Pulsed control of an electric machine with notched filter

Abstract

A method for controlling the operation of at least one first electric machine on board a vehicle, wherein the vehicle has at least one resonant frequency, is provided. Pulsed operation of the first electric machine is conducted such that it provides a desired average output, the pulsed operation causing the first electric machine to oscillate between a first output level greater than the desired output level and a second output level less than the desired output level. At least some transitions between the first and second output levels are controlled. At least one notch filter for the at least one resonant frequency of the vehicle is provided.

Description

REFERENCE TO A RELATED REGISTRATION

[0001] This application claims the priority benefit of U.S. Application No. 63 / 500,493, filed on May 5, 2023, which is incorporated by reference into this document for all purposes. BACKGROUND OF THE INVENTION

[0002] The present invention relates generally to the control of an electric machine. More specifically, control schemes and control designs are described that uniformly pulse the operation of an electric machine during selected operating conditions in order to facilitate the operation of the electric machine in a more energy-efficient manner.

[0003] The term "electric machine," as used herein, should be interpreted broadly to include both electric motors and generators. Electric motors and generators are structurally very similar. Both comprise a stator with a number of poles and a rotor. When an electric machine operates as a motor, it converts electrical energy into mechanical energy. When the electric machine operates as a generator, it converts mechanical energy into electrical energy.

[0004] Electric motors and generators are used in a very wide variety of applications and under a wide variety of operating conditions. Modern electric machines generally exhibit relatively high energy conversion efficiencies. However, the energy conversion efficiency of most electric machines can vary considerably based on their operating load. In many applications, an electric machine must operate under a wide variety of different operating load conditions. As a result, many electric machines operate at or near their highest levels of efficiency at certain times, while at other times they operate at a lower efficiency.

[0005] Battery-powered electric vehicles are a good example of an electric machine operating at a wide range of efficiency levels. During a typical driving cycle, an electric vehicle will accelerate, maintain a constant speed, decelerate, brake, corner, and so on. Within certain rotor speed and / or torque ranges, the electric machine operates at or near its most efficient operating point, that is, its "ideal point." Outside of these ranges, the operation of an electric machine is less efficient. As driving conditions change, the electric machine switches between levels of high and low operating efficiency because the rotor speed and / or torque requirements change.If the electric motor could be made to operate in highly efficient operating ranges for a larger portion of a driving cycle, the vehicle's range for a given battery charge level would increase. Since the limited range of battery-powered electric vehicles is a significant economic barrier to their use, increasing the vehicle's operating range is highly advantageous.

[0006] Although the energy conversion efficiency of conventional electrical machines is generally good, there are currently efforts to further improve energy conversion efficiencies over wider ranges of operating conditions. SUMMARY

[0007] A variety of methods, controls, and systems for electrical machines are described that facilitate the pulsed control of multiple drive systems of electrical machines (for example, electric motors and generators) to improve the energy conversion efficiency of the electrical machines when operating conditions permit. More specifically, a method for controlling the operation of at least one first electrical machine on board a vehicle is provided, wherein the vehicle has at least one resonant frequency. Pulsed operation of the first electrical machine is conducted such that it provides a desired average output, the pulsed operation causing the first electrical machine to alternate between a first output level greater than the desired output level and a second output level less than the desired output level.At least some transitions between the first output level and the second output level are controlled. At least one notch filter is provided for at least one resonant frequency of the vehicle.

[0008] In a further embodiment, a control system is provided for controlling at least one first electric machine of at least one electric machine on board a vehicle, wherein the vehicle has at least one resonant frequency. A pulse control system is provided that performs pulsed operation of the first electric machine, the pulsed operation causing the first electric machine to switch between a first output level that is greater than a desired average output and a second output level that is less than the desired average output. The pulse control system comprises a transition profile generator that controls transitions from the second output level to the first output level, and a notch filter control system that provides at least one notch filter for the at least one resonant frequency.

[0009] In a further embodiment, a control system is provided for controlling at least one first electric machine of at least one electric machine on board a vehicle, wherein the vehicle has at least one resonant frequency. A pulse control system is provided which enables pulsed operation of the first electric machine, the pulsed operation causing the first electric machine to switch between a first output level that is greater than a desired average output and a second output level that is less than the desired average output. The pulse control system includes a notch filter control system that provides at least one notch filter for the at least one resonant frequency.

[0010] In a further embodiment, a method for controlling the operation of a first electric machine of at least one electric machine on board a vehicle is provided, wherein the vehicle has at least one resonant frequency. Pulsed operation of the electric machine is conducted such that it delivers a desired average output, the pulsed operation causing the electric machine to switch between a first output level that is greater than the desired average output and a second output level that is less than the desired average output. At least one notch filter for the at least one resonant frequency of the vehicle is provided.

[0011] These and other features of the present revelation are described in more detail below in the detailed description of the revelation and together with the following figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention and its advantages can best be understood with reference to the following description in conjunction with the accompanying drawings, in which: Fig. 1 is a representative torque / speed / efficiency diagram that illustrates the energy conversion efficiency of a representative electrical machine during operation as an electric motor under various operating conditions. Fig. Figure 2 is a diagram showing a pulsed current signal applied to an electric machine in response to a torque request during operation as a motor. Fig. 3 is a block diagram of a control system for an electrical machine according to a non-exclusive embodiment of the present invention. Fig. 4A is a diagrammatic representation of a continuous three-phase alternating current waveform, transmitted to an electrical machine. the Fig. 4B and Fig. 4C are different examples of a pulsed three-phase alternating current waveform with a similar duty cycle, which produce the same torque as the continuous waveform of Fig. 4A provides. Fig. 5 is a diagram illustrating a representative efficiency of an electrical machine system as a function of the machine torque at a constant machine speed. the Fig. Figures 6A-6C are a series of related diagrams showing angular jerk, angular acceleration and torque profiles for an exemplary third-order transition torque profile. the Fig. Figures 7A-7E are a series of related diagrams showing quintic, quartic, cubic (angular jerk), angular acceleration and torque profiles for an exemplary fifth-order (quintic) transition torque profile. the Fig. Figures 8A-8E are a series of related diagrams showing quintic, quartic, cubic angular acceleration and torque profiles for an exemplary fifth-order (quintic) transition torque profile under a condition in which the period of a desired off-section of a pulse cycle is shorter than the torque transition time. the Fig. Figures 9A-9E are a series of related diagrams showing quintic, quartic, cubic angular acceleration and torque profiles for an exemplary fifth-order (quintic) transition torque profile under a condition in which the period of a desired one-section of a pulse cycle is shorter than the torque transition time. Fig. 10 is a schematic illustration of a graph of excitations caused by the pulsed operation of an electrical machine. Fig. 11A is a diagram of a rectangular wave pulse and an S-curve pulse. Fig. Figure 11B shows a diagram of the attenuation of harmonics, provided by the S-curve pulse relative to the harmonics of a rectangular pulse. Fig. 12A is a diagram of a square wave pulse and a single notch filter S-curve pulse. Fig. Figure 12B is a diagram of the attenuation of harmonics provided by the single-notch filter S-curve pulse. Fig. 13A is a diagram of a square wave pulse and a double notch filter S-curve pulse. Fig. Figure 13B shows a diagram of the attenuation of harmonics, provided by the double-notch filter S-curve pulse relative to the harmonics of a rectangular pulse. Fig. 14A shows a diagram of a square wave pulse and a notch-filtered S-curve pulse when the inverter is switched off during the off section of the pulse to provide zero electromagnetic torque. Fig. Figure 14B shows a diagram of the attenuation of harmonics provided by a notch filter S-curve pulse relative to the harmonics of a rectangular pulse. Fig. 15 is a block diagram of a control of an electric machine for controlling three electric machines according to a non-exclusive embodiment of the present invention.

[0013] Drawings sometimes use the same reference symbols to denote identical structural elements. It is understood that the representations in the figures are schematic and not to scale. DETAILED DESCRIPTION OF PREFERRED EXECUTION FORMS

[0014] The present application relates to the pulsed control of a wide variety of electrical machines (for example, electric motors and generators) that would otherwise be operated continuously. Pulsed control of electrical machines is described in U.S. patent applications Nos. 16 / 353,159 and 16 / 353,166, filed on March 14, 2019, and 16 / 818,570, filed on March 13, 2020. Each of the foregoing applications is incorporated herein by reference in its entirety. As described in the applications incorporated into this document, pulsed control of an electrical machine offers the advantage of improving the efficiency of the conversion of the machine's operating energy.

[0015] When pulsing is used, frequent changes occur in the commanded output of the machine. A potential disadvantage of pulsed control is that the frequent output transitions can increase the operational noise, vibration, and harshness (NVH) generated by the electrical machine. In electrical machines with higher electrical time constants, the NVH problems associated with pulsing tend to worsen because the electrical time constants can impose practical limitations on the frequency at which pulsing can occur. When pulsing frequencies are in frequency ranges generally perceptible to humans, the NVH problems tend to be more pronounced. Consequently, it is desirable to manage pulsing transitions in an effective and efficient manner.

[0016] The present invention proposes, in certain pulsed applications for electric machines, the use of cubic or higher-order pulse-transition torque profiles, as well as a notch filter, to dampen one or more resonant frequencies. Furthermore, some embodiments utilize pulsed frequencies to attenuate NVH. Such control can help mitigate NVH problems while efficiently managing transitions. In some embodiments, quintic pulse-transition profiles are used.

[0017] Referring to Fig. Figure 100 illustrates an exemplary diagram of the efficiency of an electric machine during its operation as a motor under different load and speed conditions. In diagram 100, the torque (N*m) is plotted along the vertical axis as a function of the speed (rpm) of the electric machine along the horizontal axis. The maximum continuous output power is shown by curve 102.

[0018] The area under the peak torque-speed curve 102 is plotted into a multitude of regions, each labeled with a percentage operating efficiency. For the specific electric machine shown, the following characteristics are evident: • The most efficient range, or the range with the “ideal point” of its operating range, is the operating range designated 104, which is generally in the range of 4500–6000 rpm with a torque output in the range of approximately 40–70 N*m. In range 104 of the ideal point, the energy conversion efficiency is on the order of 96%, making it the “ideal point” at which the motor operates in its most efficient operating range. • If the motor speed increases above approximately 6000 rpm, the efficiency tends to decrease, regardless of the output torque. • When the output torque increases above 70 N*m or decreases below 40 N*m, there is a tendency for the efficiency to decrease, starting from its peak value, in some situations quite significantly. For example, if the motor is operating at approximately 2000 rpm with an output torque of 100 N*m, the efficiency is about 86%. If the torque output falls below approximately 30 N*m, the efficiency decreases regardless of the motor speed and approaches zero at no load. • At a certain speed of the electric machine, a corresponding most efficient output torque will be observed, which is illustrated diagrammatically by curve 106 of maximum efficiency.

[0019] Figure 100 applies to an electric synchronous machine with an internal permanent magnet. Specifically, it was derived from a traction motor used in a 2010 Toyota Prius. It should be understood that Figure 100 is merely illustrative and should not be interpreted as restrictive in any way. A similar representation can be developed for almost any electric machine, regardless of whether it is used in a vehicle or another application.

[0020] As can be seen from Figure 100, the electric machine is generally most efficient when driving a vehicle if it operates within the speed and torque ranges of the ideal point 104. If the operating conditions can be controlled so that the motor operates at or near its ideal point 104 for a greater proportion of the time, the overall energy conversion efficiency of the motor can be significantly improved.

[0021] From a practical standpoint, however, many driving situations dictate that the motor operates outside the speed and torque ranges of the ideal point 104. Electric vehicles typically do not have a transmission, so the ratio between the electric motor's speed and the wheel speed is constant. In this case, the motor speed can vary from zero when the vehicle is stopped to a relatively high speed when driving at a constant speed on a highway. Torque requirements can also vary significantly, based on factors such as whether the vehicle is accelerating or decelerating, driving uphill or downhill, traveling on a level surface, braking, and so on.

[0022] As also in Fig. As can be seen in Figure 1, a corresponding most efficient output torque will be observed at a given speed, which is schematically illustrated by the maximum efficiency curve 106. From a conceptual perspective, if the desired motor torque is below the most efficient output torque for the current motor speed, the overall efficiency of the motor can be improved by pulsing the motor. This involves operating the motor at or near its peak efficiency for part of the time at the given speed and at a low or zero torque output level for the remainder of the time. The average torque generated in this way is controlled by controlling the duty cycle of the peak efficiency torque applied to the electric machine.

[0023] It is understood that the electric machine would exhibit a similar efficiency representation characterizing its efficiency if it were functioning as a generator.

[0024] Fig. Figure 2 is a diagram illustrating an example of pulsed motor operation. In this specific example, the desired motor torque is 10 Nm, but the most efficient torque output for the current operating motor speed is 50 Nm. During conventional operation, the motor would continuously produce 10 Nm, assuming the desired torque remained at this value. Conceptually, the motor can be driven to deliver an average net torque of 10 Nm by causing it to deliver 50 Nm of torque for 20% of the time and then no (zero) torque for the remaining 80% of the time. Consequently, the motor's net output meets the operational requirement of 10 Nm.Since the motor operates more effectively at a torque output of 50 Nm than at a torque output of 10 Nm, the overall efficiency of the motor can be conceptually improved by pulsing the motor operation in the manner described.

[0025] In Fig. Figure 2 shows diagram 20 on the vertical axis the total current applied to an electric machine (acting as an electric motor) as a function of time, shown on the horizontal axis. For illustrative purposes, it is assumed that each ampere of applied current produces 1 Nm of output torque. In this specific example, a desired motor output torque is 10 Nm, which requires 10 A of current, as shown by the dashed line 22. Also in this example, the most efficient torque output for the motor is 50 Nm, which corresponds to 50 A of applied current.

[0026] In the Fig. In the illustrated example 2, the motor produces a motor output of 50 Nm (labeled 24) for a period of one time unit out of five time units; then, during the four time units in between, the motor is switched off (or controlled to produce zero torque), which corresponds to an operating cycle of 20%. Of course, the operating cycle is not limited to 20%. Provided the desired motor output does not exceed 50 Nm, the desired motor output can be achieved through a wide range of different operating cycles. For example, if the desired motor output changes to 20 Nm, the operating cycle of the motor operating at 50 Nm can be increased to 40%; if the desired motor output changes to 40 Nm, the operating cycle can be increased to 80%; if the desired motor output changes to 5 Nm, the operating cycle can be reduced to 10%, and so on.In general, pulsed motor control can potentially be used advantageously at any time when the desired motor torque is below the curve of its maximum efficiency (i.e., curve 106 of ). Fig. 1) falls.

[0027] On the other hand, if the desired motor torque lies on or above its maximum efficiency curve, the motor can be operated in a conventional manner (continuous or non-pulsed) to deliver the desired torque. Pulsed operation, therefore, offers the potential for efficiency gains when the motor needs to deliver an average torque below its peak efficiency torque for a given motor speed.

[0028] It should be noted that the current and torque values ​​and time scales given herein are for illustrative purposes only and are not intended to be limiting in any way. In actual applications of pulsing an electrical machine, the pulse duration used may vary considerably based on the design requirements of the specific system. Generally, however, the time scale for each pulse cycle is expected to be on the order of 10 µsec to 10 seconds (i.e., pulsing at a frequency in the range of 0.5 to 100,000 Hz), for example, between 20 milliseconds and 2 seconds (0.5 to 5000 Hz). In some embodiments, the time scale for each pulse cycle is expected to be on the order of 10 milliseconds to 2 seconds with a frequency range of 0.5 Hz to 100 Hz.Furthermore, there is a wide variety of different electrical machines, and each machine has its own unique efficiency characteristics.

[0029] In Fig. Figure 2 shows the transitions of the applied drive current and the resulting torque as step functions, which are useful for explaining the advantages of pulsing. However, it is understood that in practice, time delays will occur between applying a voltage to the windings of an electric machine and the establishment of the magnetic flux linkages required to produce the desired torque. Consequently, in practice, it is unlikely that the profile of the produced torque pulses will be rectangular, as shown in Figure 2. Fig. 2 shown.

[0030] Fig. Figure 3 is a block diagram illustrating a system with a controller 10 for an electric machine that enables pulsed operation of an electric machine 12, which forms part of a vehicle. The electric machine 12 can be of any type, including induction motors / machines, permanent magnet synchronous reluctance machines, IPM machines, and others. The illustrated electric machine 12 is a three-phase electric machine; however, it is understood that the electric machine can be designed to use any desired number of phases, including a single phase.

[0031] The control unit 10 of the electric machine comprises an inverter 14, a pulse controller 30 and a torque modulation decision module 62. The inverter 14 can be operated as an inverter or a rectifier - depending on the direction of the energy flow through the system.

[0032] When the electric machine 12 is operated as a motor, the inverter 14 is responsible for generating a three-phase alternating current (designated 18A for phases A, B, and C, respectively) from the DC power supply 16. The three-phase input current is applied to the windings of the stator of the electric machine 12 to generate a rotating magnetic force (RMF). In an induction motor, this rotating field induces a current that flows in the rotor windings, which in turn induces a rotor magnetic field. The interaction of the rotor and stator magnetic fields generates an electromagnetic force (EMF) that causes the rotor to rotate, which in turn rotates a motor shaft. The rotating shaft provides the motor's output torque. In most common permanent magnet motors, the rotor field is the same as that of the permanent magnet.

[0033] The three phases 18A-18C are each represented by lines with arrows at both ends, indicating that current can flow in both directions. When used as a motor, current flows from the power supply 16 through the inverter 14 to the electric machine 12. When used as a generator, current flows from the electric machine 12 through the inverter 14 to the power supply 16. When operating as a generator, the inverter 14 essentially acts as a rectifier, converting the alternating current from the electric machine 12 into direct current, which is stored in the DC power supply, for example, a battery or a capacitor.

[0034] The pulse control 30 is responsible for selectively pulsing the three-phase, sinusoidal input current signals 18A-18C to the electric machine 12. During conventional (i.e., continuous) operation, the three-phase input current supplied to the electric machine 12 is in the form of continuous sinusoidal signals, each with a phase shift of 120° relative to the others. During pulsed operation, the three-phase sinusoidal current signals 18A-18C are selectively pulsed using one of the approaches described herein.

[0035] Referring to Fig. 4A-4C, diagrams are provided that illustrate the difference between continuous and pulsed three-phase current supplied to / by the electrical machine 12. In each diagram, current is represented on the vertical axis, and time is represented along the horizontal axis.

[0036] Fig. Figure 4A illustrates a conventional, sinusoidal three-phase current 42a, 42b, and 42c, supplied to or produced by the electrical machine 12. Phase B, denoted by curve 42b, lags phase A, denoted by 42a, by 120 degrees. Phase C, denoted by curve 42c, lags phase B by 120 degrees. The period of the sine wave is T. The three-phase current 42a, 42b, and 42c is continuous (non-pulsed) and has a designated maximum amplitude of approximately 50 A. It is understood that 50 A is only a representative maximum current and that the maximum current can have any value.

[0037] Fig. 4B and Fig. Figure 4C illustrates two examples of different pulsed, three-phase, sinusoidal current waveforms: 44a, 44b and 44c, and 46a, 46b and 46c, respectively. It should be noted that each set of waveforms has a duty cycle of fifty percent (50%) and a peak amplitude of approximately 100 A.

[0038] In Fig. The period of the sinusoidal waveforms 44a, 44b, and 44c is τ in 4A, however, the sinusoidal waveforms are modulated in and out. The difference between the pulsed currents 44a-c and 46a-c from Fig. 4C corresponds to the duration of their respective current pulses and the nested off periods. In Fig. In 4B, the current pulses 44a-c with off periods of equal length are nested. The length of each on and off period is 2τ. Fig. In example 4C, the current pulses 46a-c and the interleaved off periods again have the same duration. In this case, the duration is T / 2. In both examples, the duty cycle is 50%. However, the duration of the on and off times differs, meaning the pulsed modulation frequency is different. The pulsed modulation frequency can vary based on the type of electrical machine used, noise and vibration aspects, the current operating rotor speed, and other factors.

[0039] When operating as a motor, the excitation current delivers in Fig. 4B and Fig. 4C produces the same average torque as the continuously applied three-phase current. Fig. 4A (assuming that the torque is proportional to the current, which is often the case with surface permanent magnet electric machines).

[0040] Fig. 4B and Fig. Figure 4C illustrates applications where the single-drive pulses are evenly spaced while the electric machine operates at a desired constant output level. Such an approach works well in many circumstances, but it is not a requirement. The duty cycle does not have to be 50%, but can be set to correspond to the desired average torque. Fig. 4B and Fig. 4C, the phase of the pulses is synchronized with the applied alternating current; however, in some embodiments, the phase of the pulses need not be synchronized with the phase of the applied alternating current. Thus, the relative magnitudes and / or the timing of the drive pulses of the electric machine can be varied, as long as they are averaged to the desired average output torque.

[0041] Referring again to Fig. 3. During operation of the electric machine, the torque modulation decision module 62, also referred to as a pulsating decision module, receives a torque request. In response, the torque modulation decision module 62 determines whether the requested torque is greater or less than a defined "pulsating" threshold associated with the current machine speed. In most embodiments, the pulsating threshold varies as a function of the speed of the electric machine 12. In some embodiments, the pulsating threshold for a given speed may be at or near the peak efficiency torque of the electric machine 12 for that speed. However, this is not a requirement. It is understood that there are a number of factors that may influence the determination of the appropriate pulsating threshold for a given motor / generator speed.The net operating efficiency of the electric machine, or of a larger system incorporating the electric machine, is an important factor in determining the pulsating threshold, as discussed in more detail below. However, other factors (for example, aspects of NVH reduction) can also be taken into account.

[0042] If the torque demand is higher than the pulsating threshold, the torque modulation decision module 62 instructs the electric machine 12 to operate in a continuous mode. In this case, the torque demand is passed on to the inverter 14 in a conventional manner as an inverter control signal 39, and the inverter 14 continuously controls the operation of the electric machine to deliver the desired torque.

[0043] If the torque demand is less than the pulsating threshold, the torque modulation decision module 62 determines the desired pulsed control operating state. The desired pulsed control operating state is passed via 32 to the pulse controller 30, which then controls the operation of the inverter 14 via the inverter control signal 38. In this context, the pulsating operating state can include an indication of whether pulsed control is enabled, and if so, (a) the desired target output level during torque on-periods (sometimes referred to as the target pulse torque); (b) the desired pulsating operating cycle; and (c) whether the inverter should remain active or be disabled during periods without torque.In practice, the characteristics of the electric machine, the combination of the electric machine and its control system, and / or a larger system that includes the electric machine / machine control, can be characterized by creating operating maps, such as the efficiency maps described above. Based on such maps, the most efficient operating state can be determined for all operating conditions (for example, all possible combinations of machine speed and output level). In some embodiments, this information can be stored in a data structure, such as a lookup table, which can be used by the torque modulation decision module 62 to determine the appropriate operating state for each commanded output (for example, torque requirement) based on the current machine speed and any other relevant control parameters.In other embodiments, the torque modulation decision module 62 can utilize algorithmic or other suitable approaches to make such decisions.

[0044] The pulse controller 30 is responsible for controlling / instructing the timing of the pulsing of the electric machine 12 when pulsed operation is commanded. In the illustrated embodiment, the pulse controller 30 includes a frequency controller 33, a transition profile generator 34, and a notch filter controller 35. The frequency controller 33 receives a vehicle frequency input 31. The vehicle input 31, such as the vehicle speed or torque requirement, can be data provided to the frequency controller 33, which the frequency controller 33 uses to determine the frequency of the pulses. The notch filter controller 35 receives vehicle resonance data 37. Transition control

[0045] When implementing pulsed control of an electric machine, frequent transitions of the commanded torque occur between a low value (usually zero) and a higher value with a higher energy conversion efficiency, and vice versa. For optimal efficiency, these transitions are preferably very rapid. The resulting benefits are described with reference to… Fig. 5 understandable. Fig. Figure 5 is a diagram that schematically represents the energy conversion efficiency (vertical axis) of an electric machine operating as a motor at a fixed speed for varying torque requirements (horizontal axis). It should be obvious that rapid transitions through the low torque / efficiency ranges help to maximize the overall energy conversion efficiency.

[0046] In the Fig. In the illustrated example of pulsed control, transitions between the low output level (e.g., zero) and the higher drive pulse level, and vice versa, are shown as step functions. In practice, however, such abrupt transitions are practically unattainable for many electrical machines, impair the machine's energy conversion efficiency, and / or can generate undesirable NVH effects.

[0047] More specifically, when a voltage is first applied to the windings of a motor, the formation of the magnetic flux chains, the magnetization, begins rapidly. (λdre) and the drive (λqse) The applied voltage lags behind, as in all inductive circuits. If the goal of the control is to achieve a pulsating target torque as quickly as possible, then the control could theoretically compensate for the lagging magnetizing flux chains by increasing iqse To achieve the required torque, the system compensates for these losses. This leads to an increase in the applied current and thus to an increase in motor and inverter losses, which contradicts the goal of pulsed control, namely to minimize losses. Consequently, it is desirable to control the amplitude and phase of the applied current during transitions to ensure that these transitions are performed with minimal losses. In other words, during transitions, the flux linkages are preferably controlled to result in the most efficient overall solution to the torque equation.

[0048] Fast and efficient transitions are relatively easy to achieve in motors / machines that, in conjunction with the setup of the magnetic flux linkages required to support the target torque, have a relatively small time constant. However, as the time constant increases, the speed at which transitions can practically be achieved decreases, thus limiting the practical pulsing frequency. For example, the time constants associated with some induction motors are high enough that pulsing at relatively low frequencies, on the order of 0.5 to 20 Hz, may be desirable. Humans are quite sensitive to vibrations in such frequency ranges, highlighting the need to consider NVH (noise, vibration, and harshness) issues in pulsed motor control.

[0049] To meet the competing requirements of fast transition times, energy-efficient transitions, and the reduction of NVH problems, the present disclosure proposes the use of transition torque profiles with specific characteristics and at least one notch filter. In several preferred embodiments, the commanded torque is changed smoothly but slowly from zero, then rapidly increased through most of the lower-efficiency range, and finally slowly transitioned to the desired pulsating torque (for example, a value at or near the peak-efficiency torque for the current machine speed). In some embodiments, this is achieved by using an S-shaped transition torque application profile. This approach has several advantages.

[0050] This includes: 1. A smooth initial transition from zero torque is used to establish the rotor flux linkages. λdre to build up while the applied motor phase current is regulated to a low level in order to minimize losses during this period. 2. The rate of change through most of the lower-efficiency region is optimized for minimal losses, regardless of the need to build up rotor flux. 3. The smooth transition to the pulsating operating target torque occurs with an efficiency that is close to that of the peak efficiency.

[0051] The same (reverse) approach is used for transitions from operating torque to the zero torque state, which facilitates an orderly extraction of the energy stored in the magnetic field of the motor.

[0052] One way to provide a smooth S-shaped curve is to use a third-order (cubic) transition torque request profile generator. Cubic control is sometimes referred to as "jerk control" in various control fields because, in physics, jerk is the third derivative of position. Similarly, angular jerk is the third derivative of angular momentum. In other embodiments, higher-order functions, such as quintic (fifth order) or higher, are used to generate the transition torque profiles. The specific torque profiles commanded by the impulse control 30 during transitions are specified by the transition profile generator 34. The specific transition torque profiles used under any specific operating conditions can be determined in any desired manner.In some embodiments, the profiles are generated algorithmically in real time by the transition profile generator 34. In other embodiments, a suitable search table or other suitable data structure can be provided so that the transition profile generator can easily search for the appropriate transition torque profile for the current operating state.

[0053] The Fig. Figures 6A-6C diagrammatically illustrate an example of a jerk base transition torque profile that can be applied by the transition profile generator 34. In particular, Fig. 6A a diagram showing the jerk profile (also known as a cubic or 3rd order profile) in association with the exemplary transition torque profile. Fig. Figure 6B is a diagram showing the resulting angular acceleration (second-order profile) – which is the integral with respect to time of the in Fig. 6A illustrated angle jerk). Fig. Figure 6C is a diagram showing the resulting transition torque profile (first-order profile) – the integral with respect to time of the in Fig. 6B illustrated angular acceleration). It should be obvious that this is in Fig. Figure 6A illustrated the jerk profile, the second derivative with respect to the time of the in Fig. 6C illustrated torque (and the third derivative with respect to time of the angular momentum, not shown).

[0054] In the illustrated embodiment, when torque is initially applied, the angular jerk is set to a first value 611 and held constant for an initial period 610, as shown in Fig. 6A is shown. During this time, the angular acceleration increases steadily, as shown in Fig. 6B is visible and labeled 613. Simultaneously, the torque slowly increases (labeled 615). After the initial period 610, the jerk is set to zero, 621, and held constant for a second period, labeled 620. During this period 620, the angular acceleration remains constant (623 in Fig. 6B) and the torque increases relatively quickly (625 in Fig. 6C). As the torque approaches the target impulse torque, the jerk is set to a negative second value 631 for a third period 630. During this period, the angular acceleration decreases (633 in Fig. 6B). When the angular acceleration reaches zero, the target torque 636 is reached and the jerk is set to zero for a fourth period 640, which extends over the duration of the impulse.

[0055] The transition from the target torque to the zero period (“off”) of the pulsed control can be achieved reciprocally. When the transition begins, at point 649, the jerk is set to a negative value 651 and held constant for a fifth period 650. During this period, the angular deceleration steadily increases 653 and the torque slowly begins to decrease 655. After the transition period 650, the jerk is set to zero 661 and held constant for a sixth period, designated 660. During this period 660, the angular acceleration remains constant 663. Fig. 6B) and the torque decreases relatively quickly (665 in Fig. 6C). As the torque approaches zero, the jerk is set to a positive value 671 for a third period 670. During this period, the angular acceleration decreases (673 in Fig. 6B). With proper control, the angular deceleration and torque simultaneously reach zero (point 682), at which point the jerk is set to zero, thus initiating the off-period of the pulsed control 680. Depending on the type of control desired for the off-periods of the pulsed control, the inverter can be switched off during this phase, or it can maintain operation, which commands zero torque. The commanded torque remains zero until the next pulse is directed, whereupon the process just described is repeated for the next pulse.

[0056] In general, the goal is to ensure that the total torque delivered in one pulse (the area 600 below the torque pulse curve 601 in Fig. 6C) is essentially equal to the desired total torque of the impulse.

[0057] It goes without saying that the example of Fig. Figures 6A-6C are illustrative in nature. The relative magnitudes of changes in the affirmative jerk settings can be varied considerably to meet the needs and design objectives of a particular situation. In the illustrated embodiment, the magnitude of the changes in the jerk settings is shown to be the same for all jerk transitions. This includes the transition away from an existing torque level, the approach to a new target torque level, and intermediate changes. Likewise, the jerk setting is shown to be the same for both the transition from zero to the target torque and the transition from the target torque to zero. Neither of these statements is a requirement. Rather, the relative magnitude (and corresponding time intervals) of the various transitions can be varied to meet the requirements of implementing a particular pulsed control design.In practice, the specific values ​​for each design are based on a number of aspects, including the time constants of the electric machine, NVH aspects, power requirements, etc.

[0058] Although the described jerk-based torque profiling can significantly reduce NVH in many applications, further improvements can be achieved under certain circumstances by using higher-order control. Specifically, one characteristic of the illustrated jerk-based control is that it results in abrupt changes in the resulting angular acceleration (i.e., corner points in the context of the calculation), as shown in Fig. 6B. These abrupt changes / corner points occur at the transitions between different jerk levels, which are shown in Fig. 6B is designated as points 607, 617, 627, 637, 647, 657, 667, and 677. In practice, such abrupt changes in acceleration can increase the likelihood of perceptible NVH being generated. One way to eliminate abrupt changes in angular acceleration (and thereby further reduce NVH) is to use a higher-order airfoil generation control. In practice, quintic (5th order) or higher airfoil generation can be used to completely eliminate abrupt changes in angular acceleration.

[0059] The generation of a quintic profile is in the Fig. 7A-7E are illustrated diagrammatically. In particular, Fig. 7A a diagram showing a representative quintic profile (5th order) generated by a quintic torque profile generator. Fig. Figure 7B is a diagram showing the corresponding quartic (4th order) response to the illustrated quintic profile (the time-based integral of the quintic profile shown in Fig. 7A illustrates this. Fig. 7C is a diagram showing the resulting cubic or jerk profile (3rd order) (the time-based integral of the in Fig. 7B illustrates the quartic profile). Fig. 7D is a diagram that shows the resulting angular acceleration (the time-based integral of the in Fig. 7C illustrates angular jerk). Fig. 7E is a diagram showing the resulting torque profile (the time-based integral of the in Fig. The angular acceleration shown in 7D is shown. It should be obvious that this is shown in Fig. Figure 7A illustrated the jerk profile, the fourth derivative with respect to the time of the in Fig. 7E illustrated torque (and the fifth time derivative of angular momentum, not shown).

[0060] A notable feature of quintic profile generation schemes is that, by definition, there are no abrupt changes (vertices) or discontinuities in angular acceleration ( Fig. 7C). The absence of abrupt changes tends to further reduce NVH. It is understood that higher-order profile generation than quintic profile generation (e.g., 6th order, 7th order, etc.) has the advantage of ensuring that no discontinuities or abrupt changes in angular acceleration occur and can therefore be used for similar purposes, although they tend to add extra complexity to the torque profile generator.

[0061] In the Fig. In the example of generating a quintic torque profile shown in Figures 7A-7E, the magnitude of the changes in the quintic settings is the same for all quintic transitions. Similar to the jerk transition discussed above, this is not a requirement, and the relative magnitude and timing of the transitions can be varied widely to meet the needs and design objectives of a particular implementation. In general, the goal is to ensure that the total torque delivered in a pulse (the area 700 below the torque pulse curve 701 in Figure 7A-7E) is as high as possible. Fig. 7E) is essentially equal to the desired total torque of the impulse.

[0062] There are a number of other factors to consider when determining when pulsing is advantageous and desirable, and some of these can be influenced by the transition control scheme used by the transition profile generator 34 (for example, step changes of the requested torque, generation of a cubic profile, generation of a quintic profile, etc.).

[0063] The nature of some of these factors can be understood by examining how a higher-order torque profile is generated. For example, if the pulsating duty cycle becomes too long relative to the transition time, the pulsed control could lead to a situation where the commanded torque is never actually reduced to zero. Such a situation is diagrammatically represented in the Fig. Figures 8A-8E illustrate the effects of generating a quintic torque profile when the off-phase of the pulsating operating cycle is shorter than the torque transition time. As shown in Fig. As can be seen in the 8E diagram, the commanded torque never actually reaches zero. As shown in the efficiency diagram of Fig. As can be seen in Figure 5, the energy conversion efficiency of many motors does not drop too rapidly from the peak efficiency torque at many motor speeds. Thus, under such circumstances, continuous operation at a slightly lower torque level may be more energy-efficient than pulsed operation at peak efficiency. In such operating ranges, continuous operation may be preferable to pulsed operation. Such determinations can be made as part of the characterization / mapping of the electric machine, and the machine's control law can be designed to utilize the approach deemed more energy-efficient and / or otherwise desirable for a given operating state of the electric machine.

[0064] Conversely, if the pulsating operating cycle becomes too short relative to the transition time, situations can arise in which the commanded torque never actually reaches the pulsating target torque. This situation is found in the Fig. Figures 9A-9E illustrate this diagrammatically. Under such circumstances, the overall energy conversion efficiency of the motor is likely to be better than in continuous operation. However, there are a variety of ways to further improve the overall energy efficiency. For example, the pulsing frequency can be reduced under certain circumstances so that torque pulses with a longer period are generated. Additionally or alternatively, the target torque used by the controller can be increased to a value higher than the peak efficiency torque, so that the torque levels actually commanded by the torque profile generator actually reach (or at least come closer to) the desired level.The relative effects of such control can be determined during the characterization / mapping of the electrical machine, and the control law of the machine can be designed to utilize the approach that is considered more energy-efficient and / or otherwise desirable for a particular operating state of the electrical machine.

[0065] In the Fig. In the illustrated embodiment 3, the pulse control is shown as a component separate from the torque modulation decision module 62 to facilitate an explanation of its function. However, in various embodiments, the pulse control can be implemented as part of a machine control system that includes the torque modulation decision module 62, as a separate component, as part of the power control / inverter 14, or in other suitable forms. Some of the basic functions and operation of the representative pulse controls 30 are described in U.S. patent applications Nos. 16 / 353,159 and 16 / 353,166, which are incorporated into this application.

[0066] The pulsing frequency at which the energy is pulsed can be determined by the torque modulation decision module 62 or the frequency control 33 in the pulse control 30. In some embodiments, the pulsing frequency can be fixed for all operations of the electric machine, while in others it can vary based on operating conditions, such as machine speed, torque requirements, etc. For example, in some embodiments the pulsing frequency can be determined using a search table. In other embodiments the pulsing frequency is not necessarily fixed for specific operating conditions and can vary depending on the setting by the frequency control. This type of variation is common when using sigma-delta conversion in determining the pulses, as in the patent application incorporated in this application. The patent application filed on 26.The US patent application filed in January 2021, serial number 17 / 158,230, which is incorporated herein by reference for all purposes, contains some of the conditions that can be used to determine the pulsating frequency based on noise, vibration, and harshness (NVH). Such conditions can be caused either by a measurable parameter of the vehicle or by a feature on the vehicle that establishes an acceptable level of NVH.Specific examples of such conditions include at least one of the following: transmission status, wheel drive status, weight of the load carried by the vehicle, selectable economy mode, selectable sport mode, selectable NVH control, which allows the driver to select different levels of acceptable NVH, occupants, temperature, a first model that models the NVH characteristics of the vehicle as the vehicle ages, active noise reduction, active vibration reduction, and road conditions. In some embodiments, the selected transition depends on the selected pulsing frequency.

[0067] The pulsating frequency generates excitations at the fundamental frequency and harmonics of the pulsating frequency. Fig. Figure 10 is a schematic representation of a diagram of excitations caused by an S-shaped pulsating frequency of approximately 33 Hz in a vehicle with a resonant frequency of approximately 360 Hz. In the schematic illustration, the pulsating fundamental frequency 1008 is at approximately 33 Hz. Since the vehicle has a resonant frequency of approximately 360 Hz, the highest vibrations are caused by the pulsating fundamental frequency 1008 of approximately 33 Hz and the resonant frequency of approximately 360 Hz, which is caused by the 11th harmonic 1012 of the fundamental frequency. The thicknesses of the lines for the pulsating fundamental frequency 1008 and the 11th harmonic 1012 are greater than the thicknesses of the other harmonics to schematically illustrate how the pulsating fundamental frequency 1008 and the 11th harmonic 1012 cause stronger vehicle vibrations than the other harmonics.Although fundamental frequencies at the vehicle's resonant frequencies can be more easily avoided when selecting the pulsing frequency, higher-frequency resonances excited by harmonics of the fundamental frequencies are more difficult to avoid. For example, at a resonant frequency of approximately 360 Hz, resonant frequencies of approximately 2, 3, 4, 5, 6, 8, 9, 10, 11, 25, 12, 15, 18, 20, 22.5, 24, 30, 36, 40, 45, 60, 72, 90, 120, and 180 Hz exhibit harmonics of approximately 360 Hz. Therefore, it would be more difficult to avoid fundamental frequencies with harmonic frequencies of approximately 360 Hz. Furthermore, it would be more difficult to provide an S-curve transition that attenuates oscillations at a fundamental frequency and all resonant harmonic frequencies.

[0068] Therefore, various embodiments provide at least one notch filter in the vicinity of at least one or more resonant frequencies of the vehicle. Fig. Figure 11A is a diagram of a rectangular wave pulse 1108, shown with dashed lines, and an S-curve pulse 1112, shown with a solid line. Fig. Figure 11B is a diagram of harmonic attenuation provided by the S-curve pulse 1112. The graph shows that the S-curve pulse is able to attenuate harmonics at frequencies above 500 Hz by at least about 10 decibels (dB), while the S-curve is not able to attenuate harmonics significantly at frequencies below 500 Hz.

[0069] Fig. Figure 12A is a diagram of a square wave pulse 1208, shown with dashed lines, and an S-curve pulse 1212 of a single notch filter, shown with a solid line. The S-curve pulse of the single notch filter provides a single notch filter for approximately 300 Hz. The waveform of the notch filter is exaggerated for illustrative purposes. Fig. Figure 12B is a diagram of harmonic attenuation provided by the S-curve pulse 1212 of a single notch filter. The diagram shows that the S-curve pulse of a single notch filter is capable of attenuating harmonics at frequencies above 500 Hz by at least about 10 decibels (dB) and at about 300 Hz by about 40 dB. Lower desired attenuation at the notch frequency may result in smaller variations in the notch-filtered S-curve pulse.

[0070] Fig. Figure 13A is a diagram of a square wave pulse 1308, shown with dashed lines, and an S-curve pulse 1312 of a double-notch filter, shown with a solid line. The S-curve pulse of the double-notch filter provides two notch filters for approximately 300 Hz and 420 Hz. Fig. Figure 13B is a diagram of the attenuation of harmonics provided by the S-curve pulse 1312 of a double-notch filter. The diagram shows that the S-curve pulse of a double-notch filter is capable of attenuating harmonics at frequencies above 500 Hz by at least about 10 dB, at about 300 Hz by about 40 dB, and at about 420 Hz by about 50 dB. Other embodiments may include more than two notch filters. Other embodiments may provide notch filters with different frequencies and exhibit different attenuation values.

[0071] For the purpose of increased efficiency during dynamic motor drive operation, it may be desirable to completely switch off inverter 14. This would reduce the electromagnetic torque to zero during the off period. In this case, it would not be possible to regulate the motor torque to the notch-filtered value. However, the notch-filtered torque command can still be used during the on-phase of the pulse. Fig. Figure 14A shows such a combined approach with the notch-filtered torque command during the on-section and a zero value during the off-section. This results in lower damping at the target frequency and can enhance some other higher harmonics to which the vehicle / structure is not sensitive (harmonics that do not coincide with a structural / acoustic resonance). Fig. 14B is a diagram of the attenuation of harmonics provided by a notch filter, which in one embodiment is for Fig. 14A is used. In some embodiments, the notch filter is continuously provided. However, when inverter 14 is switched off, the notch-filtered torque request is ignored because inverter 14 is switched off. In Fig. 14A, a dashed line indicates a square wave pulse 1408, and the solid line indicates a notch-filtered S-curve pulse 1412, where, at a torque of zero, the notch-filtered S-curve pulse 1412 provides a torque output of zero because the inverter 14 is switched off.

[0072] Some electric vehicles have more than one motor. For example, an electric vehicle may have three or more motors. Fig.Figure 15 is a block diagram illustrating a system comprising a controller 10 for an electric machine, which in some embodiments enables pulsed operation of a first electric machine 12a, a second electric machine 12b, and a third electric machine 12c, forming part of a vehicle. In some embodiments, a first inverter 14a provides energy to the first electric machine 12a, a second inverter 14b provides energy to a second electric machine 12b, and a third inverter 14c provides energy to a third electric machine 12c. A first feedback sensor 64a receives feedback information from the first electric machine 12a, a second feedback sensor 64b receives feedback from the second electric machine 12b, and the third feedback sensor 64c receives feedback from the third electric machine 12c.The notch filter controller can provide a first notch filter for the first inverter 14a, a second notch filter for the second inverter 14b, and a third notch filter for the third inverter 14c. In some embodiments, the first electric machine 12a can be used to drive and brake the front wheels of the vehicle, the second electric machine 12b can be used to drive and brake one rear wheel, and the third electric machine 12c can be used to drive and brake the other rear wheel. Since the first, second, and third electric machines 12a-c have different functions and positions, they may require different notch filters to provide the desired damping to avoid resonance.For example, in some embodiments, the notch filter controller 35 can provide a first notch filter of a 300 Hz notch filter for the first inverter 14a, a second notch filter with a 250 Hz and 570 Hz dual notch filter for the second inverter 14b, and a third notch filter that does not provide notch filtering for the third inverter 14c. In some embodiments, the vehicle can have at least one resonant frequency at the location of the first electric machine 12a and a second resonant frequency at the location of the second electric machine 12b, so that the notch filter for the first electric machine 12a would differ from the notch filter for the second electric machine 12b. In some embodiments, the notch filter of the first electric machine 12a would be the same as the notch filter of the second electric machine 12b.

[0073] In some embodiments, the notch filters are provided by hardware. Such notch filters would be difficult to adjust and would be used for constant vehicle resonance frequencies. In some embodiments, the notch filter is adjustable using software. Such notch filters can be dynamically changed and would be used for either constant or variable vehicle resonance frequencies. Vehicle resonance data 37, which provides the vehicle's resonance frequencies, is fed to the pulse controller 30. The notch filter controller 35 provides one or more notch filters at one or more of the vehicle's resonance frequencies. The notch filter characteristic can be defined by a target frequency and a q-factor, or by a center frequency and a desired bandwidth to be filtered.The vehicle resonance data 37 can be data in a search table or data received from a vibration sensor. The vehicle resonance data 37 are used to determine the desired notch filter characteristic. The vehicle resonance frequencies can change depending on various vehicle parameters or user settings, such as transmission status, wheel drive status, weight of the load carried by the vehicle, selectable economy mode, selectable sport mode, selectable NVH control (allowing the driver to choose different levels of acceptable NVH), occupants, temperature, an initial model that simulates the vehicle's NVH characteristics as the vehicle ages, active noise reduction, active vibration reduction, and road conditions.

[0074] Although some illustrative embodiments of notch filters provide attenuation of a target frequency of 40 to 60 dB, some embodiments may provide less attenuation, resulting in a small visible fluctuation of the filtered curves.

[0075] During pulsed operation of the electric machine 12, the inverter is activated during the pulses and ideally deactivated between them. Deactivating the inverter is conceptually desirable because it helps reduce inverter losses and inverter-induced losses during periods without torque. However, there are times when it will be desirable for the inverter to actively command zero torque during periods without torque (or at least during a portion of those periods). There are several reasons for this. One of the most easily understood relates to back electromotive force (BEMF). If the BEMF of a permanent magnet motor exceeds the supply voltage used by the motor, a lag torque is generated, which can significantly reduce the motor's efficiency.Field weakening is typically used to reduce or eliminate deceleration torque. The BEMF generated by a motor is primarily a function of the motor speed. Consequently, the BEMF remains a problem during the torque-free periods of pulsed motor control. Since field weakening is applied by the inverter, disabling the inverter during the torque-free periods of pulsed control in motor operating conditions where field weakening is desired would allow the BEMF to decelerate the motor during these periods, thereby reducing the overall efficiency of the motor (sometimes significantly). To mitigate these effects, the inverter is preferably left in zero-torque mode during the torque-free periods of pulsed control in operating regions where the BEMF exceeds the supply voltage.Of course, there may be other circumstances where it is desirable to keep the inverter switched on during the torque-free periods of pulsed operation. In various embodiments, the pulse controller 30 or the torque modulation decision module 62 can instruct the inverter 14 to switch off when desired. The pulse controller 30 controls transitions between a first output level and a second output level to allow pulsed transitions between a first torque and a second torque.

[0076] Although only some embodiments of the invention have been described in detail, it is understood that the invention can be implemented in many other forms without deviating from the essence or scope of the invention. For example, although the generation of cubic and higher-order functions for generating the torque transition profiles is described, it is understood that uniform S-shaped transition profiles that eliminate discontinuities in the angular acceleration, or that eliminate both discontinuities and corner points in the angular acceleration, can also be generated in other ways.

[0077] Most of the preceding discussion focuses on controlling torque during transitions and therefore relates to controlling the transition torque profile. As those familiar with motor control will recognize, the same or similar results can be achieved by controlling the current in the same way (i.e., using cubic or higher-order transition profiles). It is therefore understood that, unless the context requires otherwise, the claimed transition management can be applied regardless of which parameter is actually controlled by the controller.

[0078] The various machine control components described, including the torque modulation decision module, pulse control, transition profile generator, inverter control, notch filter control, frequency control, and other control elements, can be implemented, grouped, and configured in a variety of different architectures and embodiments. For example, in some embodiments, pulse control may be integrated into a motor control or an inverter control, or it may be provided as a separate component. Similarly, in a generator, pulse control may be integrated into a generator control or a rectifier control, and in combined motor / generators, pulse control may be integrated into a combined motor / generator control or a combined inverter / rectifier control.In some embodiments, the described control functionality can be implemented algorithmically in software or firmware running on a processor that can take any suitable form, including, for example, general-purpose processors and microprocessors, DSPs, etc.

[0079] Pulse control can be part of a larger control system. For example, in automotive applications, pulse control can be part of a vehicle control system, a powertrain control system, a hybrid powertrain control system, or an ECU (engine control unit), etc., which performs a variety of functions related to vehicle control. In such applications, the vehicle or other relevant control system, etc., may take the form of a single processor that performs all the necessary control, or it may include multiple processors arranged together as part of a powertrain or vehicle control module, or distributed at various locations within the vehicle. The specific functionalities performed by any one of the processors or control units can vary considerably.

[0080] The invention was primarily described in the context of motor control and / or inverter / motor control. However, it is understood that the described approach is equally applicable to generator and / or generator / rectifier control. Consequently, in any description of motor control, it is understood that analogous techniques can be applied to generator control. Unless the context requires a different interpretation, a description of a feature of pulsed motor control, pulsed generator control, or pulsed motor / generator control is to be understood as applying equally to pulsed motor control, pulsed generator control, and pulsed control of combined motors / generators.

[0081] Various control schemes can be implemented within pulse control. Generally, these schemes can be digital, algorithmic, using analog components, or hybrid approaches. The pulse generator and / or motor control can be implemented as code running on a processor, on programmable logic such as an FPGA (Field Programmable Gate Array), in circuits such as an ASIC (Application Specific Integrated Circuit), on a digital signal processor (DSP), using analog components, or on any other suitable hardware component.In some implementations, the described control schemes may be integrated into object code to be executed on a digital signal processor (DSP) that is integrated into an inverter controller (and / or rectifier controller in the context of a generator and / or a combined inverter / rectifier controller).

[0082] In various embodiments, pulse width modulation, sigma-delta conversion, or other techniques can be used to generate the pulsed inverter control signal 38. Regardless of the type of modulation used, the transitions between pulse levels can be managed in the manner described. Likewise, the described pulse transition management can be used with any type of motor in which pulsed control is employed, regardless of the machine's time constant and / or the switching frequency used. Therefore, the present embodiments should be considered illustrative and not limiting, and the invention is not intended to be restricted to the details specified herein but may be modified within the scope and equivalents of the appended claims.

[0083] Although this disclosure has been described in relation to several preferred embodiments, there are changes, modifications, permutations, and various substitute equivalents that fall within the scope of this disclosure. It should also be noted that there are many alternative ways of implementing the methods and devices of the present disclosure. It is therefore intended that the following appended claims be interpreted as including all such changes, modifications, permutations, and various substitute equivalents that fall within the true nature and scope of the present disclosure. When used herein, the expression "A, B, or C" should be interpreted logically ("A OR B OR C"), using a non-exclusive logical "OR," and should not be interpreted as meaning "only one of A or B or C."Each step within a process can be optional and is not required. In different embodiments, one or more steps may be omitted, or steps may be provided in a different order. Additionally, different embodiments may provide different steps simultaneously rather than sequentially. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 500,493

[0001] US 16 / 353,159 [0014, 0065] US 16 / 353,166 [0014, 0065] US 16 / 818,570

[0014] US 17 / 158,230

[0066]

Claims

[1] Method for controlling the operation of at least one first electric machine of at least one electric machine on board a vehicle, wherein the vehicle has at least one resonant frequency, the method comprising: Conducting the pulsed operation of the first electrical machine so that it provides a desired average output, wherein the pulsed operation causes the first electrical machine to alternate between a first output level that is greater than the desired average output and a second output level that is less than the desired average output; Controls at least some transitions between the first output level and the second output level; and Providing at least one notch filter for at least one resonant frequency of the vehicle. [2] Method according to claim 1, further comprising providing a pulsating frequency, wherein the control of at least some transitions depends on the pulsating frequency. [3] Method according to claim 2, wherein the pulsating frequency is determined taking into account noise, vibration and roughness (NVH), either caused by a measurable parameter of the vehicle or a feature on the vehicle that sets an acceptable level of NVH on the vehicle. [4] Method according to claim 1, wherein the second output level is zero torque. [5] Method according to claim 4, wherein the first electric machine is controlled by a first inverter and the first inverter is switched off in at least some operating states during at least one period of time in which the first electric machine is caused to output zero torque. [6] Method according to claim 1, wherein the transitions between the first output level and the second output level are controlled by controlling a torque generated by the first electric machine. [7] Method according to claim 1, wherein the transitions between the first output level and the second output level are controlled by controlling a current supplied to the first electrical machine. [8] Method according to claim 1, further comprising receiving vehicle resonance data from at least one sensor and / or a search table. [9] Method according to claim 1, wherein the at least one resonance frequency of the vehicle is variable and wherein the notch filter is adjustable to adapt to changes in the at least one resonance frequency. [10] Method according to claim 1, wherein the vehicle has at least two resonant frequencies and wherein at least two notch filters are provided at the at least two resonant frequencies. [11] Method according to claim 1, wherein the control of at least some transitions between the first output level and the second output level utilizes a transition profile of cubic or higher order. [12] Method according to claim 1, wherein the at least one electric machine further comprises a second electric machine, wherein a second inverter controls the second electric machine and wherein at least one second notch filter is provided for the second electric machine. [13] Method according to any one of claims 1-3, wherein the second output level is zero torque. [14] Method according to claim 13, wherein the first electric machine is controlled by a first inverter and the first inverter is switched off in at least some operating states during at least one period of time in which the first electric machine is caused to output zero torque. [15] Method according to one of claims 1-3 and 13-14, wherein the transitions between the first output level and the second output level are controlled by controlling a torque generated by the first electric machine. [16] Method according to one of claims 1-3 and 13-15, wherein the transitions between the first output level and the second output level are controlled by controlling a current supplied to the first electrical machine. [17] Method according to one of claims 1-3 and 13-16, further comprising receiving vehicle resonance data from at least one sensor and / or a search table. [18] Method according to one of claims 1-3 and 13-17, wherein the at least one resonance frequency of the vehicle is variable and wherein the notch filter is adjustable to adapt to changes in the at least one resonance frequency. [19] Method according to one of claims 1-3 and 13-18, wherein the vehicle has at least two resonant frequencies and wherein at least two notch filters are provided at the at least two resonant frequencies. [20] Method according to one of claims 1-3 and 13-19, wherein the control of at least some transitions between the first output level and the second output level utilizes a transition profile of cubic or higher order. [21] Method according to one of claims 1-3 and 13-16, wherein the at least one electric machine further comprises a second electric machine, wherein a second inverter controls the second electric machine and wherein at least one second notch filter is provided for the second electric machine. [22] Control system arranged for controlling at least one first electric machine of at least one electric machine on board a vehicle, wherein the vehicle has at least one resonant frequency, the control system comprising: a pulse control that performs pulsed operation of the first electrical machine, wherein the pulsed operation causes the first electrical machine to switch between a first output level that is greater than a desired average output and a second output level that is less than the desired average output, wherein the pulse control comprises the following: a transition profile generator that controls transitions from the second output level to the first output level; and a notch filter control that provides at least one notch filter for at least one resonant frequency. [23] Control according to claim 22, wherein the notch filter control determines at least one resonance frequency from vehicle resonance data and provides a notch filter for the at least one resonance frequency. [24] Control according to claim 22, wherein the pulse control further comprises a frequency control which provides a pulsating frequency, wherein the transition profile generator provides a transition profile which depends on the pulsating frequency. [25] Control according to claim 24, wherein the frequency control is designed to receive a vehicle input or feature on the vehicle and to adjust the pulsating frequency to provide an acceptable amount of noise, vibration and harshness (NVH). [26] Control according to claim 22, wherein the transition profile generator controls transitions from the second output level to the first output level using a quintic or higher transition profile. [27] Control according to claim 22, further comprising a pulsed decision module that determines when pulsed operation of the first electrical machine is desirable and when continuous operation of the first electrical machine is desirable in order to provide a desired average output, wherein the pulsed control leads to pulsed operation of the first electrical machine when the pulsed decision module determines that pulsed operation of the first electrical machine is desirable. [28] Control according to claim 22, wherein the at least one resonant frequency of the vehicle is variable and wherein the notch filter control adjusts the at least one notch filter so that it is adapted to changes in the at least one resonant frequency. [29] Control according to claim 22, wherein the vehicle has at least two resonant frequencies and wherein the notch filter control provides at least two notch filters at the at least two resonant frequencies. [30] Control according to claim 22, wherein the transition profile generator, which controls transitions from the second output level to the first output level, provides a transition profile of cubic or higher order. [31] Control according to claim 22, wherein the second output level is zero torque and wherein a first inverter is switched off during at least one time period in which the first electrical machine is caused to output zero torque. [32] Control according to claim 22, wherein the control is arranged to further control a second electric machine of at least one electric machine on board the vehicle, wherein the notch filter control provides a second notch filter for the second electric machine. [33] Control according to one of claims 22-23, wherein the pulse control further comprises a frequency control which provides a pulsating frequency, wherein the transition profile generator provides a transition profile which depends on the pulsating frequency. [34] Control according to claim 33, wherein the frequency control is designed to receive a vehicle input or feature on the vehicle and to adjust the pulsating frequency to provide an acceptable amount of noise, vibration and harshness (NVH). [35] Control according to one of claims 22-23 and 33-34, wherein the transition profile generator controls transitions from the second output level to the first output level using a quintic or higher transition profile. [36] Control according to one of claims 22-23 and 33-35, further comprising a pulsed decision module that determines when pulsed operation of the first electrical machine is desirable and when continuous operation of the first electrical machine is desirable in order to provide a desired average output, wherein the pulsed control leads to pulsed operation of the first electrical machine when the pulsed decision module determines that pulsed operation of the first electrical machine is desirable. [37] Control according to one of claims 22-23 and 33-36, wherein the at least one resonant frequency of the vehicle is variable and wherein the notch filter control adjusts the at least one notch filter so that it is adapted to changes in the at least one resonant frequency. [38] Control according to one of claims 22-23 and 33-37, wherein the vehicle has at least two resonant frequencies and wherein the notch filter control provides at least two notch filters at the at least two resonant frequencies. [39] Control according to one of claims 22-23 and 33-38, wherein the transition profile generator, which controls transitions from the second output level to the first output level, provides a transition profile of cubic or higher order. [40] Control according to one of claims 22-23 and 33-39, wherein the second output level is zero torque and wherein a first inverter is switched off during at least one time period in which the first electrical machine is caused to output zero torque. [41] Control according to one of claims 22-23 and 33-40, wherein the control is arranged to further control a second electric machine of at least one electric machine on board the vehicle, wherein the notch filter control provides a second notch filter for the second electric machine. [42] Control system arranged for controlling at least one first electric machine of at least one electric machine on board a vehicle, wherein the vehicle has at least one resonant frequency, the control system comprising: a pulse control that performs pulsed operation of the first electrical machine, wherein the pulsed operation causes the first electrical machine to switch between a first output level that is greater than a desired average output and a second output level that is less than the desired average output, wherein the pulse control comprises the following: a notch filter control that provides at least one notch filter for at least one resonant frequency. [43] Control according to claim 42, wherein the notch filter control determines at least one resonance frequency from vehicle resonance data and provides a notch filter for the at least one resonance frequency. [44] Control according to claim 42, wherein the pulse control further comprises a frequency control which provides a pulsating frequency. [45] Control according to claim 44, wherein the frequency control is designed to receive a vehicle input with respect to a measurable parameter of the vehicle or a feature on the vehicle and to adjust the pulsating frequency to provide an amount of noise, vibration and harshness (NVH) that is acceptable. [46] Control according to claim 42, wherein the at least one resonant frequency of the vehicle is variable and wherein the notch filter control adjusts the at least one notch filter to adapt to changes in the at least one resonant frequency. [47] Control according to claim 42, wherein the vehicle has at least two resonant frequencies and wherein the notch filter control provides at least two notch filters at the at least two resonant frequencies. [48] ​​Control according to claim 42, wherein the control is arranged to further control a second electric machine of at least one electric machine on board the vehicle, wherein the notch filter control provides a second notch filter for the second electric machine. [49] Control according to one of claims 42-43, wherein the pulse control further comprises a frequency control which provides a pulsating frequency. [50] Control according to claim 49, wherein the frequency control is designed to receive a vehicle input with respect to a measurable parameter of the vehicle or a feature on the vehicle and to adjust the pulsating frequency to provide an amount of noise, vibration and harshness (NVH) that is acceptable. [51] Control according to one of claims 42-43 and 49-50, wherein the at least one resonant frequency of the vehicle is variable and wherein the notch filter control adjusts the at least one notch filter so that it is adapted to changes in the at least one resonant frequency. [52] Control according to one of claims 42-43 and 49-51, wherein the vehicle has at least two resonant frequencies and wherein the notch filter control provides at least two notch filters at the at least two resonant frequencies. [53] Control according to one of claims 42-43 and 49-52, wherein the control is arranged to further control a second electric machine of at least one electric machine on board the vehicle, wherein the notch filter control provides a second notch filter for the second electric machine. [54] Method for controlling the operation of a first electric machine of at least one electric machine on board a vehicle, wherein the vehicle has at least one resonant frequency, the method comprising: Controlling the pulsed operation of the electrical machine so that it delivers a desired average output, wherein the pulsed operation causes the electrical machine to alternate between a first output level that is greater than the desired average output and a second output level that is less than the desired average output; and Providing at least one notch filter for at least one resonant frequency of the vehicle. [55] Method according to claim 54, further comprising receiving vehicle resonance data from at least one sensor and / or a search table. [56] Method according to claim 54, wherein the at least one resonance frequency of the vehicle is variable and wherein the notch filter is adjustable to adapt to changes in the at least one resonance frequency. [57] Method according to claim 54, wherein the vehicle has at least two resonant frequencies and wherein at least two notch filters are provided at the at least two resonant frequencies. [58] Method according to one of claims 54-55, wherein the at least one resonance frequency of the vehicle is variable and wherein the notch filter is adjustable to adapt to changes in the at least one resonance frequency. [59] Method according to one of claims 54-55 and 58, wherein the vehicle has at least two resonant frequencies and wherein at least two notch filters are provided for the at least two resonant frequencies.

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