WO2011032357A1

WO2011032357A1 - Balancing device for hybrid output power and control mothod thereof

Info

Publication number: WO2011032357A1
Application number: PCT/CN2010/001414
Authority: WO
Inventors: 李书福; 杨健; 张彤; 余卫; 马智涛; 于海生
Original assignee: 上海华普国润汽车有限公司; 浙江吉利控股集团有限公司
Priority date: 2009-09-15
Filing date: 2010-09-15
Publication date: 2011-03-24
Also published as: CN102271946A; CN102019843B; CN102019843A

Abstract

A balancing device for hybrid output power and the control mothod thereof are provided. The balancing device for hybrid output power includes an engine (5), a large electric motor (2), a small electric motor (1), a battery, a power coupling device and multiple brakes. The coupling device is a planetary gearing containing a planet carrier, planets, long planets, a small sun gear, a large sun gear and an outer annulus gear. The power output shaft of the engine (5) is connected with the revolving shaft of the planet carrier. The planets on the planet carrier mesh with the small sun gear respectively. The small sun gear and the small electric motor (1) have the same revolving shaft. The planets on the planet carrier mesh with the long planets respectively, and the long planets mesh with the large sun gear respectively. A brake (3) for the samll electric motor is provided on the revolving shaft of the small sun gear, and an engine brake (4) is provided on the planet carrier.

Description

Hybrid output power balance device and control method thereof

The present invention relates to a hybrid vehicle, and more particularly to a hybrid power output power balancing device and a control method therefor. Background technique

Existing double-star four-axis hybrid power transmission device, small sun gear and generator

The E1 is connected, the large sun gear is connected to the motor E2, the engine is connected to the carrier, the drive half shaft is connected via the differential, and the reducer is connected to the outer ring gear. The vehicle control system achieves by coordinating the control of generator E1 and motor E2: 1) Optimizing the output power of the engine to maximize the efficiency of the entire hybrid system and reduce the fuel consumption of the entire vehicle while meeting the driver's driving performance requirements. 2) Balance the battery charge and discharge power, protect the battery but overcharge, improve battery life.

In 1997, Toyota introduced the first hybrid Prius. In 2005, it introduced the 2006 Prius equipped with the latest 3rd generation electromechanical hybrid system. It still uses the THS hybrid structure to re-engineer the engine's output power using the planetary gear system. Distribution, to achieve a reasonable balance of engine load. Figure 1 shows the vehicle layout of the Toyota Prius Hybrid. The hybrid system assembly consists of an engine (ICE), a generator (MG1), an electric motor (MG2), a power coupling system, an inverter, and a power battery. In this mechanism, the engine is coupled to the planet carrier, and the planetary gears transmit power to the external gear and the sun gear. The ring gear shaft is coupled to the motor and the drive shaft, and the sun gear shaft is coupled to the generator. The system transfers most of the engine's torque directly to the drive shaft, passing a small portion of the torque to the generator, which is used to charge the battery or to drive the motor to increase drive. This configuration allows the engine to be variably adjusted to keep the engine in a high efficiency zone or a low emission zone. In addition, by adjusting the speed of the components of the planetary row, it works like a continuously variable transmission.

The control characteristics of this structure can generally be summarized as follows:

1) The key to hybrid power system control is to adjust the speed of generator MG1 to meet the drive torque requested by the current driver and to optimize the optimal efficiency of the engine. 2) In order to maintain the balance of the battery state of charge (SOC), the hybrid system adopts a control method of setting the SOC target value: when the SOC deviates from the target value, the control battery is charged or discharged as much as possible to make the SOC close to the setting. aims.

3) In pure electric working condition, the traction motor MG2 output shaft is fixed to the outer ring gear of the planetary gear through the reduction gear, so the drive controller of the system only needs to control the MG2.

However, when the vehicle is driving at a high speed, the generator E1 sometimes needs to work in the fluctuation range of zero speed to adjust the optimal power output of the engine. Since the working efficiency is very low in this speed range, the overall efficiency of the hybrid system is significantly reduced, and the energy is reduced. A lot of loss. Summary of the invention

One object of the present invention is to solve the problems of low efficiency, high energy loss, and the like of the power system of the hybrid vehicle existing in the prior art, and to provide a hybrid power output with convenient operation, high work efficiency and low energy consumption. Power balance device and its control method.

Specifically, the present invention provides a hybrid output power balancing device that can include an engine, a large motor, a small motor, a battery, a power coupling device, and a plurality of brakes (one or more), wherein the engine, the large motor, and the small motor They are respectively connected to the power coupling device. Specifically, in the present invention, the large motor and the small motor are electrically connected to an inverter, the inverter is electrically connected to a motor controller, the motor controller is electrically connected to a battery management system, the battery management system and the battery Electrically connected, the engine is provided with a speed sensor, the signal output end of the speed sensor is connected to an engine management system, and the engine management system is respectively provided with a signal output terminal of the throttle control, the ignition control and the valve control. They are respectively connected to the engine circuit, and the motor controller, the battery management system, and the engine management system are respectively connected to the vehicle controller, and the engine and the small motor are respectively provided with brakes. The power coupling device is responsible for combining multiple powers of the hybrid vehicle to achieve reasonable power distribution between the multiple power sources and transmitting power to the drive axle; the small motor converts part of the output power of the engine into electrical energy through the power coupling system; The motor outputs electrical energy generated by the small motor to the power coupling system in the form of mechanical power; the battery transfers power to the small motor and the motor and transmits electrical energy from the small motor and the motor. The control method preferably includes the following steps:

1) determining the driver's power demand on the external gear shaft according to the driver's operation of the accelerator pedal and/or the brake pedal and the current vehicle speed; 2) determining whether the engine is required to participate in the drive according to the driver's power demand and the current battery SOC state;

3) If the engine is not required to participate in the drive, the engine is controlled to be in a stop state, and the large motor and the small motor are controlled to transmit the required power to the outer ring gear shaft, thereby driving the vehicle through the deceleration and the differential;

4) If the engine is required to participate in the drive, control the large motor and the small motor to adjust the engine to optimally output the required power and output it to the drive shaft to meet the driver's acceleration request.

Preferably, the power coupling device is a planetary gear device including a planet carrier, a planetary gear, a long planetary gear, a small sun gear, a large sun gear and an outer ring gear, wherein the power output shaft of the engine is connected to the rotating shaft of the carrier The planet gears on the planet carrier mesh with the small sun gear respectively. The shaft of the small sun gear is a small motor shaft. The planet gears on the planet carrier mesh with the long planet wheels, respectively. The long planet wheels mesh with the large sun gear. . The small sun gear is connected to the small motor, the large sun gear is connected to the engine, the engine is connected to the satellite frame, and the output torque of the entire system is output through the outer ring gear. In the power coupling device of the present invention, the planetary gear and the long planetary gear constitute a double planetary row which shares the carrier and the outer ring gear such that the planetary gear and the long planetary gear mesh with each other. The power coupling device substantially constitutes a double-row four-axis planetary gear mechanism, wherein the small sun gear, the large sun gear, the ring gear and the planet carrier are respectively fixed to the small motor, the large motor, the reduction gear and the crankshaft of the engine or coupling. Since the power coupling device is a four-degree-of-freedom mechanism, that is, three inputs determine one output, in the actual control process, it is necessary to simultaneously control the torque output of the small motor, the large motor, and the engine, and finally the power output required by the driver. To the ring gear, the power output to the gums is then ultimately transmitted to the drive wheels via the reduction gear mechanism and the differential.

Preferably, a small motor brake is disposed on a rotating shaft of the small sun gear; and an engine brake is disposed on the planetary carrier. When the whole vehicle is running at high speed, the engine is in the economic operation area, and the engine output power can meet the requirements of the whole vehicle working condition. At this time, the motor brake is used to lock the small motor to reduce the energy transfer process in the intermediate link, thereby reducing The energy loss increases the energy conversion efficiency of the system; when the vehicle is running in pure electric working condition, the engine is locked by the engine brake, and the whole vehicle power is completely provided by the battery. Locking the engine prevents engine reversal and reduces the complexity of vehicle system control under pure electric conditions.

Preferably, the vehicle controller is respectively provided with an input end of an accelerator pedal signal, a brake pedal signal, a gear position signal, and a vehicle speed signal. Vehicle controller VCU based on input accelerator pedal The signal, the brake pedal signal and the input gear position signal, the vehicle speed signal are calculated for the torque demand of the ring gear connected to the drive wheel due to the torque required by the vehicle, and the power demand required to drive the hybrid vehicle.

In order to complete the control of the apparatus of the present invention, the present invention provides a method of controlling a hybrid output power balancing apparatus comprising the steps of:

In the first step, the change of the torque demand T _req to the acceleration pedal opening APS, the brake pedal opening BPS and the vehicle speed V _SPD is stored as a torque demand T _req data table in the vehicle controller, and the vehicle controller is based on The corresponding torque demand T _{req is} determined using the data table given the accelerator pedal opening APS and the given vehicle speed V _SPD difference. Obtained by the power demand P _req torque demand T _req. The power demand P _req can be calculated, for example, by:

Where: P _b is the charge-discharge power requirement of the battery; P _sysl . _Ss is the sum of the potential loss of the whole vehicle system; T _req is the torque demand on the ring gear; n _H0 is the rotational speed of the ring gear shaft, which can be calculated by multiplying the vehicle speed V _SPD by the conversion coefficient k.

In the second step, the power demand P _req set in the first step and the pure electric drive upper limit power demand limit P _ev , the current battery state of charge state SOC and the lower limit value SOC _{min of the} preset battery state of charge sufficient state are performed. Comparison.

The third step, according to the comparison result of the second step, when P _req ≤P _ev and soc≥soc _min , the whole vehicle is driven by pure electric motor, the engine is turned off and braked by the engine brake, the large motor drives the vehicle, and the small motor idles. The target speed n _{e of the} engine and the target torque T _e can be: n _e =0 , T _e =0 target torque command T _{E1 of the} small motor El, calculate and set the target torque command T _{E2 of the} large motor and large The motor speed command n _E2 , wherein the target torque command T _{E2 of the} large motor can be obtained by:

TE2 = T _req lo2 where: T _E2 is the target torque command for the large motor; T _req is the ring gear shaft torque demand command; i ₀₂ is the gear ratio of the large sun gear to the outer ring gear. The target speed command n _{E2 of the} large motor can be obtained from:

ΠΕ2 ⁼ ΠνΜίθ2 ^+η Ηθ ( 1- i.2 )

Where: n _VM is the planetary carrier speed of the planetary gear train; n _H0 is the rotational speed of the outer ring gear of the planetary gear train; 1⁄2 is the gear ratio of the large sun gear to the outer ring gear. Since the engine is locked by the engine brake at this time, the upper formula can be simplified as:

When P _req > P _ev or SOC < SOC _min , the vehicle controller sets the engine target speed n _e and the target torque T _e corresponding to the power demand P _req . The target speed n _{e of the} engine and the target torque T _e may be determined based on the engine optimal power-speed curve and the power demand torque P _req .

In the drive control program, the hybrid vehicle controller VCU first collects various data required for receiving control, including acceleration pedal opening APS, brake pedal opening BPS, vehicle speed V _SPD , small motor, and large motor speed. n _E1 and n _E2 , engine speed n _e and battery temperature T _bat , charge-discharge power demand, maximum discharge current and maximum charge current. Wherein, the engine speed is preferably calculated from a pulse signal measured by a magnetoelectric sensor mounted on the crankshaft. The speeds of small and large motors are preferably collected by small motors and rotary transformers on large motors. The battery temperature, charge and discharge power demand, battery state of charge SOC, input limit current, and output limit current are calculated by the battery management detection system BMS real-time monitoring of the battery pack (preferably based on the battery pack charge and discharge test).

Preferably, the steps from the first step to the third step are repeatedly performed at predetermined time intervals of 10-50 ms.

Preferably, when the current vehicle speed is high and the engine operating point is substantially in the optimal efficiency region, if the target speed of the small motor fluctuates within a small range of zero speed, the vehicle controller VCU controls the small motor brake lock. Dead small motor. The vehicle controller VCU can improve the overall working efficiency of the hybrid system by controlling the small motor brake to lock the small motor. Preferably, the vehicle controller calculates the target rotational speed of the small motor and the large motor according to the target rotational speed n _{e of the} engine, the rotational speed n _{H( ) of the} gingival axis, and the gear ratio in the planetary gear mechanism, and the calculation formula is : nV = ⁿ e

nEi = n _H . Io i ⁺ nvM ( 1- ioi )

HE2 ⁼ n _H0 i ₀₂ +n _V M ( 1 - i. ₂ ) According to the above formula, the target torques T _E1 and T _E2 of the small and large motors can be calculated separately using the following formula.

TE I= T _req n _E2 / ( n _E1 i ₀₂ - n _E2 ioi )

T _req n _E ] / ( n _E2 ioi- n _E ii ₀ 2 ) Preferably, the vehicle controller sends the engine target speed n _e and the target torque T _e to the engine management system EMS before the end of the control program operation cycle. At the same time, send small motor and large motor torque command T _e , , T _e2 to the motor controller MCU.

The hybrid output power balance device and the control method thereof of the invention solve the problems of low work efficiency, large energy loss and the like in the prior art hybrid power system, and the operation is convenient, the work efficiency is high, and the energy consumption is small. DRAWINGS

1 is a schematic structural view of a conventional hybrid system;

Figure 2 is a block diagram showing the structure of a preferred embodiment of the hybrid output power balancing device of the present invention;

Figure 3 is a schematic flow chart of a preferred embodiment of the control method of the present invention;

4 is a torque demand diagram in accordance with a preferred embodiment of the present invention;

Figure 5 is a schematic diagram of the rotational speed torque simulation lever of each shaft under pure electric operating conditions in accordance with a preferred embodiment of the present invention;

6 is a diagram showing a relationship between an optimal power-speed curve of an engine and a power demand torque according to a preferred embodiment of the present invention; 7 is a schematic diagram of a rotational speed torque simulation lever of each shaft in a low speed engine driving condition according to a preferred embodiment of the present invention;

Figure 8 is a schematic diagram of the rotational speed analog lever of each axle in a high speed engine drive condition, in accordance with a preferred embodiment of the present invention. detailed description

Figure 2 is a schematic view of the structure of the present invention. The present invention is a hybrid output power balance device, including an engine 5, a large motor 2, a small motor 1, a battery, a power coupling device, and a plurality of brakes. The engine, the large motor, and the small motor are respectively connected to the power coupling device, The power coupling device is a planetary gear device, and the power output shaft of the engine is connected to the planetary frame rotating shaft. The planetary gears on the planetary carrier respectively mesh with the small sun gear, and the rotating shaft of the small sun gear is a small motor rotating shaft, on the planet carrier. The planet gears mesh with the long planet wheels, respectively, and the long planet wheels mesh with the large sun gears. The large motor and the small motor are electrically connected to an inverter, the inverter is electrically connected to a motor controller MCU, the motor controller MCU is electrically connected to a battery management system BMS, and the battery management system BMS is electrically connected to the battery. The engine is provided with a speed sensor. The signal output of the speed sensor is connected to an engine management system EMS. The engine management system EMS is respectively provided with a throttle output, an ignition control, a valve control signal output, and respectively respectively. The circuit is connected, and the motor controller MCU, the battery management system BMS, and the engine management system EMS are respectively connected to the vehicle controller. The vehicle controller is provided with an input of an accelerator pedal signal, a brake pedal signal, a gear position signal, and a vehicle speed signal, respectively. A small motor brake 3 is provided on the small sun gear shaft; an engine brake 4 is provided on the planet carrier. The power coupling device is responsible for combining multiple powers of the hybrid vehicle to achieve reasonable power distribution between the multiple power sources and transmitting power to the drive axle; the small motor converts part of the output power of the engine into electrical energy through the power coupling system; The motor outputs electrical energy generated by the small motor to the power coupling system in the form of mechanical power; the battery transfers power to the small motor and the motor and transmits electrical energy from the small motor and the motor.

3 is a schematic flow chart of a preferred embodiment of the control method of the present invention. In order to complete the control of the apparatus of the present invention, the present invention provides a control method of a hybrid output power balance apparatus comprising the following steps and each step being repeatedly executed at, for example, a predetermined time interval of preferably 20 ms, In the first step, the change of the torque demand T _req to the acceleration pedal opening APS, the brake pedal opening BPS and the vehicle speed V _SPD is stored as a torque demand T _req data table in the vehicle controller, and the vehicle controller is based on The corresponding torque demand T _{req is} determined using the data table given the accelerator pedal opening APS and the given vehicle speed V _SPD difference. Obtained by the power demand P _req torque demand T _req. The power demand P _req can be calculated, for example, by:

Preq—Pb+Psysloss+Treq+ TreqUHO where: P _b is the charge-discharge power requirement of the battery; P _sysl . _Ss is the sum of the potential loss of the whole vehicle system; T _req is the torque demand on the ring gear; n _HO is the rotational speed of the ring gear shaft, which can be calculated by multiplying the vehicle speed V _SPD by the conversion coefficient k. With regard to torque demand, for example, reference is made to Figure 4, which is a torque demand map in accordance with a preferred embodiment of the present invention.

In the second step, the power demand P _req set in the first step and the pure electric drive upper limit power demand limit P _ev , the current battery state of charge state SOC and the lower limit value SOC _{min of the} preset battery state of charge sufficient state are performed. Comparison

In the third step, according to the comparison result of the second step, when P _req ≤P _ev and SOC ≥ SOC _min , the whole vehicle is driven by pure electric driving (for example, see FIG. 5 , which is a pure electric worker according to a preferred embodiment of the present invention. In the case of the shaft torque simulation lever diagram of each axis, the engine is closed and braked by the engine brake, the vehicle is driven by the large motor, the small motor is idling, the target speed n _{e of the} engine and the target torque T _e are respectively: n _e -0 , T _e =0 The target torque command T _{E1 of the} small motor, calculate and set the target torque command T _{E2 of the} large motor and the speed command η _Ε2 of the large motor, wherein the target torque command τ _{Ε2 of the} large motor can be The following formula gets:

Where: Τ _Ε2 is the target torque command for the large motor; T _req is the _yoke axis torque demand command; i ₀₂ is the gear ratio of the large sun gear to the external gear 。.

The target speed command _{nE2 of the} large motor can be obtained by: ΠΕ2 ⁼ ΠνΜΪθ2 ^+η Ηθ ( 1- i.2 )

n _e =n _V ⁼ 0 where: n _VM is the planetary carrier speed of the planetary gear train; n _H0 is the rotational speed of the external gear of the planetary gear train; is the gear ratio of the large sun gear to the external gear. Since the engine is locked by the engine brake at this time, the upper formula can be simplified as:

When Preq > P _ev or SOC < SOC _min , the vehicle controller sets the target rotational speed n _e and the target torque T _e of the engine corresponding to the power demand P _re q . The target speed n _{e of the} engine and the target torque T _e may be determined according to an engine optimal power-speed curve and a power demand torque P _req , see for example FIGS. 6 - 8, wherein FIG. 6 is a preferred embodiment according to the present invention. FIG. 7 is a schematic diagram of a rotational speed torque simulation lever of each axle in a low speed engine driving condition, and FIG. 8 is a schematic diagram of a rotational speed torque simulation lever of each axle in a low speed engine driving condition according to a preferred embodiment of the present invention. A preferred embodiment of a rotational speed torque simulation lever schematic for each shaft under high speed engine drive conditions.

In the drive control program, the hybrid vehicle controller VCU first collects various data required for receiving control, including acceleration pedal opening APS, brake pedal opening BPS, vehicle speed V _SPD , small motor, large motor. Rotating speed! ^And! !^, engine speed n _e and battery temperature T _bat , charge-discharge power demand, maximum discharge current and maximum charge current. Among them, the engine speed is calculated from the pulse signal measured by the magnetoelectric sensor mounted on the crankshaft. The speeds of small motors and large motors are collected by small motors and rotary transformers on large motors. The battery temperature, charge and discharge power demand, battery state of charge (SOC), input limit current _IN and output limit current are calculated by battery management detection system BMS real-time monitoring battery pack (preferably based on battery charge and discharge test) ).

Claims

Rights request

A hybrid output power balance device comprising an engine, a large motor, a small motor, a battery, a power coupling device, and a plurality of brakes, wherein the engine, the large motor, and the small motor are respectively connected to the power coupling device, and are characterized by:

The large motor and the small motor are electrically connected to an inverter, the inverter is electrically connected to a motor controller, the motor controller is electrically connected to a battery management system, the battery management system is electrically connected to the battery, and the engine is provided with a The speed sensor, the signal output end of the speed sensor is connected to an engine management system, and the signal management end of the throttle control, the ignition control and the valve control are respectively arranged on the engine management system, and are respectively connected with the engine circuit, the motor controller and the battery The management system and the engine management system are respectively connected to the vehicle controller, and the engine and the small motor are respectively provided with brakes;

The power coupling device is a planetary gear device including a planet carrier, a planetary gear, a long planetary gear, a small sun gear, a large sun gear and an outer ring gear, wherein the power output shaft of the engine is connected to the rotating shaft of the carrier, the carrier The upper planetary gears mesh with the small sun gear respectively, and the small sun gear shaft is a small motor shaft, the planetary gears on the planet carrier mesh with the long planetary gears, and the long planetary gears respectively mesh with the large sun gear;

A small motor brake is disposed on the small sun gear rotating shaft, and a launching mechanism is disposed on the planetary carrier.

The hybrid output power balance device according to claim 1, wherein the vehicle controller is provided with an input end of an accelerator pedal signal, a brake pedal signal, a gear position signal, and a vehicle speed signal, respectively.

A control method of a hybrid output power balance device, characterized in that the hybrid output power balance device is the hybrid output power balance device according to any one of claims 1 - 2, and the control The method includes the following steps:

In the first step, the change of the torque demand T _req to the acceleration pedal opening APS, the brake pedal opening BPS and the vehicle speed V _SPD is stored as a torque demand T _req data table in the vehicle controller, and the vehicle controller is based on The corresponding torque demand T _{req is} determined using the data table given the accelerator pedal opening APS and the given vehicle speed V _SPD difference. Power demand P _req obtained by the torque demand T _req; a second step, the first step will set power demand P _req and the upper electric driving power demand value P _ev, the current battery state of charge SOC with a preset amount The lower limit value soc _{min of the} battery charge state is sufficient for comparison; In the third step, according to the comparison result of the second step, when P _req < P _ev and SOC > soc _min , the whole vehicle is driven by pure electric motor, the engine is turned off and braked by the engine brake, the large motor drives the vehicle, and the small motor idles. When P _req 〉P _ev or soc < soc _min , the vehicle controller sets the engine target speed n _e and the target torque T _e corresponding to the power demand P _req , wherein the target speed n _{e of the} engine and the target torque T _{e is} determined based on the engine optimal power-speed curve and the power demand torque P _re q .

The control method according to claim 3, characterized in that each of the first to third steps is repeatedly executed at predetermined time intervals of 10-50 ms.

5. The control method according to claim 4, characterized in that, when the current vehicle speed is high and the engine operating point is substantially in the optimum efficiency region, if the target speed of the small motor fluctuates within a small range of zero speed When the vehicle controller controls the small motor brake lock 'dead small motor.

The control method according to any one of claims 3 to 5, characterized in that: the vehicle controller is based on the target rotational speed n _{e of the} engine, the rotational speed n _{H ( ) of the} ring gear shaft, and the transmission in the planetary gear mechanism Than ^, i. ₂ to calculate the target speed of small and large motors.

The control method according to any one of claims 3 to 6, characterized in that: before each control program operation cycle ends, the vehicle controller transmits the engine target speed n _e and the target torque T _e to the engine management The system simultaneously sends small motors and large motor torque commands T _el , T _e2 to the motor controller.