EP2820755A2

EP2820755A2 - Selection unit for selecting the configuration of an electric motor, transport machine and associated method

Info

Publication number: EP2820755A2
Application number: EP13712237.0A
Authority: EP
Inventors: Gunter Freitag; Karl-Josef Kuhn
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2012-05-07
Filing date: 2013-03-25
Publication date: 2015-01-07
Also published as: WO2013167309A3; DE102012207534A1; WO2013167309A2

Abstract

The invention relates to a selection unit (60, 280) for selecting the configuration (K1 to K3) of an electric motor (10, 54, 250), comprising: an input unit (EE), which can receive at least one signal (295) or data, which indicates a driving state (B1 to B4) of a transport machine (240) or a rotational speed (n) of an electric motor (10, 54, 250); a determination unit, which determines a configuration of the electric motor (10, 54, 250) depending on the signal (295) or data received by means of the input unit (MP); an output unit (AE2), which outputs at least one signal (298) or data, which designates or specifies the selected configuration (K1 to K3).

Description

description

Selection unit for selecting the configuration of an electric motor, transport machine and associated method

The invention relates to a selection unit for selecting the configuration of an electric motor. In particular, the electric motor can be used in a transport machine as a drive motor.

Electric motors are increasingly used in cars, commercial vehicles but also in motorcycles and bicycles. Frequently, a fixed configuration of the electric motor is predetermined, to which the vehicle and the control unit or a possibly used control unit are tuned. But also ships and airplanes are equipped with electric motors as propulsion to water or in the air.

The invention relates to a selection unit for selecting the configuration of an electric motor, comprising:

an input unit that can receive a signal or data indicating a driving state of a haulage machine or a rotational speed of an electric motor,

a determination unit which determines a configuration of the electric motor as a function of the signal or data received with the input unit, and

an output unit that outputs at least one signal or data that designates or dictates the selected configuration.

Furthermore, the invention relates to a transport machine with such a selection unit.

The invention also relates to a method for selecting a configuration on an electric motor, comprising:

Detecting a first driving state or a first rotational speed, Selecting a first configuration of an electric motor depending on the detected first driving state,

- detecting a second driving state or a second rotational speed, and

Selecting a second configuration of an electric motor depending on the sensed second driving condition, wherein the second configuration is different from the first configuration. It is an object of the embodiments to provide a selection unit that allows a reconfiguration of an electric motor and in particular ensures the further use of the electric motor even with errors in the electric motor. In addition, a transport machine with such a selection unit and an associated method should be specified.

This object is achieved by a selection unit according to claim 1 and by a transport machine and a method according to the independent claims. Further developments are specified in the subclaims.

One embodiment relates to a selection unit for selecting the configuration of an electric motor, comprising:

an input unit that can receive at least one signal or data that indicates a driving state of a haulage machine or a rotational speed of an electric motor,

a determination unit which preferably automatically determines a configuration of the electric motor depending on the signal or data received with the input unit, and an output unit which outputs a signal or data designating or defining the selected configuration.

A driving condition can be, for example, starting up. Another driving state may be, for example, driving at medium speeds, for example in the range of 30 km / h (kilometers per hour) to 50 km / h. A third driving condition may be driving at high speeds. But there are others too Driving conditions are used, which are less speed related. So also errors in the electric motor or its control can mark a certain driving condition. Instead of or in addition to the driving conditions, the rotational speed of the electric motor can also be used.

The determination unit contains, for example, a processor or a microprocessor. Alternatively, the detection unit may include an electronic circuit without a microprocessor. Depending on the current driving state and / or the rotational speed, the determining unit selects a favorable configuration, in particular according to a predetermined method or according to predetermined criteria, e.g. high efficiency of the electric motor in the relevant driving condition, safe engine operation when an error occurs in the electric motor or in the control or regulation of the electric motor. The selection can be made according to comparatively simple specifications. But you can also use more complex selection strategies.

The configuration can then be e.g. can be set directly via the output unit or another configuration unit is used, which reconfigures the electric motor. Thus, the configuration can be done software-technically via the on-control signals of the half-bridges or full bridges. Alternatively, a switch matrix may allow the setting of all theoretically possible configurations. However, switching elements can also be used with which the practically relevant configurations can be set.

The reconfiguration can be done by changing the number of windings used for the operation of the electric motor. Even with a constant number of windings, the wiring of the windings can be changed, for example, by a change between star point circuit and polygonal circuit. Also, various types of polygonal circuit can be used. By means of the selection unit, it is possible to determine various configurations of the electric motor based on efficiency specifications for the electric motor, for example for different speeds of rotation relative to torque values. From these configurations, the configuration belonging to a particular driving state is then selected by the selection unit. If, for example, a configuration with high efficiency of the electric motor is always selected, the range of electric vehicles can be determined on the basis of the efficient

Enlarge energy input significantly. In case of faults, configurations can be selected to ensure the most reliable backup operation of the electric motor. The selection unit thus opens up new applications and new modes of operation for the electric motor.

The determination unit may determine a configuration with a high efficiency of the electric motor at a driving state or at a rotational speed. The efficiency can be defined as the ratio of the absorbed electrical power to the delivered mechanical power.

For example, not all windings or phases of a three-phase machine are used in a lower speed range of the electric motor, in order to enable high efficiency here as well. At high speeds then more windings or all windings are used, since then results in addition to the larger power and high efficiency. The efficiency of the electric motor is crucial for the energy consumption and thus for the range of an electric car or electric vehicle.

The efficiency can be increased by selecting a suitable number of windings or windings to use. The number of current-wound windings may change during a first configuration of the number of current-carrying windings differ in a second configuration. Both configurations may relate to a faultless operation of the electric motor.

The number of electrical phases used for driving can remain the same for different number of turns. Alternatively, however, the number of electrical phases used for driving can also differ with different numbers of windings. Thus, more arise

Degrees of freedom for changing the efficiency of the electric motor.

Alternatively, the efficiency can be changed by selecting a suitable for the driving condition or speed number of electrical phases used for driving, for example. Half bridges or full bridges. The number of phases used may differ in a first configuration from the number of phases used in a second configuration, preferably with the same number of windings used. In error-free operation, preferably all existing windings are used.

Changing the number of phases is a simple but effective measure for changing the efficiency of a

The electric motor. This measure can also be done easily by means of microprocessor or microcontroller. Other degrees of freedom for varying the efficiency result in combination with other measures, e.g. Change from star connection to delta connection or to polygonal circuits, whereby in multi-way circuits also different numbers of voltages can be used (English: "Span").

However, in another embodiment, the determination unit can also switch between error-free operation of the

Electric motor and a fault operation differ. In error-free operation, efficiency efficiency can be decisive for the selection of the configuration. In error mode, however, safety can be decisive, for example the safety of a transport machine containing the selection unit. The determination unit can not use a winding containing an error in error operation by selecting a configuration without this winding.

The determination of the cause of the error can take place automatically, for example by detecting winding parameters, e.g. Winding resistance, or otherwise, e.g. from a motor model that is simultaneously simulated. The error may also be due to a drive of the electric motor, e.g. in a converter. In this case, the detection unit selects a configuration that does not use the half bridge or full bridge of the drive affected by the fault.

In error mode, the determination unit can select a configuration that allows it to counter or control a moment caused by the error. Thus, for example, a pendulum moment or a blocking moment can be counteracted. The electric motor is thus divided into two sub-machines, in which case one sub-machine is faulty and the other sub-machine counteracts the fault and realizes an auxiliary drive. The auxiliary drive can also be realized by a third sub-machine of the electric motor to separate the error compensation of the function as an auxiliary drive.

Another embodiment relates to a transport machine comprising a selection unit according to one of the preceding claims. Thus, the technical effects mentioned for the selection unit also apply to the transport machine. The transport machine is, for example, a fully electric car. Alternatively, the transport machine is a car with hybrid drive, ie there is an electric drive and a further drive, such as an internal combustion engine. With electric cars the range is a decisive acceptance criterion. The range can be increased by increasing the efficient use of the motor by turning windings on or off based on choices of the selection unit.

The transport machine may include an electronic drive unit for controlling the windings of the electric motor in accordance with control signals. The electronic switches in the control unit may be field effect transistors (FETs), such as MOSFETs (Metal Oxide FET). But also IGBT (Isolated Gate Bipolar Transistor) or Thyristor (GTO) can be used, depending on the required switching capacity. The switching elements may form in the drive unit a half-bridge circuit for the connection of a winding terminal or a full-bridge circuit for the connection of the two terminals of a winding. The mentioned switching elements are also suitable for the configuration. Thus, a configuration can already be made via the half-bridges or the full-bridges by, for example, certain bridge circuits not being used or in which specific bridge circuits are driven with the same control signal. A configuration can be maintained for more than one second, more than 10 seconds or even more than one minute.

The transport machine may include a control unit for generating the control signals of the drive unit according to at least one control method. The regulation can be, for example, a field-oriented regulation. Field-oriented controls are based on a rotation vector (Vector Control) that rotates with the rotor angular velocity. In rotating field machines, the rotor coordinates can be used more easily for a control because the rotating field in rotor coordinates rests relative to the rotating field of the stator (synchronous machine) or has only a small speed relative to the rotating field of the stator (Asyn- chron machine). The transformation into rotor coordinates for control and the inverse transformation into the stator coordinates for generating the control signals for the drive unit can be performed by powerful processors, in particular by microprocessors or by special signal processors.

The control can also be based on a motor model of the electric motor. In addition, controller elements can be used, such as PI (Proportional Integral) or PID (Proportional, Integral, Differential) controllers.

But regulations other than field-oriented regulations or controls can also be used.

The transport machine may include a configuration unit coupled to the output unit that sets the designated or defined configuration. The configuration unit may thus contain the drive unit or else additional electronic switches, e.g. Transistors, or electromechanical switches, such as relays.

Switches can also be used which switch between the configurations used, e.g. between two configurations, three configurations or more than three configurations. Alternatively, a switch matrix may be used that allows a variety of configurations.

In a star configuration, one connection of each winding is routed to a common neutral point. In a polygonal configuration, ie without neutral point, one winding connection of one winding is always connected in succession to a winding connection of another winding in series connection. In this context, three windings speak of a triangle and more than three windings of a polygon. Spatially adjacent windings can be connected directly, or, for example, a Wiek- or two or more winding terminals of other windings lying between the connected windings are skipped. Here also the term span or English "span" is used.

The configuration unit may also include the control unit, so that depending on the configuration and the relevant engine models are included in the scheme. In particular, the type of control or control can be configured.

The transport machine may include at least one wheel hub motor, for example two wheel hub motors on one axle of a vehicle or four wheel hub motors on the two axles. By selecting unit can be in case of error, the

Adjust driving characteristics or rolling properties of a freely rotating wheel. In particular, blocking can be avoided and fault moments can be counteracted, e.g. Pendulum moments.

These technical effects are particularly relevant if there is no clutch and no mechanical brake, as is the case with many wheel hub engine concepts. A legal approval for a vehicle without a mechanical brake can, for example, depend decisively on the use of the selection unit.

The wheel hub motor may, for example, contain a tooth coil winding. The wheel hub motor can be realized as an external rotor or as an inner rotor.

But other electric motors are used, for example. Central electric motor for an axle or even for a vehicle.

The electric motor may, for example, 4 or more than 4 windings or grooves, 9 or more than 9 windings or grooves, 12 or more as 12 turns or even more than 24 turns. The number of windings or grooves can be less than 100. In addition, a method for selecting a configuration on an electric motor is disclosed, comprising:

Detecting a first driving state or a first rotational speed,

Selection of a first configuration of an electric motor as a function of the detected first driving state,

Detecting a second driving state or a second rotational speed,

Selecting a second configuration of an electric motor depending on the sensed second driving condition, wherein the second configuration is different from the first configuration.

Thus, for the process, the technical effects mentioned above for the selection unit apply.

The second configuration may differ from the first configuration in terms of the number of windings involved. The windings are divided into distributed windings, which occupy more than two slots, and concentrated windings, which occupy only two slots. A winding may contain several turns, eg more than 10 turns, more than 100 turns but eg less than 10,000 turns. The windings can also be referred to as coils. In connection with the selection unit, each winding has a winding connection or else two winding connections which, depending on the selection made, are connected with half bridges or full bridges of respectively two or four switching elements. In some configurations, the winding terminals of two or more than two windings may also be connected to the center node of the full and half bridges. In other configurations, however, then these winding connections are again separated from each other. The electric motor can be faultless in both configurations. The configurations can then be selected, for example, in terms of efficiency.

Alternatively, in the method as well, the efficiency can be changed by selecting a suitable number of electrical phases used for the driving state or the rotational speed. The number of phases used may differ in a first configuration from the number of phases used in a second configuration, preferably with the same number of windings used. In error-free operation, preferably all existing windings are used.

Changing the number of phases is again a simple but effective measure for changing the efficiency of an electric motor. This measure can also be carried out simply by means of a microprocessor or microcontroller. Further degrees of freedom for changing the efficiency result in combination with other measures, e.g. Change from star connection to delta connection or to polygonal circuits, whereby in multi-way circuits also different numbers of voltages can be used (English: "Span").

The configurations can be selected such that, depending on the driving condition, the greatest possible efficiency of the operation of the electric motor results. This increases the efficiency and thus the range of, for example, electric vehicles.

However, the electric motor may also contain an error when using the first configuration and / or when using the second configuration. However, the configuration used can itself be error-free. In particular, there may be at least two configurations for two different error cases. In all the arrangements mentioned, the individual windings can, for example, be wound back on the outside of the stator. Alternatively, two-layered tooth coil winding can be used. Single-layered tooth coil windings can be used with twice the number of grooves. But also distributed windings are possible.

In other words, a load-optimized hub motor is specified.

Electric drives usually have a much lower efficiency in the lower speed range than in their optimum operating range. Especially in the lower speed range, which is very common in driving practice, for example, turns on

Hub motor therefore in a non-optimal speed range. Therefore, more energy is converted into heat loss and not used for the actual propulsion. Electrical machines have an optimal operating point.

This is usually identified according to the application and then the machine is designed for this operating point. In vehicle operation but different load and speed points are dynamically requested.

Today, most switchable transmissions are used to optimize the speed of the drive in relation to the wheel speed. For example. in a wheel hub drive, however, the complexity of the drive and the weight in the wheel would be significantly increased by a switchable transmission.

In classic electric drives, three phases are implemented to produce the rotating field. For example. In an optimized wheel hub drive, more than three phases can be implemented, so that the selective switching off of phases can represent different partial engine concepts. Thus, for each speed, the partial motor can be activated, the has the best efficiency. As a result, an optimal high efficiency of the electric drive, eg wheel hub drive, can be represented over a larger rpm band and the energy used can be used more optimally.

The drive consists, for example, of:

an electric motor, e.g. Hub motor, with more than three phases,

- Power electronics with one output stage per phase or power electronics with as many power amps as the motor has phases / windings, and

- A scheme consisting of control electronics and evaluation and control software that calculates and uses the right number of phases for each speed.

Due to the variable use of the active engine components, different sub-engines result, which are integrated in one engine. This can increase the efficiency of an electric drive for electric vehicles (electric vehicles) and increase the driving range of electric vehicles accordingly. Since the drive machine consists of different sub-machines, the redundancy can be used. If one phase fails, the other partial motors can take over the drive. A pendulum moment or blocking torque, which arises in the event of a fault short circuit, could counteract each functional submachines and so reduce the pendulum moment or locking torque. In the following, embodiments of the invention will be explained with reference to the accompanying drawings. 1 shows a wheel hub motor,

FIG. 2 operating states in one rotational speed to torque diagram,

FIG. 3 units for configuring and operating an electric motor; FIG. 4 shows a first configuration of an electric motor with, for example, twelve windings,

FIG. 5 shows a second configuration of the electric motor,

FIG. 6 shows an example of the arrangement of windings for the second configuration of the electric motor,

FIG. 7 shows a third configuration of the electric motor, which is also suitable for a fault,

FIG. 8 shows an example of the arrangement of windings for the third configuration of the electric motor,

FIG. 9 shows method steps of a method for configuring an electric motor;

Figure 10 units of an electric car,

11 shows an example of the arrangement of windings for a fourth configuration of the electric motor, and

Figure 12 shows an example of the arrangement of windings for a fifth configuration of the electric motor.

FIG. 1 shows a wheel hub motor 10 which is arranged on a vehicle axle 12. It is, for example, an internal rotor motor.

A radial bearing 16 is fixed with its inside on the vehicle axle 12 and mounted or fastened on its outer side in a bearing block 18. For example, a rotor base disc 20 has a circular circumference and may form the sidewall of a rotor housing. At the periphery of the disc 20, permanent magnets PM1 to PMn are mounted, e.g. 12 pieces.

The stator housing 21 carries coils SP1 to SPn, e.g. 12 or 24 windings, which are also referred to below as Wl to Wn.

On the inner rotor or rotor, more precisely on the disc 20, a composite of a rim 22, a rim 24 and a wheel flange is fastened by means of wheel bolts 28, 30 or wheel nuts. A tire 32 is supported by the rim 22 and rests on the rim 22. The wheel hub motor 10 may have a dimension along its central axis M which is smaller than its diameter, in particular smaller than half the diameter. The length is given, for example, by the length of the coils SP1 or by the length of a housing. The diameter is predefined, for example, by the position of the outer surfaces of the coils SP1 to SPn or by a housing. Instead of the wheel hub motor 10, it is also possible to use another wheel hub motor, for example with a squirrel-cage rotor (short-circuit ring rotor). Instead of a wheel hub motor 10 with internal rotor and a hub motor with external rotor can be used, which contains permanent magnets or a short-circuited ring rotor.

However, it is also possible to use other electric motors, in particular an asynchronous motor or a synchronous motor having a length in the longitudinal direction of the axis of rotation, wherein the length is greater than an outer diameter of the relevant electric motor.

The electric motor may be used in a haulage machine or other machine, e.g. in a machine tool or similar The same principles apply not only to motors but also to generators.

FIG. 2 shows operating states at a speed n to torque M diagram. The speed n is plotted on the horizontal axis of the diagram. The torque M, on the other hand, is plotted on the vertical axis of the diagram.

Two curves K1 and K2 are each associated with an equal efficiency, wherein the efficiency of the curve K2 is higher than the efficiency of the curve K2. The curves K1 and K2 separate regions having different degrees of efficiency from each other when the hub motor is used in only one configuration. In this case, the radar For example, it is tuned to an operating state B4, for which it is operated with a high degree of efficiency. Thus, the area Gl encompassed by the curve Kl refers to an area having operating states that have high efficiency.

A region G2 between curves K1 and K2, on the other hand, relates to medium efficiency operating states, e.g. an operating condition B3.

An area G3 lies to the left and below the curve K2 and relates to operating states with a low efficiency, see operating states Bl and B2. With the present invention, an approach is now chosen in which not only a configuration of the electric motor is used but a plurality of configurations. Thus, in the operating state Bl when starting, for example, the same torque M of the motor can be achieved, as in the operating state B4, e.g. Driving at the moment of acceleration at high speed, i. four or five people plus any luggage. The configuration of the wheel hub motor 10 will be explained in more detail with reference to the following figures 3 to 12. Figure 3 shows units for configuring and operating an electric motor 54, e.g. the wheel hub motor 10, namely:

a control 50, and

- A power electronics 52. The motor 10, 54 may, for example. Include a tooth coil winding. The motor 10, 54 can be realized as an external rotor or as an internal rotor. Instead of a tooth coil winding, other winding schemes may be used, e.g.

Two-layer break hole winding, two-layer full-turn winding, etc.

The controller 50 includes: a drive unit 56,

a control unit 58, and

a selection unit 60. The drive unit 56 contains, for example, a number of pulse width modulation circuits (PWM) or PWM circuit pairs which correspond to the number of half-bridge circuits in the case of power electronics 52 with half bridges or with the number of full bridge circuit in the power electronics 52 matches.

The control unit 58 contains, for example, for each adjustable configuration its own control / control or at least for each adjustable configuration own control parameters (time constants of the controller, gain factors of the controller, command values, manipulated variables or controlled variables) or model parameters. In closed-loop control there is a closed loop in which a control difference, which results from the actual value and setpoint of the controlled variable, becomes as small as possible. An example of a regulation is field-oriented regulation. In the case of a controller, on the other hand, there is an open chain of effects.

The selection unit 60 selects a suitable configuration of the motor 54 depending on the operating state of the engine 54 or a machine including this motor 54, and causes the configuration corresponding to the selected configuration. The structure of the selection unit 60 will be explained in more detail below with reference to FIG.

The power electronics 52 includes half bridges 62 to 66. Alternatively, instead of the half bridges 62 to 66 and full bridges can be used. For example, the electric motor 54 has twelve or more than twelve windings Wl to Wn. The power electronics 52 can then, for example, twelve or more than twelve half bridges in the case of a power electronics 52 with half bridges or twelve or more full bridges in the case of Power electronics 52 with full bridges included. Thus, in at least one configuration, a separate control of the windings, each with a half-bridge or each with a full bridge done.

FIG. 4 shows a first configuration K1 of the electric motor 54 with, for example, twelve windings W1 to W12, wherein only the windings W1 to W6 are shown for reasons of symmetry. The switching bridges associated with the windings W7 to W12 are, like the switching bridges assigned to the windings W1 to W6, driven in the opposite direction of winding of the windings W7 to W12 in comparison to the winding sense of the windings W1 to W6. With the same sense of winding / wiring, the windings W7 to W12 associated with switching bridges inversely to the windings Wl to W6 associated switching bridges are driven, inversely means that, for example, the control signals for the upper bridge transistor / switch and the drive signals for the lower bridge transistor / - switches are reversed.

In the configuration K1, six phases are used to drive the half-bridges HB1 to HB12, with the half-bridges HB6 to HB12 not shown because of the above-mentioned symmetry of the motor 54. Alternatively, only the six half-bridges HB1 to HB6 are used, as will be described in more detail below is explained.

The windings Wl to W12 are connected to each other at a neutral point SP. For the other ends of the windings W1 to W6, the following circuit is present:

- The winding Wl is connected to the center node of the half-bridge HB1, wherein the central node is connected to the working distances of both switching elements of the half-bridge, which also applies to the other half-bridges.

the winding W2 is connected to the middle node of the half-bridge HB2, the winding W3 is connected to the middle node of the half-bridge HB3,

the winding W4 is connected to the middle node of the half-bridge HB4,

- The winding W5 is connected to the center node of the half-bridge HB5, and

- The winding W6 is connected to the center node of the half-bridge HB6. The lower switching element of the half bridges HB1 to HB6 is in each case connected to a common minus line 100.

The upper switching element of the half bridges HB1 to HB6 is in each case connected to a common positive line 102. Each half-bridge HB1 to HB6 is controlled by a drive signal.

Line pair Sl controlled to S6, wherein the one control line respectively to a control terminal of the upper switching element, e.g. Gate, and the other drive line in each case leads to a control terminal of the lower switching element of the respective half-bridge.

In the configuration K1, the six phases are arranged one another with increasing phase shift between adjacent phases, i. e.g. 0 angular degrees, 60, 120, 180, 240, and 300 degrees of angle. Due to the use of six phases for controlling twelve windings W1 to W12, a first sub-machine of the electric motor 12 with its own torque characteristic as a function of speed results. The efficiency of the first part of the machine is dependent on the speed unlike other sub-machines, which, for example. Below with reference to the figures 5 to 8 will be explained in more detail.

The half-bridges belonging to the unillustrated windings W6 to W12 are driven like the half-bridges of the windings W1 to W6 based on the six phases. However, it can also be worked with only six half-bridges greater power when the half-bridge HB1, for example. The current through the windings Wl and W7, the half-bridge HB2 controls the current through the windings W2 and W8 and so on.

For Figure 4, Q = 12, p = 1 and m = 6, where Q is the number of slots used, p is the pole pair number and m is the number of electrical phases. Furthermore:

q = Q / (2p * m) = 1,

where q is the number of grooves used per winding. FIG. 5 shows a second configuration K2 of the electric motor 54. In the configuration K2, only three phases are used to drive the half bridges HB1 to HB12, the half bridges HB8 to HB12 not being shown because of the above-mentioned symmetry of the motor 54. Alternatively only the six half bridges HB1 to HB6 used, as explained in more detail below.

The windings Wl to W12 are connected to each other at a neutral point SP. For the other ends of the windings W1 to W6, the circuit explained above with reference to FIG. 4 is present, i. e.g. that the winding Wl is again connected to the center node of the half-bridge HB1.

The lower switching element of the half bridges HB1 to HB12 is in each case again connected to the common negative line 100. The upper switching element of the half bridges HB1 to HB12 is respectively connected to the common positive line 102.

However, in the configuration K2, the control terminals of the half bridges HB1 to HB12 are each connected in groups of four via line pairs LI to L3, Llb, Llc and other line pairs, not shown.

Each half-bridge quadrature group is controlled by a drive signal line pair Sl, S2 or S3, wherein the one drive line respectively to a control terminal of the upper switching element, eg gate, and the other drive line respectively leads to a control terminal of the lower switching element of the respective half-bridge.

The following interconnection exists:

the line pair LI connects the control signals of the Hall bridges HB1 and HB2,

the line pair L2 connects the control signals of the Hall bridges HB3 and HB4,

the line pair L3 connects the control signals of the Hall bridges HB5 and HB6,

the line pair Llb connects the control signals of the Hall bridges HB7 and HB8,

an unillustrated line pair connects the control signals of the Hall bridges HB9 and HB10,

- An unillustrated line pair connects the control signals of the Hall bridges HB11 and HB12, and

a line pair Llc connects the line pairs LI and Llb to the first group of four half bridges HB1, HB2, HB7 and HB8.

For the other two groups of four HB3, HB4, HB9 and HB10 or HB5, HB6, HB11 and HB12 there are also not yet shown connecting line pairs analogous to the line pair LI.

In the configuration K2, the three phases are arranged in relation to one another with increasing phase shift between adjacent phases, ie, for example, 0 angular degrees, 120 and 240 degrees of angle. Due to the use of three phases for the control of twelve windings W1 to W12, a second sub-machine of the electric motor 12 results, with its own torque characteristic as a function of the rotational speed. The efficiency of the second part of the machine is dependent on the speed differently than in the first part of the machine or a third sub-machine explained in more detail below. The half-bridges belonging to the unillustrated windings W9 to W12 are driven like the half-bridges of the windings W3 to W6 based on the three phases. However, it is also possible to work with only six half-bridges of greater power if the half-bridge HB1, for example, controls the current through the windings W1 and W2, and the half-bridge HB3 controls the current through the windings W3 and W4.

Also, operation can be done with only three half-bridges when a half bridge controls the current through 4 windings, e.g. the half-bridge HB1 the current through the windings Wl, W2, W7 and W8.

For Figure 5, Q = 12, p = 1 and m = 3, where Q is the number of slots used, p is the pole pair number and m is the number of electrical phases. Furthermore:

q = Q / (2p * m) = 2,

where q is the number of grooves used per winding. FIG. 6 shows an example of the arrangement of windings for the second configuration of the electric motor 54. Windings of equal numbers are supplied with the same sine signal or cosine signal, the three phases 1, 2, 3 being present.

In the arrangement shown in FIG. 6, the individual windings can, for example, be wound back on the outside of the stator. Alternatively, two-layered tooth coil winding can be used. Single-layered tooth coil windings can be used with twice the number of grooves. But also distributed windings are possible.

FIG. 7 shows a third configuration K3 of the electric motor 54, which is also suitable for a fault. In the configuration K3, only three phases are also used to drive the half bridges HB1, HB3, HB5, HB7, HB9 and HB11, the half bridges HB6 to HB12 not being shown are, because of the above-mentioned symmetry of the electric motor 54. Alternatively, only the three half-bridges HB1, HB3 and HB5 are used, as will be explained in more detail below. However, the third configuration can also be used in driving situations in which a lower power of the electric motor 54 is required and in which there is no fault.

The windings Wl to W12 are again connected together at a neutral point SP. For the other ends of the windings Wl to W6 is the above with reference to FIG 4 explained

Circuit before, i. e.g. that the winding Wl is again connected to the center node of the half-bridge HB1.

The lower switching element of the half bridges HB1 to HB6 is connected to the common minus line 100 again. The upper switching element of the half bridges HB1 to HB6 is connected to the common positive line 102, respectively.

However, in the configuration K3, only the half bridges HB1, HB3, HB5, HB7, HB9 and HB11 are used.

The line pairs S1, S3 and S5 are used to control the half-bridges HB1, HB3 and HB5, the one drive line each being connected to a control terminal of the upper switching element, e.g. Gate, and the other drive line respectively leads to a control terminal of the lower switching element of the respective half-bridge.

In configuration K3, the three phases are mutually adjacent with increasing phase shift between each other

Phases are arranged, i. e.g. 0 angular degrees, 120 and 240 degrees of angle. Due to the use of three phases for the control of six windings W1, W3, W5, W7, Wp and Wll, a third sub-machine of the electric motor 12 results, with its own torque characteristic as a function of the rotational speed.

The efficiency of the third part machine is dependent from the speed unlike the first part machine or the second part machine.

The half bridges corresponding to the windings W7, W9 and W11, which are not shown, are driven like the half bridges of the windings W1, W3 and W5 based on the three phases. However, it can also be worked with only three half-bridges greater power when the half-bridge HB1, for example, the current through the windings Wl and W7, the half-bridge HB3 the current through the windings W3 and W9, etc. controls.

The configuration K3 is particularly suitable for error cases. For example, if an error 104 occurs in the winding W6, e.g. Windungsschluss, it can, for example, be switched from the configuration Kl or K2 to the configuration K3. In the configuration K3, the winding W6 is not used, so that the fault has no influence on the operation of the electric motor 54 or a vehicle driven therewith. The error 104 could also refer to the half-bridge HB6, e.g. Short circuit or interruption in a switching unit. In this case too, the configuration K3 is suitable for keeping the influence of the fault 104 as small as possible and nevertheless ensuring emergency operation of the electric motor 54.

Instead of the star circuits of the windings W1 to W12 or Wn shown in FIGS. 4 to 7, it is also possible to use polygonal circuits (ie, a delta circuit, square circuit, etc.). In a polygon circuit, the windings W1 to Wn can be the outside of the polygon form. Alternatively, however, the windings can also be cross-connected, which is referred to as a so-called span (span). For Figure 7, Q = 6, p = 1 and m = 3, where Q is the number of slots used, p is the pole pair number and m is the number of electrical phases. Furthermore:

q = Q / (2p * m) = 1,

where q is the number of grooves used per winding.

FIG. 8 shows an example of the arrangement of windings for the third configuration of the electric motor 54.

In the event of an error, one of two submachines can be used, i. either the sub-machine assigned to the phases 1, 2, 3 from the windings W1, W3, W5, W7, W9 and W11 or the sub-machine assigned to the phases 1 ', 2' or 3 'from the windings W2, W4, W6, W8 , W10 and W12. In the arrangement shown in FIG. 8, the individual windings can, for example, be wound back on the outside of the stator. Alternatively, two-layered tooth coil winding can be used. Single-layered tooth coil windings can be used with twice the number of grooves. But also distributed windings are possible.

Figure 9 shows process steps of a method for configuring an electric motor, e.g. the wheel hub motor 10 or the electric motor 54.

The method begins in a method step 201, which will also be referred to as step in the following. In a step 202 immediately following step 201, the driving situation is automatically determined, e.g. from a central control of a vehicle. The driving situation may, for example, depend on the instantaneous torque M, on the rotational speed n and / or on other variables.

Thereafter, in a step 203 of the selection unit 60 or 280, see Figure 10, a configuration with the highest possible efficiency for the determined in step 202 driving situation selected. Then, in a following step 204, the selected configuration is switched over, which is possible, for example, within short times, for example in a time that is less than 100 ms or even less than 10 ms. During switching, the electric motor 54, for example, can be switched off.

In an optional step 205, it is checked whether there is an error case, for example detecting an error signal, irregular deviations, etc. If there is no error, the method is continued in step 202 and is then in a loop from steps 202 to 205.

This loop is only exited in step 205 if an error occurs. If there is an error, then in a step 205 immediately following step 206, a configuration is selected in which the error has no effect or only the smallest possible influence on the engine operation. So a sub-machine of the engine is switched off, which contains the error.

If such a sub-machine can not be switched off, it is optionally checked whether a counter-regulation with the aid of another sub-machine of the electric motor 54 is possible. If the counter-regulation is possible, a corresponding configuration of the electric motor 54 is selected and the counter-regulation is activated. If a counter-regulation is not possible, the electric motor 54 is, for example, automatically switched off. The counter-regulation can also be used as an alternative to switching off.

The process is terminated in a step 207, e.g. by switching off the vehicle.

In another embodiment, step 205 is not performed, treating faults in a different manner, such as completely shutting off the electric motor 54. In a further embodiment, a change in the configuration can also be carried out only in the event of an error. FIG. 10 shows units of an electric car 250 containing at least one electric motor MGes or 250, in the case of wheel hub motors, at least two wheel hub motors MGes and 250, respectively. Each motor MGes or 250 contains several sub-machines Ml to Mn, which are alternative to one another or can be configured at the same time.

Half bridges or full bridges 260 serve to drive the windings of the motor 250 in the various configurations. For example. There are more than six half bridges HB1 to HBn or full bridges.

A control unit 270 contains control loops or control paths for the individual configurations. The control unit 270 may be processor-based or operate without a processor.

A selection unit 280, e.g. The selector unit 60 is used to select the configurations of the electric motor 250. The selector unit 280 includes, for example:

an input unit EE via which the operating state is transmitted, for example, from a central control of the electric car 240,

a determination unit which determines the configuration belonging to the respective operating state, for example by using a processor or microprocessor MP or a microcontroller and an electronic memory M in which program instructions and data are stored.

- Output units AE1, AE2, wherein the output unit AE1 is coupled to the control unit 270 and the output unit AE2, for example, with a switching unit, not shown. Instead of the microprocessor MP and the memory M, it is also possible to use an electronic circuit without a microprocessor, eg an FPGA (Field Programmable Gate Array).

In another embodiment, the selection unit 280 may also be part of the central control of the vehicle / car 240. Target size (s) 290 are given to the control unit 270 (possibly also only control) by a central control of the electric car 240, e.g. a target torque. The control unit 270 outputs controlled variable (s) 292 and half bridges / full bridges 260 depending on the configured control.

The half bridges / full bridges 260 are connected to the winding terminals 293 via an optional switching unit. For example, at least one detection signal 294 detects the current in the windings Wl to Wn and is used for the regulation. The detection signal may also be a speed signal that is detected, for example, with an additional rotation angle sensor. The driving state signal 295 is input to the selecting unit 280. The selection unit 280 outputs an optional selection signal 296 to the control unit 270 to configure a control appropriate to the selected configuration or appropriate parameters. For example. Here, too, the number of phases to be used is taken into account. In the case of six phases, for example, a first field-oriented control for phases 1, 3 and 5 can be used. A second field-oriented control is used for phases 2, 4 and 6. These phases are respectively sinusoidal and cosinusoidal. However, other control methods are also used.

An optional selection signal 298 is sent from the selector 280 to a non-illustrated switching unit, and serves for example for interconnecting the windings of the electric motor 250 with each other and for connecting to the half bridges HB1 to HBn or corresponding full bridges depending on the selected configuration.

48 48 48 48 48

2 2 2 2 2

3 4 6 1 2

4 3 2 12 6

Q = 36

P = 2

m = 3

q = 3

Q = 24 16 24 24 24

p 2 2 2 2 2

m = 3 4 6 1 2

q 2 1 1 6 3

Q 12 12 12 12 8 6 m

Fig. 5/6 Fig.11 Fig.4 Fig.12 Fig.7 / 8 where Q is the number of slots used, p is the number of pole pairs and m is the number of electrical phases. Furthermore: q = Q / (2p * m),

where q is the number of grooves used per winding.

Other configurations are also possible, especially with non-integer q.

In addition to tooth coil windings are also possible, which is wound around the outside of the stator. The number coil windings may be single-layered or two-layered, wherein the two-layered tooth coil winding can be regarded as a special case of the two-layer brushless winding. Other distributed windings can also be used.

Figure 11 shows an example of the arrangement of windings for a fourth configuration of the electric motor with Q = 12, p = 1 and m = 2. The two electrical phases 1 and 2 can be distributed to the individual windings in the slots as shown.

FIG. 12 shows an example of the arrangement of windings for a fifth configuration of the electric motor with Q = 12, p = 1 and m = 4, ie four phases, with some slots remaining free. Also in the arrangements of Figures 11 and 12, the individual windings, for example, be externally wound back on the stator. Alternatively, two-layered tooth coil winding can be used. Single-layered tooth coil windings can be used with twice the number of grooves. But also distributed windings are possible.

The exemplary embodiments explained with reference to the figures can be combined in particular with the exemplary embodiments mentioned in the introduction. The embodiments are not to scale and are not restrictive. Modifications in the context of expert action are possible. Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention. Other electric motors, other pole pair numbers (rotor) and other winding numbers or winding schemes may be used. The electric motors may be DC or AC motors, in particular AC motors with at least three-phase rotating field.

Claims

claims

A selection unit (60, 280) for selecting the configuration (K1 to K3) of an electric motor (10, 54, 250), comprising:

an input unit (EE) capable of receiving at least one signal (295) or data indicating a driving state (Bl to B4) of a haulage machine (240) or a rotational speed (n) of an electric motor (10, 54, 250),

a determination unit which, depending on the signal (295) received with the input unit (MP), or data

Configuration of the electric motor (10, 54, 250) determined

an output unit (AE2) which outputs at least one signal (298) or data designating or specifying the selected configuration (K1 to K3).

Second selection unit (60, 280) according to claim 1, wherein the determining unit (MP) to a driving state (Bl to B4) or to a rotational speed (n) determines a configuration with high efficiency of the electric motor (10, 54, 250).

A selection unit (60, 280) according to claim 2, wherein the efficiency is increased by selecting a suitable number of windings (Wl to Wn) to be used for the running condition (Bl to B4) or the number of revolutions (n), and wherein the number in a first configuration (K1, K2) differs from the number in a second configuration (K3),

or wherein the efficiency is changed by the selection of a number of phases (m) suitable for the driving state (Bl to B4) or the rotational speed (n), and wherein the number in a first configuration (K1, K3) depends on the number a second configuration (K2), preferably with a constant number of windings used (Wl to Wn).

4. Selection unit (60, 280) according to one of the preceding claims, wherein the determination unit (MP), between a error-free operation of the electric motor (10, 54, 250) and a fault operation is different (205).

5. Selection unit (60, 280) according to claim 4, wherein the determination unit (MP) in error operation does not use a winding (W6) which contains an error (104).

6. Selection unit (60, 280) according to claim 4, wherein the determination unit (MP) selects a configuration in the error mode, which allows to control or control a caused by the error (104) Moment (M).

7. Transport machine (240) containing a selection unit (60, 280) according to one of the preceding claims.

8. Transport machine (240) according to claim 7, comprising an electronic drive unit (56, 260) for driving the windings (Wl to Wn) of the electric motor (10, 54, 250) in accordance with control signals.

9. Transport machine (240) according to claim 8, comprising a control unit (50, 270) for generating the control signals according to at least one control method.

10. Transport machine (240) according to one of claims 7 to 9, comprising a configuration unit, which is coupled to the output unit (AE2), and which sets the designated or predetermined configuration (Kl to K3).

11. Transport machine (240) according to one of claims 6 to 9, comprising at least one wheel hub motor (10).

12. A method of selecting a configuration (K1 to K3) of an electric motor (10, 54, 250) comprising:

Detecting a first driving state (Bl to B4) or a first rotational speed (n), Selecting a first configuration (K1, K2) of an electric motor (10, 54, 250) as a function of the detected first driving state (B1 to B4),

Detecting a second driving state (Bl to B4) or a second rotational speed (n),

- Selection of a second configuration (K3) of the electric motor (10, 54, 250) depending on the detected second driving state (Bl to B4), wherein the second configuration (K3) differs from the first configuration.

13. The method according to claim 11, wherein the second configuration (K3) differs from the first configuration (Kl, K2) with regard to the number of included windings (Wl to Wn),

the second configuration (K2) differs from the first configuration (Kl, K3) in terms of the number of phases (m), preferably with a constant number of windings (Wl to Wn) used.

14. The method of claim 11 or 12, wherein the electric motor (10, 54, 250) is error-free in both configurations (Kl to K3).

15. The method according to any one of claims 10 to 12, wherein the configurations (Kl to K3) are selected so that depending on the driving condition (Bl to B4) the greatest possible efficiency results in the operation of the electric motor (10, 54, 250).