阅读说明：本技术 用于降噪地运行开关磁阻马达的方法 (Method for operating a switched reluctance motor with reduced noise ) 是由 桑德罗·普尔弗斯特 罗伯特·赖彻特 于 2020-02-27 设计创作，主要内容包括：本发明涉及一种借助于磁阻马达装置来降噪地运行开关磁阻马达(1)的方法,所述磁阻马达装置具有开关磁阻马达(1)、控制与分析单元(2)、数据存储器(3)、电流调节器(4)、转子角度传感器(5)和扭矩评估器(6),其中,所述开关磁阻马达具有定子(7)、转子(8)和马达线圈(9)。施加到所述马达线圈(9)的电流的大小,为了不同的转子角度而保存在所述数据存储器(3)中的数值表中。获取实际扭矩,并且得出额定扭矩和获取到的所述实际扭矩之间的偏差。在此基础上重新计算电流值。重新计算出的所述电流值记入所述数值1表并且构成下一运行的基础。(The invention relates to a method for operating a switched reluctance motor (1) with noise reduction by means of a reluctance motor arrangement having a switched reluctance motor (1), a control and evaluation unit (2), a data memory (3), a current regulator (4), a rotor angle sensor (5) and a torque estimator (6), wherein the switched reluctance motor has a stator (7), a rotor (8) and a motor coil (9). The magnitude of the current applied to the motor coil (9) is stored in a table of values in the data memory (3) for different rotor angles. An actual torque is determined and a deviation between a setpoint torque and the determined actual torque is determined. The current values are recalculated on this basis. The recalculated current values are entered into the value 1 table and form the basis for the next run.)

1. Method for operating a switched reluctance motor (1) with noise reduction by means of a reluctance motor arrangement having a switched reluctance motor (1), a control and evaluation unit (2), a data memory (3), a current regulator (4), a rotor angle sensor (5) and a torque estimator (6), wherein the switched reluctance motor has a stator (7), a rotor (8) and a motor coil (9), having the following method steps:

a) defining a value table in the data memory (3), said value table having table points, wherein the table points are formed by value tuples, and wherein each value tuple has a value pair consisting of a setpoint torque and a rotor angle and an associated current setpoint value,

b) performing a partial loop, where

b)1 predetermining a nominal torque

b)2 detecting a first actual rotor angle by means of the rotor angle sensor

b)3 selecting the current setpoint value assigned to the value pair consisting of the setpoint torque and the first actual rotor angle to the setpoint torque by means of the control and evaluation unit (2), in which case the closest setpoint point is obtained, and calculating the difference between the actual value of the setpoint torque and the actual value of the first actual rotor angle to the setpoint point, wherein the current setpoint value is obtained from the respective current setpoint value of the four setpoint points by means of a bilinear interpolation method,

b)4 regulating the current rating by the current regulator

b)5 applying current to the motor coil (9)

b)6 estimating the actual torque by means of the torque estimator (6),

b)7 a torque deviation is determined by means of the control and evaluation unit (2) by comparing the target torque and the actual torque,

b) calculating a corrected current setpoint value by means of the control and evaluation unit (2) on the basis of the torque deviation, wherein the calculation for all four last applied table points is carried out in relation to the applied interpolation interval,

b)9 recording the calculated values of the corrected current setpoint value into four associated value tuples of the value table by means of the control and evaluation unit (2) and deleting the previous values of the current setpoint value,

c) the partial cycle is repeated until a rotor angle corresponding to the complete motor state is reached, so as to constitute a total cycle,

d) repeating the total cycle

2. The method for operating a switched reluctance motor with noise reduction according to claim 1, wherein the table of values is constructed for one full rotation of the rotor.

Technical Field

The invention relates to a method for operating a switched reluctance motor with reduced noise.

Background

Switched reluctance motors are known from the prior art. Control methods are also known for modulating the phase currents in order to achieve a reduction in operating noise. The disadvantage here is that either the respective motor has to be adapted in a cost-effective manner or the operating noise cannot be reduced optimally.

Disclosure of Invention

The object of the invention is to provide a method which can be applied to different types of reluctance motors at low cost and which effectively reduces the noise level.

This object is achieved by the features specified in claim 1. Preferred variants are found in the dependent claims.

The method for operating a switched reluctance motor with noise reduction is carried out by means of a reluctance motor arrangement having the features explained below.

According to the invention, the reluctance motor arrangement has a switched reluctance motor, a control and evaluation unit, a data memory, a current regulator, a rotor angle sensor and a torque estimator. The data memory, the current regulator, the rotor angle sensor and the torque estimator are each connected to the control and evaluation unit in terms of data.

The control and evaluation unit is designed to receive data from the rotor angle sensor and the torque estimator and to process said data. Furthermore, the control and evaluation unit is designed to control the current regulator, to read data from the data memory and to write data into the data memory. The control and evaluation unit preferably relates to the electronics of a computer or a controller, for example. In particular, the data memory, the torque estimator and the current regulator can together form an integrated structural unit with the control and evaluation unit.

According to the present invention, the switched reluctance motor has a stator, a rotor, and a motor coil. The rotor is preferably located inside the rotationally symmetrical stator and is rotatably mounted about the axis of rotation. The stator and the rotor have soft magnetic material in the tooth structure. This is also referred to hereinafter as stator teeth and rotor teeth. The rotor teeth are also referred to in part as rotor arms hereinafter. The motor coils are preferably arranged symmetrically on the stator with respect to the axis of rotation of the rotor on the stator teeth. The reluctance motor is configured to generate a magnetic flux through the rotor by applying a current to the motor coil. By means of the reluctance forces, the rotor teeth are oriented with respect to the stator teeth, so that the reluctance is reduced. The rotor is thus caused to rotate by the geometric arrangement of the rotor teeth and the stator teeth relative to each other. By switching in and out the motor coils on different stator teeth, such a magnetic flux is always re-generated again, which flux acts on the rotor to minimize the reluctance. The switched reluctance motor is also referred to below, partially shortened, as a reluctance motor or motor.

The knowledge on which the method according to the invention is based is that the rotor teeth and the stator teeth are deformed, in particular transversely to their longitudinal axis, as a result of the detent forces. This deformation leads to oscillations of the rotor teeth, oscillations of the stator teeth and oscillations of parts of other mechanically connected components of the reluctance motor or of the driven unit, which are perceived as noise. In order to reduce said oscillations and thereby reduce noise, the method sets forth a solution according to which the forces on the rotor teeth and the stator teeth are controlled such that the oscillations of the rotor teeth and the stator teeth are reduced. In this case, the torque is kept as constant as possible in all angular positions of the rotor. Whereby a substantially constant force transverse to the longitudinal axis of the rotor teeth and the longitudinal axis of the stator teeth also acts on the rotor teeth and the stator teeth. The method herein provides a solution that is not related to the specific geometry and other structural configurations of the rotor and stator teeth.

According to the invention, the method comprises the following method steps:

a) defining a table of values in the data store, the table of values comprising a plurality of table points, wherein the table points are formed as tuples of values. The value tuples each contain a value pair consisting of a setpoint torque and a rotor angle and an associated current setpoint.

b) Performing a partial loop

b)1 predetermining a nominal torque

b)2 detecting a first actual rotor angle by means of the rotor angle sensor

b)3 selecting the current setpoint value assigned to the first value, which is composed of the setpoint torque and the first actual rotor angle, for the setpoint torque by means of the control and evaluation unit. In this case, two closest table points are determined with respect to the predetermined target torque, and two closest table points are determined with respect to the actual rotor angle, and the difference between the actual value of the target torque and the actual value of the first actual rotor angle is calculated from the table points. The current nominal values are derived from the respective current nominal values of the four table points by means of a bilinear interpolation method.

b)4 regulating the current rating by the current regulator

b)5 applying current to the motor coil

b)6 estimating the actual torque by means of the torque estimator

b)7 comparing the target torque with the actual torque, determining a torque deviation by means of the control and evaluation unit

b) On the basis of the torque deviation, a corrected current setpoint value is calculated by means of the control and evaluation unit, the calculation for all four last applied table points being carried out in relation to the applied interpolation interval.

b)9, the calculated values of the corrected current setpoint value are entered into the four associated value tuples of the value table by means of the control and evaluation unit, and the previous values of the current setpoint value are deleted.

c) The partial cycle is repeated until a rotor angle corresponding to the complete motor state is reached and thus constitutes the total cycle.

d) Repeating the total cycle

The method is described in detail below with reference to the method steps.

a) Definition value table

An example of a corresponding numerical table is shown in table 1.

The respective current rating for the motor coil to which the current is to be applied is assigned to the rotor angle (& ltu & gt)_ist) And rated torque. The table points constitute a value tuple having the rotor angle (')_ist) Rated torque (M)_soll) And at least one current rating, or preferably two current ratings, in particular for two adjacent motor coils (I)₁、I₂) One current rating each.

Table 1 shows a table of values for a reluctance motor having two coils. When the reluctance motor has more coils, the tuple of values receives an additional current rating for each of the other coils.

Table 1 numerical table example

The table of values is stored in the data memory. The control and evaluation unit is designed to access the data memory and the value table.

b) Performing a partial loop

b)1 predetermining a nominal torque

The predetermined value of the rated torque is determined by the load that should be applied by the motor. The predetermined setting of the setpoint torque is carried out by the control and evaluation unit during the start-up of the switched reluctance motor.

b)2 detecting a first actual rotor angle by means of the rotor angle sensor

The rotor angle sensor measures the mechanical angular position of the rotor. In this way it is known how the rotor teeth and the stator teeth are positioned relative to each other. The rotor angle sensor thereby simultaneously determines the position of the rotor within the motor state.

b) Selection of the current setpoint value by means of the control and evaluation unit

The control and evaluation unit selects the current setpoint value for the closest rotor angle and setpoint torque from a value table in a data memory. The values of the four selected adjacent table points are calculated together with the real value, and the difference between the real value of the rated torque and the real value of the first actual rotor angle relative to the table points is determined. Examples of four derived points are highlighted by boxes in the numerical table.

The current nominal values are calculated from the respective current nominal values of the four table points by means of a bilinear interpolation method.

b)4 regulating the current rating by the current regulator

The current regulator regulates the calculated current ratings for each motor coil. Various current regulators known from the prior art with sufficiently fast switching times can be used. Preferably a digital current regulator.

b)5 applying current to the motor coil

The current regulator directs the current rating to the respective motor coil, thereby generating a magnetic flux and thus a force on the rotor.

b)6 estimating the actual torque by means of the torque estimator

The torque estimator determines an actual torque. The actual torque is preferably derived from available characteristic values, for example from the current actual value and the rotor angle.

b)7 deriving a torque deviation by means of the control and evaluation unit

By comparing the nominal torque and the actual torque, the control and evaluation unit determines a torque deviation.

b) Calculating a corrected current setpoint value by means of the control and evaluation unit on the basis of the torque deviation

As a result of the determined torque deviation, the magnitude of the current setpoint is not completely suitable for setting the predetermined setpoint torque. At the same time, a decision is made from the magnitude of the determined torque deviation, i.e. how far the changed current setpoint would be expected to bring the actual torque into conformity with the setpoint torque.

The calculation of the table points for all four last applications is performed according to the invention. The calculation is related to the applied interpolation interval (h, I) and the torque deviation (M)_soll-M_ist) The process is carried out. The calculation further includes a learning constant (K)_Lern)。

b)9, the calculated values of the corrected current setpoint value are entered into four associated value groups of the value table by means of the control and evaluation unit, and the previous values of the current setpoint value are deleted

The control and evaluation unit writes the resulting values for the corrected current setpoint value into the value tuples of the four table points.

c) Repeating the partial cycle until a motor angle is reached that corresponds to a complete motor state

The period of operation from one commutation of the motor to the next is called the motor state. In this case, the rotor passes through all angular positions from one commutation angular position until the next commutation. The angular position of the rotor at the end of a motor state is the same as the angular position at the beginning of the next motor state.

The partial cycle is repeated until the rotor of the reluctance motor reaches a rotation angle which corresponds to the exact same position relative to the rotation angle at the start of the next motor state. Depending on the number of arms of the rotor, the rotor always reaches exactly the same position for such motor states according to an angle of 360 ° divided by the number of motor states. The rotor is designed in a rotationally symmetrical manner.

When the rotor has three arms, the motor state ends every 120 °. Thereby achieving the overall cycle. The total cycle represents the entirety of all the partial cycles that are executed from the beginning of the motor state to the end of the motor state.

After reaching the first motor state, the partial cycle is also executed for the next motor state and repeated until the total cycle is reached again.

d) Repeating the total cycle

The method is repeated for all of the total cycles described below.

When the rotor has three arms, three motor states and thereby three total cycles are performed for a complete rotation of the rotor through 360 °. For each motor state, a partial cycle is always executed again until a total cycle is reached again.

In the example according to table 1, the first motor state ends after a rotor rotation of 60 °. For a complete rotor rotation of 360 °, six motor states and thus six total cycles are run.

This is repeated continuously in order to cause a permanent rotation of the rotor.

The method according to the invention has the following particular advantages.

The method learns itself iteratively. The table points are optimized with respect to the value of the current rating with each run of the partial cycle. As the method continues to execute, all of the table points are optimized. By repeated execution, the current setpoint value is always kept close to the optimum value, so that the torque deviation is adjusted progressively toward zero.

By defining an improved torque over time regulation, a very good quiet stable operation and noise reduction are achieved as advantages.

It is also advantageous that the method can be applied to different motors without adaptation or only with a low adaptation cost. It is only necessary that the value table be assigned first to the approximate values obtained, which only have to realize the operating capacity of the motor. By applying the method, the value of the current setpoint is automatically optimized in the adaptation to the respective motor as the partial cycle and the total cycle are executed.

It is also advantageous that the method provides for automatic balancing of manufacturing tolerances that may occur.

A further advantage is that the method provides automatic adaptation to changes that may first occur gradually as the motor operates, for example imbalances caused by bearing wear or uneven operation. The method adapts the current ratings to the respective physical characteristics of the motors.

According to an advantageous variant, a table of values for a complete revolution of the rotor is constructed.

When the value table is designed for a complete rotation of the rotor, i.e. for a rotation of 360 °, the table points are assigned reversibly to each physical position of the rotor teeth relative to the stator teeth. Even the slightest manufacturing differences on the individual rotor or stator teeth, or unbalance or wear phenomena on the rotor, can be compensated for by the method. Thereby, it is possible to additionally enhance the quiet and stable operation of the reluctance motor and to secure the quiet and stable operation even after a long-time operation.

Drawings

The invention is further illustrated by way of example by the following figures.

FIG. 1 shows a reluctance motor apparatus

FIG. 2 shows a schematic operating diagram of the process

FIG. 3 illustrates the torque performance of a reluctance motor in the present method

FIG. 4 illustrates calculation of numerical values, interpolation and correction

Detailed Description

Fig. 1 shows a schematic structure of the reluctance motor apparatus. The reluctance motor arrangement has a control and evaluation unit 2, a data memory 3, a current regulator 4, a rotor angle sensor 5, a torque estimator 6 and a switched reluctance motor 1. The current regulator 4, the rotor angle sensor 5 and the torque estimator 6 are connected to the switched reluctance motor 1 and the control and evaluation unit 2, respectively.

In this embodiment, the data memory 3 with the value table is integrated in the control and evaluation unit 2.

The switched reluctance motor 1 has a stator 7, a rotor 8, and a plurality of motor coils 9.

The current regulator regulates the current setpoint value for the motor coil to the value transmitted by the control and evaluation unit.

The rotor angle sensor 5 determines the position of the rotor 8 and transmits this position information to the control and evaluation unit 2 and the torque estimator 6. The torque estimator 6 derives the actual torque from characteristic values attached to the reluctance motor 1, in the present exemplary embodiment in particular from the actual current, in relation to a specific rotor angle, and transmits the actual torque likewise to the control and evaluation unit 2. The control and evaluation unit 2 calculates the torque deviation therefrom and, on the basis thereof, calculates the optimized current setpoint value, and, instead of the current setpoint value up to now, registers this current setpoint value in the value table of the data memory 3.

Fig. 2 shows a simplified diagram of a method for operating a switched reluctance motor with noise reduction. The diagram shows in general terms all the method steps from a) to d), wherein the method step b) is shown by means of all the partial steps. The partial loop (method step b)) is repeated until the end of the first motor state is reached, and repeated after the first motor state is reached until the end of the next motor state is reached (method step c)). The overall cycle is referred to herein.

The overall cycle is repeated for all motor states until a complete rotation of 360 ° of the rotor is reached (method step d)). If the complete rotor rotation is complete, the entire operating process can be repeated at will in order to bring about a permanent rotation.

The value table is continuously updated in method step b).

Fig. 3 shows a graphical overview of the torque performance of a reluctance motor in an application of the present method. At the beginning (t ═ 0 or to the left), the switched reluctance motor also exhibits high torque peaks, which are also referred to as torque ripples, which are produced by an unoptimized superposition of partial torques and in particular in the transition from one motor state to the next (lower left). Over a plurality of total cycles, the torque peaks are significantly reduced (lower right) and the partial torques are more advantageously superimposed. The torque peaks are the origin of rotor tooth oscillations and stator tooth oscillations and thereby serve as the origin of the larger operating noise of the reluctance motor. Reducing the torque peak thereby also reduces motor noise.

Fig. 4 shows the interpolation of the values in the coordinate system a) and the calculation in table b) for the correction of the current setpoint value.

The interpolation of the values according to method step b)3 in the coordinate system a) is graphically shown. The control and evaluation unit receives a predetermined setpoint torque and the rotor angle sensor provides an actual rotor angle (& lt, & gt & lt & gt)_ist). The control and evaluation unit derives the four closest table points (P)₁₁、P₁₂、P₂₁、P₂₂) And the current rating (I) is scaled by bilinear interpolation_soll) And (6) interpolating. The current nominal value (I) obtained by interpolation_soll) Is adjusted by the current regulator and conducted to the motor coil in method steps b)4 and b) 5.

In a method step b)6, the loaded actual torque (M) is evaluated by means of a torque evaluator_ist) And in method step b)7 the actual torque and the setpoint torque (M) are compared by a control and evaluation unit_soll) Settling torque bias (M)_soll-M_ist)。

FIG. 4 shows in table b) the interpolation intervals (h, I), the learning constants (K) by means of the application_Lern) And torque deviation (M)_soll-M_ist) For the correction value with the torque deviation (according to method step b) 8).

Reference numerals

1 switched reluctance motor

2 control and analysis unit

3 data memory

4 current regulator

5 rotor angle sensor

6 torque estimator

7 stator

8 rotor

9 motor coil.