阅读说明：本技术 用于调节电机的方法、用于电机的调节设备和电驱动系统 (Method for controlling an electric machine, control device for an electric machine, and electric drive system ) 是由 F.马尔肖 M.希尔施 M.曼德拉 于 2018-03-02 设计创作，主要内容包括：本发明涉及对电机的调节。为了调节电机,从电机的调节或测量参量提取预先确定的频率部分,并且将其与之前计算的调节矩阵相乘。调节矩阵在此可以提前进行计算。针对不同的应用情况可以提前形成不同的调节矩阵。由此,电机的简单有效和稳定的调节是可能的,尤其是用以优化和最小化谐波。(The invention relates to the regulation of an electric machine. For the regulation of the electric machine, a predetermined frequency component is extracted from the regulated or measured variable of the electric machine and multiplied by a previously calculated regulation matrix. The adjustment matrix can be calculated in advance. Different adjustment matrices can be formed in advance for different application scenarios. Thereby, a simple, effective and stable regulation of the motor is possible, in particular to optimize and minimize harmonics.)

1. Method (100) for controlling an electric machine (4), comprising the steps of:

detecting (110) at least one control or measurement variable (P);

-ascertaining (120) a portion of a predetermined frequency in the detected control or measurement variable (P);

calculating (130) a control variable (R) using the determined portion of the predetermined frequency of the detected control or measurement variable (P) and a predetermined control matrix; and

controlling (140) the electric machine (4) using the calculated control variable (R).

2. Method (100) according to claim 1, wherein the at least one regulating or measuring variable (P) comprises a torque of the electric machine (4), a current into the electric machine (4), a noise development of the electric machine (4), and/or a control voltage of the electric machine (4).

3. The method (100) according to claim 1 or 2, wherein the step for calculating the control quantity (R) comprises converting the control quantity (R) into the time domain.

4. The method (100) according to any one of claims 1 to 3, having the steps of:

providing a plurality of predetermined adjustment matrices; and

selecting an adjustment matrix from the plurality of predetermined adjustment matrices for calculating the control variable (R).

5. Method (100) according to claim 4, wherein the adjustment matrix is selected according to a preset operating mode for the electric machine (4).

6. Method (100) according to one of claims 1 to 5, having a step for calculating a target quantity from the known portion of the predetermined frequency of the detected regulating or measuring quantity (P).

7. Adjusting device for an electric machine (4), having:

a first conversion device (1) designed to: -learning the predetermined frequency fraction from at least one control or measurement variable (P); and

a first computing device (2) designed to: the control variable (R) is calculated using a predetermined control matrix and a known portion of a predetermined frequency of the control or measurement variable (P).

8. The adjusting apparatus according to claim 7, having a control device (3) which is designed to: the electric machine (4) is controlled using the calculated control variable (R).

9. The regulating device according to claim 7 or 8, having a second computing means (24) which is designed to compute the target variable from the known portion of the predetermined frequency of the detected regulating or measured variable (P).

10. Electric drive system with an electric motor (4) and a regulating device according to any one of claims 7 to 9.

Technical Field

The invention relates to an adjusting device for an electric motor, a method for adjusting an electric motor and an electric drive system.

Background

Document DE 102009000930 a1 discloses a method and a device for reducing torque ripple in permanent magnet motor systems. The motor system includes a permanent magnet motor coupled with an inverter. The method described in the document comprises a step for modifying the operational control signal in order to generate an operational control signal that reduces the waviness. The modified operational control signal is provided to an inverter for controlling the permanent magnet motor.

Rotating field machines, such as squirrel cage asynchronous machines or permanent magnet synchronous machines, do not have an ideal sinusoidal magnetic flux distribution in the air gap due to their design. In operation, this results in an inhomogeneous torque with harmonics when using sinusoidal current regulation. To minimize harmonics, two basic schemes are possible. One solution is to selectively connect the superimposed external compensation voltage to the motor voltage in a controlled manner. An alternative is based on an additional regulating circuit. In this case, for example, in a cascade structure in the internal control circuit, the setpoint torque can be initially preset, which is then superimposed from the outside by a compensation method for higher harmonics.

Disclosure of Invention

The invention discloses a method for regulating an electric motor according to claim 1, a regulating device for an electric motor according to claim 7, and an electric drive system according to claim 10.

Correspondingly, the following steps are set:

method for regulating an electric machine. The method comprises the steps of detecting at least one control or measurement variable and of ascertaining a predetermined frequency portion of the detected at least one control or measurement variable. Furthermore, the method comprises a step for calculating the control variable using a predetermined control matrix and using the determined portion of the detected predetermined frequency of the control or measurement variable. Finally, the method may comprise a step for controlling the electric machine using the calculated control variable.

Furthermore, it is provided that:

a control device for an electric machine has a first conversion device and a first computing device. The first conversion device is designed to: the predetermined frequency portion is known from at least one control or measurement variable. The first computing device is designed to: the control variable is calculated using a predetermined control matrix and the known part of the predetermined frequency of the control or measurement variable.

Furthermore, it is provided that:

an electric drive system having an electric motor and a regulating device according to the invention.

The invention is based on the recognition that disturbance variables, such as ripple (ripple) or harmonics, can occur in the electric drive system. Such disturbances may, for example, result in torques with harmonics, depending on the design. For example, electrical variables, for example phase currents for feeding into the electric machine, can also be influenced, or higher-frequency disturbances can be propagated to the drive system via the feed-in point of the electrical energy. Compensation or minimization of such disturbances requires complex or partially costly adjustment systems.

The invention is therefore based on the idea of taking this knowledge into account and of providing a simple, effective and stable regulation for an electric machine. Such a regulation of the electric machine should in particular achieve an effective regulation for minimizing or optimizing disturbances in the electric drive system. In this case, the focus is in particular on minimizing or compensating for disturbance variables having frequencies that are harmonics of the motor frequency.

For this purpose, it is provided that a predetermined frequency portion is extracted from one or more control or measurement variables of the electric drive system, and the control variable is calculated using the previously calculated control matrix and the known frequency portion of the control or measurement variable. Since the control matrix for calculating the control variable only has to be known once in advance, the control variable can be determined very easily during operation. Very rapid adjustment of the electric drive system can thereby be achieved. In particular, a small computational load is also required for this adjustment, so that relatively simple and inexpensive hardware can be used for implementation. Thereby, the cost for implementation can be reduced.

In this case, a predetermined frequency or, if appropriate, a plurality of predetermined frequencies (for which the frequency component is extracted from the control or measurement variable) can be determined in particular on the basis of the electrical frequency of the electric machine. For this purpose, in particular one or more harmonics of the electric drive system can be taken into account as a basis for the frequency component knowledge. In this way, the influences and disturbances can be optimized and adapted very well, in particular on the basis of harmonics in the electric machine and in the entire drive system.

The control or measurement variable which can be taken into account for controlling the electric machine can include, for example, changes, in particular harmonics, in the course of a torque change of the electric machine. In addition, fluctuations, in particular influences, can also be implemented at harmonic frequencies in the current or voltage in the electric machine or electric drive system as control or measurement variables for the regulation according to the invention. Furthermore, further parameters (which are directly available as control or measurement variables) or further variables (which can be derived indirectly from other control or measurement variables) can also be used for the control. It is thus also possible, for example, to preset parameters for the intentional noise development of the electric machine. Thus, by targeted adjustment, increase or decrease of the frequency components, in particular harmonics, the noise development of the electric machine and thus of the entire drive system can be influenced. In this way, it is also possible, for example, to increase the noise development of the electric machine in a targeted manner by means of the regulation. This can divert the attention of a user or a person in the environment of the electric machine to a dangerous or possible event, for example.

According to one embodiment, the at least one control or measurement variable includes a torque or a torque profile of the electric machine, a current and/or a voltage of the electric machine, and/or a desired noise development of the electric machine. In addition, any other variable can also be used as a control or measurement variable. These control or measurement variables can in particular also be taken into account together, from which further variables can be derived. The adjustment of the motor can therefore also be adjusted to a preset value which cannot be detected directly with measurement technology.

According to one specific embodiment, the method comprises, in the step for calculating the control variable, a step for converting the control variable into the time domain. In this case, the computation of the frequency component by means of the control matrix and the control or measurement variable is first carried out in the frequency domain, and the result is then converted into the time domain by conversion, so that the control variable is then available for the control in the time domain.

According to an embodiment, the method comprises a step for providing a plurality of predetermined adjustment matrices. In this case, different adjustment matrices can be provided, in particular for different application situations. In this case, for example, a plurality of control matrices can be calculated in advance, so that no further calculation of the control matrices is necessary during the control of the electric machine. The provided adjustment matrix can be stored in a memory, for example. Alternatively, providing the adjustment matrix may also comprise, for example, calculating the adjustment matrix in the calculation unit itself. In this case, the necessary control matrix can also be calculated online, i.e. during operation, if necessary. Furthermore, the method may comprise a step for selecting an adjustment matrix from a plurality of predetermined adjustment matrices. The control variable can then be implemented from the frequency component of the manipulated or measured variable by means of the selected control matrix. In this way, an appropriate, adapted adjustment matrix can be selected for different application situations in each case on the basis of a plurality of different adjustment matrices. This allows simple adaptation of the adjustment to different application situations.

According to an embodiment, the adjustment matrix may be selected according to a preset operation mode for the motor. This mode of operation may, for example, allow for different optimization of the parameters. Thus, different adjustment matrices may, for example, adapt different portions of the harmonics with different strengths. Different noise development of the electric machine can also be achieved, for example, on the basis of different control matrices. In addition, any other optimization objectives can also be preset by different control matrices.

According to one specific embodiment, the method further comprises a step for calculating the target variable from the determined portion of the predetermined frequency of the detected control or measurement variable. Such target variables may include, for example, variables that cannot be detected directly in the motor or drive system by measurement techniques. By calculating, i.e. deriving, the target variable from a further variable that can be detected in a measuring technique in the electric machine or in the drive system, an efficient detection of the variable that can only be detected indirectly is also possible. In particular, a further matrix which can also be set up in advance can also be used for calculating the target variable from the manipulated or measured variable.

According to an embodiment of the electric drive system, the electric machine comprises an asynchronous machine or a permanently excited synchronous machine.

The above-described embodiments and modifications can be combined with one another as desired, provided that they are of interest. Further embodiments, improvements and implementations of the invention also include combinations of features of the invention not mentioned in detail before or after the description of the examples. In particular, a person skilled in the art will add individual aspects here as an improvement or supplement to the corresponding basic form of the invention.

Drawings

The invention is explained in detail below on the basis of embodiments illustrated in the schematic drawings of the figures. Here:

fig. 1 shows a schematic diagram of an electric drive system with a regulating device for an electric motor according to an embodiment;

fig. 2 shows a schematic diagram of an electric drive system with a regulating device for an electric motor according to a further embodiment; and is

Fig. 3 shows a schematic representation of a flow diagram on which, for example, a method for regulating an electric machine according to an embodiment is based.

Detailed Description

Fig. 1 shows a schematic representation of an electric drive system with a regulating device for an electric motor 4. The regulating device here comprises first conversion means 1 and first calculation means 2. The control variable R calculated in the control device can be supplied to the control device 3, which uses the calculated control variable R to control the electric machine 4.

Any desired control or measurement variable P can be used as an input signal for the control device. For example, a control voltage of the electric drive system can be used as the input signal. Furthermore, for example, the current of the electric machine 4, for example the current in the phase connection of the electric machine 4, can also be detected and provided as a measurement variable. Furthermore, the course of the torque of the electric machine 4 can also be detected or calculated and used as an input variable P for the control device. In addition, further control or measurement variables are also possible. The preset for a defined noise development of the electric machine 4 can also be provided, for example, as an input variable P. Thus, the noise development of the electric machine 4 can be influenced, for example, by fluctuations in the torque variation of the electric machine 4. Furthermore, measured variables can also be implemented from which further parameters of the electric machine 4 or of the entire electric drive system, which cannot be measured directly if necessary, can be derived. Furthermore, if necessary, the course of the voltage or current can also be evaluated at the input of a rectifier (not shown here) of the electric drive system and included in the regulation of the electric motor 4. In this way, for example, the reaction of the electric drive system to the energy supply network fed into the drive system can be adapted or minimized.

The control or measurement variable P provided on the input side of the control device is first split into predetermined frequency portions at the first conversion device 1. In this case, for each control or measurement variable P, a predetermined frequency portion or also a plurality of predetermined frequency portions can be extracted. The predetermined frequency (the portion of which is extracted from the control or measurement variable) may be in particular a frequency which is a harmonic of the electrical frequency of the electric machine 4. The cosine and sine components of the harmonic to be modulated can be extracted, for example, from the time signal of the modulation or measurement variable P by demodulating the signal, i.e. multiplying, with the corresponding basis function. This can be achieved, for example, by means of multipliers 11 and 12 in first conversion device 1.

For example, a permanent-magnet excited synchronous machine generates a current reference angle Φ = m · N · Φ _ mech for the respective harmonic. Here, Φ _ mech represents a mechanical rotor position angle, N represents a pole pair number, and m represents a harmonic order. From the sine part Vs and the cosine part Vc thus calculated, for example, a complex vector V = Vs + jVc can be formed. However, in principle, a purely real implementation without further restrictions is also possible. The complex vector V or the respective sine or cosine part can be summarized in a weighting matrix H. For the next adjustment, a quality function J may then be formed: j = V × H × HV.

Here, the transposed conjugate complex element is denoted by an asterisk. The minimization of the quality function J corresponds to the minimization of the harmonic component in the manipulated or measured variable P. The weighting matrix H already mentioned above is used for determining the different weights and thus the different importance of the individual objects to one another. The quality function J can be understood as a function of harmonics in the control or measurement variable P of the electric machine 4, taking into account the stable transmission behavior in the electric machine 4. Based on the gradient-based optimization, the coefficients for the manipulated or measured variable P of the electric drive system can be adapted in a final iteration so that the quality function J is minimized. This finally results in that the coefficients of the manipulated variable can be calculated by simple multiplication of the matrix G associated with the operating point and the complex vector of the frequency component of the manipulated or measured variable. This can be realized, for example, in the multiplication means 20. Here, the complex matrix G associated with the operating point can already be calculated in advance and therefore does not burden the computational performance during the adjustment.

A corresponding multiplication of the matrix G associated with the operating point and the coefficient vector V can be carried out, for example, in the first calculation device 2.

Finally, the control variable R can be formed by modulation with corresponding basis functions in the modulators 21 and 22, which is supplied to the control device 3. The control device 3 thus uses the established control variable R to control the electric machine 4.

Fig. 2 shows a schematic illustration of a regulating device for an electric motor 4 according to a further embodiment. This embodiment substantially corresponds to the embodiment described above, and is further extended by a second computing device 24. In the second computing device 24, for example, parameters of the electric machine 4 or of the entire electric drive system which cannot be directly detected in a measurement technique can be derived from the measured variables. It is thus also possible to set target values which cannot be directly known in the electric drive system. The calculation of further parameters of the electric drive system can also be carried out, for example, by simple multiplication of the detected measured values with a matrix formed beforehand. This also makes it possible to achieve a particularly simple adjustment of the electric drive system and in particular of the electric motor 4 for target values which cannot be detected or may not be detected directly. In order to set the preset setpoint values Sa and Sb, the setpoint values Sa and Sb can also be provided as preset setpoint values in the control unit.

Fig. 3 shows a schematic representation of a flow chart on which, for example, a method 100 for regulating an electric machine 4 according to an embodiment is based. In step 110, at least one control or measurement variable is detected. In step 120, the predetermined frequency range is determined from the at least one detected manipulated or measured variable. As already described before, these parts can be formed by demodulation (multiplication) with the corresponding basis functions. In principle, the frequency component of the manipulated or measured variable P can also be extracted in any other way. Preferably, but not necessarily, a complex vector may be formed from the extracted frequency components. The frequency component can be in particular a component of a frequency of a predetermined harmonic of the electric machine 4.

In step 130, the control variable is calculated using the predetermined control matrix G and the frequency component of the control or measurement variable determined in step 120. Subsequently, in step 140, the electric machine can be operated accordingly using the calculated control variables.

As already mentioned above, the control matrix G for controlling the electric motor 4 can be calculated here already offline in advance, and therefore the computational performance of the control system is not burdened during the operation of the electric motor. In this case, if necessary, different control matrices G can also be implemented for different operating modes of the electric drive system. For this purpose, a plurality of different control matrices G can be calculated in advance, if necessary. The adjustment matrix can be stored in a corresponding memory device if necessary. The adjustment characteristic for the motor adjustment can therefore be adapted during operation of the motor 4 by simply replacing the adjustment matrix G. For example, different control matrices G can be formed in order to track different targets during the control of the motor 4. It is therefore possible, on the one hand, to minimize harmonics in the torque variation process of the electric machine 4. This minimization of fluctuations during torque changes of the electric machine results in a particularly smooth operation of the electric machine.

It is desirable to deviate intentionally from this optimized torque profile, for example, in order to increase the noise development of the electric machine 4. This can, for example, call the attention of a user or other persons in the surroundings of the electric machine 4. This may for example indicate a possible dangerous situation to the user. Furthermore, noise development can also be used, for example, by deliberately increasing the noise development of the drive in an electric or hybrid vehicle, in order to draw the attention of persons in the surroundings of the vehicle to the vehicle.

Furthermore, the reaction of the electric drive system to an energy supply network connected to the drive system can also be minimized, for example, by corresponding regulation. Furthermore, by targeted adaptation of the respective control matrix, it is possible not only to track this or further targets, but also to track combinations of a plurality of targets and to weight the respective target default values accordingly.

In summary, the invention relates to an adjustment for an electric machine. For the regulation of the electric machine, a predetermined frequency component is extracted from the regulated or measured variable of the electric machine and multiplied by a previously calculated regulation matrix. The adjustment matrix can be calculated in advance. Different adjustment matrices can be formed in advance for different application cases. In this way, a simple, effective and stable regulation of the electric machine can be achieved, in particular for the purpose of optimizing and minimizing harmonics.