阅读说明：本技术 用于确定绕线转子同步电机的转子的位置和速度的方法 (Method for determining the position and speed of the rotor of a wound rotor synchronous machine ) 是由 M·科泰希 A·梅萨利 M·加恩斯 于 2019-07-02 设计创作，主要内容包括：本发明涉及一种用于对由三相逆变器供电的绕线转子同步机器的转子的速度和位置进行估计的方法,该方法包括：独立于该电机的参数、诸如该电机的定子电感值而根据位置增益参数(K_e)以及所计算的误差(ε)的符号(0~(11))估计该转子的位置(Θ)的步骤；以及独立于该电机的参数、诸如该电机的定子电感值而根据速度增益参数(K_((J))以及所计算的误差(ε)的符号(0~(11))估计转子速度的步骤。(The invention relates to a method for estimating the speed and position of the rotor of a wound rotor synchronous machine powered by a three-phase inverter, the method comprising: dependent on a position gain parameter (K) independent of a parameter of the motor, such as a stator inductance value of the motor e ) And the sign (0) of the calculated error (epsilon) 11 ) A step of estimating the position (Θ) of the rotor; and a speed gain parameter (K) dependent on a parameter of the motor, such as a stator inductance value of the motor (J ) And the sign (0) of the calculated error (epsilon) 11 ) Estimating rotor speed The step (2).)

1. A method for estimating the speed and position of a rotor (20) of a wound rotor synchronous machine (20) powered by a three-phase inverter, the method comprising:

-measuring the three-phase current (i) at the input of the wound rotor synchronous machine (20)_a，i_b，i_c) A step (2);

-measuring the three-phase currents (i)_a，i_b，i_c) Transformation into a two-phase reference frameA step (2);

-the first part (11) comprises:

-a step of injecting a high frequency voltage signal at the input of the machine;

-a demodulation step for determining an error value (epsilon) of the position estimate of the rotor (20); characterized in that the method comprises a second part (12) comprising:

-a step of calculating the sign (σ) of the position estimation error (ε);

-a position gain parameter (K) dependent on a parameter of the electric machine, such as a stator inductance value of the electric machine_θ) Estimating the position of the rotor by the sign (sigma) of the error (epsilon) calculated therebyA step (2); and

-a speed gain parameter (K) dependent on a parameter of the electric machine, such as a stator inductance value of the electric machine_ω) Estimating the speed of the rotor by the sign (sigma) of the error (epsilon) calculated therebyThe step (2).

2. Estimation method according to claim 1, characterized in that the position of the rotor is estimated at a given instant (k +1)As the position estimated at the previous time (k)And the velocity estimated at the previous moment (k)As a function of (c).

3. An estimation method as claimed in claim 1 or 2, characterized in that the speed of the rotor estimated at a given instant (k +1)As the estimated velocity at the previous time (k)As a function of (c).

4. The estimation method according to any one of claims 1 to 3, characterized in that it also implements the acceleration estimated from the sign (σ) of the error (ε) and at the previous instant (k)Calculating accelerationThe step (2).

5. The estimation method according to any one of claims 1 to 4, characterized in that the method further comprises estimating the acceleration dynamic range value (m) from the sign (σ) of the error (ε) and the acceleration dynamic range value (m) estimated at the previous time (k)Calculating acceleration dynamic rangeThe step (2).

6. The estimation method of claim 5, wherein the acceleration is calculatedAs estimated at the previous time (k)Dynamic range of acceleration value of meterAs a function of (c).

7. The estimation method according to any of the claims 4 to 6, characterized in that the position gain parameter (K) is a function of the position gain parameter (K)_θ) And a speed gain parameter (K)_ω) Is the value of the acceleration dynamic range estimated at the previous moment (k)As a function of (c).

8. The estimation method according to any of claims 5 and 6, characterized in that the position gain parameter (K) is a function of the position gain parameter (K)_θ) And a speed gain parameter (K)_ω) Is the acceleration value estimated at the previous time (k)As a function of (c).

9. An assembly comprising a wound rotor synchronous machine and apparatus for carrying out the method of any one of claims 1 to 8.

10. A motor vehicle comprising the assembly of claim 9.

Technical Field

The invention relates to the field of wound rotor synchronous motors.

More particularly, the present invention relates to a method for determining the position and speed of the rotor of a wound rotor synchronous machine.

Background

In order to control a wound rotor synchronous machine (abbreviated WRSM), it is generally necessary to know the position and speed of the rotor.

One solution known in the prior art comprises mounting one or more mechanical position and speed sensors on the machine shaft of the machine.

However, these mechanical sensors are expensive, bulky, sensitive to the environment (temperature, noise, mechanical oscillations, electromagnetic compatibility, etc.), and can reduce the reliability of the system.

Therefore, in order to avoid the use of mechanical sensors, control methods have been developed that do not use mechanical sensors to ensure an equal or even better quality control compared to methods using mechanical sensors for control.

Typically, these sensorless control methods use algorithms, also known as software sensors, that estimate the machine position/velocity based only on current measurements in closed-loop mode.

Also known are methods for estimating the position/speed of the rotor by injecting high frequency signals, as described in document US 2004070360 a1, which have the effect of allowing detection with less dependence on machine parameters.

However, these methods still depend on the parameters of the machine, and more particularly for WRSM, on the stator inductance experienced by the rotor. In addition, these techniques rely on knowing the characteristics of the injected signal, such as amplitude and frequency.

Therefore, there is a need for a method for estimating position/speed that is more reliable and less dependent on the parameters of a wound rotor synchronous machine.

Disclosure of Invention

To this end, a method for estimating the speed and position of the rotor of a wound rotor synchronous machine powered by a three-phase inverter is proposed, the method comprising:

-a step of measuring the three-phase currents at the input of the wound rotor synchronous machine;

-a step of transforming the measured three-phase currents into a two-phase reference frame;

-the first part comprises:

-a step of injecting a high frequency voltage signal at the input of the machine;

-a demodulation step for determining an error value (epsilon) of the position estimate of the rotor;

characterized in that the method comprises a second part comprising:

-a step of calculating the sign of the position estimation error;

-a step of estimating the position of the rotor from a position gain parameter, the sign of the error thus calculated, independently of a parameter of the motor, such as a stator inductance value of the motor; and

-a step of estimating the speed of the rotor from a speed gain parameter, the sign of the error thus calculated, independently of a parameter of the motor, such as a stator inductance value of the motor.

Thus, the speed and position of the rotor can be estimated solely from motor-independent parameters, which improves robustness and ease of adaptation to any wound rotor machine.

Advantageously and in a non-limiting manner, the step of estimating the position of the rotor at a given instant is a function of the position estimated at the previous instant and of the speed estimated at the previous instant. Thus, by estimating the position by this cyclic pattern method, a fast, simple and robust estimation can be obtained.

Advantageously and in a non-limiting manner, the step of estimating the position of the rotor at a given instant is a function of the speed estimated at the previous instant. Thus, by estimating the velocity by this cyclic mode method, a fast, simple and robust estimation can be obtained.

Advantageously and in a non-limiting manner, the method also implements a step of calculating the acceleration from the sign of the error and the acceleration estimated at the previous instant. Thus, a robust and motor parameter independent acceleration estimation can be obtained.

Advantageously and in a non-limiting manner, the method further comprises a step of calculating the acceleration dynamic range from the sign of the error and the acceleration dynamic range value estimated at the previous instant. Thus, a robust and motor parameter independent estimation of the acceleration dynamic range can be obtained. This estimation allows to improve the other estimations of the method.

Advantageously and in a non-limiting manner, the step of calculating the acceleration is performed as a function of the acceleration dynamic range value estimated at the previous instant. Thus, an even more accurate acceleration value may be obtained.

Advantageously and in a non-limiting manner, the position gain parameter and the velocity gain parameter are functions of the acceleration dynamic range value estimated at that previous moment. Thus, an adaptive gain can be obtained, thereby improving the position estimation and the velocity estimation.

Advantageously and in a non-limiting manner, the position gain parameter and the velocity gain parameter are functions of the acceleration value estimated at that previous moment. Thus, an adaptive gain can be obtained, thereby improving the position estimation and the velocity estimation.

The invention also relates to an assembly comprising a wound rotor synchronous machine and an apparatus for implementing the method as described above.

The invention also relates to a motor vehicle comprising an assembly as described above.

Drawings

Further particular features and advantages of the invention will become apparent from reading the following description of particular embodiments of the invention, given by way of indication and not limitation, with reference to the accompanying drawings, in which:

figure 1 is a schematic view of a process according to the invention;

figure 2 is a schematic representation of a rotor and a calculating shaft employed in the method according to the invention;

FIG. 3 is a schematic view of the steps of calculating a position estimate and a speed estimate of the rotor according to a first embodiment of the invention;

FIG. 4 is a schematic view of the step of calculating a position estimate and a speed estimate of the rotor according to a second embodiment of the invention; and

figure 5 is a schematic view of the steps of calculating a position estimate and a speed estimate of the rotor according to a third embodiment of the invention.

Detailed Description

A method for estimating the speed and position of the rotor of a wound rotor synchronous machine comprises the steps of measuring 10 three-phase currents and two distinct parts: a first part 11 of the processed signal, in particular comprising injecting a High Frequency (HF) signal and extracting an error expression, and a second part 12 of the estimate from the injected signal.

Firstly, the method implements a measurement of the three-phase current i at the input of a 10-wound-rotor synchronous machine_a、i_b、i_cThe step (2). The wound rotor synchronous machine is powered by a three-phase inverter. However, this step need not necessarily be performed before the first part 11 of the method, but it may also be performed during the first part 11 of the method, for example, when the need relates to the measured three-phase current values i_a、i_b、i_cAnd previously executed.

The first part 11 of the method comprises implementing a method for injecting a high frequency signal (commonly referred to as a pulsing technique). In other words, by rotating the reference frame at the estimationIn which a high frequency signal (here, a high frequency voltage) is added to the input voltage of the inverter for injection.

The pulsation technique known to the person skilled in the art allows to mixInjection of high frequency voltage into estimated park reference frameReferring to FIG. 2, the park reference frame is related to angle according to the following equationOrientation, which corresponds to the position estimate of the rotor 20:

wherein:

V_cis the amplitude of the injected high frequency voltage.

Is the frequency of the injected high frequency voltage.

Deriving the measured two-phase current from the measured three-phase current by applying the following equation

This equation (1) describes the three-phase current i carried out according to the measurement step 10 of the method_a、i_b、i_cAnd a steady-state three-phase two-phase transformation α β according to a kenkokia (concodia) transformation.

Assuming an estimated axis of rotationThe current at (assuming this is zero)The axes are decoupled) and then by passing the obtained two-phase currentRotation angleTo obtain an estimated axis of rotationA single measurement result of (a).

In practice, though the shaft is consideredCurrent ofApproximately zero, but in practice it is an errorAs a function of (c). This is why it is useful to implement a so-called tracking algorithm method which minimizes the position error epsilon in order to restore the correct position theta of the rotor. In other words, due to the currentAnd position errorProportional, and therefore seeking to eliminate the angular value of the currentIn this case

A demodulation step is then applied, here a heterodyne demodulation step known to the person skilled in the art. In this step, the current is appliedMultiplication by sin ω_ct, and then filtering the result by applying a low pass filter, where the low pass filter is first order, but the low pass filter may also be second or higher order.

Therefore, the error can be calculated by the following equations (3) and (4):

wherein:

ld, Lq correspond to the stator inductances of the reference frames d, q of the machine,

vc is the amplitude of the injected signal; and is

ω_cIs the ripple of the injected signal.

Now, the error function epsilon still depends on the parameters of the machine, here the stator inductances Ld, Lq in the reference frame d, q of the machine.

Therefore, in order to make the estimation method independent of the parameters of the machine, the method comprises obtaining the estimated second part 12 from the injected signal, which is more robust than the methods of the prior art.

According to a first embodiment of the invention, with reference to fig. 3, an independent parameter is defined, called estimator parameter σ, or more simply estimator, according to the following equation:

and when

Wherein:

the obtained estimate σ is therefore independent of the parameters of the machine, in particular of the inductance value, and is decoupled from the characteristics of the injected signal relating to equation (3).

Only errors are requiredThe position and speed of the ac machine can be estimated at a given instant k +1, without mechanical sensors, by means of innovative estimators (8) (9) proposed according to the following equation:

wherein

If it is not

If it is not

If it is not

Selecting parameter K_θAnd K_ωTo ensure rapidity of convergence and suppression of disturbances (jitter, offset, etc.). For example, K can be defined_θ1 and K_ωThis ensures good quality estimation and limited temporal stability at 1500. Ts is the sampling period of the estimator.

Thus, at time k +1, it is possible to depend on the machine parameters only from the position estimated at the previous timeVelocity estimated at previous timeAnd calculating the estimated position of the rotor from the sign sigma of the position estimation error

At the time k +1, it is also possible to depend on the speed estimated at the previous time only, independently of the machine parametersAnd calculating the estimated speed of the rotor from the sign sigma of the position error

Thus, by using equation (7) which defines the estimator σ, a relatively robust estimate of position and velocity can be obtained.

According to the second embodiment of the present invention, referring to fig. 4, the robustness of the estimation of the speed and position of the rotor can be further improved.

For this purpose, another calculation mode is proposed based on the following equations (13), (14) and (15), which is augmented with respect to the model according to the first embodiment of equations (8) and (9).

A second embodiment of the invention takes into account the dynamic range of the speed of the rotor in order to correct the estimation error of the speed and position in the acceleration phase.

Therefore, the estimation equations (8) and (9) of the first embodiment are replaced by the following equations:

where the function S is defined by the preceding equations (10), (11) and (12).

Thus, the estimation of this second embodiment of the invention comprises estimating the position of the rotor of the machineSpeed of rotationAnd acceleration

This estimator thus makes it possible to counteract the speed and position estimation deviations during the acceleration phase of the machine by taking into account the dynamic range of the speed, without in any way involving the knowledge of the mechanical parameters of the machine (inertia, load torque, friction depending on the characteristics of the tires and of the road), which allows avoiding the use of mechanical system observers.

Furthermore, the second embodiment of the invention allows to obtain information about the torque budget of the machine via the estimation of the acceleration (speed dynamic range) independently of the knowledge of the mechanical parameters of the machine.

Referring to fig. 5, a third embodiment of the invention, derived from the second embodiment of the invention, also modifies the estimation equations (13), (14) and (15) by seeking to reduce the fluctuations in acceleration, the effect of which is to allow a more accurate estimate of position and velocity to be obtained.

Then, the modified estimation equation is given by the following equations (16), (17), (18), and (19):

wherein the functionDefined by equations (10), (11) and (12).

Therefore, the acceleration dynamic range value is calculated at the time k +1 from the error sign at the previous time k

Then, the acceleration value at time k +1 according to equation (18) is the acceleration dynamic range value calculated at the previous time kAs a function of (c).

A fourth embodiment (not shown) includes adjusting the gains of the position estimate and the velocity estimate of equations (13) and (14) based on the acceleration estimate based on equation (15), and adjusting the gains of the position estimate, the velocity estimate, and the acceleration estimate of equations (16), (17), (18) based on the dynamic range of acceleration (19).

This allows a more accurate estimation. Therefore, the gains of the estimator adjustment for equations (13), (14) of the second embodiment are defined by the following equations (20) to (22):

and the gains adjusted for the estimators of equations (16), (17), and (18) of the third embodiment are:

wherein the functionDefined by equations (10), (11) and (12).