WO2008122167A1 - An operating control method of a servo control system of a cascade motor assembly - Google Patents

Abstract

An operating control method of a servo control system of a cascade motor assembly comprises following steps: a shaft of a first rotor (3) is directly connected to a shaft of an engine (1); a first servo driver (11) performs servo control to a coupling torque between the first rotor and a second rotor (4) according to a relative position of the first rotor and the second rotor and a torque set value of a first motor provided by a control unit (12) so as to realize a regulation to an operation point of the engine independently of running conditions of a whole vehicle; and a second servo driver (14) performs servo control to a coupling torque between a stator (9) and a third rotor (8) in according to a position of the third rotor and a torque set value of a second motor provided by the control unit so that the second motor drives the whole vehicle.

Description

 Operation control method of servo control system of cascade motor assembly

 The present invention relates to an operation control method for a servo control system of a motor, and more particularly to an operation control method for a servo control system of a cascade motor assembly of a hybrid vehicle. Background technique

 Due to the shortage of energy, oil prices continue to rise. The fuel consumption and pollution of vehicles driven by pure fuel engines have become the focus of attention. The reason is related to the inconvenience of adjusting the working point and low efficiency of the engine, and countries have accelerated the research on electric vehicles.

 Years of research have found that there are many problems with pure electric vehicles, mainly because current battery performance cannot meet the requirements of driving vehicles. The energy-saving ratio of the battery is far from that of gasoline. The energy of a fully-charged battery with a weight of one ton is not as high as that of the engine. The output of a pure electric vehicle is limited. In addition, the charging time is long and the conversion efficiency is low. Although the fast charging time is short, the battery efficiency is further reduced. In particular, the number of repeated charging of the battery is limited. The longer the usage time, the lower the capacity is, and it is generally scrapped soon. A large number of used batteries will cause environmental pollution.

 The current research shows that the hybrid electric vehicle is a more practical and energy-efficient vehicle, so the focus of research is transferred to the hybrid electric vehicle. The car is equipped with a fuel engine and a battery, as well as a generator and an electric motor. The design principle is to adjust the operating point of the engine through the engine, generator/motor, and battery to match the engine speed and torque in the economic operation zone, so that the fuel engine can be operated intermittently or continuously efficiently to achieve greater consumption of the same amount of fuel. Kinetic energy. The usual method is to output a part of the mechanical kinetic energy generated by the fuel engine to the drive shaft to obtain a certain torque and speed according to the driving condition of the vehicle, and the remaining kinetic energy is used to drive the generator to generate electricity and store it in the battery. When a certain location or battery is saturated, the battery drives the motor to drive the vehicle. It also allows the fuel engine to operate intermittently in a high-efficiency state. The kinetic energy is transferred from the generator to the electric energy directly to the motor or stored in the battery, and the motor drives the car to run. In this way, the operating efficiency of the fuel engine is improved.

The power structure schemes of the existing hybrid electric vehicles are series, parallel and series-parallel hybrid. Although different levels of energy savings have been achieved, existing power structures are inherently The limitations directly affect the manufacturing cost and energy saving effect of the vehicle. The power structure of current hybrid electric vehicles is difficult to meet the requirements for further improvement in performance and practicality.

 A control method for controlling a dual motor structure consisting of a clutch motor and an auxiliary motor is described in U.S. Patent No. 5,973,460, the entire disclosure of which is incorporated herein by reference. The first drive circuit and the second drive circuit employed in this patent document are actually two frequency converters. Driven by the respective inverters, there is sufficient output at startup without damaging the battery and reducing the size of the motor. In addition, the two frequency converters can adjust the operating point of the engine by adjusting the torque of the respective motors for economic operation. However, the frequency converter technology used in this patent to adjust torque is not sufficient for precise and fast adjustment. In particular, when controlling the clutch motor, a rotatable transformer structure is employed to transfer electrical energy from the primary coil to the secondary coil by electromagnetic induction in an attempt to provide reliable current control to the rotating armature winding, but the transformer The mode of transmitting energy determines that the structure cannot perform effective winding current control with relatively low relative rotational speed between the two rotors of the clutch motor, and thus it is impossible to perform precise torque control on the motor. Specifically, when the relative rotational speeds of the inner and outer rotors are low, the transformer will operate at a very low frequency, and the efficiency of the energy transfer and the energy per unit volume of the electromagnetic induction transformer in the case of low frequency power supply The size is very low, especially when the relative rotational speed of the inner rotor and the outer rotor is zero, the primary and secondary sides of the transformer will be direct current (that is, the current alternating frequency is zero), and the primary side is mounted. The first drive circuit can not effectively control the current of the secondary side of the transformer (ie, the current of the motor winding), of course, it can not implement effective torque control on the motor, and of course, the engine can always work at the optimum efficiency point. .

The European patent application EP 0820894 A2, which is hereby incorporated by reference in its entirety to the entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire The two inverters are actually two frequency converters. The main and auxiliary two motors are connected to the respective inverters, and under the control of the control unit, the high-efficiency stepless speed regulation and torque adjustment between the input shaft and the output shaft are realized; the gear ratio control through the stepless transmission makes the motor The system operates in any torque and speed range. However, because the patent application still uses the inverter drive scheme, the accuracy and response speed of the torque control are greatly reduced. In addition, the battery is directly connected to the DC bus, so that the charge and discharge of the battery are not independently controllable. Furthermore, when the operating point of the output drive shaft is originally located in a triangular region of relatively high efficiency, the speed and torque of the engine follow the change of the external load. Therefore, the effect that the engine operating point does not work stably with the external load on the optimum efficiency curve cannot be achieved.

In summary, U.S. Patent No. 5,973,460 A and European Patent Application No. EP 0 820 894 A2 fail to provide a practical method for cascading motor operation control.

The invention is not sufficient to realize the defect of accurately and quickly adjusting the torque of the motor. The present invention provides a method for controlling the operation of the servo control system of the cascaded motor assembly, and the operation control method of the servo control system of the cascaded motor assembly can be realized Independent adjustment of the operating point of the engine, so that the working point does not work stably with the external load on the optimal efficiency curve. The power output from the hybrid vehicle using the operation control method of the cascade motor assembly servo control system is more flexible.

 The solution to the above technical problem is to provide an operation control method for a servo control system of a cascade motor assembly, wherein the servo control system of the cascade motor assembly includes a first motor, a second motor, and the first a first servo drive associated with the motor, a second servo drive associated with the second motor, and a control unit coupled to the first and second servo drives, wherein the first motor includes a first rotor electromagnetically coupled to each other And a second rotor comprising a stator and a third rotor electromagnetically coupled to each other, the shaft of the first rotor being an input shaft of the cascade motor assembly, the shaft of the second rotor being coaxial with the third rotor and serving as the stage An output shaft of the integrated motor assembly, the operation control method comprising the steps of: directly connecting a shaft of the first rotor with an engine shaft; and being given by the first servo driver according to the relative positions of the first and second rotors and the control unit The torque setting value of the first motor is servo-controlled to the coupling torque between the first rotor and the second rotor to realize The motive working point is independent of the independent adjustment of the operating state of the vehicle; and the coupling torque between the stator and the third rotor is determined by the second servo driver according to the position of the third rotor and the torque setting value of the second motor given by the control unit Servo control is performed to drive the second motor to the entire vehicle.

Compared with the prior art inverter-based control method, the present invention adopts a torque servo control method, which can be applied to the engine regardless of whether the first and second rotors of the first motor rotate or not, and the relative speed of rotation. The applied load torque is precisely controlled, making it easy to control the engine on its optimum fuel efficiency curve for the most economical operation. And, the first servo driver can be controlled by its own "servo, control characteristics. Precise control of the first motor, followed by precise torque servo control of the first motor. In the US patent US5973460A, the method adopted is carried out by the 3-2 and 2-3 vector analysis methods of the conventional frequency converter, and the control of the clutch motor is even inserted into the energy transmission link of the resolver, so that The control mode has not seen any theoretical analysis and actual product that can accurately control the torque of the motor like the servo control technology of the present invention.

 The technical problem further solved by the present invention is to reduce the energy dissipation of the system, and the further solved technical problem is achieved by the following further technical solution, that is, installing one of the first rotor and the second rotor a magnetic pole, a first winding wound on the core is mounted on the other of the first rotor and the second rotor; a permanent magnet pole is mounted on one of the third rotor and the stator, A second winding wound on the core is mounted on the other of the third rotor and the stator. The first servo driver directly loads a corresponding current vector to the first winding through a slip ring mounted on the second rotor shaft to perform torque servo control on the first motor; the second servo driver directly faces the stator The second winding or a corresponding current vector is applied to the second winding on the third rotor via a slip ring to perform torque servo control on the second motor. Since the slip ring is in direct contact with the conductor, the purpose of the slip ring is to directly send the current sent by the first servo driver to the first winding of the first motor. This method is almost the same as the friction heat and the contact resistance heat. No energy loss. In U.S. Patent No. 5,973,460, the transformer structure employed, even if it is capable of transmitting energy at a rated operating frequency point (i.e., the relative rotational speed of the inner rotor and the outer rotor is a rated speed), the energy transfer efficiency is not as good as the present invention.

A further advantage of the operation control method of the servo control system of the cascade motor assembly of the present invention is that: the first and second servo drives respectively load different torques on the first and second motors according to the operation requirement, the cascade motor The component can be operated according to a new power transmission method of power transmission, power generation, power generation, and braking feedback power; in addition, the servo control system of the cascade motor assembly can load the engine servo with appropriate torque to make the engine work. On the optimal efficiency curve, the same amount of fuel is consumed to obtain greater kinetic energy; the magnetic fields of the first and second motors of the cascaded motor assembly are independent of each other, so that independent servo control can be performed without interference; The operation control method of the servo control system embodying the cascade motor assembly of the present invention requires low cost and is suitable for popularization and application. DRAWINGS 1 is a schematic structural view of a servo control system of a cascade type motor assembly according to the present invention;

 2 is a schematic flow chart of a first motor torque servo control method;

 3 is a schematic flow chart of a second motor torque servo control method.

 In the figure, the correspondence between the reference numerals and the elements is as follows:

 1. Engine, 2. Engine shaft is the input shaft, 3. First rotor, 4. Second rotor, 5. Slip ring, 6. Output gear, 7. Output shaft, 8. Third rotor, 9. Stator, 10 , first speed / position sensor, 11, first servo drive, 12, control unit, 13, common DC bus, 14, second servo drive, 15, energy storage unit, 16, power unit, 17, second speed /position sensor. detailed description

 As shown in Fig. 1, the structure of the servo control system of the cascade type motor assembly according to the present invention includes a first motor and a second motor, and the first motor includes a first rotor 3 and a second rotor 4. The first rotor 3 is embedded with a permanent magnet pole to provide a magnetic field for the second rotor 4, the second rotor 4 is mounted with a first winding wound on the core, and the first winding is mounted on the output shaft 7 of the second rotor 4. The slip ring 5 is connected to the first servo driver 11. The first rotor 3 is directly connected to the shaft of the engine 1, and the shaft of the engine is the input shaft 2 of the system. The engine 1 is usually a fuel engine or a gas engine. The shaft of the second rotor 4 is the output shaft of the cascaded motor unit 7, and the output gear 6 is mounted thereon, and the output gear 6 is connected to the external load. The second motor comprises a stator 9 and a third rotor 8 therein, the stator 9 is mounted with a second winding wound on the core, and the third rotor 8 is embedded with a permanent magnet pole. The third rotor 8 is coaxial with the first rotor 2 of the first motor.

The servo control system of the cascade motor assembly further includes first and second servo drives 1 1 , 14 , first and second speed/position sensors 10 , 17 , a control unit 12 , and a power unit 16 and an energy storage unit 15 . A first speed/position sensor 10 is mounted on the input shaft 2 for measuring the rotational speed and position of the first rotor 3. The first servo driver 11 is connected to the winding of the second rotor 4 of the first motor via a slip ring 5, and the first speed/position sensor 10 is also connected to the first servo driver 11. A second speed/position sensor 17 is mounted on the shaft of the third rotor 8 of the second motor for measuring the rotational speed and position of the third rotor 8. The second speed/position sensor 17 is connected to the second servo driver 14 and the first servo driver 11, and the second servo driver 14 is connected to the coil winding of the second motor stator 9. Control unit 12 The first and second servo drivers 1 1 and 14 are connected, and the first and second speed/position sensors 10, 17 are connected to the control unit 12. The main body of the control unit 12 is a computer that gives the torque settings of the first and second motors as needed. The first and second servo drives 1 1 , 14 are connected via a common DC bus 13 . The common DC bus 13 is connected to the energy storage unit 15 and can also be connected to the power unit 16. The energy storage unit 15 includes a capacitor, a battery, and a charge and discharge control and protection circuit thereof. The electric unit is an air conditioner, a lamp or other electric appliance.

 The operation control method, mechanism and beneficial effects of the servo control system of the cascade motor assembly of the present invention are described in detail below.

In the case of an external engine operation, the first rotor of the first motor is driven by mechanical kinetic energy of an external engine directly connected thereto, and the first servo driver performs torque servo control on the first motor such that the first rotor is coupled to the engine Apply load torque. The control unit adjusts the torque setting of the first motor, so that the torque and the speed of the engine are matched according to the optimal efficiency curve data of the engine, so that the engine operating point is always maintained on the optimal efficiency curve to achieve energy saving purposes. When the first motor applies a torque load to the engine, the second rotor is simultaneously subjected to a reaction force, which is transmitted to the external load through the output gear, and directly performs external work, and the output power is the transmitted power. At this time, along the direction of rotation of the engine, if the second rotor rotational speed is lower than the rotational speed of the first rotor, the first motor is in the generator state, and the electric energy generated by the first motor is transmitted to the common DC bus through the first servo driver. The energy storage unit or the electric power unit; if the second rotor rotation speed is higher than the rotation speed of the first rotor, the first motor is in the motor state, and the electric energy taken from the common DC bus is converted by the first servo driver and the first motor The kinetic energy of the second rotor is sent to the output shaft along with the energy transmitted by the engine. At the same time, the third rotor of the second motor coaxial with the second rotor of the first motor also rotates. If the torque setting direction obtained by the second servo driver is the same as the third rotor rotation direction, the second servo driver Absorbing electric energy through the common DC bus, driving the second motor to work in the motor state, and the kinetic energy of the third rotor rotating also works on the external load through the output gear; if the torque setting direction of the second servo driver is opposite to the direction of rotation thereof, then The second servo drive controls the second motor to be in the generator state, converting the mechanical energy on the shaft into electrical energy and feeding the common DC bus, and the second motor electrically braking the load to feed the electrical energy. A new power transmission method for power generation, energy storage, electricity work, and brake feedback. When the first servo driver controls the first motor, the second rotor is applied to the first rotor and the engine shaft When rotating the torque in the opposite direction, due to the principle of the force and the reaction force, the first rotor simultaneously applies the same magnitude and opposite direction torque to the second rotor, that is, the second rotor simultaneously receives the electromagnetic torque direction and the first rotor. The direction of rotation is the same. At this time, the second rotor drives the load to rotate, and the second rotor outputs mechanical power externally. This power is the kinetic energy obtained by the first rotor of the first motor from the engine during the control operation of the servo system, and the electromagnetic coupling between the two rotors is directly transmitted. The mechanical power of the load is passed, so it is called the transmitted power. The electromagnetically coupled transmission power is delivered to the final load 100% without any attenuation. The difference between the mechanical power obtained by the first rotor of the first motor and the mechanical power output by the second rotor is the power used by the first motor to generate electricity (if the value is positive) or the first motor obtains the electrical energy converted from the DC bus. Mechanical power (if the value is negative).

 By using the servo control system of the cascade motor assembly of the present invention and its operation control method, since part of the energy is delivered to the load side without being attenuated by 100%, the total energy transfer efficiency is much higher than that of the conventional power generation-storage energy- Electric drive mode.

 When the external engine stops running, the second motor can absorb electric energy through the common bus through the second servo driver, and operates in the motor mode to work on the external load; the first servo driver makes the current vector of the first motor winding zero, first The electromagnetic force between the second rotor of the motor and the first rotor is zero, the first rotor of the first motor is stationary, and the second rotor is rotated with the coaxial third rotor. The first motor at this time realizes the function of "off" of the normal clutch.

 When the car needs to start the engine in a static state, an external force is required to assist the engine to stop running. The first and second motors can absorb electric energy through the common bus through their servo drives, and operate in the motor mode, and the first and second motors are applied. The torques on the coaxial shaft are equal in opposite directions, so that the common shaft of the two motors is stationary, and the applied torque of the second rotor of the first motor to its first rotor causes the external engine directly connected to the first rotor to rotate.

 When the vehicle needs to start the engine in a stationary state, the second motor can also be controlled to perform zero speed control or position locking, so that the common shafts of the two motors are stationary, and the control unit controls the second rotor of the first motor through the first servo driver. A rotor applies torque to rotate an external engine directly coupled to the first rotor.

When the vehicle needs to start the engine in the running state, an external force is required to assist the engine to stop entering the running state, and the control unit superimposes the equal size of the first and second motors on the torque tomb required for the original second motor to be separately driven and operated. In the opposite torque, under the premise that the common shaft output force state of the two motors is constant, the second rotor of the first electric machine acts on the first rotor to rotate the external engine directly connected to the first rotor. When the vehicle brakes, the control unit can apply a reverse torque setting to the second servo drive, and the second servo drive controls the second motor to operate in a forward-rotating, reverse-output generator state, and the vehicle motion system passes through a third The kinetic energy fed by the rotor shaft is converted into electrical energy for transmission to the common DC bus, and the reverse torque of the third rotor to the output shaft brakes the vehicle. During the above braking process, the first motor has two working states: First, the first servo driver controls the first motor to apply a limited drag load torque to the engine, that is, the applied torque is the same as the engine turning direction, but its power The engine will not be extinguished. At this time, the external torque of the second rotor of the first motor is the torque in the braking direction, which can assist the electric braking of the second motor to a certain extent, and feedback the braking energy to the DC bus; For the first servo driver, the current vector magnitude of the first motor winding is zero, the electromagnetic force between the first motor and the first rotor of the first motor is zero, and only the second motor is operated in the generator mode when the external load is braked. Electric brake. When braking, kinetic energy is converted into electrical energy to reach the DC bus. The energy storage unit absorbs this energy according to its own charging strategy, thereby improving the overall efficiency.

 According to the operating condition of the entire servo drive system, the advantages of the operation control method of the cascaded motor component servo control system of the present invention are compared to the operation control method of the conventional dual motor assembly.

1. It is not affected by the external load. The servo motor can independently load the shaft of the fuel engine. It is convenient to adjust the fuel engine working point to use the same amount of fuel to output more kinetic energy. 2. The kinetic energy of the engine is directly transmitted by mechanical energy, and the other part is converted into electric energy transmission. Compared with the pure mechanical energy transmission method of the engine, the invention is more efficient in adjusting the working point of the fuel engine and converting the chemical energy of the fuel into kinetic energy; After the engine's kinetic energy is fully converted into electrical energy and then driven by the electric motor to drive the series transmission of the car, part of the kinetic energy is directly transmitted to the load side through the transmission power 100%, and the average efficiency of the engine's kinetic energy to the external load mechanical energy is further obtained. 3. The servo drive adjusts the first rotor interaction torque in the first motor connected to the engine, so that the two can engage with each other without force or with a certain controllable torque, thereby realizing the function of the clutch; 4. Fuel engine The three power sources of the first and second motors are electromagnetically coupled to achieve non-contact power or torque superposition, flexible combination, convenient control, no combined noise and wear; 5. The first and second motors can be in the servo Four-quadrant operation under drive control, convenient for each power group 6. The first and second motors can work in four quadrants to facilitate recovery of braking energy or assist engine output. 7. This operation control method is suitable for hybrid electric vehicles, as opposed to The conventional series, parallel, and hybrid power structure greatly simplifies the structure of the hybrid electric vehicle, and the implementation cost is significantly reduced.

More specifically, the first motor torque servo control method of the servo control system of the cascade motor assembly of the present invention is shown in FIG. 2, and the first servo driver 11 acquires the absolute position signal 6 of the first rotor from the first speed/position sensor 10. ₁ (step 201), obtaining an absolute position signal θ _{2 of the} second rotor from the second speed/position sensor 17 (step 202), and obtaining a position angle (Θ Θ ₂ ) of the first rotor with respect to the second rotor (step 203) Obtaining the direction of the winding current vector according to the principle that the current vector and the back potential vector are in phase (step 204), reading the torque setting value T1 from the control unit 12 (step 205), and calculating the magnitude of the current vector (step 206) Obtaining the instantaneous set values i _al , i _bl , i _cl of the three-phase current (step 207 ), respectively performing three-phase current closed-loop control (step 20 ⁸ ), driving the power amplifying circuit (step 209), thereby controlling the The torque of a motor (step 210).

The second motor torque servo control method of the servo control system of the cascade motor assembly of the present invention is shown in FIG. 3, and the second servo driver 14 acquires the absolute position signal θ _{2 of the} third rotor from the second speed/position sensor 17 (step 301). Obtaining the direction of the winding current vector according to the principle that the current vector and the back EMF vector are in phase (step 302), reading the torque setting value Τ2 from the control unit 12 (step 303), and calculating the magnitude of the current vector (step 304), Obtaining the instantaneous set values i _a2 , i _b2 , i _c2 of the three-phase current (step 305 ), respectively performing three-phase current closed-loop control (step 306 ), driving the power amplifying circuit (step 307), thereby controlling the second motor Torque (step 30 ⁸ ).

 The torque servo control method adopted by the present invention can independently and accurately control the magnitude and direction of the motor torque independently of the rotational speed of each motor, and the response speed reaches milliseconds. It should be emphasized that the means for implementing the servo control method of the present invention is not limited to the above-described embodiments, and it is also contemplated that other variations will occur to those skilled in the art without departing from the scope of the invention.

 In implementation, the operation control method of the servo control system of the cascade motor assembly of the present invention is embodied in the following forms:

1 engine 1 is not started, first rotor 3 is stationary, second motor drives load separately: second servo driver 14 draws electric energy through common DC bus 13, according to the signal of second speed/position sensor 17 and control unit 12 to second motor The torque setting, the current vector is applied to the stator 9 of the second motor, the second motor operates in the motor state, converts the electric energy into kinetic energy, and outputs the torque to the load drive shaft. At this time, the first servo drive 1 1 The current vector loaded by the two rotors 4 is zero, the interaction force between the second rotor 4 and the first rotor 3 is also zero, and the first rotor 2 rotates with the third rotor 8 and the first rotor 3 remains stationary.

 When reversing, the control unit provides a negative torque setting to the second servo drive 14, which allows the second motor to output a reverse torque to drive the output shaft 8 to reverse operation.

 2 When the engine 1 is started, an external force is required to assist in driving the engine into the running state, and the first and second servo drives 1 1 and 14 absorb the electric energy through the common DC bus 13 to control the first and second motors to operate in the motor mode. Drive the shaft of the engine 1 to rotate:

 When the hybrid electric vehicle is not started, the cascade motor assembly outputs an initial torque of zero. When the engine is started, the first servo driver 11 obtains the relative positions of the first rotor 3 and the second rotor 4 based on the position signals of the first and second speed/position sensors 10, 17, and simultaneously sets the torque according to the torque of the control unit 12. The windings of the two rotors 4 apply a current vector to perform torque servo control on the first motor; at the same time, the control unit 12 sets the torques of the second servo driver 14 in opposite directions, and the second servo driver 14 sets and second according to the torque. The position signal of the speed/position sensor 17 applies a current vector to the stator 9 of the second motor to perform torque servo control on the second motor, so that the torques applied to the second rotor 4 and the third rotor 8 of the first motor are equal in opposite directions, The two rotors 4 and the third rotor 8 are coaxially stationary, and the second rotor 4 acts on the first rotor 3 to drive the first rotor 3 to drive the shaft rotation of the engine 1.

 When the hybrid electric vehicle is in normal operation, the first motor output initial torque is zero, and the second motor output initial torque is the torque T that maintains the original operating state. When the engine is started, the first servo driver 1 1 obtains the relative positions of the first rotor 3 and the second rotor 4 according to the position signals of the first and second speed/position sensors 10, 17, while setting according to the torque of the control unit 12 The winding of the second rotor 4 applies a current vector to perform torque servo control on the first motor; at the same time, the control unit 12 superimposes the torque setting of the second servo driver 14 on the basis of the initial setting with a setting of the first servo driver. In the increment of the opposite direction, the second servo driver 14 applies a current vector to the stator 9 of the second motor according to the torque setting and the position signal of the second speed/position sensor 17, and performs torque servo control on the second motor, so that The combined torque of the coaxial output of the second rotor 4 and the third rotor 8 still maintains the initial enthalpy value, and the second rotor 4 acts on the first rotor 3 to drive the first torque under the premise of the vehicle operating state. The rotor 3 drives the shaft of the engine 1 to rotate.

3 When the electric vehicle brakes, the engine runs at idle speed, the first and second servo drives 11, 14 drive the first and second motors to work in the generator state, perform electric braking on the load drive shaft, and recover the braking energy:

 The first servo driver 11 applies a current vector to the second rotor 4 according to the relative positions of the first rotor 3 and the second rotor 4 and the torque setting of the control unit 12, so that the first motor applies a drag load to the engine, that is, the applied The torque is the same as the direction of rotation of the engine 1, but the strength is insufficient to cause the engine 1 to be extinguished. At this time, the external transmission torque of the second rotor 4 of the first motor is the torque in the braking direction; the second servo driver 14 is based on the second speed/ The position signal of the third rotor 8 obtained by the position sensor 17 and the torque of the control unit 12 are set to the stator 9 of the second motor to apply a current vector such that the third rotor 8 applies a braking torque to the outside. At this time, both the first and second motors are operated in a reverse output state, and the first motor second rotor 4 and the third rotor 8 collectively apply braking torque to the load drive shaft through the output gears 6 mounted on the common shaft, cascading The kinetic energy obtained by the motor assembly from the load drive shaft is converted into electric energy by the first and second motors and sent to the common DC bus 13 via the first and second servo drives 11 and 14; the common DC bus 13 feeds the electric energy into the energy storage unit. 15 or directly to the power unit 16 to achieve the purpose of recovering braking energy.

 4 When the electric vehicle is braking, the engine runs at idle speed and does not participate in the drive. The second rotor 4 of the first motor is isolated from the engine 1. The second motor operates in the state of the generator, and the electric brake is applied to the load drive shaft. Dynamic energy:

 The first servo driver 11 makes the current vector of the second rotor 4 zero, and the first motor second rotor 4 and the first rotor 3 have zero interaction torque, which is isolated from the engine 1. The second servo driver 14 loads a current vector to the stator 9 of the second motor according to the signal of the second speed/position sensor 17 and the torque of the control unit 12, and controls the second motor to operate in the reverse output state, and the third rotor 8 passes The output gear 6 on the shaft applies a braking torque to the load drive shaft, and the kinetic energy obtained from the load drive shaft of the shaft of the third rotor 8 causes the third rotor 8 to rotate, and is converted into electric energy by the second motor via the second servo drive 14 It is sent to the common DC bus 13 to achieve braking and recovery of energy without changing the status quo of the engine 1.

 5 engine input kinetic energy, its input kinetic energy can meet the driving drive requirements, the first motor works in the loading state according to the optimal efficiency curve, the second motor works in the driving state, part of the engine kinetic energy is directly transmitted to the load side, and the other part is passed through the first After the motor servo system is converted into electrical energy, the load is driven by the second motor servo system:

Engine 1 outputs mechanical power to input shaft 2, and input shaft 2 rotates at revolutions per minute (rpm). Based on this speed signal, control unit 12 follows the optimal economic operation line. The first servo driver sends a matching torque setting; the first servo driver 11 obtains relative position signals of the first and second rotors 3, 4 according to the position signals of the first speed/position sensor 10 and the second speed/position sensor 17, At the same time, according to the torque setting of the control unit 12, the first motor is torque-controlled for the winding load current vector of the second rotor 4 of the first motor, and the input shaft 2, that is, the axis of the engine 1 is applied with T-meter (Nm). Load torque, then the first motor 3 rotor 3 input mechanical power (ie the mechanical power output of the engine 1) is:

 χΤ/9.55 watts (W). (9.55 is the unit conversion constant)

 The torque applied by the first motor to its first rotor 3 is equal to the torque exerted by its second rotor 4 on the engine shaft 2, since the torque T(Nm) is that the control unit 12 matches the optimum efficiency curve data according to the speed of the engine 1. And its control is performed by the servo system, which is not directly related to the motion state of the car, and is not related to the motion state of the second rotor, so the operating point of the engine 1 is always accurately positioned on the optimal efficiency curve. Energy saving purposes.

Let the output shaft 7 of the cascade motor assembly rotate at a speed of N ₂ ( rpm ):

When >: ₂ , the product of the electromagnetic torque T (Nm) between the second rotor 4 and the first rotor 3 and the rotational speed of the second rotor 4 is the mechanical power that is sent from the first motor to the load side via the output gear 6 ( Weighing power):

P ₂ =N ₂ T/9.55 ( W)

The first motor and the first servo driver 11 directly apply the transmission power to the load drive shaft on the one hand, and convert the partial input mechanical power P ₃ to the electric power P ₄ to the common DC bus 13 on the other hand; P ₃ = PP ₂ , The electric power P is P ₃ and multiplied by the power generation conversion efficiency η ρ of the first motor and the first servo driver 11 is also:

Ρ ₄ = _{η ι} (P _r P ₂ ) =n^ (NN ₂ ) xT/9.55 (W) .

η ! η ₂ Τ χ ( N_rN₂ ) /Ν₂， 其中 η ₂ 为第二电机伺服系统将电能转化为机械能的效率， 第二伺服驱动器 14 驱动第二电机对第三转子 8的轴施加驱动扭矩。 The third rotor 8 of the second motor rotates at the same speed as the second rotor 4 by N ₂ (rpm), and the control unit 12 sets the driving torque Τ ₂ to the second servo driver according to the size of the crucible ₄ , which satisfies: Ρ ₄ χ η

η ! η ₂ Τ χ ( N _r N ₂ ) /Ν ₂ , where η ₂ is the efficiency of the second motor servo system for converting electrical energy into mechanical energy, and the second servo driver 14 drives the second motor to apply the axis of the third rotor 8 Drive torque.

 The total output torque of the first and second motors is:

Τ = Τ + Τ ₂ = ( 1 + _{η ι} η ₂ ( NN ₂ ) / N ₂ ) T

The output mechanical power of the cascaded motor assembly is: P ₀ = ( η, η, Ν ^ ( 1- _{η ι} η ₂ ) N ₂ ) χ T/9.55 ( W)

 When Ν, -:^, the mechanical power output from the engine is directly sent to the output shaft, that is, the output mechanical power of the cascade motor assembly is:

Ρ ₀ = Ν! XT/9.55 ( W)

When N, <N ₂ , the first motor servo system not only supplies the mechanical power from the engine to the output shaft, but also extracts the electric energy from the DC bus and converts it into mechanical energy for output. At this time, the output mechanical power of the first motor is:

 At this time, the control unit 12 sets the torque setting of the second servo driver 14 into three cases: a forward setting, a zero setting, and a reverse setting, and controls the second motor to be driven forward, not driven, and reversely driven. If the driving torque required for driving is equal to Τ, the second motor is not driven; if the driving torque required for driving is less than Τ, the second motor reversely outputs the driving torque so that the total output torque is equal to the torque required for driving. In the above three cases, the second motor servo system operates in the motor state, the non-drive state, and the generator state, respectively.

 6 engine running input kinetic energy, but the input kinetic energy can not meet the driving power required for driving, the first motor works in the loading state according to the optimal efficiency curve.

 The engine 1 outputs mechanical power to the input shaft 2, and the input shaft 2 rotates at 1^ revolutions per minute (rpm). Based on the speed signal, the control unit 12 sends a matching torque setting to the first servo driver according to the optimal economic operation line. The first servo driver 11 obtains the relative position signals of the first and second rotors 3, 4 according to the position signals of the first speed/position sensor 10 and the second speed/position sensor 17, while setting according to the torque of the control unit 12 Performing torque servo control on the first motor for the winding load current vector of the second rotor 4 of the first motor, and applying a load torque of T Nm (Nm) to the input shaft 2, that is, the shaft of the engine 1, the first motor is first The input power of the rotor 3 (ie the mechanical power output from the engine 1) is:

 P, = N, X T/9.55 watts (W). ( 9.55 is the unit conversion constant)

 The torque applied by the first motor to its first rotor 3 is equal to the torque exerted by its second rotor 4 on the engine shaft 2, since this torque T (N.m) is the control unit 12 according to the engine

The speed of 1 is matched by the optimal efficiency curve data, and its control is performed by the servo system. It is not directly related to the motion state of the vehicle, and is not related to the motion state of the second rotor, so the operating point of the engine 1 is always accurate. The ground is positioned on the optimal efficiency curve to achieve energy saving. Let the output shaft 7 of the cascade motor assembly rotate at a speed of N ₂ ( rpm ):

When N, > N ₂ , the first motor transmits part of the mechanical power from the engine directly out of the output shaft, and converts the remaining power into electrical power to the DC bus.

 The transmission power is:

P ₂ =N ₂ T/9.55 ( W )

 The electrical power emitted is:

Ρ ₄ = η ! ( PP ₂ ) = Π ! ( NN ₂ ) T/9.55 ( W )

 The generated electrical power is converted to mechanical power on the output shaft via the second motor servo system

P ₅ :

 The second servo driver 14 and the second motor not only use all the electric energy emitted by the first motor at this time, but also draw power from the common DC bus 13, according to the torque setting value of the control unit 12 and the second speed/position sensor 17 The position signal applies a larger current vector to the stator 9 of the second motor, the second motor is driven to apply a greater drive torque to the third rotor 8, and the output shaft is driven together by the third rotor 8 and the second rotor 4. At this time, the energy storage unit 16 supplies energy from the battery to the common DC bus to supplement the electric power demand of the second motor according to its charging and discharging strategy.

 When Ν, - ϊ^, the first motor transmits all the mechanical power from the engine directly to the output shaft, the main control unit 12 applies a torque setting to the second servo driver according to driving needs, and the second motor servo system outputs a corresponding torque to the outside. And power, supplementing the drive power requirements. The lack of parts.

When 1^ <:^ ₂ , the first motor servo system not only supplies the mechanical power from the engine to the output shaft, but also extracts the electric energy from the DC bus and converts it into mechanical energy for output. At this time, the output mechanical power of the first motor is:

Ρ ₂ = Ν ₂ T/9.55 ( W )

 If the driving torque still cannot meet the driving demand, the main control unit 12 applies a torque setting to the second servo driver according to the driving demand, and the second motor servo system outputs the corresponding torque and power to supplement the insufficient driving power requirement.

Claims

Rights request A method for controlling a servo control system of a cascade motor assembly, wherein a servo control system of the cascade motor assembly includes a first motor, a second motor, and a first servo driver associated with the first motor a second servo driver associated with the second motor, and a control unit coupled to the first and second servo drivers, wherein the first motor includes a first rotor and a second rotor electromagnetically coupled to each other, the second motor including a stator and a third rotor electromagnetically coupled to each other, the shaft of the first rotor being an input shaft of the cascade motor assembly, the shaft of the second rotor being coaxial with the third rotor and serving as an output shaft of the cascade motor assembly The operation control method includes the following steps:  Directly connecting the shaft of the first rotor to the engine shaft;  Performing servo control on the coupling torque between the first rotor and the second rotor by the first servo driver according to the relative positions of the first and second rotors and the torque setting value of the first motor given by the control unit The engine operating point is independent of the independent regulation of the vehicle operating state;  The second servo drive performs servo control on the coupling torque between the stator and the third rotor according to the position of the third rotor and the torque setting value of the second motor given by the control unit, so as to realize the driving of the second motor to the whole vehicle. .  2. The operation control method of a servo control system of a cascade motor assembly according to claim 1, wherein: the relative positions of the first and second rotors are by installing a first speed on a shaft of the first rotor a position sensor and a second speed/position sensor mounted on a common axis of the second rotor and the third rotor, wherein the first speed/position sensor is coupled to the first servo drive; the second speed/position sensor connection First and second servo drives.  3. The operation control method of a servo control system of a cascade motor assembly according to claim 2, wherein: the first motor is a permanent magnet synchronous motor or a brushless DC motor, wherein the first rotor And a permanent magnet pole is mounted on one of the second rotors, and a first winding wound on the iron core is mounted on the other of the first rotor and the second rotor; the second motor is a permanent magnet a synchronous motor or a brushless DC motor, wherein a permanent magnet pole is mounted on one of the third rotor and the stator, and a winding on the iron core is mounted on the other of the third rotor and the stator Two windings. 4. The operation of the servo control system of the cascaded motor assembly according to claim 3. The row control method is characterized in that: the first servo driver directly loads a corresponding current vector to the first winding through a slip ring mounted on the second rotor shaft to perform torque servo control on the first motor; The servo drive directly applies a corresponding current vector to the second winding on the stator or through the slip ring to the second winding on the third rotor to perform torque servo control on the second motor.  The operation control method of a servo control system of a cascade type motor assembly according to claim 3, wherein the step of servo-controlling the coupling torque between the first rotor and the second rotor comprises the following steps: The first servo driver acquires the absolute position signal θ _{1 of the} first rotor from the first speed/position sensor, and acquires the absolute position signal θ _{2 of the} second rotor from the second speed/position sensor to obtain the first rotor relative to the second rotor Position angle ( θ ^ θ ^ ;  Obtaining the direction of the current vector of the first winding according to the principle that the current vector and the back EMF vector are in phase; Reading the torque set value from the control unit, calculating the magnitude of the current vector; obtaining the instantaneous setpoints i _al , i _bl , i _{cl of the} three-phase current;  Perform three-phase current closed-loop control separately;  Drive the power amplifier circuit.  6. The operation control method of a servo control system of a cascade type motor assembly according to claim 3, wherein the step of performing servo control on the coupling torque between the stator and the third rotor comprises the following steps: The second servo driver acquires the absolute position signal θ _{2 of the} third rotor from the second speed/position sensor;  Obtaining the direction of the second winding current vector according to the principle that the current vector and the back EMF vector are in phase; Reading the torque set value from the control unit, calculating the magnitude of the current vector; obtaining the instantaneous setpoints i _a2 , i _b2 , i _{c2 of the} three-phase current;  Perform three-phase current closed-loop control separately;  Drive the power amplifier circuit. 7. The operation control method of a servo control system of a cascade type motor assembly according to claim 1, wherein: when the second servo driver controls the second motor, the torque direction obtained by the third rotor is related to the second motor When the rotor rotates in the same direction, the second motor draws electric energy to work in the motor state, and is sucked by the common bus through its corresponding servo driver. Conversely, when the torque direction obtained by the third rotor is opposite to the direction of rotation, the second motor is in the generator state, and the servo drive outputs power to the common bus. 8. The operation control method of a servo control system of a cascade type motor assembly according to claim 1, wherein: an output gear is mounted on an output shaft between the first and second motors, the output gear and the outer Load connection.  9. The operation control method of a servo control system of a cascade motor assembly according to claim 1, wherein: the control unit uses all of the electric energy generated by the first or second motor system for the second or first motor system. Drive output to minimize the charge and discharge process of the battery by the energy storage unit.  10. The operation control method of a servo control system of a cascade type motor assembly according to claim 1, wherein: the energy storage unit actively absorbs the electric energy from the busbar when the first/second motor system is in a power generation state as a whole. The internal battery is charged; when the first/second motor system is in a power state as a whole, the power is actively absorbed from the internal battery to the bus.  11. The operation control method of a servo control system of a cascade type motor assembly according to claim 1, wherein: the control unit realizes that the hybrid vehicle is stationary or running by torque control of the first or second motor system. The engine is started smoothly in the state.