Multivariable harmonic suppression of electric machine using inverse signal generation in spatial vector representation

Abstract

A control device for controlling an electric drive comprises a basic control loop having a deviation detection element (RA), an actuator (IRT) and a controlled system (RS). In a feedback section (FBG) of the basic control loop, the current intensity of the inverter (INV) is fed back as an actual value (IEM) in the feedback section. The basic control loop refers to the fundamental wave angular frequency ([omega] G), and the harmonic detection element (OE, RTO) is connected downstream of the feedback section (RS). The harmonic detection element determines an actual value (IEM) or a harmonic component (IO; Id (O), Iq (O)) in a supply signal of the inverter (INV). An inverse signal generating element (GSRZ) generates an inverse signal (GS) to be fed in, the inverse signal generating element (GSRZ) being arranged to generate an inverse signal (GS) from the harmonic component (IO) by two vectors represented by a spatial vector of the adjusted inverse signal. Id (O), Iq (O)) in order to minimize both the actual value (IEM) or the harmonic component (IO) in the supply signal and to reduce the harmonic component in the torque or to maximize the efficiency or performance.

Description

[0001] For example, it is known to provide an electric drive system for electric vehicles, in which a motor generates traction. In this case, not only is a rotational field generated at the desired speed (or, in the case of an asynchronous machine, a rotational field generated at the desired rotor speed), but also harmonic components are generated due to various effects. These harmonic components are undesirable and cause losses, noise, and similar side effects.

[0002] To suppress harmonic components, an inverse signal, out of phase with the interfering harmonics, can be generated such that when this inverse signal is fed in, at least partial cancellation is achieved. This active suppression (“active cancellation”) is based on an inverse signal with the correct amplitude and, most importantly, the correct phase (compared to the interfering signal) to enable its cancellation. By suppressing harmonics in the electro-actuation signal or DC supply current, the load on the DC link capacitor can be reduced, and excessively high voltage values ​​can be avoided. This can be used for the custom design of electrical and electronic components. Furthermore, harmonics, which are particularly detrimental to noise generation, appear not only in the actuation voltage or supply voltage but also in the torque curve.

[0003] Therefore, the object of the present invention is to demonstrate the possibility of actively suppressing electrical and mechanical harmonics in a simple manner.

[0004] This objective is achieved by the subject matter of claim 1. Further features, characteristics, embodiments, and advantages will become apparent from the dependent claims, the description, and the drawings.

[0005] A spatial vector representation of the generation of the inverse signal is proposed in the basic control loop of a motor. The spatial vector representation is based on two vectors representing different variables (such as magnetic flux density and torque), where these variables are phase-shifted relative to each other. These vectors can be viewed as two variables with a physical relationship between them (especially a physical relationship based on electromagnetic induction), which provides the time derivative shown in the phase shift. The first vector (e.g., the d-component [DC component] or α-component) specifically represents the magnetic flux density, while the second vector (e.g., the q-component [quadrature component] or β-component) represents the torque in the motor (possibly neglecting cross-dependency due to magnetoresistive effects). For example, the second vector represents the direct active variable (i.e., the in-phase variable, such as torque or the current or voltage component that generates the torque), while the first vector represents the phase-shifted reactive component (magnetic flux density). This involves a simplified model that does not consider magnetoresistive effects. In a model that takes magnetoresistive effects into account, these two vectors do not fully reflect their respective physical variables (flux density or torque). In a representation that also considers the magnetoresistive effect, one vector reflects a portion of the flux density and a portion of the torque, while another vector reflects different portions of the flux density and different portions of the torque. Because these two vectors reflect different portions of the flux density and different portions of the torque, they exhibit orthogonality with respect to the two variables, making it possible to use two vectors to adjust the two variables (even when they are entangled or not completely separated).

[0006] The second vector (in the simplified model without considering reluctance) refers to the harmonic torque (i.e., the oscillating force caused by harmonics) in the inverse signal, but it can also refer to efficiency or performance (maximum recoverable mechanical power). The first vector (in the simplified model without considering reluctance) relates to electrical variables, such as the harmonic current component in the phase current of a motor or the harmonic voltage or current component in the DC supply voltage of an inverter. Considering reluctance, these two vectors reflect torque and electrical amplitude respectively, but in different proportions, giving two adjustment options (degrees of freedom) for adjusting these two variables (harmonic torque and the harmonic components of the electrical variables) using these two vectors.

[0007] Therefore, minimizing electrical harmonic variables (minimizing phase currents or harmonic components in the supply voltage or supply current, typically minimizing harmonic components in the inverter's power supply signal [DC] or DC link) can be the first objective criterion for generating the inverse signal, while minimizing (oscillating) harmonic components in the torque as a mechanical harmonic variable, or efficiency or performance, can be the second objective criterion. Thus, the first control objective can be minimizing the ripple load of the DC link supplying the inverter, while the second control objective can be minimizing torque ripple, maximizing efficiency, or maximizing performance. Efficiency is preferably given by the ratio of electrical power received by the motor to mechanical power delivered by the motor (in the form of traction power). Performance is preferably given by the maximum mechanical power delivered by the motor (in the form of traction power). In particular, harmonics in the generated torque (which do not contribute to traction power) are associated with an undesirable reduction in the mechanical power delivered by the motor (in the form of traction power). Therefore, harmonics in the generated torque must be reduced, where the second control objective discussed can be minimizing torque ripple, or maximizing efficiency or performance, which may be affected by torque ripple. "Torque ripple" specifically refers to harmonics in torque.

[0008] Because the inverse signal vector representation (which includes two vectors) allows for the simultaneous pursuit of two objectives. Specifically, the control objective is the control objective of the harmonic control loop that includes the inverse signal generation element (as an actuator). Minimization does not necessarily refer to global maximum optimization; it can also refer to local minimization or reduction, and does not necessarily mean reducing to zero.

[0009] Therefore, it has been recognized that when generating an inverse signal in vector terms, both vectors can be used to optimize (minimize) two variables (i.e., the electrical harmonic variable and the mechanical harmonic variable, or the associated efficiency or performance) such that both variables can be reduced individually (at least partially) as part of the inverse signal generation, since the two vectors can be adjusted individually (to reduce in two target directions). As an additional secondary condition in inverse signal generation, the amplitude of the inverse signal can be minimized (or at least reduced).

[0010] This invention describes a control device for controlling an electric drive unit, particularly a traction drive unit of a vehicle. The drive unit has an inverter and a multiphase motor connected to the inverter. The motor has a stator, the windings of which are connected to the inverter. The inverter is configured to generate a rotating magnetic field in the stator by correspondingly actuating the windings. The inverter has a DC voltage side connected to a DC power supply terminal or DC supply voltage. Harmonics are generated in the DC supply voltage by switching events of the inverter, etc. The inverter generates multiphase currents (“phase currents”), thereby generating a rotating magnetic field in the stator. Harmonics also appear in the currents due to the operation of the motor, the switching events of the inverter, and possible other effects. These current harmonics or harmonics in the DC supply voltage are reduced by a reverse signal. However, the reverse signal is preferably not injected directly into the supply voltage or phase current, but rather combined with a signal present therein in the control device to reduce the corresponding harmonics. In particular, with respect to AC loads, harmonic reduction lightens the load on the DC link (or DC supply voltage). This specifically reduces the load (including the AC component) on the DC link capacitor. Oscillatory effects in the torque, which originate from harmonics, are also reduced. This reduces noise generation.

[0011] The control device is preferably designed for vector control.

[0012] The control device has a basic control loop, which includes a deviation detection element, an actuator, and a controlled system. The controlled system includes an inverter and a motor. The actuator preferably has an inverter actuation element. This generates a switching signal for the inverter's switching element. The switching signal is preferably a pulse-width modulation signal. The input variable of the actuator is a control variable, preferably represented by a spatial vector. The control variable is, in particular, a voltage signal having d-components and q-components, or a voltage signal having an active component (torque-q component) corresponding to a second vector of the spatial vector transformation and a reactive or orthogonal component (magnetic flux density or excitation-d component) corresponding to a first vector of the spatial vector transformation. The vectors do not necessarily have to reflect purely active and purely orthogonal variables, but rather different weights on these components (i.e., phase offsets between vectors represented by spatial vectors > 0) are sufficient to reflect the manipulated variable (complex, i.e., with phase information). A simplified model that does not consider magnetoresistance effects allows one vector to be directly assigned only to the active component and the other vector to the reactive component only. If magnetic reluctance is considered, one vector is assigned to both the active and reactive components, and the other vector is directly assigned to both. However, since assigning one vector to two components is different from assigning another vector to both, these vectors can be used to adjust the two components (considering the cross-dependency of the vectors relative to the components). By adjusting these two vectors, the two components can be adjusted, and in particular, their minimization can be achieved with or without considering cross-dependency and magnetic reluctance effects.

[0013] The actuator is preferably designed for inverse space vector transformation or has a corresponding transformation device. The actuator generates switching signals in the time domain (particularly in the form of pulse width modulation). These switching signals are suitable for actuating a (multiphase) inverter. The actuator is connected to the inverter for actuation purposes. The switching signals affect different phases (U, V, W) of the inverter. The pulse width modulation of the switching signals is performed based on control variables represented as space vectors.

[0014] The basic control loop (like any control loop) has a feedback section. This feedback section feeds back (as a controlled variable) the current flowing between the inverter and the motor, or the current flowing in the motor or supplied by the inverter. In this case, the current is fed back as a signal or variable representing the flowing current. The current (or the variable representing the current) is fed back as an actual value (or as a controlled variable). A measuring device can be provided to acquire the actual value (of the controlled system, inverter, or motor), particularly the current. The current is fed back for deviation detection purposes, i.e., it is fed back to a deviation detection element. The deviation detection element is configured to determine the error (or difference) between the fed-back actual value and the target value. The result is output as a controlled difference to, for example, a control element in the basic control loop. If the target value is represented by a spatial vector, a spatial vector transformation element is provided in the feedback section that transforms the (multiphase) actual value, represented in the time domain, into a spatial vector representation of the actual value. If a target value in time domain representation is input at the input (target value input), another space vector transformation element can be provided for the target value between the deviation detection element and the input. If the target value is in time domain representation, the actual value can also be fed to the deviation detection element in time domain representation. A subtraction element can be set in the feedback section to subtract the inverse signal, so that the inverse signal fed / modulated into the control variable can become effective and not be unintentionally suppressed by the control device (e.g., by the controlled element). Furthermore, not only the target value (speed, torque) can be input at the target value input, but also operating parameters or secondary condition parameters, such as the current temperature of the motor and / or inverter, and / or the amplitude of the DC voltage forming the supply voltage of the inverter, or the ripple strength of the DC voltage. Therefore, this input can have target value inputs for speed and torque and actual value inputs for (actual) operating parameters. However, only the input target value (speed, torque) is input to the deviation detection element; the operating parameters (actual variables of secondary conditions) are specifically output to the inverse signal generation element of the control device.

[0015] The basic control loop references a fundamental angular frequency. This is particularly applicable to the variables of the basic control loop (target variable, actual value, error or deviation or controlled difference, output variable upstream of the control element of the basic control loop, etc.), which can be provided as spatial vectors. In this case, the corresponding variable refers to a rotational vector representation, where the angular velocity of this rotation corresponds to the fundamental frequency. Therefore, the spatial vector representation can have a phasor whose angular frequency corresponds to the fundamental angular frequency.

[0016] Angular velocity depends in particular on the electric angular velocity of the motor (or the power signal emitted by the inverter), and therefore also on the speed of the motor.

[0017] The control device has a harmonic detection element. The harmonic detection element is configured to detect harmonic components from actual values ​​(existing in the time domain or represented as a spatial vector). The harmonic detection element is configured to detect at least one harmonic component from the actual values ​​by Fourier analysis (particularly discrete Fourier analysis), by bandpass filtering, or by integrating a signal generated by modulation at at least one harmonic frequency. A harmonic component refers to a harmonic relative to the fundamental frequency, and specifically includes at least one AC component whose frequency corresponds to n times the fundamental frequency, where n = an integer and > 1. The harmonic detection element can be configured to generate harmonic components by transforming the actual values ​​(multiphase) into a spatial vector representation, wherein the spatial vector representation is rotated at the harmonic angular frequency of the basic control loop (relative to the fundamental angular frequency). Based on this spatial vector representation of the reference harmonic angular frequency (“harmonic spatial vector representation”), the harmonic intensity of the harmonic angular frequency can be determined by absolute value formation. The phase position is determined based on the phase position of the vector in the spatial vector representation. To identify harmonics with different harmonic angular frequencies, the actual values ​​can be transformed into multiple spatial vector representations with different harmonic angular frequencies. Harmonic detection elements are preferably configured for this purpose. The harmonic detection element can be connected downstream (corresponding to the feedback section) of a measuring device (phase current measuring device) that detects or determines the actual values. The harmonic detection element is connected downstream of the feedback section of the basic control loop in such a way that it receives the actual values ​​transmitted in the feedback section. The harmonic detection element receives the actual values ​​(phase currents from the inverter / motor) as signals represented in the time domain (multiphase) or as spatial vectors.

[0018] The control device has an inverse signal generating element configured to generate an inverse signal. The inverse signal is complementary to the harmonics and thus can at least partially compensate for these harmonics (when combined). Specifically, the inverse signal is phase-shifted by 180° relative to the detected harmonics or the signal reproducing these harmonics (including phase information). The inverse signal generating element receives the harmonics or the signal reproducing these harmonics (preferably including phase information). For this purpose, the inverse signal generating element is connected downstream of the harmonic detection element. The inverse signal is combined with the harmonics within the control device (or with the signal containing these harmonics). The inverse signal is combined with the control variable of the actuator. This is performed by means of a feed element. The control variable preferably corresponds to a voltage signal input to the actuator. The voltage signal preferably exists in a spatial vector representation, but may also exist in the time domain. When the control variable exists in a spatial vector representation, the inverse signal preferably exists in a spatial vector representation. When the control variable exists in the time domain, the inverse signal preferably exists in the time domain. For this purpose, the representation of the inverse signal or the control variable can be adjusted by means of a transformation between the spatial vector representation and the representation in the time domain. The control element is preferably connected downstream of the deviation detection element, and the feed element is then connected downstream of the control element. The feed element is preferably connected upstream of the actuator. The feed element combines the inverse signal with the control variable, and thus at least partially compensates for harmonics present in the control variable.

[0019] The inverse signal generating element is configured to generate an inverse signal from the harmonic components determined by the harmonic detection element. The inverse signal is provided in spatial vector representation either by determining the harmonic components in spatial vector representation using the harmonic detection element or by converting the signal emitted by the harmonic detection element (which indicates the harmonic components) into a spatial vector representation. The spatial vector representation of the harmonic components is based on a vector rotating at the harmonic angular frequency (i.e., at an angular frequency greater than the fundamental angular frequency).

[0020] The inverse signal is displayed as a spatial vector representation based on two rotation vectors. The spatial vector representation specifically provides two rotation axes that are perpendicular to each other (or generally angularly offset). When the axes are perpendicular, the spatial vector representation involves a complex representation, where the two axes correspond to the real and imaginary components of the complex representation, respectively.

[0021] These vectors are phase-shifted relative to each other by a fixed angle, specifically 90°. This allows for multiple degrees of freedom in generating the inverse signal, especially since the absolute value and phase of the inverse signal can be represented by almost any linear combination of these vectors. The same applies if, considering magnetoresistance effects, the two vectors involve the active and reactive components (of the harmonic inverse signal), but these vectors are assigned to the active or reactive components in different ways. Even with this cross-dependency of the vectors relative to the components, each of these two components can be adjusted, and in particular, minimized.

[0022] When generating the inverse signal, multiple optimization objectives can be achieved. As a primary (first) optimization objective, the harmonic components, i.e., the harmonic components output by the feed element (as a control variable of the actuator), can be minimized. As an additional (second) optimization objective, the harmonic components in the motor torque (or the harmonic components in the DC supply voltage of the inverter; alternatively, this corresponds to the primary optimization objective). Additionally, one of these objectives can be maximizing (or improving) efficiency or performance. The inverse signal generation element is configured to optimize according to these two optimization objectives. The inverse signal generation element can be configured to execute the corresponding optimization algorithm. Alternatively, for different harmonic amplitudes, harmonic phases, and / or harmonic angular frequencies (“optimized input values”), vector parameters optimized according to these optimization objectives are stored in the inverse signal generation element. In particular, the vector parameters reproduce at least one phase angle and at least one amplitude of the two vectors of the inverse signal. The inverse signal generation element is preferably configured to retrieve the associated, optimized vector or vector parameters of the optimized input values. The optimized input values ​​and associated vector parameters can be stored in a lookup table within the inverse signal generation element, or as parameters of an approximate equation. The inverse signal generation element is preferably configured to compute the optimized vector using an approximate equation (in approximate form). Both of these variations require less computation than real-time optimization.

[0023] Therefore, in addition to deviations in the basic control loop, the inverse signal is also essential for the control variables. Thus, besides control based on the basic control loop, harmonic suppression can be implemented in the actual values ​​and motor torque of the (basic control loop) by modifying the control equipment (harmonic detection element, inverse signal generation element) according to harmonics. In addition to the harmonic components in the actual values, the inverse signal generation element receives harmonic components in the motor torque, which are specifically obtained through torque detection or by deriving the harmonic components in the torque from the operating variables of the inverter and / or the motor. Furthermore, the inverse signal generation element receives efficiency or performance, or variables characterizing efficiency or performance.

[0024] The spatial vector representation based on the fundamental angular frequency can be related to the rotation of the rotor and can be static relative to the rotor. However, the inverse signal and harmonic components rotate relative to the rotor by a multiple, especially when the inverse signal is fed into the element. If the inverse signal or harmonic components involve n times the fundamental frequency, then the inverse signal and harmonic components exist as harmonic angular frequencies corresponding to n times the fundamental angular frequency. The inverse signal (especially when it exists as a spatial vector representation) can be modulated by a desired multiple of n, that is, modulated using a cosine or sine signal whose frequency corresponds to the harmonic angular frequency. For this purpose, a modulator (for the signal in the time domain or for the spatial vector representation) can be provided. When the inverse signal is fed in as a time-domain signal, the inverse signal is combined as a signal modulated by the harmonic angular frequency. Therefore, the harmonic components to be reduced and the inverse signal have the same frequency (i.e., the frequency corresponding to the harmonic angular frequency), such that at a suitable phase position, the harmonic components can be at least partially canceled.

[0025] When calculating harmonic components represented as spatial vectors, it is necessary to consider whether the representation references the rotor or the stator. This depends on the type of spatial vector representation (d, q representation or α, β representation). Differences arise if the fundamental spatial vector representation of the relevant manipulated variable is fixed to the stator or has rotated with the rotor and is therefore fixed to the rotor. In this case, the harmonic components represented as spatial vectors are obtained by mapping the actual values ​​(represented by spatial vector representations based on the fundamental angular frequency) using spatial vector representations based on the harmonic angular frequency.

[0026] Harmonic detection elements can also take the form of high-pass or band-pass filters. These filters are configured to block the fundamental angular frequency while allowing harmonic angular frequencies to pass. Specifically, the filters are designed to attenuate the fundamental angular frequency by at least five dB, ten dB, 20 dB, or 30 dB more than the harmonic angular frequency, or a frequency more than twice the harmonic angular frequency, or its reciprocal, or a frequency more than four times the harmonic angular frequency, or its reciprocal. In addition to the signal strength (amplitude) of the harmonics(s), the filter also reflects the phase position in question. Alternatively, harmonic detection elements can also take the form of spectrum analysis devices, such as those performing Fourier transforms. These spectrum analysis devices are designed to extract the components of the harmonic angular frequencies, particularly along with the phase positions of these components. The harmonic detection element and the inverse signal generation element are designed to handle one or more different harmonics.

[0027] Considering the angular relationship between the control variables (d and q components of voltage) and the controlled variables (i.e., actual values ​​or multiphase currents) in the controlled system, the harmonic components are mapped to the inverse signal.

[0028] Therefore, the spatial vector representation of the inverse signal is preferably reproduced by two rotational axes fixed at a fixed angle to each other, these two rotational axes are not parallel and specifically form a 90° angle. Thus, the spatial vector representation of the inverse signal can be particularly complex, with the real axis offset by 90° from the imaginary axis. The inverse signal calculation element provides a first reduction condition, namely, the minimization of harmonic components in the power signal, which can be satisfied using only one axis of the spatial vector representation or using both axes, while preserving (another) degree of freedom. "Power signal" refers to the actual value or (multi-phase) phase current of the motor or inverter, or the power supply signal of the inverter (representing the inverter's DC voltage supply or DC supply). The power signal is an electrical variable. This results in an underdetermined system. These two axes generate two degrees of freedom, allowing the first degree of freedom to be used to minimize the harmonic components in the power signal as a first optimization objective, while the other axis can be chosen substantially freely, for example, according to an additional (second) optimization objective. The additional optimization objective could be to minimize the harmonic components present in the motor torque, or to maximize efficiency or performance. Therefore, the additional optimization objective involves mechanical variables, but an electrical equivalent can exist, based on which optimization can be performed. The two optimization objectives can affect the two vectors represented by spatial vectors at once, or one optimization objective can affect one of the two vectors represented by spatial vectors, while the other optimization objective affects the other of the two vectors.

[0029] It can be specified that the inverse signal calculation element is configured to map the value of one of the vectors calculated for the inverse signal according to a first reduction condition or a first optimization objective, while the value source specifies the associated values ​​of other axes. Preferably, one vector is assigned to only one mechanical variable (torque) and the other vector is assigned to only an electrical variable (current, voltage). In particular, considering the cross-dependencies between the two vectors on one hand and between the two variables (mechanical variable, electrical variable) on the other, it can be specified that vector value pairs having a first vector value and a second vector value are assigned to different harmonic value pairs, each of which has a harmonic value for the power signal and a harmonic value for the torque. The vector value indicates the value of the vector whose harmonic components are minimized or reduced when associated harmonic value pairs exist. This assignment can be implemented using multidimensional lookup tables combined with approximation functions, etc. The assignment can be based on calculations, particularly model-based calculations involving the inverter and / or motor used; or these calculations can be the results of tests based on existing motors / inverters; or a combination of both, such as interpolation test results performed through model-based calculations.

[0030] Therefore, in addition to the basic control loop, the control device can have a harmonic control loop that generates an inverse signal, represented by a spatial vector (having two vectors), based on two control objectives. The actual parameters of the harmonic control loop are the harmonic components (or the strength of their (electrical) power signals) or the harmonic components in the motor torque from which they can be derived. Thus, the actual parameters are a pair of values ​​or a vector containing two entries. The inverse signal generating element serves as the actuator in the harmonic control loop, where, for example, each harmonic component is considered an error deviating from 0, corresponding to a deviation detection of the harmonic. In this case, the harmonic spatial vector transformation of the actual values ​​(if present in the time domain) can be considered as a deviation detection of the harmonic (deviation of 0). The feed of the inverse signal to the basic control loop (or its control variables) is used as the execution part of the actuator(s) of the harmonic control loop. (The remainder of the specification and...) Figure 1 Additional features are shown that are particularly associated with the spatial vector representations of harmonics and fundamental frequencies.

[0031] The feedback section of the basic control loop preferably includes a subtraction element. This subtraction element is configured to subtract a harmonic component from the actual value transmitted by the feedback section, wherein the resulting signal (i.e., the difference) is transmitted from the subtraction element within the feedback section. In this way, the effects of the (detected) harmonics are suppressed within the feedback section, preventing the basic control loop from altering the manipulated variable due to harmonic components. Alternatively, it can be specified that the subtraction element subtracts the inverse signal from the controlled variable, rather than subtracting the harmonic component from the controlled variable.

[0032] The subtraction element operates in spatial vector representation; therefore, subtraction is performed using variables present in the spatial vector representation. The actual value (or the relevant variable being fed back) is input to the subtraction element in spatial vector representation. Harmonic components or inverse signals are also output to the subtraction element in spatial vector representation. For this purpose, harmonic components in, for example, the actual value (or power signal) can be detected in spatial vector representation, or acquired as a time signal and transformed into spatial vector representation via harmonic spatial vector transformation (before being supplied to the subtraction element). The subtraction element receives the actual value (typically, the fed-back variable) in the form of a spatial vector representation based on a rotation at the fundamental angular frequency. Since the spatial vector representation of the harmonic component or inverse signal used to subtract from the controlled variable should also reference the fundamental angular frequency, the harmonic component or inverse signal is output to the subtraction element in the form of harmonic angular frequency modulation. Therefore, a modulator that modulates the variable fed back at the harmonic angular frequency can be connected upstream of the subtraction element. Therefore, the subtraction element receives a harmonic component or inverse signal that is represented as a spatial vector based on the fundamental angular frequency but modulated by the harmonic angular frequency, taking into account the fact that the feedback section transmits the controlled variable as a spatial vector representation based on the fundamental angular frequency, and that the harmonic component has a higher frequency, i.e., the harmonic angular frequency. If the inverse signal is fed in instead of the harmonic component, the output to the subtraction element is not the fundamental source signal, but a version of the fundamental source signal rotated 180 degrees or a version of the fundamental source signal multiplied by negative 1.

[0033] The subtraction element is located in the feedback section of the basic control loop, in the part where the signal is transmitted in the form of a space vector. Here, the space vector represents the reference fundamental angular frequency. The subtraction element also subtracts harmonic components represented by a space vector, which is based on the harmonic angular frequency.

[0034] It can be stipulated that the harmonic space vector transformation transforms the actual value (or power supply signal) existing in the time domain into a space vector representation for propagation, particularly to the subtraction element or the inverse signal generation element. Since the output of the harmonic space vector transformation is ultimately introduced into the basic control loop, whose space vector transformation also references the fundamental angular frequency, the harmonic components in the power signal are transformed according to the ratio of the harmonic angular frequency to the fundamental angular frequency. The latter is first used to subtract the space vector representation to rotate its coordinate system at the same angular frequency (fundamental angular frequency), taking into account the fact that the harmonic components rotate faster (i.e., at the harmonic angular frequency) compared to the signal represented by the space vector in the basic control loop. This latter is achieved through a space vector transformation based on the ratio of the harmonic angular frequency to the fundamental angular frequency (applicable to both positive and negative harmonic angular frequencies; negative harmonic angular frequencies involve the inverse rotating harmonic system).

[0035] A further embodiment specifies a two-part linear controller between the deviation detection element and the subsequent feed element of the inverse signal. This controller specifically has a first controller section and a second controller section. The first controller section relates to a first axis represented by a spatial vector, and the second controller section relates to a second axis represented by a spatial vector. Specifically, the first controller section may relate to the real axis of the spatial vector representation of the signal transmitted in the controlled system, and the second controller section may relate to the imaginary axis of the spatial vector representation. Therefore, these controller sections also operate using signals represented by spatial vectors. This simplifies control. Each of these controller sections is preferably a linear controller, such as a PID controller. These controller sections are preferably not intertwined and are controlled independently. Each of these controller sections is particularly a continuous-action controller.

[0036] A limiter can be connected downstream of the inverse signal generation element or the inverse signal calculation element. The limiter reduces the amplitude of the spatial vector representation of the inverse signal. Preferably, the limiter is connected upstream of the modulator, through which the limited signal is output to the inverse signal feed element. Alternatively, the limiter is connected downstream of the modulator to provide amplitude limitation for the modulated inverse signal (in spatial vector representation). The limiter is also suitable for signals provided in spatial vector representation, particularly in spatial vector representation with a reference rotated at the fundamental angular frequency.

[0037] Sensors, particularly angle sensors, can be arranged on the motor, or alternatively, a unit can be arranged to determine the current rotor angle of the motor, for example, by power signals (current and / or voltage signals) used to operate the motor. The angle signal output by the sensor can be output to the input of a harmonic detection element. The harmonic detection element is configured to reference the angle signal to the power signal of the motor or the power signal output by the inverter, so as to output a spatial vector representation of the harmonic components and the correct angle. The angle signal is preferably adapted to the variable used by the harmonic detection element to operate, wherein the harmonic detection element receives a modulation signal. Thus, at least one harmonic modulator can be provided to modulate the angle signal so that it is adapted to the rotation of the spatial vector representation of the harmonic detection element. In particular, two harmonic modulators can be provided to modulate the angle signal, one for modulating the angle signal at a frequency corresponding to the harmonic angular velocity plus 1 (corresponding to the rotation of the basic system or rotor) or plus 2π (corresponding to the rotation of the basic system or rotor expressed as angular velocity), thereby generating a harmonic system rotating in the same direction. Another modulator can be configured to multiply the angle signal by 1 (based on a single velocity of the fundamental angular velocity) or 2π (based on a single fundamental angular velocity) and subtract the difference in harmonic angular velocities, thereby producing a harmonic system rotating in the opposite direction. These modulation factors take into account the fact that the spatial vector representation of the fundamental control loop has already rotated at the fundamental angular velocity and is therefore fixed to the rotor rather than the stator; and that the harmonic components rotate relative to the fundamental component and are therefore rotating relative to the rotor rather than the stator. In other words, the angle signal is modulated to produce harmonic systems rotating in the same direction and in the opposite direction, which rotate relative to the fundamental system fixed to the rotor at the harmonic angular frequency, or at the ratio of the harmonic angular frequency to the fundamental angular frequency, and the rotation at the fundamental angular frequency already implies a single rotation (1 and 2π respectively), while the harmonic system is mounted on the already rotating fundamental system.

[0038] Downstream of the target input can be a transformation or mapping element that converts the input value into a variable represented by a space vector, specifically into a variable controlled by the input. This transformation can be called a space vector transformation and can also include converting the target variable (speed, torque) into a target current (represented by a space vector or as its parameter). This produces currents Id and Iq represented by space vectors. The actuator of the basic control loop, in the form of an inverse space vector transformation element, receives the controller's output variable (after the inverse signal is fed in as a space vector and modulated with harmonic angular frequencies to adapt to the fundamental-related space vector representation in the basic control loop). Through this variable, the inverse space vector transformation element of the basic control loop generates a (multiphase) signal in the time domain for actuating the inverter. This signal is pulse-width modulated and input to the inverter's control input.

[0039] According to one embodiment, the inverse signal generating element can be designed to be optimized according to the following three optimization objectives: (i) minimizing harmonic components in the actual value, (ii) minimizing harmonic components in the power supply signal, and (iii) reducing harmonic components in the motor torque, or maximizing efficiency or maximizing performance (i.e., the maximum recyclable or transportable mechanical traction power).

[0040] Another embodiment specifies that the provided inverse signal, represented by spatial vectors, generates two voltage vectors perpendicular to each other, where a first vector represents the harmonic flux density and a second vector characterizes the harmonic torque. Specifically, when considering magnetoresistive effects (or generally cross-dependencies between vectors and variables), the first vector represents at least a portion of the flux density (and a portion of the torque), and the second vector represents a (different) portion of the torque (and a different portion of the flux density). Therefore, cross-dependencies may exist between these vectors and the two variables, but these do not prevent optimization / minimization or a sufficiently accurate representation of the two variables. If these variables are divided into two vectors that have separate effects on their respective variables, the second vector is adjusted based on minimizing the harmonic component in the torque (or maximizing efficiency or performance), depending on the harmonics. The first vector can be adjusted based on minimizing the reactive component, which is provided by or corresponds to the harmonic component within the actual value. Both vectors can be adjusted to adjust or minimize / optimize the harmonic component in the torque and adjust or minimize / optimize the reactive component.

[0041] It can be specified that the inverse signal generation element is configured to generate an inverse signal from harmonic components by adjusting two vectors represented by spatial vectors, so as to minimize harmonic components in the actual value and / or power supply signal, reduce harmonic components in motor torque, and also reduce the signal strength of the inverse signal. Therefore, minimizing the signal strength of the inverse signal can be provided as an additional control objective, or the inverse signal can be generated at the lowest possible amplitude (without affecting other control objectives).

[0042] The inverse signal generating element is preferably configured to minimize harmonic components in the actual value and / or the power supply signal when generating the inverse signal as a first requirement (or as a control objective). A second requirement (or additional control objective) may also be specified to minimize harmonic components in the motor torque, maximize efficiency, or maximize performance. The first and second requirements can be incorporated into the generation of the inverse signal according to corresponding predetermined weights. Therefore, all or at least two of the aforementioned control objectives can be provided simultaneously (effectively or simultaneously) for the design of the inverse signal generating element, wherein the objectives are weighted relative to each other, particularly where pursuing one objective leads to a change in the pursuit of another objective.

[0043] The harmonic detection element can be configured to determine the harmonic component as the signal strength and associated phase position. In particular, the harmonic component can be determined together with the load angle and / or power factor.

[0044] For harmonic detection, there are several ways to generate harmonic components from actual values ​​or supply signals (typically power signals). For example, harmonic components can be generated from the power signal (actual value or supply signal, DC) through Fourier analysis, bandpass filtering, integration after modulation at at least one harmonic frequency, or by transforming the actual value (or supply signal or its AC component) into a spatial vector representation (which represents a reference harmonic angular frequency). Typically, the harmonic components of the actual value or the harmonic components of the supply signal (or its AC component) can be determined, or both harmonic components can be determined.

[0045] The harmonic detection element is preferably configured to determine the harmonic components in the actual value (and / or power supply signal) as a discrete spectral representation of the harmonic components having an associated frequency-specific phase position, a time-domain representation of the harmonic components, or a spatial vector representation rotated at the harmonic angular frequency. In particular, the harmonic components are determined together with phase information.

[0046] The actual value can be fed back to the deviation detection element as a multiphase signal in the time domain, or it can be fed back as a spatial vector representation rotated at the harmonic angular frequency. The latter can also be applied to the harmonic components in the power supply signal.

[0047] An embodiment of the control device includes an inverse signal modulator configured to modulate at a harmonic angular frequency. An inverse signal generating element can be connected via the inverse signal modulator to a point in the basic control loop located between the actuator and the deviation detection element. The modulator is used to adapt the inverse signal to an angular frequency (fundamental angular frequency) that forms the basis of the signal representation in the basic control loop.

[0048] Another embodiment of the control device includes a harmonic modulator. The harmonic modulator is configured to modulate at a harmonic angular frequency. A harmonic detection element is preferably connected via the harmonic modulator to a feedback deviation detection element (SUB), which is disposed in the feedback section, preferably between the actual value tap (measuring device) or a point downstream of the actual value tap where the feedback and pilot variables (pilot / forward section) or control section of the deviation detection element or basic control loop meet. The feedback deviation detection element is specifically configured to subtract the signal of the harmonic modulator from the signal of the feedback section or to determine the difference between these variables.

[0049] An electric vehicle traction drive may be equipped with a motor and an inverter, as well as control equipment as shown herein. The control equipment is specifically connected to the inverter (and, if necessary, to the motor or associated measuring equipment) for actuation or signal transmission purposes.

[0050] The spatial vector representations mentioned here (especially the d and q representations) are generated, for example, by the Park transform. Alternatively, the spatial vector representations can be representations of positive and / or negative phase sequence systems with symmetric components, generated, for example, by the Fortescue transform. The spatial vector representation is preferably the spatial vector representation of the reference rotor. Alternatively, the spatial vector representation of the reference stator can be used, such as the spatial vector representation generated by the Clarke transform. Therefore, the spatial vector representations can also be α and β representations.

[0051] Regarding the objective of minimizing the harmonic components of the power supply signal (or the harmonic components in the actual value, especially when the harmonic components in the actual value are reflected in the signal mentioned above), the following considerations can be provided: After simplification, the control objective can be expressed as the following condition: (Equation 1) in: -P_VE: Power of harmonic components at the inverter's power input. -I_d': The first component of the space vector representation of current I -I_q': The second component of the spatial vector representation of current I -U_d: The first component of the space vector representation of voltage U -U_q: The second component of the spatial vector representation of voltage U Wherein, current I indicates the current at the inverter control output or in the motor, voltage U indicates the voltage at the inverter control output or in the motor, the suffix (ω_O) of the variable indicates the reference harmonic angular frequency represented by the space vector of the variable, the suffix (ω_G) of the variable indicates the reference fundamental angular frequency represented by the space vector of the variable, and the variable's reference numerals correspond to... Figure 1 The accompanying figure labels.

[0052] Variables P_VE, I_d', I_q', U_d', and / or U_q' can also be standardized variables, for example, normalized to total power, nominal current, operating current (RMS value), nominal voltage, or operating voltage, respectively. If the spectral range of the relevant variables is to be considered, the character ' The ' character can represent convolution, or multiplication if the relevant variable is a scalar (e.g., a scalar represented by a spatial vector).

[0053] Therefore, in short, the condition (control objective: minimizing harmonic components in the supply signal) can be represented by (minimizing) the sum of all products consisting of the spatial vector components of the current and voltage, where the two factors of each product relate to spatial vector representations of different angular frequencies (fundamental angular frequency or harmonic angular frequency). In this case, current and voltage relate to the inverter control output or the motor. Equation I_d U_d + I_q U_q = 0 can be provided as one of several control objectives or reduction conditions. As one of several control objectives, it can also be specified that the d-components and q-components of the harmonic components in the phase current are minimized (e.g., minimizing I_d'(ω_O) and I_q'(ω_O)). Additionally, as one of several control objectives, it can be specified that the amplitude of the inverse signal is minimized, for example, by minimizing signals U_q(O), U_d(O), or combinations thereof (e.g., their sum or the square root of the sum of squares of these signals). This is particularly applicable to the space vector representation of the inverse signal, where minimizing the moving average of the instantaneous power of the inverse signal can also correspond to one of several control objectives.

[0054] Figure 1 The symbols used are intended to explain the control device described herein and the control method implemented by the control device, using exemplary embodiments.

[0055] Figure 1 A control device with a basic control loop GRK is shown, which has a controlled system having a target value input EG, a subsequent deviation detection element RA, an actuator IRT (designed for pulse width modulation), and an inverter connected downstream of the actuator IRT. The inverter is used to actuate the motor.

[0056] The feedback section FB_G of the basic control loop feeds back the current signals (I_U, I_V, I_W) of the inverter INV to the deviation detection element RA. The basic control loop GRK operates (partially) using signals represented as spatial vectors, characterized by adding d and q to the two vectors in the spatial vector representation. The spatial vector representation within the basic control loop GRK is based on the fundamental angular frequency ω_G. Specifically, between the actuator IRT, which transforms signals U_d and U_q into pulse-width modulated signals in the time domain, and the spatial vector transformation RT_G within the feedback section FB_G, a (multiphase) signal representation in the time domain is used, particularly with respect to the pulse-width modulated signal. In other cases, spatial vector representation (refer to ω_G) is used in the basic control loop GRK.

[0057] Figure 1 The harmonic control loop ORK within the control device is also shown. Power signals (such as multiphase currents I_U – I_W) and / or supply signals (such as the supply voltage U_HV or supply current I_HV of the inverter INV) are used as inputs. In particular, the harmonic components of these power signals (especially their signal strength, and, where applicable, phase information) are used as inputs. Figure 1 One of several possible configurations for determining harmonic components is shown, in which, Figure 1An exemplary determination of the harmonic components of the phase currents I_U – I_W is shown in more detail. According to this variation, the power signal is reproduced using a space vector representation based on the harmonic angular frequency. Since components without a reference harmonic angular frequency are canceled out in this case, the relevant harmonic components (already shown in space vector representation), see reference numeral RZO. The harmonic control loop ORK has an inverse signal generation element GS_RZ connected downstream of the input. This is represented symbolically by the reduction condition RBF, where the inverse signal generation element GS_RZ provides not only the reduction condition RBF (as an objective, which aims to minimize harmonic components or in the supply signal), but also, as an additional objective, to reduce harmonic components in the motor torque, or to maximize efficiency or performance. For the latter objective, the calculation of the torque (of the harmonic components) of the motor EM is provided in the harmonic control loop ORK, or the harmonic components of the torque are already minimized within the inverse signal generation element GS_RZ or within the reduction condition RBF. Torque (and its harmonic components) can be derived from the phase current (represented in the time domain or as a spatial vector) and the magnetic characteristics of the motor (especially its inductance), preferably considering the mass moment of inertia relative to the harmonic components. Specifically, torque is derived from the phase current in the motor and the resulting magnetic flux. The inverse signal generation element GS_RZ or reduction condition RBF can be considered as a harmonic deviation detection element, in which the target value of the harmonic is zero or corresponds to a minimum value (the minimized desired value), and the actual value of the harmonic corresponds to the harmonic components in the actual value of the basic control loop or in the power supply signal, or to the harmonic components in the torque. An inverse signal is generated based on the deviation (from zero or the minimum value).

[0058] The input variables for the harmonic control loop ORK are the actual values ​​(inverter current / motor phase current) or the harmonic components in the supply signals U_HV or I_HV. These harmonic components can be obtained from these input variables (which exist in the time domain) by means of a space vector transformation RT_O with reference to the (to be considered) harmonic angular frequency ω_O. For example, in this case, the 6th harmonic is considered to be ω_O = 6. ω_G. Here we consider the current angle θ(t). The spatial vector representation of the harmonic components includes both a spatial vector representation that rotates (in the same direction) with the fundamental-related spatial vector representation (i.e., the reference ω_G) and a spatial vector representation that rotates in the opposite direction (in the opposite direction). To properly handle the existing reference to the fundamental-related representation, for the spatial vector representation of the harmonic components, we obtain a component rotating in the same direction with an angular velocity of ω_G + ω_O (in the example of the 6th harmonic: 1 + 6 = 7) and a component rotating in the opposite direction with an angular velocity of ω_G - ω_O (in the example of the 6th harmonic: 1 – 6 = -5). This is demonstrated by harmonic modulation OM, where the modulation of ω_G utilizes (-5) and (+7), that is, corresponding to the -5th harmonic (order -5) and the 7th harmonic (order +7), respectively.

[0059] The harmonic component RZO generated by the space vector transformation RT_O is thus input to the modulator MOD' downstream of an optional low-pass filter TP, and most importantly, it is also input as I_d(O) and I_q(O) (i.e., as the space vector representation I_O_RZ) to the inverse signal generation element GS_RZ, which also operates using a signal represented in a space vector. Instead of the above-described harmonic detection based on the space vector representation (refer to RT_O), the harmonic components can also be determined by a harmonic detection element OE operating in the time and / or frequency domains from the actual values ​​I_U – I_W and / or from the supply signal (present in the time domain). This is illustrated by the dashed line connected to the harmonic detection element OE. The result is a representation of the harmonic component I_O, which is fed to the inverse signal generation element GS_RZ and, if necessary, converted to a space vector representation before being supplied. The harmonic detection element OE preferably also receives the angle θ(t) of the motor EM in order to output the harmonic components in a phase-dependent or angle-dependent manner.

[0060] In addition to the harmonic component I_O_RZ, the inverse signal generation element GS_RZ also receives the actual value I_dq(G) and the control variable (the output variable of the controller REG) U_dq(G). The inverse signal generation element GS_RZ operates using two components, denoted as d and q, in a spatial vector representation. The inverse signal generation element GS_RZ has a reduction condition RBF, which relates to the two components in the spatial vector representation. Multiple degrees of freedom exist with respect to the control objective, allowing multiple control objectives to be pursued simultaneously.

[0061] The first control objective or the first condition A of the reduction condition minimizes the harmonic components in the actual value I_EM. This is in Figure 1 The following equation represents I_d,q U_d,q (O) = 0 (Full form: I_d) U_d + I_q U_q = 0), which provides the power I of the harmonic (O) in a symbolic manner. The zero value (or minimum value) of U. The second condition B of the second control objective or reduction condition can reduce the harmonic component T_O in the motor torque. In alternatives not shown, efficiency or performance can be maximized. The reduction of the harmonic component T_O in the motor torque is represented symbolically by the equation T_O = min, where "min" is the minimum value. The third condition C of the third control objective or reduction condition can reduce the harmonic component in the power supply signal U_P (in this case, U_P represents the power signal supplied to the inverter, i.e., the voltage, current, or power signal generated by U_HV and I_HV). This is represented symbolically by the equation U_P = min, where "min" is the minimum value. Objectives A and B (excluding objective C), objective B and C (excluding objective A), or objective A and objective B and objective C can be provided as a set of control objectives to be pursued. Objective A can be provided as a control objective, while objective B and / or objective C can be provided as secondary conditions subordinate to it. Target C or Target B can also be provided as a control target, while at least one of the remaining targets can be provided as a secondary condition. Specifically, a third control target can replace the first control target. A lookup table LT can be provided to provide associated (according to the reduction condition) optimized values ​​for different operating points and harmonic components of different intensities, these optimized values ​​characterizing the (minimized) inverse signal optimized according to the reduction condition. The amplitude and / or phase positions of the two components d and q of the spatial vector representation GS_ω_O (with U_q(O) and U_d(O) as components) can be used as indicators. The spatial vector representation GS_ω_O represents the inverse signal. The lookup table LT outputs the optimized value QE to the inverse signal generation element GS_RZ. As shown, one of the two vectors (the q vector) can optionally be directly output by the lookup table LT as part of the inverse signal (without including the inverse signal generation element GS_RZ), since the lookup table already contains the minimized or optimized value. The signal U_q(O) is optimized according to at least one of targets A to C such that it is no longer constrained by the reduction condition RBF. U_q(O) and U_d(O) can be provided separately from each other based on several of the conditions A, B, and C, thus generating an optimized inverse signal. These two variables are not necessarily precisely assigned to a single condition; instead, one or more of these conditions may affect the two variables (d and q components) separately. When applying two of these objectives, there may be multiple numerical ranges for U_d(O) and U_q(O), which are optimized based on the two objectives (A, B or A, C or B, C), such that when pursuing the remaining third objective (C, B, or A), these ranges can be selected and optimized. Therefore, using these two variables U_q(O) and U_d(O), more than two objectives can be applied for optimization, especially when the objectives are weighted and incomplete minimization (i.e., no global minimum) is considered in achieving the objectives.The term "minimize" should be understood as meaning that the resulting value is lower than the value produced without the inverse signal or harmonic control loop.

[0062] The inverse signal (represented as a space vector) emitted by the inverse signal generation element GS_RZ is supplied to the feed element of the basic control loop via the modulator MOD. The modulator MOD modulates the inverse signal GS_ω_O emitted by the inverse signal generation element GS_RZ at a harmonic angular velocity ω_O (its space vector representation is based on rotation at the harmonic angular velocity ω_O) to take into account the fact that the feed element is located in the basic control loop GRK, whose variables are based on the space vector representation at the feed element EGS, which rotates only at the fundamental angular velocity ω_G. In the example shown, this corresponds to the 6th harmonic, i.e., 6... ω_G. Alternatively, the signal GS_ω_O can be transformed into a time-domain signal via an inverse space vector transformation (not shown) to be superimposed on the control or actuation signal of the basic control loop existing in the time domain, for example, at the feed element EGS'. An optional limiter Lim can be provided between the inverse signal generating element and the feed element, for example between the inverse signal generating element GS_RZ and the modulator MOD (or between the modulator MOD and the feed element EGS).

[0063] The basic control loop GRK uses a signal represented as a space vector, REF_RZ, with a reference fundamental angular frequency ω_G (which corresponds to the electric speed). For example, this applies to representing the d-component I_d and q-component I_q of a (multi-part, two-dimensional) target variable. This variable is generated from the input variable EG by means of a target variable generating element SE, which generates variables I_d and I_q from the target speed n and target torque Tq by means of a space vector transformation RT. These variables represent the target current in the motor EM / inverter INV in space vector representation (relative to ω_G). Other target parameters or input parameters (considered when generating I_d and I_q) can be the temperature Temp (of the motor or inverter) and / or the amplitude of the supply voltage U_HV (= supply signal) of the inverter INV.

[0064] Following the target value generation element SE is the deviation detection element RA. This deviation detection element is two-part, meaning it provides one value for each vector in the spatial vector representation. The deviation detection element RA determines the deviation between the signal (actual variable – feedback variable R) fed back to the deviation detection element RA through the feedback path FB_G and the target variables I_d and I_q. The feedback variable R exists as a spatial vector representation of the reference ω_G.

[0065] Following the deviation detection element RA is the (two-part) controller REG. The two parts of the controller REG, REG' and REG'', involve two vectors represented in spatial vector form, namely, the d-component and the q-component. The output of the controller REG is controlled by the manipulated variable or control variable U_dq(G). This variable also exists as a spatial vector representation of a reference fundamental angular frequency. An inverse signal GS is fed into the variable U_dq(G) output by the controller REG. For this purpose, the feed element EGS receives both the inverse signal GS and the variable U_dq(G) output by the controller REG. In the example shown, both variables fed into the feed element EGS exist as spatial vector representations of a reference fundamental angular frequency ω_G. For this purpose, the inverse signal is modulated by the modulator MOD at a harmonic angular frequency ω_O, and then the signal modulated in this way is supplied to the feed element EGS. This produces components U_d and U_q corresponding to the signal U_dq(G) modulated using the inverse signal GS. The feeding of the inverse signal into the control variables, where these variables and the feed are based on spatial vector representations, is shown here. However, this point in control can also be conceived of variables existing in the time domain. This also applies to controllers and deviation detection elements, as well as the target variable.

[0066] Figure 1 The modulated space vector representation RZG of the (two-part) control variables U_d and U_q is supplied to the actuator IRT of the basic control loop. The actuator generates a (multiphase) pulse width modulation signal PWM_U - PWM_W (reference numeral PS), except for the inverse space vector transformation (which is omitted if the variables are guided in the time domain, and the same applies to the space vector transformation RT). When generating this signal in the time domain, the instantaneous angle θ(t) of the motor EM, detected by the angle encoder SN, is preferably considered. The angle encoder SN is connected to the motor shaft. As a supplement or alternative to the angle encoder SN, the current of the motor EM can also be used to detect the angle θ(t). The multiphase pulse width signal PS is output specifically at the modulation output MA. If the inverse signal is fed in the time domain instead of as a space vector representation, the inverse signal can be considered when generating the pulse width signal PS, thus generating the inverse signal in the time domain during pulse width modulation and generating it as a component of the pulse width signal PS. This is symbolically represented by the inverse signal feed point EGS'.

[0067] A pulse-width modulation (PWM) signal PS is output to the inverter INV for actuation. The inverter INV receives a power supply signal from the battery Batt (high-voltage traction battery) in the form of a DC voltage power signal U_HV and a DC power signal I_HV. Signals U_HV or I_HV can be referred to as the power supply signal. The power supply signal is essentially a DC signal, but due to the operation of the inverter INV and the motor EM, it contains (unwanted) AC components in the form of harmonics. The dashed lines show the taps of the signal that reproduces the power supply signal containing harmonic components. This signal is fed to either the harmonic detection element OE (which operates in the time domain) or RT_O (which operates in space vector representation).

[0068] The inverter INV has an input I_IN for receiving the pulse width signal PS, a power supply input for receiving the power supply signals U_HV and I_HV, and a multiphase output for connecting to the motor EM. A tap or measuring device SM is provided to detect the actual value I_EM of the basic control loop. The actual value I_EM exists in the time domain.

[0069] exist Figure 1 In this context, the actual value I_EM is supplied to the space vector transformation element RT_G of the feedback element R or the feedback portion FB_G. If the feedback element operates in the time domain, the transformation element RT_G is omitted. The space vector transformation element RT_G generates the space vector representation I_G_RZ of the motor current, which is also represented by components I_d' and I_q'. This current exists in a space vector representation (referencing the fundamental angular frequency G) and corresponds to I_dq(G), that is, represented by d and q components.

[0070] To prevent the two-part controller REG from detecting the inverse signal G as a deviation and compensating for it through the control process, a subtraction element SUB is connected downstream of the space vector transformation element RT_G within the feedback path FB_G of the basic control loop. The modulated space vector representation of the harmonic component ω_O is fed there. For this purpose, the detected harmonic component RZO is supplied to the modulator MOD', which modulates this harmonic component (signal form: cos(ω_O)) at the harmonic angular frequency ω_O. In the example shown, the 6th harmonic to be compensated is 6 times the fundamental angular frequency ω_G. The modulated harmonic component supplied to the subtraction element SUB is subtracted from signals I_d' and I_q'. The resulting feedback variable R of the basic control loop is supplied to the deviation detection element RA. Since the control deviation forms the input variable of the two-part controller REG, the controller will not respond to the harmonic components I_O_RZ, because, as mentioned above, the subtraction has already removed these harmonic components from the feedback R of the basic control loop.

[0071] The following relationship can be used to calculate the harmonic components (torque ripple) in torque: (Equation 2) The terms on the left side of the equation in equation 2 correspond to P. el That is, due to the current i dq and voltage u dq The electrical power generated (which is an instantaneous value in its respective case).

[0072] The first additive term in equation 2 corresponds to P. j That is, due to the resistance R dq The resulting current resistance heat loss; and the second added term in Equation 2 corresponds to P. m That is, mechanical power, where ω el It is the electric angular velocity, L dq It is an inductor, and Ψ It is magnetic flux.

[0073] The third additive term in Equation 2 corresponds to the changing mechanical power, which is related to the magnetic variable (L). dq --inductance, Ψ —related to magnetic flux, these magnetic variables change in the direction of rotation, that is, in terms of angle. (Electrical angle, which is related to the rotor angle θ) change.

[0074] The fourth addend in equation 2 corresponds to P. mag That is, the magnetic power required to accumulate and reduce magnetic energy in the motor. Current i, resistance R, and inductance L are each represented by d and q components; additional independent components are added for multi-camera systems. Flux, denoted by "PM," refers to the flux shift caused by the permanent magnet.

[0075] The superscript t represents transpose, which makes a transpose matrix generated for any matrix or vector with the superscript t.

[0076] In Equation 2, J represents the fixed transformation matrix generated by the Park transformation: Figure 1 Many variables in the code are represented as spatial vectors, which is usually indicated by adding RZ to the quoting character. Specifically, for each variable, "_d" and "_q" are added as the d and q components of the corresponding variable in the spatial vector representation.

[0077] In the illustrated embodiment, the space vector representation is fixed to the rotor; that is, it represents the system or coordinate axis that is fixedly mounted on the rotor (or fixedly linked to the rotating system generated by the stator) and therefore needs to rotate at a certain angular frequency. This angular frequency corresponds to the fundamental angular frequency ω_G, specifically within the basic control loop GRK. Unless otherwise shown, the harmonic angular frequencies ω_O are based on the space vector representation in the harmonic control loop ORK.

[0078] The attached figures use the following reference numerals: GS: Inverse signal GSS: Signal strength of the inverse signal R: Feedback FB_O: Inverse signal feedback EG: Input variables, target value input RA: Control deviation, deviation detection element RS: Manipulated variable guiding element REG: Linear Controller GSE: Inverting signal feed element EG_T: Transformation of input variables to spatial vector representation Add _RZ: spatial vector representation PS: Pulse Width Signal MA: Modulation output RZG: Spatial Vector Variables (Interference Suppression) IRT: Inverse Space Vector Transformation RT_O: Harmonic Space Vector Transform / Harmonic Detection Element INV: Inverter I_IN: Inverter control input I_OUT: Inverter control output I_EM: Inverter output signal SN: Sensor θ: Rotor angle, θ(t): Time signal of rotor angle ω_G: Fundamental angular frequency ω_O: Harmonic angular frequency OM: Harmonic Modulator TP: Low-pass filter I_d(O), I_q(O): Complex d-components and q-components of the harmonics. I_O_RZ — Complex space vector representation of harmonics; EGS — Feed element for inverse signal (GS). Lim: Limiter GS_RZ: Inverse signal calculation in spatial vector representation MOD, MOD': Modulator RT: Transformation to spatial vector representation SM: Current measuring device (used to detect the operating current of the EM) GRK: Fundamental Wave Control Loop ORK: Harmonic Control Circuit LT: Lookup table The components described herein in terms of function are preferably in the form of equipment elements.

Claims

1. A control device for controlling an electric drive unit, the electric drive unit comprising an inverter (INV) and a multiphase motor (EM) connected to the inverter, wherein, The control device includes a basic control loop with a deviation detection element (RA), an actuator (IRT), and a controlled system (RS). The controlled system includes an inverter (INV) and a motor (EM). The current intensity of the multiphase current flowing between the inverter (INV) and the motor (EM) is fed back as an actual value (I_EM) to the deviation detection element (RA) in the feedback section (FB_G) of the basic control loop. The basic control loop references a fundamental angular frequency (ω_G). The control device also includes a harmonic detection element (OE, RT_O) connected downstream of the feedback section (RS) of the basic control loop and configured to determine the actual value (I_EM). The control device has an inverse signal generating element (GS_RZ) connected downstream of the harmonic detection element (OE, RT_O) and configured to generate an inverse signal (GS). This inverse signal is fed into the control variable (RZG) of the actuator (IRT) via a feed element (EGS) connected upstream of the actuator (IRT). The inverse signal generating element (GS_RZ) is configured to generate an inverse signal (GS) provided in the space vector representation from the harmonic components (I_O; I_d(O), I_q(O)) using two vectors represented by the adjusted space vector, so that... - It can minimize either the actual value (I_EM) or the harmonic components (I_O) in the power supply signal. - It can reduce the harmonic components in the motor's torque, or maximize efficiency, or maximize the maximum recoverable mechanical power.

2. The control device as described in claim 1, wherein, The inverse signal generation element (GS_RZ) is configured to adjust the two vectors represented by the space vector so that... - Minimize the harmonic components (I_O) in the actual value (I_EM), minimize the harmonic components in the supply signal (U_HV), and - Reduce the harmonic components in the motor's torque, maximize efficiency, or maximize the maximum recoverable mechanical power.

3. The control device as described in claim 1 or 2, wherein, The inverse signal (GS) provided in spatial vector representation generates two voltage vectors that are perpendicular to each other, wherein a first vector (U_q(O)) represents at least a portion of the harmonic flux density, and a second vector (U_d(O)) characterizes at least a portion of the harmonic torque, wherein the first vector and the second vector are adjusted according to minimizing the harmonic component in the torque according to minimizing the reactive component, wherein the reactive component is provided as the harmonic component (I_O) in the actual value (I_EM), or the reactive component corresponds to the harmonic component (I_O) in the actual value (I_EM).

4. The control device as described in claim 1, 2, or 3, wherein, The inverse signal generating element (GS_RZ) is configured to generate the inverse signal (GS) from the harmonic component (I_O; I_d(O), I_q(O)) using two vectors represented by the adjusted spatial vector, so that... - It can minimize the harmonic components (I_O) in either the actual value (I_EM) or the power supply signal (U_HV). - It can also reduce the harmonic components in the motor's torque, or maximize efficiency, or maximize the maximum recoverable mechanical power, and additionally - Reduce the signal strength of the inverse signal (GS).

5. The control device as described in any of the preceding claims, wherein, The inverse signal generating element (GS_RZ) is configured to: minimize the harmonic component (I_O) in the actual value (I_EM) or the power supply signal (U_HV) as a first requirement; and minimize the harmonic component in the motor torque as a second requirement, or maximize efficiency or maximize the maximum recoverable mechanical power, wherein the first requirement and the second requirement are incorporated into the generation of the inverse signal according to a corresponding predetermined weighting.

6. The control device as described in any of the preceding claims, wherein, The harmonic detection element (OE, RT_O) is configured to determine the harmonic component (I_O; I_d(O), I_q(O)) as the signal strength of the harmonic component and the associated phase position.

7. The control device as described in any of the preceding claims, wherein, The harmonic detection element (OE, RT_O) is configured to generate the harmonic component (I_O; I_d(O), I_q(O)) from the actual value (I_EM) by Fourier analysis, bandpass filtering, integration after modulation at at least one harmonic frequency, or by transforming the actual value (I_EM) into a spatial vector representation rotated at the harmonic angular frequency.

8. The control device as described in any of the preceding claims, wherein, The harmonic detection element (OE, RT_O) is configured to determine the harmonic components (I_O; I_d(O), I_q(O)) in the actual value (I_EM) as a discrete spectral representation of the harmonic component assigned a frequency-specific phase position, a time-domain representation of the harmonic component, or a spatial vector representation rotated at the harmonic angular frequency.

9. The control device as claimed in any of the preceding claims, wherein, The actual value (I_EM) is fed back to the deviation detection element (RA) as a polyphase signal in the time domain, or it is fed back as a spatial vector representation rotated at the harmonic angular frequency.

10. The control device as claimed in any of the preceding claims, comprising an inverse signal modulator (MOD) configured to modulate at a harmonic angular frequency (ω_O), wherein, The inverse signal generating element (GS_RZ) is connected via the inverse signal modulator (MOD) to the point in the basic control loop located between the actuator (IRT) and the deviation detection element (RA).

11. The control device as claimed in any of the preceding claims, comprising a harmonic modulator (MOD') configured to modulate at a harmonic angular frequency (ω_O), wherein, The harmonic detection element (OE, RT_O) is connected via the harmonic modulator (MOD') to a feedback deviation detection element (SUB) disposed between the feedback section (FB_G), wherein the feedback deviation detection element (SUB) is configured to subtract the signal of the harmonic modulator (MOD') from the signal of the feedback section (FB_G).

12. An electric vehicle traction drive device having a motor (EM) and an inverter (INV) and having a control device as described in any one of the preceding claims, wherein, The control device is connected to the inverter and the motor (EM).

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