjusts the size of feedback current according to output of the direct current bus voltage control loop. The invention also provides an energy-saving method capable of feeding back electric energy to the power grid from parallel connection. By implementation of the energy-saving device and the method disclosed by the invention, the beneficial effects are that: firstly, double closed-loop control of the direct current bus voltage control loop and the feedback current control loop are adopted, and the size of the feedback current is adjusted according to the output of the direct current bus voltage control loop so as to ensure that no effect on the power grid is generated while feeding back electric energy to the power grid, and secondly, field application and field combination are flexible, one energy-saving device is connected between the power grid and one or more transducers to achieve electric energy feedback on the occasion of low power, and a plurality of energy-saving devices are connected between the power grid and one or more transducers to achieve electric energy feedback.