564 results about "Three phase windings" patented technology

The invention belongs to the technical field of simulation analysis, and particularly relates to a transformer turn-to-turn insulation degradation fault simulation identification method based on box cover temperature, which comprises the following steps: constructing a three-dimensional geometric model of the original size of a transformer, importing the three-dimensional geometric model into finite element simulation software to obtain a simulation geometric model, and establishing an electromagnetic-fluid temperature field coupling model of the transformer; based on a transformer entity test, performing comparison verification on a simulation result; simulating the temperature change of the fuel tank shell under different active loss levels and different fault positions, and establishing a sample database of the active loss, the fault positions and the temperature change rate of the fuel tank shell; determining threshold values of an active loss change rate and an oil tank shell temperature change rate when the winding turn-to-turn insulation degradation fault occurs; in the operation process of the transformer, the position of the turn-to-turn insulation degradation fault of the winding is calculated according to the voltage and current of the three-phase winding obtained through real-time measurement. According to the invention, power-off-free detection can be realized, and further expansion of faults is avoided.

The invention discloses an open-phase self-fault-tolerant control method for a phase-shift-free dual three-phase permanent magnet synchronous motor. The method can automatically adjust a current distribution relation in the case of an open-phase fault and suppress torque pulsation in combination with neutral point voltage compensation. Comprising the following steps: driving two pairs of three-phase winding modules of the phase-shift-free DTP-PMSM in parallel by adopting two two-level three-phase voltage source inverters, and providing a mathematical model of the motor; current distribution is automatically adjusted; compensating the voltage of the neutral point, and calculating the offset of the fault module; the current is redistributed to suppress the torque ripple after the fault, and the secondary oblique wave component generated by the phase failure fault is eliminated; a current loop controller is improved through dead-beat predictive control; the speed ring controller is optimally designed into an improved sliding mode controller; an improved double-loop controller system is formed by combining improved sliding mode control and dead-beat prediction control, high-gain parameters are set to improve the dynamic response performance of the system, and a new self-fault-tolerant control system is formed.

The invention provides a motor drive control method and system for a high-speed hair dryer. The method comprises the following steps: acquiring a real-time sampling value of bus voltage; when the real-time sampling value reaches a preset voltage threshold value, performing vector operation on a torque current integral value of the motor current, and determining an initial position angle of a rotor; performing Clark transformation on the three-phase winding endpoint voltage according to the initial position angle of the rotor to generate a voltage component; determining a wind power interference coefficient of the torque current according to the voltage component, and determining a corresponding wind power state identifier in combination with a preset threshold value; configuring a sliding-mode observer according to a starting parameter group of a motor starting control mode corresponding to the wind power state identifier, and determining a rotor motion state parameter by performing phase tracking on output of the sliding-mode observer; and generating a three-phase pulse width modulation driving signal through the rotor motion state parameters to perform driving control on the motor. According to the scheme, the starting reliability and control precision of the motor can be remarkably improved, and the service life of the blowing cylinder is effectively prolonged.

The invention belongs to the related technical field of motor winding design, and discloses a design method of an alternating current winding capable of generating multipolar magnetomotive force, which comprises the following steps of: selecting n three-phase symmetrical winding units according to n required magnetomotive forces and determining the number of fundamental wave pole pairs, performing star connection on three-phase windings in each three-phase symmetrical winding unit, the same-phase windings of the n three-phase symmetrical winding units are connected in series to form a winding assembly, and star connection is kept; according to the fundamental wave pole pair number of each three-phase symmetric winding unit, determining the arrangement of the corresponding three-phase symmetric winding unit in the iron core slot, and obtaining the initial arrangement of the winding assembly in the slot; and based on the equal ampere-turn principle of the alternating current winding, combining and simplifying the winding coil conductor in each slot to obtain the final arrangement of the winding assembly in the slots. An alternating current winding is designed based on the method, useless harmonic components can be suppressed, and various principal wave magnetomotive forces with any number of pole pairs and any turning direction can be generated.

The invention discloses a function switching device for transformer testing and a testing system thereof, relates to the technical field of transformer testing, is used for solving the problem of low testing efficiency, and is used for setting a switching time reference by acquiring transformer capacity information and detecting the number of closed relays of testing nodes and loop resistance. Analyzing a resistance fluctuation index and loop harmonic characteristics by combining historical loop resistance data, correcting a switching time reference, detecting three-phase winding current, generating a current balance index, evaluating a fault risk level, screening and marking to-be-tested nodes according to the fault risk level, and after the current test node is tested, determining the current test node according to the fault risk level. And performing test processing on the marked to-be-tested nodes based on the corrected switching time reference, thereby realizing intelligent selection of a transformer test sequence, improving test efficiency and ensuring electrical state stability and test precision of each test node.

The invention discloses a low-modulation-ratio area switching control method of a dual three-phase permanent magnet synchronous motor, solves the problems that two sets of three-phase windings are required to work together in a low-modulation-ratio area of a traditional DTP-PMSM, and an operation efficiency optimization space exists, and belongs to the field of motor driving. The method comprises the steps that in a low modulation ratio area, a three-phase winding ABC operates independently, sampling is carried out at two zero vectors, and current reconstruction is completed according to sampled current; a modulation reference voltage is obtained according to the reconstructed three-phase current and the sampling rotating speed, and driving is carried out through modulation; in a normal modulation ratio area, the two sets of three-phase windings operate in a matched mode, carrier phase shifting is carried out on the three-phase windings XYZ by 0.25 Ts, sampling is carried out at the zero vector positions of the two sets of three-phase windings respectively, current reconstruction is completed according to the sampling result, modulation reference voltage is obtained according to the reconstructed six-phase current and the sampling rotating speed, amplitude limiting is carried out, and then driving is carried out through modulation. According to the control method, only one set of three-phase winding is needed for operation in a low-modulation-ratio area, and the system operation efficiency is improved.

The invention provides a motor stator temperature estimation method and device, electronic equipment and a storage medium, and relates to the technical field of motors, and the method comprises the steps: injecting positive and negative alternating DC voltage signals into a motor under a static coordinate system; obtaining a current signal of a three-phase winding of the motor, and obtaining a direct current component of current according to the current signal; obtaining a resistance value of a motor stator winding according to the DC component and the DC voltage signal; and obtaining the stator temperature according to the resistance value so as to accurately estimate the stator temperature.

The invention belongs to the technical field of motor control, and relates to a four-motor fault-tolerant working topological structure and method. The topological structure comprises twelve phases of bridge arms which are respectively connected with motors I to IV, and each motor is provided with A, B and C three-phase windings. The structure also comprises four bidirectional thyristors which are connected with the C-phase bridge arms of the four motors. During working, the duty ratio of the C-phase bridge arm is taken as a reference, the optimal duty ratio of the motor with the open-circuit fault is calculated, and fault-tolerant control is carried out on the four three-phase star-connected winding permanent magnet synchronous motors. The method not only can prolong the service life of the system, but also considers fault-tolerant control of a large number of motors, effectively improves the reliability of the motor group control system, and has important application value in the field of motor control.

The invention discloses a zero-phase-shift-angle dual three-phase permanent magnet synchronous motor control method, solves the problem that DTP-PMSM current reconstruction control needs a single current sensor to perforate more than three branches, and belongs to the field of motor driving. According to a sampling mode and a modulation mode of ISAMPLE of a sum of current between A and B two-phase lower bridge arms of a first set of three-phase windings of a motor and current between X and Y two-phase upper bridge arms of a second set of three-phase windings, and spatial distribution characteristics of the two sets of windings of the motor, a reconstruction region is constructed; constructing a motor six-phase current reconstruction expression of each reconstruction region; selecting a corresponding six-phase current reconstruction expression according to the reconstruction area where the reference voltage vector is located and the ISAMPLE collected in real time, and reconstructing the six-phase current; and controlling the motor according to the reconstructed six-phase current. Unification of current reconstruction, torque ripple suppression and dual three-phase resolver delay compensation can be realized.

The invention discloses a permanent magnet synchronous motor harmonic current separation method constructed based on a virtual winding, and relates to the technical field of motor control, and the method comprises the steps: building a generalized constraint condition of harmonic current separation, and carrying out the harmonic current separation based on the generalized constraint condition of harmonic current separation and the order of a harmonic current needing to be separated, determining the construction number of virtual windings and space intervals among the virtual windings; sampling three-phase current in a three-phase winding of the permanent magnet synchronous motor; based on the construction number of the virtual windings and the space intervals among the virtual windings, constructing the virtual windings to obtain three-phase current in each virtual winding; and based on the three-phase current in each virtual winding and the three-phase current in the three-phase winding of the permanent magnet synchronous motor, constructing a harmonic current separation expression to realize the separation of the harmonic current of the permanent magnet synchronous motor. According to the method, accurate separation of the fundamental current and the harmonic current of any frequency is realized, and a good basis is provided for subsequent control of the harmonic current.

The present invention provides a three-phase terminal block, a drive assembly and a vehicle, including a terminal block body and three single-phase terminal posts. The terminal block body extends in a cylindrical shape, and the three single-phase terminal posts are arranged along the axial direction of the terminal block body. The three single-phase terminal posts are provided on the outer periphery of the terminal block body, and a first terminal and a second terminal are respectively arranged at both axial ends of the single-phase terminal post on the terminal block body. Since the stator has a three-phase winding, the three single-phase terminal posts are arranged on the outer periphery of the terminal block body, and then the three single-phase terminal posts can be correspondingly connected to the terminal ends of the stator, thereby optimizing the wiring layout, and the space between the three single-phase terminal posts can be used to place spaces such as bearings, thereby improving the compactness of the structural layout.

The invention discloses a stator and rotor dual three-phase winding motor, which belongs to the technical field of motors and comprises a stator, a rotor and an air gap. An air gap exists between the stator and the rotor according to the number of rotor teeth; the tooth number stator of the rotor teeth comprises stator teeth, stator windings, stator permanent magnets and stator yokes, the tooth number stator windings of the rotor teeth are three-phase windings and are wound on the stator teeth, stator grooves are formed between adjacent stator teeth, and the stator permanent magnets are placed in the stator grooves; the tooth number rotor of the rotor teeth comprises rotor normal teeth, rotor teeth, rotor permanent magnets and a rotor yoke part, the tooth number rotor teeth of the rotor teeth are divided into rotor split teeth and normal teeth, every two rotor normal teeth and one rotor split tooth form a group of rotor teeth, and a plurality of groups of rotor teeth are sequentially arranged and uniformly distributed along the circumferential direction; the tooth number rotor winding of the rotor teeth is a three-phase winding and is wound on the rotor teeth; the rotor grooves are formed between the adjacent rotor teeth, and the rotor permanent magnets are placed in the rotor grooves, so that the reliability and the fault-tolerant capability of the motor are improved.

The present disclosure proposes a stator assembly including a stator core including an annular stator yoke and a plurality of stator teeth connected to a radially inner side of the stator yoke, the plurality of stator teeth being spaced apart from each other in a circumferential direction; each phase of winding comprises a first coil group and a second coil group, each stator tooth is wound with one first coil and one second coil, the first coil group comprises at least one first coil, and the second coil group comprises at least one second coil; the first coil of the first coil group and the second coil of the second coil group are wound on the same stator teeth; three first terminals, wherein the first coil group of the three-phase winding is electrically connected to one of the three first terminals; and three second terminals, wherein the second coil group of the three-phase winding is electrically connected to one of the three second terminals. And the first terminals and the second terminals are electrically connected in pairs, so that the first coil group and the second coil group in each phase winding are connected in parallel.

The invention discloses a generator stator winding single-phase earth fault positioning method, system and device and a medium, and the method comprises the steps: enabling three phases of a generator stator winding to be connected in series end to end to form a series loop; low-frequency voltage pulses are injected into the three-phase winding, and a fault phase is determined by comparing symmetry damage characteristics of tail-end current by adopting a tail-end current vector analysis method; injecting a low-frequency voltage pulse into the current phase winding, detecting the current difference between the head end and the tail end of each parallel branch, identifying a branch with abnormal leakage current by combining a leakage current characteristic analysis method, and determining a fault branch; establishing a high-frequency distribution parameter model, and performing high-frequency voltage pulse injection positioning for multiple times to obtain three independent high-frequency pulse positioning results; and performing weighted fusion on the three independent high-frequency pulse positioning results, and performing optimization by using an intelligent optimization algorithm to obtain an optimized single-phase earth fault position. According to the invention, the accuracy and rapidity of fault diagnosis and positioning can be improved.

The present invention discloses a motor stator winding reuse and battery heating control method, wherein the motor stator three-phase winding is used in parallel to form a motor stator winding combined inductance, which is combined with an inverter and a battery pack to form a battery internal heating system, so that the B1 battery pack and the B2 battery pack are mutually charged and discharged through the motor winding combined inductance, generating Joule heat to internally heat the battery pack; the present invention is suitable for internal preheating of lithium batteries at low temperatures, making full use of existing hardware resources of electric vehicles, and controlling the on and off of two sets of inverter full-control devices to generate self-heating current inside the lithium battery, and generating heat by mutual charging and discharging between batteries, thereby improving the thermoelectric conversion efficiency. The present invention is suitable for electric vehicles with multiple motors, and can meet the different needs of dual motors, multiple motor windings, and open winding motors.

The invention relates to the technical field of electro-hydraulic integrated driving, in particular to a hydraulic synchronous control system and method based on traveling wave and magnetic field composite driving, the system comprises a plurality of hydraulic cylinders, and each hydraulic cylinder comprises a piston rod assembly and a cylinder barrel; the piston rod assembly comprises a metal push rod on the inner layer, a three-phase winding module arranged around the metal push rod on the middle layer and a lining barrel on the outer layer. Each hydraulic cylinder corresponds to one pressure sensor, one displacement sensor and one controller. The cylinder barrel serves as a secondary conductor, eddy current is generated through traveling wave magnetic field induction, and axial thrust is generated. In a no-load state, the controller switches the current direction to generate auxiliary oil absorption thrust; during loading, current parameters are dynamically adjusted according to displacement, pressure and speed feedback, and synchronous compensation and speed regulation are achieved. The linear motor has the characteristics of high thrust density of a hydraulic system and quick response of the linear motor, and is suitable for high-precision engineering machinery and aerospace hydraulic actuating mechanisms.

The invention relates to a quick charge boost control method and device for a vehicle, the vehicle and a storage medium. Comprising the steps of obtaining a system state and a power battery charging power demand of a current vehicle when the current vehicle has a quick charge boosting demand, and generating an initial charging current instruction according to the system state and the power battery charging power demand; obtaining a final charging current instruction based on a preset first PI regulator according to the initial charging current instruction, obtaining a three-phase winding neutral point output current instruction based on a preset second PI regulator according to the final charging current instruction, and obtaining a three-phase winding neutral point output current instruction based on a preset third PI regulator. And obtaining a duty ratio control instruction of a three-phase bridge arm according to the three-phase winding neutral point output current instruction, and performing interleaving control on a three-phase upper bridge arm of the motor controller power module according to the duty ratio control instruction of the three-phase bridge arm. Therefore, the problems that the unexpected torque is easy to realize and the charging efficiency is relatively low in the prior art are solved, and the charging efficiency is improved while the safety is improved.

The invention discloses a three-phase four-wire system motor controller compatible with three-phase and two-phase operation and a control system, the three-phase four-wire system motor controller comprises a middle-line bridge arm, a three-phase bridge arm, a capacitor assembly, a middle bridge arm control module and a three-phase bridge arm control module, the output of the middle-line bridge arm is electrically connected with the neutral point of a three-phase four-wire system motor; three paths of outputs of the three-phase bridge arm are electrically connected with three-phase windings of the three-phase four-wire system motor respectively; the capacitor assembly is electrically connected with the positive electrode and the negative electrode of a direct current bus corresponding to the three-phase four-wire system motor controller. The middle bridge arm control module is used for controlling a middle line bridge arm; the three-phase bridge arm control module is used for controlling a three-phase bridge arm. When one phase of the three-phase four-wire system motor breaks down, the three-phase four-wire system motor can work in a two-phase operation mode by introducing the middle-line bridge arm and leading out the neutral point of the motor, so that the three-phase four-wire system motor can be compatible with the three-phase operation mode and the two-phase operation mode; therefore, safe redundancy of stable torque can be provided for the electric driving system.

According to the compressor starting method, the control system, the compressor and the air conditioner, before the compressor enters closed-loop starting, whether inertia rotation exists in a rotor or not is judged, a control signal is generated under the condition that inertia rotation exists, and an inversion module is controlled to achieve short circuit of a three-phase winding of the compressor; the rotating speed of the rotor is effectively reduced; and then, when the rotating speed is lower than a preset threshold value, a closed-loop starting strategy is executed to complete starting. According to the method, by adding the braking step in the inertia rotation state, the problem of inaccurate rotor position estimation caused by the high rotation speed is avoided, it is ensured that the compressor can be reliably switched to closed-loop operation in the low-speed state, the technical problem of starting failure in the inertia low-speed rotation scene of the rotor is effectively solved, and the reliability of the compressor is improved. And the starting success rate and the overall operation reliability of the compressor are improved.

The application provides a method for pulse heating a power battery of an electric vehicle and the electric vehicle. The electric vehicle comprises a plurality of motors and a plurality of three-phase bridge arms. A bridge arm midpoint of each three-phase bridge arm is used for connecting three-phase windings of one motor. Each three-phase bridge arm is used for connecting the power battery through a direct current bus. The control method comprises: controlling each three-phase bridge arm to generate a pulse current on the direct current bus; and adjusting a switching frequency of a switching tube of at least one three-phase bridge arm of the plurality of three-phase bridge arms to reduce a phase difference of the pulse currents generated by the plurality of inverter circuits. The phase value of the pulse current output by the at least one three-phase bridge arm is adjusted, so that the phase difference of the pulse currents generated by the plurality of three-phase bridge arms is reduced, and the heating efficiency of the power battery is improved.

Three-phase windings are wound, with a conductor, around twelve magnetic pole teeth arranged at equal angular intervals on an inner peripheral portion of a stator core configured to constitute a three-phase, twelve-pole stator. The winding of each phase comprises, at least at one location, a portion in which the conductor is drawn out from one of the slots to form a lead-out portion and is then returned to the same slot, and the conductor on both sides of the lead-out portion is fixed within the one slot by the conductor wound around one of the magnetic pole teeth forming the one slot after the lead-out portion has been formed.

The present invention relates to the technical field of multi-phase motor control. Disclosed is a third harmonic injection fault-tolerant control algorithm for a dual three-phase permanent magnet synchronous motor under a one-phase open-circuit fault. In order to improve the torque output capability after open-circuit fault fault-tolerant operation of the dual three-phase motor, disclosed in the present invention is a phase-loss reduced-order fault-tolerant control strategy of the dual three-phase motor. The implementation of the method mainly comprises: 1. when a phase-loss fault occurs, connecting neutral points of two sets of three-phase windings to the midpoint of a bus capacitor; 2, constructing a new reduced-order fault-tolerant matrix; and 3, injecting third harmonics by means of a rotating synchronous coordinate system. According to the new reduced-order fault-tolerant matrix provided by the present invention, the fault-tolerant control strategy is operated, so that the utilization rate of a motor iron core can be increased, a fault-tolerant phase current peak value and winding copper loss are reduced, and the reliability of the motor during fault-tolerant operation is improved.

This invention relates to a current reconfiguration method for a 30° phase-shift angle dual three-phase permanent magnet synchronous motor, solving the problem that a DTP-PMSM current reconfiguration control system requires a single current sensor to be inserted through three or more branches. It falls within the field of motor drives. The invention utilizes a single current Hall sensor to collect the sum of the current between the lower bridge arms of phases A and B of the first three-phase winding and the current between the upper bridge arms of phases X and Y of the second three-phase winding. SAMPLE Based on the sampling method, modulation method, and spatial distribution characteristics of the two sets of motor windings, a reconstructed region is constructed, and a six-phase current reconstructed expression for the motor in each reconstructed region is generated. A combination of IPWM and variable sampling timing is used to eliminate the blind zone at the boundary of the reconstructed region. Based on the reconstructed region where the reference voltage vector is located and the real-time acquired IPWM signal... SAMPLE Select the appropriate six-phase current reconstruction expression to reconstruct the six-phase current.

The invention discloses a dual three-phase permanent magnet synchronous motor switching control method based on single current sensor sampling, solves the problem that phase current reconstruction in a transient switching transition process is difficult due to switching operation of a DTP-PMSM single current sensor current reconstruction low modulation ratio region and a normal region, and belongs to the field of motor driving. The method comprises the steps that in a low modulation ratio area, three-phase windings XYZ operate independently, current between X-phase upper bridge arms and Y-phase upper bridge arms is sampled, three-phase current is reconstructed, the reconstructed current and the sampling rotating speed are sent into a loop to obtain modulation reference voltage, and then power module driving is completed through modulation; in a normal modulation ratio area, the two sets of three-phase windings operate cooperatively, the sum of the current between the X-phase upper bridge arm and the Y-phase upper bridge arm and the current between the A-phase lower bridge arm and the B-phase lower bridge arm is sampled at different sampling vector combination positions, six-phase current reconstruction is carried out, the reconstructed current and the sampling rotating speed are sent into a loop, modulation reference voltage is obtained, and power module driving is completed through modulation after amplitude limiting.

An electric assembly includes a box body, an electric control module, and a motor. The electric control module is disposed in the box. The motor is disposed on the box. The motor includes: a casing, a N wire connection assembly, an end cover, and three phase windings. A first end of the N wire connection assembly is configured to connect to a battery pack. The end cover is disposed at one end of the casing and configured to close the casing, and includes an opening that allows a part of the N wire connection assembly to pass through. The three phase windings are disposed in the casing. First ends of the three phase windings are connected with the electric control module, and second ends of the three phase windings are connected with a junction and connected with a second end of the N wire connection assembly.

The present invention discloses a magnetic levitation permanent magnet speed regulator based on a magnetic levitation linear motor and a speed regulation method thereof. The magnetic levitation linear motor comprises a cylindrical magnetic levitation linear motor, an axial single-degree-of-freedom hybrid magnetic bearing, and a dual cylindrical permanent magnet regulator. The control coil of the axial single-degree-of-freedom hybrid magnetic bearing is always energized, keeping the mover in a suspended state. The three-phase winding coils of the cylindrical magnetic levitation linear motor are energized according to changes in the external load to generate thrust that causes the mover to move axially, thereby driving the stator of the axial magnetic bearing to move axially. The axial air gap changes of the axial magnetic bearing are detected, and the axial magnetic bearing is controlled to generate a magnetic attraction that causes the magnetic bearing rotor to move axially, driving the sleeve on the transmission shaft to move linearly, changing the contact surface between the permanent magnet regulators, and adjusting the output torque and speed. The magnetic levitation permanent magnet speed regulator proposed by the present invention achieves more precise speed control, ensuring high-efficiency transmission. It also reduces vibration and noise, optimizes the permanent magnet regulator, and extends the service life of the equipment.

The invention discloses a motor protection method and device, a motor, a storage medium and a computer program product, and the method comprises the steps: obtaining the phase current of each phase winding of the motor for each phase winding of three-phase windings of the motor in the operation process of the motor; therefore, the three-phase current of the motor is obtained. Only according to the three-phase current of the motor, in combination with a preset fault retrieval subprogram, determining whether one phase of current in the three-phase current of the motor is lack of phase; and under the condition that it is determined that one of the three-phase currents of the motor is open in phase, a reminding message that one of the three-phase currents of the motor is open in phase is initiated, and the motor is controlled to stop, so that open-phase protection of the motor is achieved. According to the scheme, the open-phase protection is carried out only based on the three-phase current of the motor without depending on the rotor angle of the motor, so that the reliability of the open-phase protection of the motor is improved.

The invention discloses a vehicle-mounted range extending system, a vehicle and a charging method of the vehicle, and the vehicle-mounted range extending system comprises an ACDC circuit, a three-phase winding of a generator, a first switch unit, a vehicle-mounted charging unit and a second switch unit; a three-phase winding of the generator is connected with the ACDC circuit through the first switch unit, so that the three-phase winding of the generator is controlled to be communicated with the ACDC circuit; the vehicle-mounted charging unit is connected with the ACDC circuit through the second switch unit so as to control the on-off of the three-phase winding of the generator and the ACDC circuit; under the condition that the first switch unit is in an open state and the second switch unit is in a closed state, the vehicle-mounted range extending system is in an alternating current charging state, and the ACDC circuit is used for rectifying and outputting received alternating current electric energy to a battery pack of a vehicle; the device is simple in structure, low in charging loss and low in improvement cost.

The invention provides a power supply mode switching method and device, a vehicle and a storage medium, and relates to the field of high-voltage power supply. And when the motor supplies power to the whole vehicle and the power supply for supplying power to the whole vehicle needs to be converted from the motor to the high-voltage battery, the motor is controlled to stop generating power. Therefore, when the motor and the high-voltage battery are a high-voltage power supply, the high-voltage battery is regarded as a load, and the battery relay of the high-voltage battery is closed, the battery relay is prevented from being damaged. After the motor stops generating power, the motor is in a driving mode, the motor cuts a stator winding due to residual magnetism and generates back electromotive force with residual inductance, and when the back electromotive force is large, the motor enters a three-phase parallel common-path active discharge mode, so that the current of the three-phase winding is multiplied. And when the current of the three-phase winding is multiplied, the back electromotive force is rapidly reduced, and the rapid discharge of the back electromotive force can be realized. After the motor enters the active discharge mode, the counter electromotive force is detected, so that the battery relay of the high-voltage battery is closed when the counter electromotive force is small, and the error switching risk when the active discharge mode does not reach the expectation is avoided.

The invention relates to the technical field of asteroid motion simulation, and discloses a simulation experiment device suitable for a gravel pile asteroid, the simulation experiment device comprises a vacuum assembly, a suspension assembly, an objective table, a three-phase winding and a camera, the suspension assembly is arranged in the vacuum assembly, and the objective table is arranged at the top of the suspension assembly; the objective table is used for placing a gravel pile asteroid simulant, a three-phase winding is further arranged on the objective table, and a camera is arranged in the vacuum assembly, located at the top of the gravel pile asteroid simulant and used for shooting the movement condition of the gravel pile asteroid simulant; the gravel pile asteroid simulant is placed on the objective table and is in a vacuum state, the gravel pile asteroid simulant is suspended and rotated through the suspension assembly and the three-phase winding, the movement condition of an asteroid in a real state can be simulated, recording can be carried out through the camera, and follow-up observation and analysis are facilitated.