DE102020205027A1 - Control device for controlling an electrical machine, sensor arrangement for determining a rotor position of an electrical machine - Google Patents

Abstract

The invention relates to a control device (40) for controlling an electrical machine (10) which has a rotor shaft (22) rotatably mounted in a housing (12) of the electrical machine (10). The control device (40) comprises a printed circuit board (42) for carrying an electronic circuit for controlling the electrical machine (10). The invention also relates to a sensor arrangement (50) for determining a rotor position of an electrical machine (10). The invention also relates to an electrical machine (10) which is provided with the control device (40) according to the invention and / or which comprises a sensor arrangement (50) according to the invention. The invention further relates to a vehicle which comprises at least one electrical machine (10) according to the invention.

Description

The invention relates to a control device for controlling an electrical machine, which has a rotor shaft rotatably mounted in a housing of the electrical machine. The control device comprises a printed circuit board for carrying an electronic circuit for controlling the electrical machine.

The invention also relates to a sensor arrangement for determining a rotor position of an electrical machine.

The invention also relates to an electrical machine which is provided with the control device according to the invention and / or which comprises a sensor arrangement according to the invention.

The invention further relates to a vehicle which comprises at least one electrical machine according to the invention.

State of the art

Control devices of the type mentioned are known from the prior art. Electric vehicles and hybrid vehicles with an electric drive device often use an asynchronous machine or a synchronous machine as an electric motor, which can also be operated as a generator, both of which have a stationary or housing-fixed stator and a rotor rotatably mounted relative to the stator. As a rule, the stator carries three or more staggered winding strands of a drive winding, the drive strands being offset from one another by 120 ° / p, where p represents the number of pole pairs.

The asynchronous machine (ASM), for example, has a rotor which is made from electrically conductive rods which are short-circuited in a ring at the ends. If the magnetic rotor field rotates, a voltage is induced in it, which causes a current flow, which in turn builds up an opposing magnetic field, causing the rotor to rotate. Because the induced voltage becomes zero when the rotor field and stator rotate at the same speed, a differential speed occurs, which is referred to as slip and has a direct effect on the torque generated by the electric motor.

In the synchronous machine, the rotor usually consists of a rotor that carries an excitation coil in which a direct current flows, which generates a static magnetic field. Alternatively, a permanent magnet can also be used in the rotor to generate the static magnetic field. Then it is a so-called permanently excited synchronous machine (PSM), which has a higher efficiency due to the powerless excitation and is therefore very well suited for traction applications in motor vehicles. In this case, the speed of the rotor is basically identical to the speed of the exciter field, while the torque generated depends on the phase offset, i.e. the angular difference between the stator field and the rotor field.

For control, the speed of the rotor must be known in the case of the asynchronous machine and the absolute angular position of the rotor in the case of the permanently excited synchronous machine. Depending on the speed or angular position, an inverter of power electronics of the respective electric machine can be controlled in order to achieve the desired torque.

In order to determine these variables, it is known to use what is known as a resolver, which, however, requires a relatively large amount of installation space and requires complex signal preparation and processing as well as a complex structure of the resolver with wound coils. It is also known to provide speed sensors that are implemented, for example, based on one or more Hall elements that evaluate the magnetic field of the signal generator. Known operating principles of these sensors are magnetoresistive (AMR, GMR, TMR) or are based on the Hall effect. It is also known to provide inductive angle sensors based on decoupled coils or sensor devices which are based on the eddy current effect.

The sensor device built according to the current state of the art usually consists of a sensor transmitter and a sensor. The sensor is built discreetly, has its own housing, its own fastening elements and its own cable harness including connector. This is connected to an internal or external control unit or evaluation electronics.

The document DE 10 2018 200 522 A1 describes a power steering device for supporting a steering process of a motor vehicle. The power steering device comprises a rotation measuring device which can detect a rotor position and / or a steering angle.

From the document DE 10 2017 210 655 A1 a rotation angle sensor is known which comprises a stator element and a rotor element rotatably mounted about an axis of rotation.

The document DE 10 2018 213 413 A1 relates to an inductive position sensor for detecting at least one rotational property of an element rotating about at least one axis of rotation.

The document DE 10 2015 218 141 A1 discloses an apparatus for calibrating an electronically commutated electrical machine.

From the document DE 10 2013 112 169 A1 a drive for a steering system of a vehicle is known.

Disclosure of the invention

A control device for controlling an electrical machine is proposed, the electrical machine having a rotor shaft rotatably mounted in a housing of the electrical machine.

The electrical machine can be designed to be standard and designed as an asynchronous machine or synchronous machine.

The control device comprises a printed circuit board (PCB) for carrying an electronic circuit for controlling the electrical machine.

A circuit board can be understood to mean a device on which at least one electrical component can be arranged. The circuit board can be designed to be flexible. In particular, the circuit board can comprise a flexible material. The circuit board can be designed as a rigid-flex circuit board, for example as a bent rigid-flex circuit board. The circuit board can also be designed as a rigid circuit board, in particular a rigid circuit board with notches.

According to the invention, a position sensor for determining a rotor position of the electrical machine is arranged on the circuit board.

The position sensor is preferably designed as an inductive sensor that replaces the common resolver sensor technology with an inductive measuring principle. The position sensor has at least one coil arrangement which comprises at least one excitation coil and at least one receiver coil. The at least one excitation coil and the at least one receiver coil are designed as conductor tracks on the circuit board.

In the context of the present invention, a coil arrangement can in principle be understood to mean any device that comprises at least one coil. In the context of the present invention, a coil is generally understood to mean any component that has an inductance and is suitable for generating a magnetic field when a current flows, and / or vice versa. For example, a coil can comprise at least one completely or partially closed conductor loop or turn. In the context of the present invention, an excitation coil can in principle be understood to mean a coil which generates a magnetic flux when an electrical voltage and / or an electrical current is applied. The excitation coil can have at least one excitation winding. In the context of the present invention, a receiver coil is basically understood to be a coil which is set up to generate a signal based on an inductive coupling between the excitation coil and the receiver coil, which signal is dependent on the inductive coupling. For example, the coil arrangement can have a receiver coil system. In the context of the present invention, a receiver coil system can in principle be understood to mean any device which comprises at least two receiver coils.

The position sensor can be set up to detect an inductive coupling and / or a change in an inductive coupling between the at least one excitation coil and the at least one receiver coil. The excitation coil can be set up to generate an alternating electromagnetic field in response to the application of the excitation signal. The excitation coil and the receiver coils can be coupled in such a way that the electromagnetic alternating field induces an alternating voltage in the receiver coils. The receiver coils can be arranged in such a way that the receiver coils generate signals which are dependent on the angle of rotation when the rotor shaft rotates at a constant angular speed about the axis of rotation.

In the context of the present invention, an “excitation signal” can be understood to mean an electrical signal, in particular at least one alternating voltage and / or at least one alternating current. The excitation signal can be an essentially sinusoidal excitation signal. In the context of the present invention, “sinusoidal” is basically understood to mean any shape that has a course of a sinusoid. For example, a course of a complete sinusoid can be included or only part of a sinusoid. “Essentially sinusoidal” can be understood to mean embodiments with a completely sinusoidal profile, deviations being conceivable which are not more than 20%, in particular not more than 10% or even not more than 5% of the absolute value of the sinusoidal shape. A “complete sine curve” can be understood to mean, in particular, a course of a sine curve which comprises at least one period. The sine curve can be at the zero point or any other point of the Start the sine curve. The sinusoidal shape can, for example, also be composed of other functions in sections, so that overall an approximately sinusoidal shape results. The excitation signal can have an amplitude in the range from 0.1 V to 10 V, preferably 5 V. The excitation signal can have a frequency in the range from 1 MHz to 10 MHz, preferably 3.5 MHz. By applying the excitation signal to the excitation coil, an alternating electromagnetic field can arise which couples into the receiver coils and induces corresponding alternating voltages and / or alternating currents there, for example.

The at least one excitation coil can be configured to be essentially circular. In the context of the present invention, the term “essentially circular” is generally understood to mean that the component described has a radius of curvature. The radius of curvature can vary or be constant within the component.

The at least one excitation coil and the at least one receiver coil can, as in FIG DE 10 2017 210 655 A1 be designed as described.

The position sensor preferably has at least one evaluation electronics for evaluating signals from the at least one receiver coil. The at least one evaluation electronics are set up to infer an angular position of the rotor shaft from the signals of the at least one receiver coil.

The at least one evaluation electronics can be set up to provide an excitation signal for the at least one excitation coil. “To provide an excitation signal” can be understood to mean that the evaluation electronics are set up to generate the excitation signal and / or that the evaluation electronics are set up to apply the excitation signal to the excitation coil.

The at least one evaluation electronics can be set up to process signals generated by the at least one receiver coil. “Processing” can basically be understood to mean any operation of signal processing in order to generate an output signal, for example evaluation, filtering, demodulation. The signal processing can be digital and / or analog. The signal processing can preferably take place in a purely analog manner. The evaluation electronics can in particular be set up to infer an amount and a phase of the coupling by demodulating a signal induced in the receiver coils with a carrier signal, that is to say a signal from the excitation coil, also known as the transmission coil. The amount can in particular vary continuously with the angle of rotation. A phase position can be 0 ° or 180 °, for example. The at least one evaluation electronics can have at least one demodulation device which is set up to demodulate the signals from the receiver coils. The demodulation can include a multiplication by the excitation signal. For example, by multiplying the amount by a cosine function, a preferably offset-free Sin / Cos system can arise, in particular when using two receiver coils with a 90 ° phase offset in relation to the measuring range. When using three receiver coils with a typically 120 ° phase offset in relation to the measuring range, a three-phase sinusoidal signal can arise, which can be converted into a sin / cos system, for example by using the Clarke transformation. The angle of rotation can then be deduced with the help of the arctangent function. The at least one evaluation electronics can have at least one low-pass filter. For example, the at least one evaluation electronics can first demodulate the signals from the at least one receiver coil and then filter them using the low-pass filter.

The at least one evaluation electronics is preferably designed as an application-specific integrated circuit (ASIC). An application-specific integrated circuit can in principle be understood to mean any electronic circuit that has been implemented as an integrated circuit.

For processing and / or evaluating the signals generated by the at least one receiver coil and / or providing excitation signals for the at least one excitation coil, the at least one electronic evaluation system is electrically connected to the at least one coil arrangement or the at least one receiver and / or excitation coil. The electrical connection between the at least one evaluation electronics and the at least one coil arrangement can be made by means of a sensor line. The sensor line can comprise contact elements such as cables and / or plugs. The sensor line is preferably designed as a conductor track on the circuit board of the control device.

The at least one electronic evaluation system is preferably arranged on the printed circuit board of the control device and is preferably designed as a surface-mounted component (SMD).

There is also a sensor arrangement for determining a rotor position of an electrical Machine proposed, the electrical machine having a rotor shaft rotatably mounted in a housing of the electrical machine.

The sensor arrangement comprises a control device according to the invention for controlling the electrical machine, which can be arranged fixed to the housing on the housing of the electrical machine.

The circuit board of the control device can be arranged essentially coaxially to an axis of rotation of the rotor shaft. The circuit board can be designed essentially circular. With regard to the term “essentially circular”, reference is made to the definition above. As an alternative or in addition, the circuit board can also be composed of two or more segments which, for example, can each be flat or also curved and which can be connected to one another, for example. The segments can then also be arranged overall coaxially to the axis of rotation of the rotor shaft, even if the individual segments are then arranged, for example, tangentially. Furthermore, the circuit board can be arranged in a housing, in particular in an injection-molded housing.

The sensor arrangement further comprises a sensor transducer which can be connected to the rotor shaft in a rotationally fixed manner and can be arranged axially on the end face of the rotor shaft. The circuit board is arranged with the at least one coil arrangement of the position sensor above the sensor transmitter.

In the context of the present invention, a sensor transmitter can in principle be understood to mean any component that can be connected to the rotor shaft and is set up to cause at least one measurable signal, in particular a change in the magnetic field, per revolution of the rotor shaft when connected to the rotor shaft.

The sensor transmitter can, for example, be permanently or reversibly connected or connectable to the rotor shaft, or can also be embodied in one piece with the rotor shaft or integrated into the rotor shaft.

The sensor transmitter can have a sensor transmitter profile. In the context of the present invention, a sensor head profile can in principle be understood to mean an entirety of profile elements and spaces that are arranged between the profile elements. In the context of the present invention, a profile element of the sensor transmitter can in principle be understood to mean any shape of the contour of the sensor transmitter, in particular a bulge, for example a pin-shaped, tooth-shaped or jagged bulge, or a notch or a recess, for example a hole.

The sensor transmitter can advantageously be designed as a slot. This can be done in that the rotor shaft is slotted on one end face.

It is also conceivable that the sensor transmitter comprises extra components that can be arranged on the rotor shaft. For example, the sensor transmitter can be designed as a magnet.

The sensor transmitter can advantageously also be designed as a gear. A sensor transducer designed as a magnet or a gear wheel can be arranged on the front side of the rotor shaft.

As in DE 10 2017 210 655 A1 or DE 10 2018 213 413 A1 be designed as described.

The sensor arrangement can in particular be set up to determine an absolute or relative angular position of the rotor shaft from the change in the inductive coupling between the excitation coil and the receiver coil caused by the movement and / or a position of the sensor transmitter. A relative angular position can in principle be understood to mean a position with respect to a period defined by the receiver coils.

Furthermore, an electrical machine is proposed which is provided with a control device according to the invention and / or which comprises a sensor arrangement according to the invention.

Furthermore, a vehicle is proposed which comprises at least one electrical machine according to the invention.

Advantages of the invention

When used as a standalone sensor, it has its own housing. A separate wiring harness is also required for a control unit or evaluation electronics. It is attached using common joining technology. All these features lead to significant costs compared to the actual core sensor elements - the coil arrangement and possibly the evaluation electronics.

However, testing the insulation of the sensor line with respect to the operating voltage of the electrical machine is also costly.

With the control device according to the invention or the sensor arrangement according to the invention the coil arrangement can be represented on the circuit board of the control unit without additional effort, ie the excitation coil and the receiver coil are designed as conductor tracks. Therefore, only the surface of the printed circuit board is used, but no further process steps are required.

The evaluation electronics can be designed as an application-specific integrated circuit and are included in the control unit manufacture. There are no additional process steps.

With the control device according to the invention or the sensor arrangement according to the invention, external cabling, such as a cable harness and connector, can be dispensed with, since the sensor line can only take place on the circuit board.

Due to the omission of the cabling, the insulation test of the sensor cables or the implementation as part of the insulation test of the control unit is completely omitted.

This reduces the costs for the core sensor elements, namely the coil arrangement and the evaluation electronics.

Today's standalone position sensors require installation space. As a result of their design, they have their own housing and fastening points, such as screws, rivets, clamps, etc. This leads to restrictions in possible applications, particularly in the longitudinal direction of the electrical machine.

With the control device according to the invention or the sensor arrangement according to the invention, the installation space, in particular in the longitudinal direction of the electrical machine, is less noticeable.

With the standalone sensors according to the state of the art, additional connections, usually plug connectors, are necessary in the signal path. These represent an additional contact resistance and a source of error.

With the control device according to the invention or the sensor arrangement according to the invention, the sensor line can only take place on the circuit board. This also eliminates the source of error.

Figure list

Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

• 1 eine schematische Darstellung einer erfindungsgemäßen Sensoranordnung,
• 2 eine perspektivische Darstellung der erfindungsgemäßen Sensoranordnung
• 3a eine perspektivische Darstellung eines Sensorgebers der erfindungsgemäßen Sensoranordnung gemäß einer ersten Ausführungsform und
• 3b eine perspektivische Darstellung eines Sensorgebers der erfindungsgemäßen Sensoranordnung gemäß einer zweiten Ausführungsform.

Show it:

• 1 a schematic representation of a sensor arrangement according to the invention,
• 2 a perspective view of the sensor arrangement according to the invention
• 3a a perspective view of a sensor transmitter of the sensor arrangement according to the invention according to a first embodiment and
• 3b a perspective view of a sensor transmitter of the sensor arrangement according to the invention according to a second embodiment.

Embodiments of the invention

In the following description of the embodiments of the invention, the same or similar elements are denoted by the same reference numerals, a repeated description of these elements in individual cases being dispensed with. The figures represent the subject matter of the invention only schematically.

1 shows a schematic representation of a sensor arrangement according to the invention 50 for determining a rotor position of an electrical machine 10 .

The electric machine 10 is commonly implemented and in the present case designed as a permanently excited synchronous machine. The electric machine 10 includes a rotor 20th , which has several permanent magnets, not shown here, and a stator 30th , on which several stator windings, not shown here, are arranged.

The rotor 20th is on one in one case 12th of the electric machine 10 rotatably mounted rotor shaft 22nd arranged and rotates around an axis of rotation 24 hereabouts. The case 12th has an end shield 14th on that a warehouse 16 for bearing the rotor shaft 22nd records.

The sensor arrangement 50 comprises a control device according to the invention 40 to control the electrical machine 10 , fixed to the housing on the housing 12th or on the end shield 14th of the electric machine 10 is arranged.

The control unit 40 includes a circuit board 42 for carrying an electronic circuit, not shown here, for controlling the electrical machine 10 serves.

The circuit board 42 of the control unit 40 is in the present case essentially coaxial with the axis of rotation 24 the rotor shaft 22nd arranged. The circuit board 42 can be configured essentially circular. Alternatively or additionally, the Circuit board 42 can also be composed of two or more segments, which for example can each be designed flat or also curved and which can be connected to one another, for example. The segments can then also be coaxial to the axis of rotation overall 24 the rotor shaft 22nd be arranged, even if the individual segments are then arranged, for example, tangentially. Furthermore, the circuit board 42 in one housing 12th , in particular arranged in an injection molded housing.

On the circuit board 42 is a position sensor 70 arranged. The present is the position sensor 70 designed as an inductive sensor and comprises a coil arrangement 72 , which has at least one excitation coil (not shown here) and at least one receiver coil (not shown here). The at least one excitation coil and the at least one receiver coil are in this case as conductor tracks on the printed circuit board 42 of the control unit 40 educated

The sensor arrangement 50 also has evaluation electronics 74 for evaluating signals from the at least one receiver coil. The evaluation electronics 74 is in the present case designed as a surface-mounted component and also on the circuit board 42 of the control unit 40 arranged.

The evaluation electronics 74 is doing with the coil arrangement 72 electrically connected. The electrical connection between the evaluation electronics 74 and the coil assembly 72 takes place by means of a sensor cable 76 that act as the conductor track of the circuit board 42 of the control unit 40 is trained.

The sensor arrangement 50 also includes a sensor transmitter 60 , which rotates with the rotor shaft 22nd is connected and axially on the end face of the rotor shaft 22nd is arranged. The circuit board 42 is doing with the coil arrangement 72 above the sensor transmitter 60 arranged.

The sensor transmitter 60 can be used as a slot 62 (please refer 3a) be trained. This can be done by having the rotor shaft 22nd on one end face 26th (please refer 3a) is slotted.

The sensor transmitter 60 but can also be used as a gear 64 (please refer 3b) educated.

It is also conceivable that the sensor transmitter 60 be designed as a magnet.

The sensor transmitter 60 can for example be permanent or reversible with the rotor shaft 22nd be connected or connectable or can also be made in one piece with the rotor shaft 22nd formed or in the rotor shaft 22nd be integrated.

2 shows a perspective view of the sensor arrangement according to the invention 50 .

The rotor 20th is on the in the case 12th (see. 1 ) of the electrical machine 10 (see. 1 ) rotatably mounted rotor shaft 22nd arranged.

The sensor arrangement 50 includes an inventive control device 40 to control the electrical machine 10 , fixed to the housing on the housing 12th of the electric machine 10 is arranged.

The control unit 40 includes a circuit board 42 for carrying an electronic circuit, not shown here, for controlling the electrical machine 10 serves.

On the circuit board 42 is a position sensor 70 arranged. The present is the position sensor 70 designed as an inductive sensor and comprises a coil arrangement 72 , which has at least one excitation coil, not shown here, and at least one receiver coil, not shown here. The at least one excitation coil and the at least one receiver coil are in this case as conductor tracks on the printed circuit board 42 of the control unit 40 educated

The sensor arrangement 50 also has evaluation electronics 74 for evaluating signals from the at least one receiver coil. The evaluation electronics 74 is in the present case designed as a surface-mounted component and also on the circuit board 42 of the control unit 40 arranged.

The evaluation electronics 74 is doing with the coil arrangement 72 electrically connected. The electrical connection between the evaluation electronics 74 and the coil assembly 72 takes place by means of a sensor cable 76 that act as the conductor track of the circuit board 42 of the control unit 40 is trained.

The sensor arrangement 50 also includes a sensor transmitter 60 , which rotates with the rotor shaft 22nd is connected and axially on the end face of the rotor shaft 22nd is arranged. The circuit board 42 is doing with the coil arrangement 72 above the sensor transmitter 60 arranged.

The sensor arrangement 50 can, in addition to the in 1 and 2 elements shown, further comprise one or more additional elements, for example one or more further functional elements not shown in the figures, such as electrodes, electrode leads, contacts or other elements.

3a and 3b each show a perspective view of a sensor transmitter 60 of the sensor system according to the invention.

According to a first embodiment, which is shown in 3a shown is the sensor transducer 60 than a slot 62 educated. This is done in that the rotor shaft 22nd on one end face 26th is slotted.

According to a second embodiment, which is shown in 3b shown is the sensor transducer 60 as a gear 64 educated. The one as a gear 64 trained sensor sensors 60 can be permanent or reversible with the rotor shaft 22nd be connected or can also be made in one piece with the rotor shaft 22nd formed or in the rotor shaft 22nd be integrated.

The invention is not restricted to the exemplary embodiments described here and the aspects emphasized therein. Rather, a large number of modifications are possible within the range specified by the claims, which are within the scope of expert action.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102018200522 A1 [0011]
• DE 102017210655 A1 [0012, 0026, 0043]
• DE 102018213413 A1 [0013, 0043]
• DE 102015218141 A1 [0014]
• DE 102013112169 A1 [0015]

Claims (10)

Control device (40) for controlling an electrical machine (10) which has a rotor shaft (22) rotatably mounted in a housing (12) of the electrical machine (10), comprising a printed circuit board (42) for carrying an electronic circuit for controlling the electrical Machine (10), characterized in that a position sensor (70) for determining a rotor position of the electrical machine (10) is arranged on the printed circuit board (42). Control unit (40) Claim 1 , characterized in that the position sensor (70) is designed as an inductive sensor and has at least one coil arrangement (72), the at least one coil arrangement (72) comprising at least one excitation coil and at least one receiver coil. Control unit (40) Claim 2 , characterized in that the position sensor (70) has at least one evaluation electronics (74) for evaluating signals from the at least one receiver coil. Control unit (40) Claim 3 , characterized in that the evaluation electronics (74) are arranged on the circuit board (42). Control unit (40) Claim 3 or 4th , characterized in that the evaluation electronics (74) is designed as a surface-mounted component. Sensor arrangement (50) for determining a rotor position of an electrical machine (10), which has a rotor shaft (22) rotatably mounted in a housing (12) of the electrical machine (10), comprising a rotor shaft (22) which can be connected to the rotor shaft (22) in a rotationally fixed manner and is axially frontal on the rotor shaft (22) can be arranged sensor transducer (60) and a housing-fixed on the housing (12) of the electrical machine (10) can be arranged control device (40) for controlling the electrical machine (10) according to one of the Claims 1 until 5 wherein the circuit board (42) with the at least one coil arrangement (72) is arranged above the sensor transducer (60). Sensor arrangement (50) according to Claim 6 , characterized in that the sensor transmitter (60) is designed as a slot (62). Sensor arrangement (50) according to Claim 6 , characterized in that the sensor transmitter (60) is designed as a gear (64) or a magnet. Electrical machine (10) with a control device (40) according to one of the Claims 1 until 5 is provided and / or a sensor arrangement (50) according to one of the Claims 6 until 8th includes. Vehicle that has at least one electrical machine (10) according to Claim 9 includes.

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