393results about How to "Simple control strategy" patented technology

The invention relates to a direct-current micro-grid system and a control method thereof. The direct-current micro-grid system comprises a direct-current power distribution circuit, a bi-directional AC / DC (alternating current / direct current) rectifying / inverting device, a distributed energy generating device, an energy storing device, direct-current loads, alternating-current loads, a urban microclimate interactive system, a clock interactive system, a micro-grid control system and micro-grid protecting devices, an upper scheduling management system is arranged in the micro-grid control system so as to form layered management for micro-grid energy. The direct-current micro-grid control method includes: entering a grid connection mode or an island model according to working state of a large power grid, and determining the working states of the energy storing device and the distributed energy generating device according to information of the urban microclimate interactive system and the clock interactive system. The direct-current micro-grid system can independently supply power to the alternating-current and the direct-current loads and can be connected with a power grid to generate power according to processed result of urban microclimate interactive information, so that requirements on power supply for users are met, cost is reduced, designing, controlling, operation and maintenance of a micro-grid are benefited, and reliability, economy and efficiency of the micro-grid are effectively improved.

The invention discloses an unmanned plane video image target positioning system and method based on metadata and a holder control method and solves a problem that the position of a shot target of a video can not be acquired and displayed in the prior art. In combination with the target area position and the position and flight parameters of an unmanned plane, holder orientation and a pitch angle parameter are solved in real time, the target in the video is positioned, the target is assigned through frame selection of the video returned by the unmanned plane in an unmanned plane flight process, target positioning is supported, and the target area acquired through frame selection is displayed in a GIS map in real time. The method is advantaged in that a problem of inconvenience in manually adjusting a holder in the prior art is solved, point clicking on the GIS map to assign the target is supported, according to the unmanned plane, the target position, the flight parameter and the elevation data information, holder parameters are solved, the holder is controlled for rotation, and the target is made to be at a sensor vision axis center.

The invention discloses a multi-mobile robot control system based on following a pilot formation, which comprises an experimental environment image acquisition module, an upper computer positioning module, a car-like mobile robot group, a communication module and a control algorithm module, wherein the experimental environment image acquisition module is used for acquiring video images of a plurality of mobile robot formation experimental environments; the upper computer positioning module calculates absolute position information of each robot in real time by using an image processing algorithm through a coordinate system calibrated via a camera; the car-like mobile robot group is composed of a plurality of single mobile trolleys, and an autonomous decision is made to complete the formation task; the communication module performs data interaction and information sharing through a wireless communication manner; the control algorithm module coordinates and controls the whole system to complete the formation task based on the pilot-followed formation algorithm. The multi-mobile robot control system based on following a pilot formation in the invention is a multi-robot formation systemwhich is based on visual positioning and suitable for the indoor and has the characteristics of strong reliability and strong real-time performance.

The invention provides a dual-rotor wheel hub motor for a four-wheel drive electric automobile and a power transmission method of the dual-rotor wheel hub motor. The dual-rotor wheel hub motor comprises a planetary gear mechanism and a motor group formed by an inner motor and an outer motor. The motor group and the planetary gear mechanism are connected via a clutch and are arranged in a machine shell. The outer motor is formed by an outer rotor and a stator outer winding, and the inner motor is formed by an inner rotor and a stator inner winding. The planetary gear mechanism is composed of a gear ring, an output shaft, a sun wheel, a planet wheel and a planet carrier. The dual-rotor motor could achieve torque coupling, rotational speed coupling and speed differing by combining with the planetary gear mechanism, so that different vehicle condition requirements could be met under the condition that the motor with relative small power is selected, thereby reducing automobile arrangement space and cost. As the dual-rotor wheel hub motor has a single motor braking mode and a dual-motor braking mode, the braking energy can be effectively recovered, slow braking can be achieved, and the braking stability of the motor is improved.

The invention discloses an active and passive realizing method of a healthy exercise trainer. When a trainer is in passive training, a control motor is in either a position mode or a speed mode, and upper and lower limbs are driven to exercise to finish the passive training through a training device; when the trainer is in active training, the upper and lower limbs of the trainer exert strength, the motor is set to be in a torque mode, and the motor is driven to rotate through the training device; and the trainer is in assisted training, a working mode of the motor is a combination of the torque mode and the position mode or the speed mode in the different time periods, the active and passive trainings can be achieved through the real-time switching of the control motor between the position mode or the speed mode and the torque mode. According to the active and passive realizing method of the healthy exercise trainer, the initiatives of the trainers who take part in the training can be improved, and either body builders or patients can autonomously regulate the training mode, speed and intensity according to their own physical conditions and physical abilities, so that the active and passive realizing method of the healthy exercise trainer can be suitable for the healthy training of different recovery stages and different psychologic statuses.

The invention discloses a variable compression ratio engine, including a cylinder body (1) internally provided with a cylinder, a piston (2), a connecting rod (3) and a crankshaft (4), wherein, the piston (2) is arranged in the cylinder, the connecting rod (3) is linked with the crankshaft (4) and the piston (2), the cylinder body (1) is also provided with a mechanism which can change the effective length of the connecting rod (3), and two ends of the mechanism are respectively linked with the connecting rod (3) and the crankshaft (4). The mechanism which can change the effective length of the connecting rod is a retractable hydraulic lever mechanism and controlled by a hydraulic pump controlled by ECU and a triple valve. The variable compression ratio engine has the following advantages that the compression ratio can be continuously changed and the change is controllable; the structure is simple; the control strategy is relatively simple; and the dynamic property and the fuel economy of the engine can be effectively improved.

The invention discloses a mixed type multi-level current converter with direct-current fault ride-through capability and a working method. The current converter is based on a dislocation stacking theory and comprises a three-phase bridge rectifier circuit; each bridge arm of the three-phase bridge rectifier circuit comprises a dislocation stacking module, a cascading double-sub-module assembly, a half-bridge sub-module assembly and an electric reactor which are cascaded to one another; when a fault occurs, a discharging process before locking of the current converter is an oscillating discharging process under known initial conditions; and after the current converter is locked, equivalent capacitance values of the bridge arms are changed, if and only if backward voltages of cascading capacitors of the bridge arms are always greater than an alternating-current line voltage amplitude value in any loop states, a short-circuiting current is reduced to zero by the inverting blocking characteristic of diodes, and the direct-current fault is eliminated. The direct-current fault is eliminated in a self-limited manner by locking the current converter, and an extra high-voltage and direct-current circuit breaker is not required. The mixed type multi-level current converter with the direct-current fault ride-through capability is suitable for a common overhead circuit, and can be used for the fields of multi-terminal direct-current network establishment, new energy grid connection, passive network power supply and the like.

The application provides a motor control circuit, a charging method of a power battery, a heating method of the power battery and a vehicle. The motor control circuit comprises a three-phase inverter,a second switch module, a first switch module, a one-way conduction module and a control module. The control module compares the voltage of a power supply module with the voltage of a power battery;the first switch module, the second switch module and the three-phase inverter are controlled according to the comparison result; the power supply module carries out boosting charging or direct charging on the power battery; meanwhile, the one-way conduction module is additionally arranged based on the charging circuit, so that the power supply module, the one-way conduction module, the three-phase inverter and a three-phase alternating current motor form a heating circuit, so that heat is provided for a to-be-heated part in the whole vehicle, that is, the three-phase alternating current motorand the three-phase inverter are reused in different circuits through the control switch module, so that the charging function and the heating function are achieved.

The invention discloses a starting control device of a micro gas turbine and a starting control method. The starting control device comprises a data measurement module, a starting implementation module and a digital control unit, wherein the data measurement module consists of a rotating speed sensor and a temperature sensor, and the starting implementation module consists of a starting motor, an igniter, a fuel protection solenoid valve and a fuel flow control proportional solenoid valve. The starting control method comprises the following steps: controlling the starting motor through the digital control unit, driving a gas turbine to rotate at a set rotating speed, maintaining the rotating speed, adjusting fuel flow through controlling the fuel flow control proportional solenoid valve to realize proper proportional matching of fuel and air, igniting the mixed gas with the igniter, raising the rotating speed of the gas turbine, and making the gas turbine into an idling state through closed-loop control of a microcontroller according to the exhaust temperature and the rotating speed of the gas turbine, thereby completing the starting. The invention can effectively avoid the influence of changes in the fuel flow, the state of the gas turbine and the atmospheric conditions during the starting process, solve the problems of the micro gas turbine in the harsh environment such as difficult and unstable starting and the like, and ensure that the gas turbine can be started under any condition.

The invention discloses an islet microgrid unified SoC balancing control method. The method comprises the steps of obtaining state of charge (SOC) rectifying information of each distributed energy storage unit, using the state of charge (SOC) rectifying information based on the condition of low bandwidth distributed communication to adjust a drooping coefficient of each distributed energy storage unit, adjusting an angular frequency reference value of each distributed energy storage unit by adjusting the drooping coefficient of each distributed energy storage unit so that charge-discharge power of each distributed energy storage unit can be in an optimal state, and equipartition of load power and the balance of the state of charge (SOC) of each distributed energy storage unit can be finally achieved. In this way, the purpose is achieved that one control strategy is applicable to SOC balance control in the charging state and SOC balance control in the discharging state simultaneously, thus the control strategy of the charging and discharging mode is unified, and the shortcoming that the system is unstable caused by conversion of control strategies in the charging and discharging process is overcome.

The invention provides a spraying robot driven by multiple paralleled parallelogram links in a series-parallel manner. The spraying robot comprises a serial drive pedestal assembly, three sets of paralleled parallelogram link mechanisms and a movable platform (20). The spraying robot is characterized in that the serial drive pedestal assembly comprises a fixed lower pedestal (2), and three rotary pedestals which are connected in series on the lower pedestal (2) and are formed by a middle pedestal (3), an upper pedestal (4) and a top pedestal (18), a platform of the top pedestal (18) is provided with three sets of driving motors (14, 6, 17), and the three rotary pedestals (3, 4, 18) and the three sets of driving motors (14, 6, 17) drive the movable platform (20) through the three sets of paralleled parallelogram link mechanisms in a cooperation manner. Forward and inverse kinematics solutions of the spraying robot are simple and unique, track planning and control can be achieved easily, the work space of the spraying robot is large, and the spraying robot can spray large-outline complex curved surfaces.

The invention provides a traction power supply system resonance suppression method and device based on an adaptive notch filter. By adding the adaptive notch filter in a locomotive network-side rectifier control method, a control instruction at oscillation frequency is allowed to be attenuated greatly, and thus generation of system resonance is suppressed through control ability of a locomotive itself; and under the condition of not increasing extra investment, safe and stable operation of a power supply system is ensured. Through the adaptive notch filter, a low-frequency resonant component in a grid-connected current is extracted and multiplied by an appropriate proportion coefficient for attenuation, and then, a component, obtained after low-frequency resonance attenuation in the grid-connected current, is subtracted from a grid-connected instruction current obtained by a DC voltage regulator, so that effects of stabilizing the grid-connected current and voltage and suppressing oscillation are achieved, suppression effect is good, hardware cost is not increased, and no extra investment is caused.

The invention discloses a high-efficiency totem-pole bridgeless PFC rectifier control method, and belongs to the field of high-frequency switching power supplies in the field of power electronics. Thetotem-pole bridgeless PFC rectifier is mainly composed of a main circuit and a control circuit. According to the invention, a first duty ratio is calculated through a derived first duty ratio calculation formula, so that the power factor can be improved; a second duty ratio and extra conduction time are calculated through a derived second duty ratio calculation formula, so that full-range zero-voltage switching ZVS can be realized, and the power factor is further improved; a current detection link can be removed through the first duty ratio, second duty ratio and extra conduction time obtained through calculation, so that the efficiency is improved; by generating a variable-frequency triangular carrier, the circuit works in a critical inductive current CRM mode, and ripple waves of inductive current are reduced; and by improving the circuit topology and replacing diodes with MOSFETs, the circuit on-state loss and the circulation loss caused by the current are reduced. Thus, efficiencyand reliability of the rectifier can be improved.

The invention discloses a permanent magnet synchronous motor unposition sensor control method, which concretely comprises the following steps of: step 10, collecting three-phase voltage of a permanent magnet synchronous motor, switching the three-phase voltage to a dd coordinate system, and obtaining voltage ud and uq in a dq axis; step 20, collecting three-phase current of the permanent magnet synchronous motor, switching the three-phase current to a dq coordinate system, and obtaining current id and iq in the dq axis; step 30, adopting a sliding mode variable structure model reference adaptive system-based algorithm to obtain a rotor estimated electric angle speed and a rotor position of the permanent magnet synchronous motor; and step 40, according to the rotor estimated electric angle speed and the rotor position obtained in the step 30, realizing unposition sensor rotation speed close-loop vector control of the motor. The permanent magnet synchronous motor unposition sensor control method has the advantages of low cost, simple control algorithm, high rotation speed and position estimation speed, high estimation accuracy, and the like.

The invention provides a brushless double-rotor motor by using a Halbach permanent magnet array and a magnetic field modulation principle. The double-rotor motor comprises four layers which are an inner stator, a modulation ring rotor, an intermediate rotor and an outer stator in sequence from inside to outside in all; the inner stator, the modulation ring rotor and the intermediate rotor form an inner magnetic field modulation-type motor; the intermediate rotor and the outer stator form an outer permanent magnet synchronous motor; and the inner side and the outer side of the intermediate rotor are provided with Halbach array permanent magnets respectively. The modulation ring rotor is connected with an output shaft of an internal combustion engine; and the intermediate rotor is connected with the output shaft of the double-rotor motor. According to the double-rotor motor, the internal and external magnetic field coupling phenomenon of the double-rotor motor is reduced or even eliminated through the magnetic self-shielding characteristic of the Halbach array, the brushless target of the of an inner rotor of the double-rotor motor is achieved through a magnetic field modulation principle to improve the reliability of the motor, and the disadvantages caused by internal and external magnetic field coupling and a carbon brush slip ring are avoided.

The invention discloses a multi-level converter with a DC (direct current) capacitor assisted voltage-sharing circuit. The voltage-sharing circuit comprises a primary voltage-sharing circuit and a secondary voltage-sharing circuit; for the multi-level converter with N+1 levels and N DC capacitors, the primary voltage-sharing circuit comprises N / 2 inductance voltage-sharing basic circuits; a switching element SA1n and a switching element SA1 (n-1) are connected with a capacitor Cn and a capacitor C (n-1) in parallel and the central connection points between the switching elements and the capacitors are connected by an inductor LA1(n / 2), thus realizing the voltage-sharing of the capacitor Cn and the capacitor C (n-1); the secondary voltage-sharing circuit comprises N / 2-1 groups of inductance voltage-sharing basic circuits to realize the voltage-sharing of the capacitor C (n-1) and a capacitor C (n-2); and finally, the N DC capacitors C realize the equalization of all voltages. The multi-level converter is suitable for the voltage-sharing of any level, does not influence an existing main circuit and a control principle and ensures that a main circuit converter can realize power transmission of any power factor under the condition of any modulation depth. The invention also provides specific circuits of a five-level converter as well as a realization circuit for minimizing the number of the inductors and a control method thereof.

This invention relates to side path mixture excitation motor, which comprises Shell, two end covers, two sets of excitation coil set, rotor and stator, wherein, the rotor surface magnetic electrode is formed by permanent magnetic electrode and iron magnetic rotor electrode by crossing; two sets of direct current excitation sets are separately fixed on left and right end covers; the shell and end cover are made of conductive magnetize materials and the axis is of non-iron magnetic materials. This invention adopts magnetic side path method to adjust gap.

The invention relates to a wind-photovoltaic-diesel-battery independent power supply coordinated control system for communication base stations. The system comprises a wind-driven generator, a photovoltaic generation array, a battery pack, a diesel generator set, a communication base station load, a micro-grid monitoring system, a digital signal processor, an AC load, and a controllable load. The power output end of the wind-driven generator is connected with the AC power input end of a first AC / DC converter. The DC power output end of the first AC / DC converter is connected with the input end of a first DC / DC converter. The power output end of the photovoltaic generation array is connected with the input end of a second DC / DC converter. The power output end of the diesel generator set is connected with the AC power input end of a second AC / DC converter. In view of random and intermittent natural resources and the change of the communication base station load, the demand for continuous and stable power supply to a communication base station is satisfied through coordinated control on a wind-solar generation unit, an energy storage device and a diesel.

The invention discloses a converter valve module unit. The converter valve module unit comprises at least one direct-current supporting capacitor, an equalizing resistor, four power semiconductor switch modules, a bypass switch and a secondary control protective unit, wherein the equalizing resistor is connected in parallel with all the direct-current supporting capacitors; the first and second power semiconductor switch modules are sequentially connected in series with each other and then are connected in parallel with the direct-current supporting capacitors; the third and fourth power semiconductor switch modules are sequentially connected in series with each other and then are connected in parallel with the direct-current supporting capacitors; the bypass switch is connected in parallel with the second power semiconductor switch module; the converter valve module unit also comprises a power diode; the anode of the power diode is connected with the negative end of the second power semiconductor switch module; the cathode of the power diode is connected with the negative end of the first power semiconductor switch module. The structure can solve the problems that in existing flexible power transmission, the transmission power is limited by elements, equipment is relatively low in efficiency and the protection reliability is poor when equipment has faults. The invention also discloses a modular multi-electric-level current converter.

The invention discloses a control method of SVG dynamic reactive power compensation and harmonic management based on PI feedforward decoupling. The method comprises a step of inputting a difference value between DC side reference voltage and capacitor voltage to a DC side PI controller, a step of sampling three-phase load current through a current transformer, carrying out adc / dq conversion on signals and sending the signals to a low-pass filter LPF, adjusting dq axis components outputted by the LPF to be reference command current of a PI feedforward decoupling controller, comparing the reference command current and grid current under a dq coordinate system, and sending an error signal to the PI feedforward decoupling controller, a step of carrying out dq / abc conversion on an output signalof the PI feedforward decoupling controller, inputting the signal into an SVPWM driving module to generate a switching signal to control a three-phase full-bridge inverter, and allowing the three-phase full-bridge inverter to generate a compensation signals to realize the dynamic reactive compensation and harmonic management. According to the control method, a complex controller is not needed, aharmonic compensation effect can be achieved by using the PI controller, the control method is simple and easy to implement, and the compensation effect is better than that of a conventional control method.

The invention relates to a two-stage booster system capable of realizing all-working-condition EGR rate adjustability of an internal combustion engine. A gas loop, connected with an exhaust main pipe and an intake main pipe in parallel, of a traditional EGR two-stage booster system is connected with two bypass pipelines in parallel, wherein the first bypass pipeline is provided with a high-pressure-stage EGR pump in coaxial driving connection with a high-pressure-stage turbine and a high-pressure-stage air compressor and a low-pressure-stage EGR pump in coaxial driving connection with a low-pressure-stage turbine and a low-pressure-stage air compressor, and the second bypass pipeline is provided with a high-pressure-stage EGR pump bypass valve and a low-pressure-stage EGR pump bypass valve. The matching mode between the air pump bypass valves and EGR is adjusted according to the intake pressure difference change, so that a two-stage booster engine can satisfy the EGR rate requirements in the wider working condition range. The closing sequence of the high / low-pressure-stage bypass valves is set, and the valves are closed in proportion, so that the energy loss of coaxial pumps to the two-stage booster system and the influence of EGR pressure jump on combustion are reduced.

The invention relates to a tilt rotor unmanned aerial vehicle. The tilt rotor unmanned aerial vehicle comprises a fuselage (100), a wing (200), a plurality of rotors (300) rotationally mounted on the wing, and a drive device (400) for driving the rotors (300), and a linkage assembly is connected between the rotors so that the rotors can rotate together. The number of the drive mechanism for driving the rotors to rotate is one, and the rotors are in linkage, so that the drive device can control multiple rotors at the same time, and the control strategy is simplified. In addition, since the number of the drive devices is one, the weight of a body of the unmanned aerial vehicle can be reduced, and thus the ability to load other equipment can be improved.

The invention relates to the independent photovoltaic power generation technology, and simultaneously realizes the functions of large-scale boosting, three-port grounding and storage battery charging.Furthermore, the invention provides a control strategy corresponding to a converter, wherein a TPC can be safely and reliably applied to an independent photovoltaic power generation system. Accordingto the technical scheme adopted by the invention, a three-port converter system applied to an independent photovoltaic power generation occasion comprises three parts: a buck-boost bidirectional DC converter, a boost DC converter and a switch capacitor unit. In the buck-boost bidirectional DC converter, a Vpv and an ipv serve as the port voltage and the port current of a photovoltaic array respectively. The output of the photovoltaic array is applied to the parallel voltage-stabilized capacitor Cpv of the photovoltaic array as the input of the three-port converter. S1 and S2 are switching tubes which are connected in series. The system is is mainly applied to independent photovoltaic power generation occasions.

The invention discloses one triangle function limit micro variable flow method, which comprises the following steps: setting displacement transducer connection set to get needed basic voltage; using each base frequency and frequency function or different function to form triangle function limit micro variable equation with two sides as input and output signals; setting sine function transducer, power electron switch and outside circuit to get the analysis variable equation topological circuit and integrating the angle frequency and difference to form integral logic control.

The invention relates to a non-liner switching control method of a single-phase shunt active power filter, comprising the following steps: 1) building an error model of a switching system; 2) calculating the liapunov function V=xTPX of each subsystem by the linear system theory, and judging: (1) judging whether each subsystem moves in the area, if yes, proving that the subsystem is convergent and the state variable of the system approaches to zero, and switching the switching system to a corresponding subsystem, wherein in the control input of the system, arg means that a subscript satisfying the expression is taken; (2) if two subsystems both move in the area, proving that two subsystems are convergent and can cause the state variable of the system to approach to zero, calculating the subsystem which causes the switching system to be switched to a control input decision, and ensuring the highest APF convergence rate; and 3) under the action of control input u(t), carrying out precise compensation on harmonic current in a power grid by the APF.

The invention discloses a field bus communication method based on a RS485 interface. A main station is built with an ARM microcontroller and an FPGA hardware platform; the main station is in a communication connection with a slave station through a RS485 bus; the main station has a main station application layer, a main station data link layer and a main station physical layer; the main station application layer is used for calling a program of a Linux driving layer through an API function; the main station application layer is in a communication connection with the main station data link layer through a GPMC bus; the data link layer is in a communication connection with the main station physical layer through a bus; and the main station physical layer is used for transmitting a signal byadopting a RS485 interface converting chip. Through adoption of the field bus communication method, real-time and reliable communication in the field of automatic control can be met. The field bus communication method has the characteristics of flexible connection manner, understandable control strategy, simple underlying driving, high interference resistance and the like.

The invention discloses a displacement-force compound control lifting system for a forging manipulator. A port P of a proportional servo valve (2) is connected with an oil supply port (1) of an oil source; a port A of the proportional servo valve (2) is respectively connected with an inlet of a safety valve (3), an outlet of a check valve (4), an inlet of a stop valve (5), a pressure sensor (12) and lower cavities of two lifting cylinders; an oil return port (7) of the oil source is respectively connected with a port T of the proportional servo valve (2), an outlet of the safety valve (3), an inlet of the check valve (4), an outlet of the stop valve (5) and upper cavities of the two lifting cylinders; mechanisms at top ends of piston rods of the two lifting cylinders are fixedly connected; a displacement sensor (8) is internally arranged on the piston rods; and a signal output end of the displacement sensor (8), a signal output end of the pressure sensor (12) and a signal input end of the proportional servo valve (2) are connected with a displacement-force compound controller through signals. Due to the adoption of the system, the response speed can be increased, and the compliance in the vertical direction can be improved.

The invention relates to a temperature monitoring system and a temperature monitoring method for an electric vehicle charging assembly. The temperature monitoring method comprises temperature data acquisition steps and control steps. The temperature monitoring method comprises the temperature data acquisition steps of acquiring a temperature threshold of an electric vehicle charging socket and a temperature threshold of a charging gun assembly, and acquiring a temperature value of the electric vehicle charging socket and a temperature value of the charging gun assembly. The temperature monitoring method comprises the control steps of performing charging control of an electric vehicle based on the temperature value of the electric vehicle charging socket, the temperature threshold of the electric vehicle charging socket, the temperature value of the charging gun assembly and the temperature threshold of the charging gun assembly. The temperature monitoring system and the monitoring method of the electric vehicle charging assembly provided by the embodiment of the invention ensure that the temperature in the charging process of the vehicle does not exceed the tolerable temperature ofthe charging gun assembly and the electric vehicle charging socket through the whole vehicle control, thereby ensuring the safety of the charging process.

The present invention discloses a hybrid DC converter. The hybrid DC converter is formed by connecting a high frequency resonant converter and a dual active bridge converter in parallel, the high frequency resonant converter and the dual active bridge converter are connected end to end orderly, and the high frequency resonant converter comprises a full-bridge inverter A, a high-frequency transformer and an uncontrolled rectifier bridge. The full-bridge inverter A and the uncontrolled rectifier bridge are connected with the head end and the tail end of the high-frequency transformer respectively, the dual active bridge DC converter comprises a full-bridge inverter B, a medium frequency transformer and a fully-controlled rectifier bridge, and the full-bridge inverter B and the fully-controlled rectifier bridge are connected with the head end and the tail end of the medium frequency transformer respectively. The hybrid DC converter of the present invention combines the advantages of the high frequency resonant converter and the dual active bridge DC converter and considers the current capability of a high frequency resonant capacitor, the high frequency resonant converter only realizes the effect of clamping a terminal voltage, and the large-power electric energy transmission completely depends on the dual active bridge DC converter, thereby guaranteeing the stable terminal voltage and the power transmission capability. The converter overall adopts a closed loop PI control strategy.

The invention discloses an electric vehicle motor waste heat utilization system and a control method thereof, and the system enables a motor temperature control loop to be connected with a cooling liquid loop in a battery through a four-way valve, so that the two loops realize independent circulation or are connected in series into a circulation loop, and the motor waste heat is guided into the battery, and heats the battery. In addition, the system further comprises a refrigerant loop, outside the battery, which is matched with the cooling liquid loop in the battery to achieve temperature control over the power battery, and further comprises a passenger compartment temperature control loop. The control method comprises the steps of independent heating or cooling control of the passenger compartment, independent heating or cooling control of the power battery, simultaneous heating or cooling control of the passenger compartment and the power battery, and utilization control of motor waste heat in the heating process of the power battery. The motor waste heat is introduced into the power battery heat management loop, the control strategy is simple and effective, the system efficiency is improved, the energy consumption is reduced, and the endurance mileage of the whole vehicle is increased.