CN102198805B - A kind of pure electric automobile ramp method in slope that magneto drives - Google Patents

Abstract

The invention discloses the ramp parking control strategy of a kind of pure electric automobile driven for magneto.Pure electric automobile has a set of electrical system, and it includes set of cells, motor, power inverter, electric machine controller, entire car controller, and corresponding voltage sensor, current sensor, obliquity sensor.The program is divided into two steps: (1) permanent-magnetic synchronous motor rotor initial position detection: by power inverter, permagnetic synchronous motor applies detection voltage, the space initial position of rotor when calculating stationary vehicle by current feedback signal；(2) torque self-balancing strategy based on vector controlled: torque self-equilibrium characteristic can make driving torque from motion tracking load torque.It is calculated the torque needed for parking according to the angle of inclination in ramp residing for vehicle, then provides rational current amplitude and phase place according to initial position of rotor and the torque needed for staying slope so that driving torque is equal to load torque, thus realize that vehicle is quiet on ramp stays.

Description

A kind of pure electric automobile ramp method in slope that magneto drives

Technical field

The present invention relates to the pure electric automobile field that permagnetic synchronous motor is main drive motor, be specifically related to use forever Magnetic-synchro motor vector control technology prevents vehicle from slipping by slope on the slope, to reach the effect in slope.

Background technology

Pure electric automobile, with vehicle power as power, converts electrical energy into mechanical energy by motor, drives wheel row Sail.Can be applicable at present the driving motor type of electric automobile mainly have direct current generator, induction machine, permagnetic synchronous motor, DC brushless motor and switched reluctance machines etc..Owing to magneto has, efficiency is high, output torque is stable, power volume The big advantage of ratio, adds that China's rare earth resources rich reserves, the electric automobile that therefore permagnetic synchronous motor drives are following weights The developing direction wanted.

When automobile is on ramp, the downslide component of gravity can make automobile have the trend of downslide.For common manual shelves Fuel-engined vehicle, from step on clutch, loosen the brake to step on the throttle pedal time, automobile is in forfeiture power State, easily slips by slope phenomenon, and vehicle driving safety causes harm greatly；For automatic transmission fuel-engined vehicle, if There is no intelligent power control system, still can slip by slope because output is short of power when D shelves are loosened the brake.

The output machine reason of electric motor car and fuel-engined vehicle are entirely different.Internal combustion engine does not has torque defeated when shutting down Go out, and motor can export moment of torsion in full when stationary rotor.Therefore, only the defeated of power drive system need to be controlled Go out torque to balance each other with load torque, electric automobile can be realized static on ramp.

Chinese patent 201010519820.3 discloses the control method that a kind of pure electric vehicle via idle speed is anti-slip back, it Including entire car controller, electric machine controller, motor, brake pedal, hand brake device, gas pedal, electrokinetic cell, its Middle entire car controller is all connected with described electric machine controller, brake pedal, hand brake device, gas pedal, electrokinetic cell Connecing, electrokinetic cell is connected with described motor by described electric machine controller.It is electronic that this content primarily focuses on general introduction The control strategy of vehicle anti-running function and enforcement step, lack concrete operation scheme.

Chinese patent 201010156853.6 discloses a kind of ramp safe starting control system of electric vehicle, it Introduce a kind of ramp and identify system, first calculated current hill grade by entire car controller and calculate as preventing from slipping by slope required turning Square, is then sent respective torque instruction by electric machine controller, makes vehicle energy gentle start under slope condition.The program carries Supply to realize the thinking in slope by control motor torque, but how to have controlled electricity after controller sends torque instruction Machine, is not described, and lacks actual operation.

Chinese patent 200810215811.8 discloses a kind of anti-slip back scheme being applied to hybrid vehicle, it The torque first passing through the output of the vehicle motor of time in slope determines the amount preventing the wheel torque needed for vehicle rollback, and gradually decreases The moment of torsion that motor produces, increases fuel engines moment of torsion simultaneously, so that the summation of the wheel torque of electromotor and motor generation It is substantially equal to the amount of described required wheel torque, so that vehicle reaches quiet in effect.In method, when sensor refers to Show when vehicle remains static, controller calculate and obtain current motor output moment of torsion.The program can be applied equally to Pure electric automobile, but running status sensor therein adds cost and the complexity of system.

Following pure electric automobile or by commonly used permagnetic synchronous motor, its vector control mode can accurately be controlled The output moment of torsion of motor processed, thus provide splendid handling, including accelerating, brake, cruise and the function such as parking. This area relates to when stationary vehicle is on ramp, and driver is from bend the throttle of loosening the brake, it is desirable to vehicle from When resting state is accelerated, overcome the less desirable rollback phenomenon caused due to the torque command to wheel offer delay.

Summary of the invention

The invention aims to provide the ramp parking of a kind of pure electric automobile driven for magneto Control strategy.According to principle of vector control, the output torque of magneto can be by the stator current decoupled and air-gap field It is respectively controlled.Owing to permanent magnet machine rotor has intrinsic permanent magnetic field, utilize residing for output torque and rotor A kind of self-balancing stability characteristic (quality) being had between locus, it is achieved vehicle is in the parking of any gradient, it is to avoid rollback Or smooth phenomenon, concrete principle is as detailed below.

In addition to the mechanical system that vehicle is conventional, the pure electric automobile in the present invention also has a set of electrical system, Including set of cells, motor, power inverter, electric machine controller, entire car controller, and corresponding voltage sensor, Current sensor, obliquity sensor.Mechanical system and the power-driven system of vehicle are not made any changes by the present invention, it It it is a kind of additional function on described electric automobile vector control scheme.The program is divided into two steps: (1) permanent magnetism is same Step original position of electric motor's rotator detection: described electric machine controller sends detection instruction, by described power inverter pair Described permagnetic synchronous motor applies detection voltage, calculates by described electric machine controller further according to current feedback signal The space initial position of rotor during stationary vehicle；(2) torque self-balancing based on vector control mode controls: first according to The angle of inclination in ramp residing for vehicle is calculated the torque needed for parking, then with described rotor dq coordinate system For reference, according to described rotor space initial position and required torque, calculate rational current amplitude and phase place, And it is applied to described motor stator winding by described power inverter.

In described torque self-balancing controls, the angle of inclination in ramp is obtained by described obliquity sensor measurement , be converted to digital signal and be transmitted further to described electric machine controller.Further, described inclination angle can not be used to pass Sensor measures ramp inclination angle, directly applies the electric current that amplitude is sufficiently large, phase place is correct, utilizes torque self-balancing principle Making vehicle stabilization on ramp, vehicle has and slightly slips by slope phenomenon in the process.

There is speed closed loop and current closed-loop in described permagnetic synchronous motor vector control scheme.In stationary vehicle In the case of, described current closed-loop works.Described motor stator winding to apply to close by described electric machine controller Suitable electric current, to provide enough balancing moment, can make vehicle quiet residing in not slip by slope on ramp.

When electric automobile starts on ramp, gear is switched to travel shelves by driver from park position (P shelves) (D shelves), and loosen the brake, now described entire car controller sends instruction in slope to described electric machine controller, The moment of torsion of motor output is delivered to wheel by described power drive system, and balances each other with downslide moment of torsion, and vehicle keeps Static.When driver's brake pedal or pull-up parking brake, the described electric machine controller described in entire car controller order Exit state in ramp shaped, now made vehicle keep static by mechanical braking system, the energy of described on-vehicle battery can be saved Consume.

Accompanying drawing explanation

Fig. 1 is the pure electric automobile pie graph of control system in slope of the present invention.

Fig. 2 is the permagnetic synchronous motor space vector graph of a relation of the present invention.

Fig. 3 is the permagnetic synchronous motor torque self-balancing schematic diagram of the present invention.

Fig. 4 is the based on pulse voltage injection permanent-magnetic synchronous motor rotor initial position recognition methods former of the present invention Reason figure.

Wherein Fig. 1:

1, set of cells；2, voltage sensor；3, power inverter (IGBT)；4, current sensor；5、 Permasyn morot (PMSM)；6, obliquity sensor；7, electric machine controller (DSP)；8, entire car controller (VCU)

Detailed description of the invention

1, principle in slope

Below for permagnetic synchronous motor output torque and the computing formula of vehicle load torque time static:

$T_e=\frac{3}{2}p({\mathrm{\ψ}}_d{i}_q-{\mathrm{\ψ}}_q{i}_d)=\frac{3}{2}p\·I_{s}sin\mathrm{\θ}\·\[{\mathrm{\ψ}}_{pm}+(L_d-L_q)I_{s}cos\mathrm{\θ}\]---\left(1\right)$

T_L=mgr sin α (2)

Such as Fig. 2, T in formula (1)_eFor motor output torque, p is motor stator number of pole-pairs, ψ_d, ψ_qExist for magnetic linkage Component under rotor dq coordinate system, wherein ψ_pmFor permanent magnet flux linkage, direction is along d axle；i_d, i_qTurning for stator current Component under sub-dq coordinate system, I_SFor the amplitude of stator current, L_d, L_qFor stator inductance component under dq coordinate system, θ is the angle of stator current vector and initial position of rotor.T in formula (2)_LSliding force during for stationary vehicle on ramp, I.e. realizing the load torque of the vehicle of time in slope, m is complete vehicle quality, and g is gravity acceleration constant, and r is radius of wheel, α For inclination angle, ramp.

For the Section 2 in square brackets in formula (1), its value is generally much smaller than permanent magnet flux linkage amplitude, particularly with table Mounted magneto has L_d=L_q, Section 2 is zero, therefore generally Section 2 is omitted in engineering, then formula (1) is reduced to:

$T_e=\frac{3}{2}{\mathrm{p\ψ}}_{pm}{I}_{s}sin\mathrm{\θ}---\left(3\right)$

In view of system of vehicle transmission ratio and transmission efficiency, the torque balance system meeting condition in slope is:

ηT_e=T_L (4)

Wherein η is powertrain parameters.If being known a priori by the initial position angle θ of rotor₀(with A phase Axle is zero position reference point), then the phase theta of stator current vector_iDetermined by below equation:

$mgr\·sin\mathrm{\α}=\frac{3}{2}{\mathrm{p\η\ψ}}_{pm}{I}_{s}sin\mathrm{\θ}\⇒\mathrm{\θ}={\sin }^{-1}\frac{2mgrsin\mathrm{\α}}{3{\mathrm{p\η\ψ}}_{pm}{I}_s}---\left(5\right)$

θ_i=θ₀+θ (6)

There is current closed-loop in permagnetic synchronous motor vector control scheme, applied along θ by electric machine controller_iPosition Current phase instruction, and reasonably current amplitude instruction I_S, to provide enough balancing moment, vehicle can be made quiet Reside in and do not slip by slope on ramp.

2, self-balancing principle

According to Fig. 3, electric current I_SComponent I on q axle_qIt is to provide the component of torque.If driving torque is little When the electromagnetic torque of load torque, i.e. motor is less than the downslide torque of vehicle, then vehicle is satisfied slips by slope condition, and motor turns Son can be followed the reversing of wheel and be reversed, and the phase and amplitude of stator current is the most constant, then stator current and rotor magnetic The angle theta of chain increases, and motor output torque increases, thus reaches torque balance a new position, now has:

$T_L=T_e=\frac{3}{2}{\mathrm{p\η\ψ}}_{pm}{I}_s{\mathrm{sin\θ}}^{\′}=\frac{3}{2}{\mathrm{p\η\ψ}}_{pm}{I}_q^{\′}---\left(7\right)$

Equally, if driving torque is more than load torque, then vehicle advances, stator current and the angle of rotor flux Reducing, motor output torque reduces, and reaches torque balance a new position, now has:

$T_L=T_e=\frac{3}{2}{\mathrm{p\η\ψ}}_{pm}{I}_s{\mathrm{sin\θ}}^{\′\′}=\frac{3}{2}{\mathrm{p\η\ψ}}_{pm}{I}_q^{\′\′}---\left(8\right)$

According to above-mentioned analysis, no matter vehicle is in upward slope or descending, and though driving torque whether with load Torque balances each other, and all can reach new torque balance by stator current and the self-adjusting of rotor-position angle, and this is Torque self-balancing principle based on vector controlled.

As θ ＞ 90 °, torque balance condition will be false.For meeting self-balancing condition, the amplitude of stator current Is have to be larger than a minima, and it is to meet the current value needed for torque balance that this value is when θ=90 °, is expressed as:

$I_s>\frac{2mgrsin\mathrm{\α}}{3{\mathrm{p\η\ψ}}_{pm}}---\left(9\right)$

Enter unstable region for anti-locking system, need to design sufficiently large electric current I_SSo that θ angle is left the most abundant Amount.Generally, it is contemplated the maximum load that vehicle is under ruling grade, I reasonable in design_Sθ is made to be not more than 45 °, Then can realize safe and reliable ramp parking.

Due to the self-equilibrium characteristic of torque in the present invention, if original position of electric motor's rotator angle θ₀There is estimation error, Or having calculating error for the angle theta needed for realizing torque balance, the program still can be carried out.By stator current and turn The automatic adjustment of sub-position angle, new torque balance can re-establish, and now rotor and wheel only there occurs small Rotation, vehicle process in slope will not be impacted.

3, permanent magnet machine rotor initial position detection

When strategy in slope starts, in order to provide phase place current phasor accurately, need to judge initial position of rotor Angle θ₀.Current enforceable permanent magnet machine rotor initial position determination methods mainly has high-frequency rotating voltage injection method and instantaneous Pulse voltage injection method.The invention discloses a kind of permagnetic synchronous motor initial position judgement side injected based on pulse voltage Method, is applicable to surface-mount type and interior permanent magnet machines, test result indicate that its precision reaches ± 10 ° of electrical angles.Due to Above-mentioned self-balancing principle has error angle adaptivity, and the program can meet electric automobile and stay the needs on slope.

No matter surface-mount type or interior permanent magnet machines, there is difference more or less in its stator dq axle inductance value. Described initial position of rotor determination methods according to motor stator dq axle inductance difference principle, to winding apply two groups linear Unrelated wide transient pulse voltage vector, obtains transient current response, then calculates the inductance parameters containing positional information Matrix, thus calculate rotor-position.Its derivation is as follows:

The terminal voltage formula of magneto under static position:

$\left[\begin{array}{cc}{v}_{\mathrm{\α}1}& v_{\mathrm{\α}2}\\ v_{\mathrm{\β}1}& v_{\mathrm{\β}2}\end{array}\right]=R\·\left[\begin{array}{cc}{i}_{\mathrm{\α}1}& i_{\mathrm{\α}2}\\ i_{\mathrm{\β}1}& i_{\mathrm{\β}2}\end{array}\right]+\left[\begin{array}{cc}{L}_1+L_{2}cos2{\mathrm{\θ}}_0& L_{2}sin2{\mathrm{\θ}}_0\\ L_{2}sin2{\mathrm{\θ}}_0& L_1-L_{2}cos2{\mathrm{\θ}}_0\end{array}\right]\·\frac{d}{dt}\left[\begin{array}{cc}{i}_{\mathrm{\α}1}& i_{\mathrm{\α}2}\\ i_{\mathrm{\β}1}& i_{\mathrm{\β}2}\end{array}\right]---\left(10\right)$

V in formula₁, v₂It is the amplitude of twice pulse voltage, i₁, i₂For the amplitude of corresponding twice current-responsive, under Mark represents the α beta-axis component under stator stationary α β coordinate system；R is stator phase resistance, L₁, L₂For stator dq axle electricity Average and the value of sense and mean difference, be defined as:

$L_1\stackrel{\mathrm{\Δ}}{=}\frac{L_d+L_q}{2},L_2\stackrel{\mathrm{\Δ}}{=}\frac{L_d-L_q}{2}---\left(11\right)$

Calculated inductance matrix by formula (10), and define four components in inductance matrix:

$\left[\begin{array}{cc}{L}_{11}& L_{12}\\ L_{21}& L_{22}\end{array}\right]\stackrel{\mathrm{\Δ}}{=}\left[\begin{array}{cc}{L}_1+L_{2}cos2{\mathrm{\θ}}_0& L_{2}sin2{\mathrm{\θ}}_0\\ L_2\sin 2{\mathrm{\θ}}_0& L_1-L_{2}cos2{\mathrm{\θ}}_0\end{array}\right]=\left[\begin{array}{cc}{v}_{\mathrm{\α}1}-{\mathrm{Ri}}_{\mathrm{\α}1}& v_{\mathrm{\α}2}-{\mathrm{Ri}}_{\mathrm{\α}2}\\ v_{\mathrm{\β}1}-{\mathrm{Ri}}_{\mathrm{\β}1}& v_{\mathrm{\β}2}-{\mathrm{Ri}}_{\mathrm{\β}2}\end{array}\right]{\left[\begin{array}{cc}\frac{{\mathrm{di}}_{\mathrm{\α}1}}{dt}& \frac{{\mathrm{di}}_{\mathrm{\α}2}}{dt}\\ \frac{{\mathrm{di}}_{\mathrm{\β}1}}{dt}& \frac{{\mathrm{di}}_{\mathrm{\β}2}}{dt}\end{array}\right]}^{-1}---\left(12\right)$

Then rotor-position can be expressed as:

${\mathrm{\θ}}_0=\frac{1}{2}{\tan }^{-1}\frac{L_{12}+L_{21}}{L_{11}-L_{22}}---\left(13\right)$

The rotor-position that formula (13) obtains determines the direction at rotor d axle place, but does not comprise rotor polarity information, It is thus desirable to apply potential pulse further to distinguish NS pole.Its principle is, apply two axial mutually along rotor d For anti-phase potential pulse, rotor d axle is acted the effect of magnetizing by one of them potential pulse, and another potential pulse is to d axle Play demagnetizing effect.Contrast the amplitude of two primary currents, i.e. can determine whether that the calculated position of (13) formula is in N pole or S Pole: if the current-responsive of previous potential pulse is more than the latter, is then in N pole, otherwise is then S pole.

The above initial position of rotor determination methods is only preferable to carry out the description of example, every relates to electricity What the permanent-magnetic synchronous motor rotor initial position determination methods of electrical automobile self-balancing principle in slope belonged to the present invention contains model Enclose.

Although the pure electric automobile strategy in slope driven for permagnetic synchronous motor, this self-balancing principle is the suitableeest For needing the direct current generator of rotor-position closed loop control, asynchronous induction machine, brshless DC motor or switched reluctance machines The electric automobile field driven.Every electronic vapour relating to the use of motor electromagnetic torque and vehicle load torque self-balancing principle Car scheme in slope belongs to the covering scope of the present invention.

Claims (3)

1. the pure electric automobile ramp method in slope that magneto drives, its electrical system includes: set of cells, motor, merit Rate changer, electric machine controller, entire car controller, voltage sensor, current sensor, obliquity sensor, its feature It is: provided electric energy by on-vehicle battery group (1) to drive system, is forever through power inverter (3) by DC power conversion Three phase sine alternating current needed for magnetic-synchro motor (5)；The PWM count word outfan of electric machine controller (7) becomes with power Parallel operation (3) is connected, it is provided that the driving signal needed for switching tube IGBT；The voltage sensor (2) being arranged on dc bus The simulation letter obtaining busbar voltage and motor three-phase current is measured with the current sensor (4) being arranged on AC three-phase line Number, then be converted to digital signal by A/D module and flow to electric machine controller (7)；Obliquity sensor (6) controls with motor Device (7) is connected, it is provided that ramp obliquity information；Entire car controller (8) and electric machine controller (7) pass through CAN It is connected, it is achieved data exchange；Described electric machine controller (7) sends detection instruction, by described power inverter (3) described permagnetic synchronous motor (5) is applied detection voltage, further according to the feedback signal of current sensor (4) The space initial position of rotor when being calculated stationary vehicle by described electric machine controller (7).

The pure electric automobile ramp method in slope that magneto the most according to claim 1 drives, it is characterised in that: Obliquity sensor (6) detection obtains the obliquity information in ramp residing for vehicle and passes to electric machine controller (7), motor control Device processed is calculated the torque needed for parking according to angle of inclination, with permagnetic synchronous motor DQ axle as reference, according to rotor Space initial position and required torque, calculate rational current amplitude and phase place, and by described power inverter (3) It is applied to motor stator winding.

3. the pure electric automobile ramp method in slope driven according to the magneto described in claim 1 or claim 2, It is characterized in that: no matter vehicle is in upward slope or descending, no matter whether driving torque balances each other with load torque, all can Reach new torque balance by stator current and the self-adjusting of rotor-position angle, make that vehicle is quiet to be resided on ramp.