DE102013223476A1 - Control device and method for providing a setpoint torque specification for a synchronous machine - Google Patents

Abstract

A method of operating a multi-phase synchronous machine (500) in an emergency mode of the synchronous machine (500) corresponding to a malfunction in a faulted phase of a supply voltage source (530) comprises providing a desired torque command (102) extending from normal to synchronous mode (500) corresponding torque command (240; 508) discriminates when a speed of the synchronous machine (500) is greater than a predetermined speed limit (210). The operation of the synchronous machine (500) is controlled based on the desired torque command (102).

Description

Embodiments of the invention are concerned with a control device for providing a setpoint torque specification for an emergency operation of a synchronous machine corresponding to a malfunction in a faulted phase of a supply voltage source.

Synchronous machines with permanently energized rotors are in use in a variety of practical applications. For example, these are used as an electric motor drive in motor vehicles or as a support motor in a number of other applications. An example of another application in the automotive field are electric motor-assisted power steering systems, where synchronous machines can be used as drive motors.

In normal operation, the synchronous machine is often operated by means of the so-called field-oriented control (FOR), in which a current vector which indicates the current through the individual phases of the multiphase synchronous machine is calculated and regulated in a two-dimensional rotor-fixed coordinate system. For the control, the determination of a control deviation is required, which is why in the individual phases of the synchronous machine, the actual flowing current is measured and used as feedback for the control loop. If it comes to a defect of individual components of the machine or these controlling components, an emergency operation of the machine is often maintained, in which it can deliver at least a portion of the maximum torque or the maximum speed. For this purpose, deviations from the concept of field-oriented control according to some solutions proposed so far. Instead, in an emergency mode, the current in the machine or the voltage at the individual phases of the machine can be controlled, whereby a feedback can be dispensed with in the form of the currents actually measured in the individual phases. For controlling the emergency operation, different methods are known, for example, the field-oriented control (FOS), which in the German Patent Application 10 2011 075 789 is described.

Although during emergency operation at least a portion of the desired torque maintained or a portion of the available speed range can be mapped, it can by driving in emergency mode to significantly increased currents in the windings of the synchronous machine or the motor or in these supplying Power supplies come. This requires short-circuiting the synchronous machine from reaching a certain maximum permissible current intensity in order to avoid further damage to the power supply or of the inverter used or of the machine itself. This in turn has the consequence that at the moment of the short circuit of the synchronous machine suddenly no more torque is generated and instead a negative torque or braking takes place with the machine inherently inherent braking torque. When shorting the machine thus takes a big leap of the torque caused by the machine. This may be undesirable in some applications. For example, would be abrupt when using a synchronous machine in an electric motor assisted power steering the steering assistance and it would be an additional braking torque applied by the driver of the vehicle in question. Such a strong torque increase, for example, cause unexpected reactions in the driver or be uncomfortable for this. The same applies when using an electromotive drive, in which a strong bucking may be the result when the electric machine or the synchronous machine is short-circuited.

There is therefore a need to improve the operation of a synchronous machine in an emergency operation.

Embodiments make this possible by using a control device and a method according to the independent claims.

A control device provides a target torque specification for an emergency operation of the synchronous machine corresponding to a malfunction in a faulty phase of a supply voltage source. The control device has a speed input, which is designed to obtain information about a current speed of the synchronous machine. A default generator is configured to provide, using the information about the rotational speed and a torque default corresponding to a normal operation of the synchronous machine, a target torque command different from the torque command when a rotational speed of the synchronous machine is greater than a predetermined rotational speed limit.

This can make it possible to effect an adaptation of the output torque by deviating from the externally specified torque specification, in particular at higher rotational speeds, so that, for example, large torque jumps on short time scales can be avoided.

According to some embodiments, the target torque command is reduced as the speed increases, so that the torque jump in a possible short-circuiting of the synchronous machine to avoid damage at high speeds is low. In some embodiments, the target torque command is lowered to correspond to a brake torque of the synchronous machine at a limit speed, that is, the target torque command is controlled to the value that results from shorting the phases of the synchronous machine. This may result according to some embodiments, that despite successful avoidance of additional damage caused by large currents in emergency operation no torque jump in the output of the synchronous motor occurs.

According to some embodiments, the transition from the torque command to the target torque command as well as the short-circuiting or an optional cancellation of the short-circuiting of the phases are performed with a hysteresis in order to avoid rapid changes between the individual operating states. The short-circuiting of the phases of the synchronous machine takes place when a limit speed is exceeded and the cancellation of the short circuit at a second limit speed, wherein the second limit speed is less than the limit speed. The same can apply to the transition to using the target torque command or to returning to using the torque command.

Some embodiments of the invention will be illustrated in more detail below. In the figures, the thickness dimensions of lines, layers and / or regions may be exaggerated for the sake of clarity. Show it:

1 an embodiment of a control device;

2 an illustration of the target torque command provided by the controller;

3 an illustration of the coordinate systems used in the operation of synchronous motors;

4 a representation of a possible supply voltage source;

5 a schematic representation of the components that can be used in an example of a field-oriented control;

6 a flowchart of an embodiment of a method for operating a multi-phase synchronous machine; and

7 a flowchart of another embodiment of a method for operating a multi-phase synchronous machine

In the following description of the attached figures, which show only some exemplary embodiments, like reference characters may designate the same or similar components. Further, summary reference numerals may be used for components and objects that occur multiple times in one embodiment or in a drawing but are described together in terms of one or more features. Components or objects which are described by the same or by the same reference numerals may be the same, but possibly also different, in terms of individual, several or all features, for example their dimensions, unless otherwise explicitly or implicitly stated in the description.

Although embodiments may be modified and modified in various ways, exemplary embodiments are illustrated in the figures as examples and will be described in detail herein. It should be understood, however, that it is not intended to limit embodiments to the particular forms disclosed, but that embodiments are intended to cover all functional and / or structural modifications, equivalents and alternatives that are within the scope of the invention. Like reference numerals designate like or similar elements throughout the description of the figures.

Note that an element referred to as being "connected" or "coupled" to another element may be directly connected or coupled to the other element, or intervening elements may be present. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements. Other terms used to describe the relationship between elements should be interpreted in a similar fashion (eg, "between" versus "directly in between,""adjacent" versus "directly adjacent," etc.).

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the embodiments. As used herein, the singular forms "one," "one," "one," and "the one," are also intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it should be understood that the terms such as e.g. "Including," "including," "having," and / or "having," as used herein, indicates the presence of said features, integers, steps, operations, elements, and / or components, but the presence or addition of a resp one or more features, integers, steps, operations, elements, components, and / or groups thereof.

Unless otherwise defined, all terms used herein have the same meaning as commonly assigned to one of ordinary skill in the art to which the embodiments pertain. Further, it should be understood that terms, e.g. those that are defined in commonly used dictionaries are to be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not to be interpreted in an idealized or overly formal sense, unless this is so is explicitly defined.

1 shows an embodiment of a control device 100 for providing a target torque command 102 for an emergency operation of the synchronous machine corresponding to a malfunction in a faulted phase of a supply voltage source of a synchronous machine. The target torque specification 102 is used to calculate or determine the quantities required to operate the synchronous machine during emergency operation. In particular, according to the embodiments, based on the target torque specification 102 a target current specification for the synchronous machine and, as a result, a target voltage specification for the individual supply voltages to be applied to the phases of the synchronous machine are determined. The control device 100 considered when providing the target torque specification 102 information about the instantaneous speed of the synchronous machine and has for this purpose a speed input 104 which is adapted to obtain the information about a current speed of the synchronous machine.

The control device 100 also has a default generator 106 configured to provide a target torque command different from the torque command using the information about the rotational speed and a torque command corresponding to a normal operation of the synchronous machine when a rotational speed of the synchronous machine is greater than a predetermined rotational speed limit. According to an embodiment described in more detail below, the target torque command is starting from the predetermined speed limit 210 (n ₁ ) up to a limit speed 220 (n ₃ ) decreases linearly as shown in 2 is shown. 2 shows on the x-axis, the speed of the synchronous machine in arbitrary units and on the y-axis of the lower representation of the torque at the output of the synchronous machine also in arbitrary units, whereas in the upper diagram, a switching state of the control is shown schematically. At the limit speed 220 the synchronous machine will be within a safe area 254 short-circuited, so that high phase currents, which could lead to further damage to the machine, can be avoided. This leads to the braking torque 230 (M _KS ) of the synchronous machine. The embodiment described below decreases from exceeding the speed limit 210 a torque specification used in normal operation 240 continuous and linear up to the braking torque 230 that corresponds to shorting the synchronous machine.

Short circuiting the machine avoids high phase currents. On the other hand, a short-circuiting of the machine results in a braking torque. A direct switchover from the measures for generating a support torque in a basic speed range 252 short-circuiting the machine at high speeds results in a sudden torque change, which is uncomfortable for the users and may, for example, cause a shuddering of an electromobility vehicle or a hard turn in a power steering.

For this reason, an intermediate area 250 inserted so that the transition between the measures to reduce the braking torque and the short-circuiting of the machine is gentler. It is in this intermediate area 250 the setpoint torque or the setpoint torque input 102 ramped to the braking torque 230 lowered the machine when shorting the machine. The machine will be in this intermediate area 250 continued to operate with alternative measures or the control for emergency operation.

This creates three areas to switch between. The speed amount serves as a monitor signal for switching between these three areas 250 . 252 , and 254 , To avoid quick toggling between the three areas, speed hystereses can be used.

n: der aktuelle Drehzahlbetrag im Übergangsbereich 250 in [U/min], n₁: der Drehzahlbetrag beim Verlassen des Bereiches 252 und dem Eintritt in den Bereich 250, n₃: der Drehzahlbetrag beim Verlassen des Bereiches 252 und dem Eintritt in den Bereich 254, M_{Soll_n}: das neue berechnete Solldrehmoment bzw. die Solldrehmomentvorgabe im Übergangsbereich 250 [Nm], M_Soll1: das gewünschte Solldrehmoment bzw. die Drehmomentvorgabe bei dem Drehzahlbetrag n₁ [Nm], M_KS: das Bremsdrehmoment der Maschine beim aktiven Kurzschluss der Maschine beim Drehzahlbetrag n₃ [Nm]. For determining the ramp-shaped adjusted setpoint torque specification 102 the machine in the transition area 250 a speed dependent torque component is calculated. This is removed from the original torque _{specification} M _Soll1 . It increases with increasing speed. The following equation (equation 7) describes the calculation of the new torque setpoint M _{Soll_n} or the setpoint _{torque input} in this transitional range:

n: the current speed amount in the transition area 250 in [rpm], n ₁ : the speed amount when leaving the area 252 and entry into the area 250 , n ₃ : the speed amount when leaving the area 252 and entry into the area 254 , M _{set_n} : the new calculated setpoint _torque or the setpoint _{torque specification} in the transition range 250 [Nm], M _{setpoint 1} : the desired setpoint torque or the torque _input at the speed setpoint n ₁ [Nm], M _KS : the braking torque of the machine during active short circuit of the machine at the speed setpoint n ₃ [Nm].

The braking torque M _KS results when short-circuiting the machine or the synchronous machine and this depends on some machines from their speed. At n _{3 it} is to be expected that the M _KS remains the same.

In order to bring about the short-circuiting of the phases of the synchronous machine, some embodiments also have a short-circuit signal generator which is designed to switch over when the limiting rotational speed is exceeded 220 provide a short-circuit signal, which causes the short circuit of the phases of the synchronous machine.

According to some embodiments, the control device further comprises a pulse width modulator, which is designed to provide a pulse width modulated signal for controlling the plurality of phases of an inverter, which controls a switching of individual power semiconductors within the inverter. According to some further embodiments, the pulse width modulator is further configured to provide a modified pulse width signal for emergency operation of the synchronous machine based on a normal pulse width signal for normal operation of the synchronous machine, so that even in case of failure or malfunction of a phase in the supply voltage source the same means of the pulse width modulator continues to drive can be that an emergency operation of the synchronous machine is maintained.

One way to provide a modified pulse width _signal PWN _xn for the synchronous _machine based on a normal pulse width _signal PWN _{x is set forth in} more detail below. It is in advance shortly by means of 3 introduced the terminology or the usual for the operation of a synchronous machine coordinate systems based on 3 briefly explained.

Further illustrated 4 the basic mode of operation of an inverter or a supply voltage source 400 which is driven by some embodiments of control devices to enable emergency operation.

3 illustrates the three coordinate systems used using the example of a three-phase machine. The three-coordinate system (UVW) with in the associated axes 300a . 300b and 300c corresponds to a coordinate system which is given by the position of the individual stator windings. For the control of the synchronous machine or the electric motor, the state variables in a rotating with the rotor Coordinate system, the d, q coordinate system are transformed. The d-axis 302a runs parallel to the maximum magnetic flux of the permanent-magnet rotor and the q-axis 302b perpendicular to it.

Furthermore, the quantities can also be described in a Cartesian two-dimensional coordinate system, the α, β coordinate system, wherein in the in 3 shown representation without limiting the generality of the α-axis 304a is chosen so that this is identical to the U-axis 300a of the U, V, W coordinate system, with the β-axis 304b runs perpendicular to it.

In the field-oriented control (FOR), the state variables of the electric motor are transformed into the d, q coordinate system, since the differential equations describing the dynamic behavior of the electric motor are simplified in these coordinates. In these coordinates, the machine can be controlled similar to a DC machine.

As an example of a power supply is in 4 an inverter 400 with MOSFETs 402a , b, 404a , Federation 406a , b shown. With the MOSFETs 402a , b, 404a , Federation 406a , b the current can be switched through in both directions. Other embodiments may also use other power semiconductors, such as IGBTs (Insulated Gate Bipolar Transistors). Only during the off-time between the upper MOSFET 402a . 404a and 406a and the lower MOSFET 402b . 404b and 406b In each phase x (U, V or W), the flyback diodes become 412a . 414a and 416a respectively. 412b . 414b and 416b take over the current in this phase x. Depending on the sign of the current, the current over the lower (eg 412b ) or the upper diode (eg 412a ) of a phase. The upper MOSFET (eg 402a ) or the upper diode (eg 412a ) of a phase x is always connected to + U _dc and the lower MOSFET (eg 402b ) or the lower diode (eg 412b ) is always connected to - U _dc .

During the emergency operation, the operation of the synchronous machine is no longer regulated, but the operation is controlled. For this example, a structure can be used as in 5 is shown. This can, for example, enable field-oriented control or field-oriented control with adjustable dynamics. Another measure during emergency operation is the modulation or correction of the pulse width modulated signals (PWM values) generated by the control or regulation for controlling the inverter. In this case, the phase is detected with the short-circuited power semiconductor or MOSFET and the PWM value considered constant in this phase. Depending on which of the two MOSFETs is shorted in phase, the PWM value in this phase is thus set to a constant value. In the case of a short circuit of the upper MOSFET, the PWM value is set to 100%, and in case of a short circuit of the lower MOSFET, it is set to 0%. The other PWMs for the other two phases are changed so that the original voltage vector is approximately restored.

For example, in the case of a MOSFET short circuit in phase U, it is first determined which MOSFET is shorted and the new PWM value PWM _{1n of} this phase is accordingly set to a fixed value (0% or 100% for shorted low or high) MOSFET). The new PWM value in phase V, PWM _{2n is} calculated as follows: PWM _2n = (PWM _1n - PWM ₁ ) + PWM ₂ . Eq. 1)

For phase W, the new PWM value PWM _{3n is obtained} : PWM _3n = (PWM _1n - PWM ₁ ) + PWM ₃ . Eq. 2)

Analogously, in the case of a MOSFET short-circuit in phase V, its new PWM value PWM _{2n is} set and the other two phases U and W receive the following new PWM values PWM _1n and PWM _3n : PWM _1n = (PWM _2n - PWM ₂ ) + PWM ₁ , Eq. 3) PWM _3n = (PWM _2n - PWM ₂ ) + PWM ₃ . Eq. 4)

In the case of a MOSFET short-circuit in phase W the same procedure applies, the other two phases U and V receive new PWM values PWM _1n and PWM _2n : PWM _1n = (PWM _3n - PWM ₃ ) + PWM ₁ , Eq. 5) PWM _2n = (PWM _3n - PWM ₃ ) + PWM ₂ . Eq. 6)

These corrections are effective as long as the new calculated PWM values do not fall below or exceed the limit (0% and 100%). If the new calculated PWM values for each case are outside these limits, they are limited to this limit.

The sizes introduced above mean: PWM ₁ : the PWM value originally calculated from FOR or FOS for phase U in normal operation, PWM ₂ : the PWM value originally calculated from FOR or FOS for phase V in normal operation, PWM ₃ : the PWM value originally calculated from FOR or FOS for phase W in normal operation, PWM _1n : the new corrected PWM value for phase U in case of permanent semiconductor short circuit in emergency mode, PWM _2n : the new corrected phase V value for sustained semiconductor short circuit in emergency mode, PWM _3n : the new corrected PWM value for phase W in case of permanent semiconductor short circuit during emergency operation.

Since the phase currents can become very large with the previously introduced corrections at high speeds, the synchronous machine is actively shorted in this operating range. The inverter can not be operated physically under certain conditions or with too high currents. There are maximum current limits without which compliance could be destroyed.

5 schematically shows an embodiment of a control device 100 , which implements the concept of field-oriented control (FOS). The default generator 106 the control device 100 receives as information about a current speed of the synchronous machine 500 the electrical angular velocity 502 that is from the mechanical angular velocity 504 of the rotor is obtained by multiplying by the number of pole pairs. The torque specification 508 is in the concrete embodiment by means of a Stromvorgabevektors 510 reached in the d, q coordinate system. The components of the current specification vector 510 correspond to an achievable torque and are therefore equivalent to a torque specification. The control device 100 in emergency mode for controlling the synchronous motor between the synchronous machine 500 is based on a known concept of field-oriented control (FOS), which will be briefly discussed below. The default generator 106 is designed to set a predetermined torque limit when a predetermined speed limit is exceeded 512 provide, differing from the torque specification 508 different.

In the present case, the information about the target torque specification 512 by means of a voltage specification vector 514 transported, indicating the desired phase voltages in the d, q coordinate system, which in turn given given parameters of the synchronous machine to the desired target torque specification 512 correspond. To the phase voltages of the present case without limitation of the general three-phase assumed synchronous motor 500 to generate, serves a coordinate transformer 516 , which is the voltage default vector 514 transformed into the u, v, w coordinate system. The pulse width modulator 520 is configured to be based on the target torque specification in the form of the desired voltage vector 518 for controlling the plurality of phases of an inverter or a power supply 530 each a pulse width modulated signal 532a . 532b and 532c provide. In this respect, the pulse width modulator 520 by means of an error signal 534 gets notified that within the pulse inverter 530 or the power supply is a faulty phase, is the pulse width modulator 520 based on a normal pulse width signal resulting in normal operation of the synchronous machine 500 corresponds, a modified pulse width signal for the emergency operation of the synchronous machine ready, as set forth in the preceding paragraphs.

When the limit speed is exceeded 220 is used to protect the other power semiconductors or the windings of the synchronous machine 500 the machine is actively shorted. This can be done depending on which of the power semiconductors is short-circuited within the power supply. Is one of the top power semiconductors 402a . 404a or 406a short circuited, the PWM values of all three Phases u, v and w correct the duty cycle or the value 100% so that all upper power semiconductors are permanently switched through and no more rotating field is generated at the synchronous motor. Be equivalent to this when one of the lower power semiconductors 402b . 404b or 406b has a short circuit or a fault, the remaining lower power semiconductors permanently switched through, which corresponds to a PWM value of 0% in the selected notation.

6 shows a flowchart of an embodiment of a method for operating a multi-phase synchronous machine. In other words, the flow chart gives a summary of the semiconductor short circuit strategy in a power supply. In normal operation 600 the machine is operated with the FOR, if in a test 602 no permanent semiconductor short circuit is detected. Detected by means of the error signal 534 (SC_Failure) that a semiconductor of the power amplifier or the power supply 530 permanently short-circuited, the FOR is no longer used, ie the regulated operation is stopped. Instead, it becomes a controlled operation 604 changed and, for example, the driving method FOS after 5 used. The error signal 534 (SC_Failure) contains the information as to whether a semiconductor is permanently short-circuited, and which of the semiconductors of the power supply or the power amplifier has this fault. The permanent short circuit of a semiconductor can occur in any case of operation, eg due to material fatigue, driver problems, etc. Therefore, first depends on the filtered speed amount in a range selection 606 determined in which the area 250 . 252 or 254 the synchronous machine is located.

If the speed amount is too high or higher than the limit speed 220 (n> n ₃ ), the machine is in 608 actively short-circuited so that you can protect the power amplifier from high currents. It is checked which semiconductor is short-circuited. Is one of the top semiconductors 402a . 404a or 406a (at the positive potential + U _{DC of} the _DC link) permanently short-circuited, the PWM values of all three phases U, V and W are corrected to the value 100%. The machine is short circuited to the positive potential of the DC link and all three upper semiconductors 402a . 404a or 406a are switched through. In contrast, it is one of the lower semiconductors 402b . 404b or 406b (permanently connected to the negative potential -U _{DC of} the _DC link), the PWM values of all three phases U, V and W are corrected to the value 0%. The machine is short circuited to the negative potential of the DC link and all three lower semiconductors 402b . 404b or 406b are switched through.

If the speed amount is small (n <n ₁ ) or less than the predetermined speed limit 210 or the limit speed 220 , so you go directly to the mode of torque assistance 610 in the speed ranges 250 or 252 where the active measures for generating a support torque are active or the torque specification is implemented. It is determined which semiconductor of the 6 semiconductors of the output stage is permanently short-circuited, so that the corresponding correction of the PWM values can be carried out. If the speed continues to increase, you get into the transition area 250 above the predetermined speed limit 210 , The torque setpoint or the setpoint torque input 102 becomes with increasing speed amount on the brake torque 230 the machine at the beginning of the area 254 lowered. If the target _torque M _{Soll1 is} less than M _KS , then the target _{torque specification} is in the range 250 adjusted to M _KS with increasing speed. This ensures that the transition between the individual areas with weakened transients occurs. The synchronous machine can be in the range 252 be operated with good result, because it provides a positive moment of support instead of a braking torque. Only with increasing speed amount, it is gradually slowed down, so they to the area 252 returns.

Overall, so the synchronous machine in emergency mode of permanent semiconductor short circuit with limited mechanical power (in the base speed range 252 ) and the remaining semiconductors and the synchronous machine are always protected (over the entire speed range) from high currents.

7 shows a flowchart of an embodiment of a method for operating a multi-phase synchronous machine.

In a deployment step 700 A target _{torque command} M _{Soll_n is} provided, which differs from a torque _command corresponding to a normal operation of the synchronous _machine when a speed of the synchronous machine is greater than a predetermined speed limit.

In a control step 702 the operation of the synchronous _{machine is} controlled based on the target _{torque command} M _{Soll_n} .

• – Ein Sternpunktrelais sowie Phasentrenner können in einer PSM-Maschine eingespart werden. Bei großen Stückzahlen können teilweise erhebliche Kosten gespart werden.
• – Das Bauvolumen kann reduziert werden.
• – Die elektrischen Verluste wie zum Beispiel Durchschaltverluste und Spannungsabfall durch Phasentrenner können reduziert werden und damit verbessert sich der Wirkungsgrad.
• – Statt eines Bremsmomentes wie bei herkömmlichen Verfahren werden teilweise positive Drehmomente erreicht.
• – Die Phasenströme sind nicht zu hoch, so dass die restlichen Leistungshalbleiter bzw. MOSFETs einer Spannungsversorgung nicht zerstört werden und die Permanentmagnete der Maschine nicht entmagnetisiert werden.
• – Die Maschine und die Endstufe bzw. Spannungsversorgung und deren restlichen Halbleiter sind in allen Drehzahlbereichen geschützt, was einen totalen Ausfall des Antriebes verhindern kann.
• – Ein schlagartiges Umschalten zwischen den Bereichen Unterstützungsmoment generieren und aktiver Kurzschluss der Maschine wird vermieden.

Embodiments of the present invention may thus have one or more of the following advantages:

• - A star point relay and phase separator can be saved in a PSM machine. In large quantities sometimes considerable costs can be saved.
• - The construction volume can be reduced.
• - The electrical losses such as switching losses and voltage drop through phase separators can be reduced and thus improves the efficiency.
• - Instead of a braking torque as in conventional methods partially positive torques are achieved.
• The phase currents are not too high, so that the remaining power semiconductors or MOSFETs of a power supply are not destroyed and the permanent magnets of the machine are not demagnetized.
• - The machine and the power amplifier or power supply and their remaining semiconductors are protected in all speed ranges, which can prevent a total failure of the drive.
• - Generating a sudden switch between the areas assist torque and active short circuit of the machine is avoided.

Although described in the preceding paragraphs predominantly in connection with an electrically assisted power steering or an electromotive drive of a motor vehicle, further embodiments of control devices or of driving methods in any other applications with an electric motor or a synchronous machine can be used to strong torque jumps in case of failure avoid a fault operation or an emergency operation of the synchronous machine or the electric motor.

The features disclosed in the foregoing description, the appended claims and the appended figures may be taken to be and effect both individually and in any combination for the realization of an embodiment in its various forms.

Although some aspects have been described in the context of a device, it will be understood that these aspects also constitute a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device.

Depending on particular implementation requirements, embodiments of the invention may be implemented in hardware or in software. The implementation may be performed using a digital storage medium, such as a floppy disk, a DVD, a Blu-Ray Disc, a CD, a ROM, a PROM, an EPROM, an EEPROM or FLASH memory, a hard disk, or other magnetic disk or optical memory are stored on the electronically readable control signals, which can cooperate with a programmable hardware component or cooperate such that the respective method is performed.

A programmable hardware component may be provided by a processor, a central processing unit (CPU), a graphics processing unit (GPU), a computer, a computer system, an application-specific integrated circuit (ASIC), an integrated circuit (IC), a system on chip (SOC) system, a programmable logic element or a field programmable gate array with a microprocessor (FPGA = Field Programmable Gate Array).

The digital storage medium may therefore be machine or computer readable. Thus, some embodiments include a data carrier having electronically readable control signals capable of interacting with a programmable computer system or programmable hardware component such that one of the methods described herein is performed. One embodiment is thus a data carrier (or a digital storage medium or a computer readable medium) on which the program is recorded for performing any of the methods described herein.

In general, embodiments of the present invention may be implemented as a program, firmware, computer program, or computer program product having program code or data wherein the program code or data is operable as one of the methods when the program runs on a processor or a programmable hardware component. The program code or the data can also be stored, for example, on a machine-readable carrier or data carrier. The program code or the data may be present, inter alia, as source code, machine code or bytecode as well as other intermediate code.

Another embodiment is further a data stream, a signal sequence, or a sequence of signals that represents the program for performing any of the methods described herein. The data stream, the signal sequence or the sequence of signals can be configured, for example, to be transferred via a data communication connection, for example via the Internet or another network. Embodiments are also data representing signal sequences that are suitable for transmission over a network or a data communication connection, the data representing the program.

For example, a program according to one embodiment may implement one of the methods during its execution by, for example, reading or writing data or data into memory locations, thereby optionally switching operations or other operations in transistor structures, amplifier structures, or other electrical, optical, or other , magnetic or operating according to another operating principle components are caused. Accordingly, by reading a memory location, data, values, sensor values or other information can be detected, determined or measured by a program. A program can therefore acquire, determine or measure quantities, values, measured variables and other information by reading from one or more storage locations, as well as effect, initiate or execute an action by writing to one or more storage locations and control other devices, machines and components ,

The embodiments described above are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to others of ordinary skill in the art. Therefore, it is intended that the invention be limited only by the scope of the appended claims, rather than by the specific details presented in the description and explanation of the embodiments herein.

LIST OF REFERENCE NUMBERS

100

control device

102

Target torque setting

104

Speed input

106

default producers

210

predetermined speed limit

220

Limit speed

230

braking torque

240

torque setting

250

intermediate area

252

Basic speed range

254

security area

300a, b, c

U, V, W coordinates

302a, b, d

d, q coordinates

304a, b

α, β coordinates

400

inverter

402a, b

MOS FET

404a, b

MOS FET

406a, b

MOS FET

412a, b

diode

414a, b

diode

416a, b

diode

500

synchronous machine

502

electrical angular velocity

504

mechanical angular velocity

506

multiplier

508

torque setting

510

Current input vector

512

Target torque setting

514

Voltage instruction vector

516

Koordinatentransformierer

518

Target voltage vector

530

power supply

532a, b, c

 pulse width modulated signal

534

error signal

600

Normal business. Business as usual

602

To verify

604

controlled operation

606

range selection

608

Short circuit

610

torque assistance

700

Provide

702

Taxes

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102011075789 [0003]

Claims (19)

Control device ( 100 ) for providing a target torque specification ( 102 ) for a malfunction in a faulted phase of a supply voltage source ( 530 ) corresponding emergency mode of the synchronous machine ( 500 ) comprising: a speed input ( 104 ) which is adapted to receive information about a current rotational speed of the synchronous machine ( 500 ) to obtain; and a default generator ( 106 ), which is designed to use the information about the rotational speed and a normal operation of the synchronous machine ( 500 ) corresponding torque specification ( 240 ; 508 ) one of the torque specification ( 240 ; 508 ) differing setpoint torque specification ( 102 ) when a speed of the synchronous machine ( 500 ) is greater than a predetermined speed limit ( 210 ). Control device ( 100 ) according to claim 1, wherein the default generator ( 106 ) is adapted to the setpoint torque specification ( 102 ) with increasing speed. Control device ( 100 ) according to one of the preceding claims, wherein the setpoint torque specification ( 102 ) at a limit speed ( 220 ) a braking torque ( 230 ) of the synchronous machine ( 500 ) corresponds. Control device ( 100 ) according to claim 3, wherein the control device ( 100 ), the setpoint torque specification ( 102 ) from the predetermined speed limit ( 210 ) up to the limit speed continuously from the torque specification ( 240 ; 508 ) up to the braking torque ( 230 ) of the synchronous machine ( 500 ) to reduce. Control device ( 100 ) according to claim 4, wherein the target ( 102 ) M _{soll_n} from the predetermined speed _limit ( 210 ) n ₁ up to the limit speed ( 220 ) n _{3 is} reduced from a current rotational speed n linearly from the torque _input M _soll1 to the braking torque M _KS taking into account the following relationship (equation 7):

Control device ( 100 ) according to one of claims 3 to 5, further comprising: a short-circuit signal generator, which is designed to provide a short-circuit signal when the limit speed is exceeded, which causes a short circuit of the phases of the synchronous machine ( 500 ) causes. Control device ( 100 ) according to one of the preceding claims, further comprising: a control current transformer, which is designed to be based on the target torque specification ( 102 ) a target current specification for one in the phases of the synchronous machine ( 500 ) to provide flowing electricity. Control device ( 100 ) according to one of the preceding claims, further comprising: a pulse width modulator ( 520 ) configured to drive one of each of the plurality of phases of an inverter ( 530 ) to provide a pulse width modulated pulse width signal. Control device ( 100 ) according to claim 8, wherein the pulse width modulator ( 520 ) is configured to be based on a normal pulse width signal for normal operation of the synchronous machine ( 500 ) a changed pulse width signal for the emergency operation of the synchronous machine ( 500 ) to provide. Control device ( 100 ) according to claim 9, wherein the pulse width modulator ( 520 ) is _configured to provide a first pulse width signal with a fixed duty cycle PWM _fn of 0% or 100% for the control of the erroneous phase, and for the remaining phases x a modified pulse width _signal PWM _xn , the normal pulse width _signals PWM _f and PWM _x corresponds as follows: PWM _xn = (PWM _fn - PWM _f ) + PWM _x . Control device ( 100 ) according to one of the preceding claims, further comprising: a signal output which is designed to produce an output signal with information about the setpoint torque specification ( 102 ) to provide an operation of the synchronous machine according to the target torque specification ( 102 ) causes. Method for operating a multiphase synchronous machine ( 500 ) in one of a malfunction in a faulted phase of a supply voltage source ( 530 ) corresponding emergency mode of the synchronous machine ( 500 ), comprising: providing a target torque default ( 102 ), which varies from normal to normal operation of the synchronous machine ( 500 ) corresponding torque specification ( 240 ; 508 ), when a speed of the synchronous machine ( 500 ) is greater than a predetermined speed limit ( 210 ); and controlling the operation of the synchronous machine ( 500 ) based on the target torque specification ( 102 ). The method of claim 12, wherein the target torque command ( 102 ) with increasing speed of the torque specification ( 240 ; 508 ) up to a braking torque of the synchronous machine ( 500 ) is reduced at a limit speed. The method of claim 12 or 13, further comprising: determining a faulted phase in the supply voltage source ( 530 ). The method of claim 14, further comprising: operating the failed phase of the supply voltage source ( 530 ) with constant output voltage. Method according to one of claims 13 to 15, further comprising: short-circuiting the phases of the synchronous machine ( 500 ) when the limit speed is exceeded.  The method of claim 16, further comprising: cancel the short circuit when the speed falls below a second limit speed that is less than or equal to the limit speed. The method of any one of claims 12 to 17, further comprising: controlling the operation of the synchronous machine ( 500 ) based on the torque specification ( 240 ; 508 ), if the speed falls below a second speed limit that is less than or equal to the speed limit ( 210 ).  A computer program comprising program code for effecting the method of any one of claims 12 to 18 when the program code is run on a processor.

Images