Adaptive dc bus voltage system and method using fixed modulation index

Abstract

The present disclosure relates to adaptive DC bus voltage systems and methods using a fixed modulation index. One method includes setting a modulation index to a predetermined value for a motor. The method also includes calculating a bridge voltage for an output voltage command based on the predetermined value of the modulation index, and selectively controlling the motor based on the bridge voltage.

Description

Technical Field

[0001] This disclosure relates to steering systems, and more specifically, to an adaptive DC bus voltage system and method using a fixed modulation index of a permanent synchronous magnet driver. Background Technology

[0002] Vehicles (such as cars, trucks, sport utility vehicles, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable vehicles) include steering systems such as electric power steering (EPS) systems, steer-by-wire (SbW) systems, hydraulic steering systems, or other suitable steering systems. Steering systems typically include one or more controllers that control various aspects of the steering system, including but not limited to one or more electric motors and / or one or more actuators that control the steering system. Summary of the Invention

[0003] This disclosure generally relates to steering systems.

[0004] One aspect of the disclosed embodiments includes a method comprising setting a modulation index to a predetermined value for a motor. The method further includes calculating a bridge voltage for an output voltage command based on the predetermined value of the modulation index, and selectively controlling the motor based on the bridge voltage.

[0005] Another aspect of the disclosed embodiments includes a system comprising a controller configured to: set a modulation index to a predetermined value for a motor; calculate a bridge voltage for an output voltage command based on the predetermined value of the modulation index; and selectively control the motor based on the bridge voltage.

[0006] These and other aspects of this disclosure are disclosed in the following detailed description of the embodiments, the appended claims and the accompanying drawings. Attached Figure Description

[0007] This disclosure is best understood by reading in conjunction with the accompanying drawings and through the following detailed description. It should be emphasized that, by convention, the various features in the drawings are not drawn to scale. Instead, for clarity, the dimensions of the various features have been arbitrarily enlarged or reduced.

[0008] Figure 1 A vehicle based on the principles of this disclosure is shown in general.

[0009] Figure 2 A controller based on the principles of this disclosure is shown in general.

[0010] Figures 3A-3D This generally illustrates an adaptive DC bus voltage system using a permanent synchronous magnet driver with a fixed modulation index, based on the principles of this disclosure.

[0011] Figure 4 This is a flowchart that generally illustrates an adaptive DC bus voltage method using a permanent synchronous magnet driver with a fixed modulation index, based on the principles of this disclosure. Detailed Implementation

[0012] The following discussion pertains to various embodiments of this disclosure. While one or more of these embodiments may be preferred, the disclosed embodiments should not be construed as or otherwise used to limit the scope of this disclosure, including the claims. Furthermore, those skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is intended only as an illustrative discussion of that embodiment and not to imply that the scope of this disclosure, including the claims, is limited to that embodiment.

[0013] As described, vehicles (such as cars, trucks, sport utility vehicles, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable vehicles) include steering systems such as EPS systems, SbW steering systems, hydraulic steering systems, or other suitable steering systems. Steering systems typically include one or more controllers that control various aspects of the steering system, including but not limited to one or more electric motors and / or one or more actuators that control the steering system.

[0014] One or more electric motors in the steering system may include permanent magnet synchronous motor (PMSM) drives. In such drives, the direct current (DC) voltage determines the amount of power, torque, and / or energy "capacity" available in the drive. A voltage source inverter can modulate from 0 to... Line ( Any voltage between the peak amplitudes of the phases:

[0015] in, and These are the inverter phase voltage commands in the d-axis and q-axis synchronous reference frames, respectively. Depending on the load torque command and the measured speed, the nominal battery voltage may not be required, or a voltage higher than the nominal voltage may be needed to meet the requirements. Depending on the application, the nominal battery voltage can be 12V, 48V, 400V, etc. This fact is important in applications with a wide variable speed range or where the motor is stationary or at low speeds most of the time. Typically, powerpacks used in EPS steering systems include a power inverter, an electric motor, and measuring sensors such as position, current, and voltage. Figure 3AAs shown, the power unit is directly connected to the vehicle battery using a wiring harness, and then passive circuitry is used to filter the power unit to mitigate voltage ripple before the inverter's DC terminals. The inverter's DC bridge voltage is one of the main factors determining the available torque and / or power generation capability of the power unit, and the controller utilizes this capability to meet operational requirements (such as torque command, supply current limits, and regenerative current limits). The ultimate goal is to accurately and reliably provide the requested torque command from the electronic control unit (ECU), and one of the limiting factors in achieving this goal is the DC bridge voltage. The power unit controller algorithm typically measures the bridge voltage and uses it to limit torque generation during the power management phase of motor control. For example, for parameters of a PMSM motor... (Extreme Number) (back electromotive force constant) (Motor resistance [ohms]) (d-axis synchronous inductance [H]) and (q-axis synchronous inductor [H]); steady-state peak torque given DC bridge voltage ( The capability is given by the voltage constraint in equation (2a).

[0016] in, and These are electrical velocity and mechanical velocity, respectively, measured in radians per second. and This is the synchronous coordinate system current. Typically, each actuator in an SbW (steering wheel actuator (HWA) and wheel actuator (RWA)) has at least two power units. The HWA's tasks are 1) to measure the steering wheel rotation angle and send it to the RWA to generate the necessary torque to make the wheels match the driver's commanded turn angle, and 2) to replicate road conditions by generating "feel" torque at the steering wheel. The "feel" torque is several orders of magnitude smaller than the torque that the RWA must generate to turn the vehicle's wheels; therefore, the HWA is expected to generate a small (fractional) torque command that is primarily opposite to the driver's movements (quadrants 2 and 4). Given that the motor torque capability at a given speed is proportional to the bridge voltage, and since the HWA motor is expected to operate from a standstill and / or at low speeds, it is possible that the full battery voltage is not always required to modulate the necessary output. Furthermore, different original equipment manufacturers (OEMs) have different torque-speed requirements, which can be accommodated by building different motors, but the speed and power range of the same motor can be varied by changing the DC bridge voltage of the power unit. In addition, if a multi-winding, multi-ECU motor is powered by multiple batteries, an adaptive DC bridge voltage can be used to avoid asymmetrical motor core saturation.

[0017] Therefore, systems and methods such as those described herein, configured to adaptively vary the DC bridge voltage of a PMSM driver by fixing the modulation index to a fixed value, may be desirable. In some embodiments, the systems and methods described herein can be configured to adaptively vary the DC bridge voltage based on operational needs by fixing the modulation index. Simulation and dynamometer test results demonstrate that the systems and methods described herein can reduce output electromagnetic torque ripple in PMSM power units and extend the operable speed range. While the systems and methods described herein are described with respect to the specific needs of HWA in the SbW program, thus yielding optimal performance advantages in this application, the systems and methods described herein are applicable to all PMSM-based drive systems.

[0018] The systems and methods described herein can be configured to reduce torque ripple caused by the low inductance behavior of printed circuit board (PCB) stator motors. The systems and methods described herein can be configured to improve indirect costs by extending the speed and power range of existing motors, or conversely, to reduce battery input power to meet user requirements.

[0019] The systems and methods described in this paper can be configured to provide torque ripple reduction, thereby reducing total harmonic distortion and extending the torque envelope range. The mathematical relationships between the average bridge voltage and the output current and voltage ripple can be used to optimize the size of the input passive filter of the converter. It must be noted that the PMSM is modeled as a resistive-inductive (RL) load, and equations (3a) and (3b) are derived considering the resistive load; therefore, the actual ripple relationships are time-dependent in the transient (e.g., discontinuous) conduction modes of the inverter switch. However, in steady state, equations (3a) and (3b) still apply to RL loads such as the PMSM.

[0020] in, It is the switching frequency. It is the input inductor, and It is the capacitance of the large-capacity capacitor in the inverter. Equation (4) shows the modulation index in the SVM-based inverter control algorithm. By fixing the modulation index at a predetermined desired value ( The system and method described in this paper can be configured to calculate the bridge voltage for any given output voltage command.

[0021] in, It is the inverter output voltage command amplitude. Substituting (4) into (2a) and (2b), the system and method described herein can be configured to use feedforward (5a) or closed-loop inverter modulation reference voltage (5b) to derive the control laws (5a) to (5c) of the desired DC bridge voltage.

[0022] in, It is an optional gain factor, and and These are the d-axis and q-axis current regulator functions, respectively. The lower and upper limits of (5c) are incorporated to implement component voltage safety limits, and are dependent on hardware ratings. Given the requested torque and speed, an appropriate DC bridge voltage reference is calculated in (5a) through (5c), and then this appropriate DC bridge voltage reference is generated using a full-bridge converter between the battery and a large-capacity capacitor, as shown below. Figures 3B-3D As shown. A full-bridge converter is a buck-boost converter whose DC bridge voltage can be increased or decreased relative to the battery. Although a full-bridge converter is described in this paper, simpler buck or boost half-bridge converters can be used instead.

[0023] In some embodiments, the systems and methods described herein can be configured to adaptively change the DC bridge voltage of a PMSM drive system by fixing the modulation index to a desired value. The systems and methods described herein can be configured to ensure that the modulation index remains at a constant level starting from a unit value, thus preventing saturation due to sudden transient changes or measurement time delays.

[0024] The systems and methods described herein can be configured to allocate an appropriate DC bridge voltage using a fixed desired modulation index, based on motor operating requirements at each time step according to equations (5a) to (5c). The systems and methods described herein can be configured to extend previous research on PMSM drivers with adaptive DC voltages, which provide improved torque harmonic performance and extended speed range, while avoiding transient modulation index saturation problems. The systems and methods described herein can be configured to maintain an unsaturated modulation index adjusted to the desired value. The systems and methods described herein can be configured to consider physical voltage limitations based on equation (5c), even during transient dynamics.

[0025] In some embodiments, the systems and methods described herein can be configured to set a modulation index to a predetermined value for a motor. The motor may include a permanent magnet synchronous motor or other suitable motor. The motor may be associated with a vehicle's steering system (such as an SbW steering system or other suitable steering system). In some embodiments, the motor may be associated with a steering wheel actuator and / or a wheel actuator of the steering system. In some embodiments, the modulation index value is configured to control the torque harmonic performance of the motor.

[0026] The systems and methods described herein can be configured to calculate the DC bridge voltage based on a predetermined value of the modulation index. For example, the systems and methods described herein can be configured to calculate the DC bridge voltage relative to the output of the current regulator driving the inverter. In some embodiments, the systems and methods described herein can be configured to calculate the DC bridge voltage using feedforward mathematical relations as described in (5a).

[0027] The systems and methods described herein can be configured to selectively control a motor based on a DC bridge voltage. For example, the systems and methods described herein can be configured to selectively control the motor at any given time step by increasing or decreasing the DC bridge voltage relative to the nominal battery voltage, based on operational requirements.

[0028] Figure 1 A vehicle 10 based on the principles of this disclosure is generally shown. Vehicle 10 may include any suitable vehicle, such as a car, truck, SUV, minivan, crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. Although vehicle 10 is illustrated as a wheeled passenger vehicle used on a road, the principles of this disclosure can be applied to other vehicles, such as airplanes, ships, trains, drones, or other suitable vehicles.

[0029] Vehicle 10 includes a body 12 and a hood 14. A passenger compartment 18 is defined at least partially by the body 12. Another portion of the body 12 defines an engine compartment 20. The hood 14 is movably attached to a portion of the body 12 such that when the hood 14 is in a first position or open position, the hood 14 provides access to the engine compartment 20, and when the hood 14 is in a second position or closed position, the hood 14 covers the engine compartment 20. In some embodiments, the engine compartment 20 may be located at the rear of the vehicle 10 (as opposed to what is typically shown).

[0030] The passenger compartment 18 may be located behind the engine compartment 20, but in embodiments where the engine compartment 20 is located at the rear of the vehicle 10, the passenger compartment 18 may be located in front of the engine compartment 20. The vehicle 10 may include any suitable propulsion system, including: an internal combustion engine; one or more electric motors (e.g., an electric vehicle); one or more fuel cells; a hybrid (e.g., a hybrid vehicle) propulsion system including a combination of an internal combustion engine and one or more electric motors; and / or any other suitable propulsion system.

[0031] In some embodiments, vehicle 10 may include a gasoline engine or a gasoline-fueled engine, such as a spark-ignition engine. In some embodiments, vehicle 10 may include a diesel-fueled engine, such as a compression-ignition engine. Engine compartment 20 houses and / or surrounds at least some components of the propulsion system of vehicle 10. Additionally or alternatively, propulsion control devices (e.g., accelerator actuators, brake actuators, brake pedals, steering wheels, and other such components) are disposed in passenger compartment 18 of vehicle 10. The propulsion control devices may be actuated or controlled by the driver of vehicle 10 and may be directly connected to corresponding components of the propulsion system, such as throttle, brakes, axles, vehicle transmission, etc. In some embodiments, the propulsion control devices may transmit signals to a vehicle computer (e.g., drive-by-wire), which in turn may control the corresponding propulsion components of the propulsion system. Thus, in some embodiments, vehicle 10 may be an autonomous vehicle.

[0032] In some embodiments, vehicle 10 includes a transmission communicated with a crankshaft via a flywheel, clutch, or hydraulic coupling. In some embodiments, the transmission includes a manual transmission. In some embodiments, the transmission includes an automatic transmission. In the case of an internal combustion engine or hybrid vehicle, vehicle 10 may include one or more pistons that cooperate with the crankshaft to generate force, which is transmitted via the transmission to one or more axles, causing wheels 22 to rotate. When vehicle 10 includes one or more electric motors, a vehicle battery and / or fuel cell provides energy to the electric motors to rotate the wheels 22.

[0033] Vehicle 10 may include an automated vehicle propulsion system, such as cruise control, adaptive cruise control, automatic braking control, other automated vehicle propulsion systems, or combinations thereof. Vehicle 10 may be an automated or semi-automated vehicle, or other suitable type of vehicle. Vehicle 10 may include additional or fewer features compared to those generally shown and / or disclosed herein.

[0034] In some embodiments, vehicle 10 may include an Ethernet component 24, a Controller Area Network (CAN) bus 26, a Media-Oriented System Transport (MOST) component 28, a FlexRay component 30 (e.g., a brake-by-wire system), and a Local Interconnection (LIN) component 32. Vehicle 10 may use the CAN bus 26, MOST 28, FlexRay component 30, LIN 32, other suitable network or communication systems, or combinations thereof, to transmit various information from sensors, such as those inside or outside the vehicle, to various processors or controllers, such as those inside or outside the vehicle. Vehicle 10 may include additional or fewer features compared to those generally shown and / or disclosed herein.

[0035] In some embodiments, the vehicle 10 may include a steering system, such as an EPS system, a steer-by-wire system (e.g., which may include or be connected to one or more controllers that control components of the steering system without using a mechanical connection between the steering wheel and the wheels 22 of the vehicle 10), a hydraulic steering system (e.g., which may include a magnetic actuator incorporated into a valve assembly of a hydraulic steering system), or other suitable steering systems.

[0036] A steering system may include an open-loop feedback control system or mechanism, a closed-loop feedback control system or mechanism, or a combination thereof. The steering system may be configured to receive various inputs, including but not limited to: steering wheel position, input torque, one or more wheel positions, other suitable inputs or information, or a combination thereof.

[0037] Additionally or alternatively, inputs may include steering wheel torque, steering wheel angle, motor speed, vehicle speed, estimated motor torque command, other suitable inputs, or combinations thereof. The steering system may be configured to provide steering functionality and / or control to the vehicle 10. For example, the steering system may generate auxiliary torque based on various inputs. The steering system may be configured to use the auxiliary torque to selectively control the motor of the steering system to provide steering assistance to the operator of the vehicle 10.

[0038] In some embodiments, the steering system may include a steering system controller, such as controller 100, as... Figure 2The controller 100 is generally illustrated. The controller 100 may include any suitable controller. For example, the controller 100 may be configured to control various functions of the steering system. The controller 100 may include a processor 102 and a memory 104. The processor 102 may include any suitable processor, such as those described herein. Additionally or alternatively, the controller 100 may include any suitable number of processors other than or excluding the processor 102. The memory 104 may include a single disk or multiple disks (e.g., a hard disk drive) and includes a storage management module that manages one or more partitions within the memory 104. In some embodiments, the memory 104 may include flash memory, semiconductor (solid-state) memory, etc. The memory 104 may include random access memory (RAM), read-only memory (ROM), or a combination thereof. The memory 104 may include instructions that, when executed by the processor 102, cause the processor 102 to control at least various functions of the steering system.

[0039] The controller 100 may receive one or more signals from various measuring devices or sensors 106, which indicate sensed or measured characteristics of the vehicle 10. Sensors 106 may include any suitable sensors, measuring devices, and / or other suitable mechanisms. For example, sensors 106 may include one or more torque sensors or devices, one or more steering wheel position sensors or devices, one or more motor position sensors or devices, one or more position sensors or devices, other suitable sensors or devices, or combinations thereof. One or more signals may indicate steering wheel torque, steering wheel angle, motor speed, vehicle speed, other suitable information, or combinations thereof.

[0040] In some embodiments, controller 100 may be configured to set a modulation index to a predetermined value for the motor. The motor may include a PMSM or other suitable motor. The motor may be associated with a steering system of vehicle 10 (such as an SbW steering system or other suitable steering system). In some embodiments, the motor may be associated with a steering wheel actuator and / or a wheel actuator of the steering system. In some embodiments, the modulation index value is configured to control the torque harmonic performance of the motor.

[0041] The controller 100 can calculate the bridge voltage based on a predetermined value of the modulation index in response to an output voltage command. For example, the controller 100 can calculate the bridge voltage based on an output command from the inverter feedback regulator. In some embodiments, the controller 100 can use a feedforward motor model equation to calculate the bridge voltage.

[0042] The controller 100 can selectively control the motor based on the bridge voltage. For example, the controller 100 can selectively control the motor based on the bridge voltage by increasing or decreasing the DC bridge voltage relative to the nominal input battery voltage.

[0043] In some embodiments, controller 100 may perform the methods described herein. However, the methods performed by controller 100 as described herein are not intended to be limiting, and any type of software executing on the controller or processor may perform the methods described herein without departing from the scope of this disclosure. For example, a controller (such as a processor executing software within a computing device) may perform the methods described herein.

[0044] Figure 4 This is a flowchart generally illustrating method 300 according to the principles of this disclosure. At 302, method 300 sets the modulation index to a predetermined value for the motor.

[0045] At 304, method 300 calculates the bridge voltage for the output voltage command based on a predetermined value of the modulation index.

[0046] At 306, method 300 selectively controls the motor based on the bridge voltage.

[0047] In some embodiments, a method includes setting a modulation index to a predetermined value for the motor. The method also includes calculating a bridge voltage for an output voltage command based on the predetermined value of the modulation index, and selectively controlling the motor based on the bridge voltage.

[0048] In some embodiments, the motor includes a permanent magnet synchronous motor. In some embodiments, the motor is associated with a steering system of a vehicle. In some embodiments, the steering system includes a steer-by-wire steering system. In some embodiments, the motor is associated with a steering wheel actuator of the steering system. In some embodiments, the motor is associated with a wheel actuator of the steering system. In some embodiments, calculating the DC bridge voltage includes calculating the bridge voltage based on the output of the inverter feedback regulator. In some embodiments, the modulation index value is configured to control the torque harmonic performance of the motor. In some embodiments, calculating the DC bridge voltage includes using a feedforward motor equation. In some embodiments, selectively controlling the motor based on the bridge voltage includes increasing or decreasing the DC bridge voltage relative to the nominal input battery voltage.

[0049] In some embodiments, a system includes a controller configured to: set a modulation index to a predetermined value for a motor; calculate a DC bridge voltage based on the predetermined value of the modulation index; and selectively control the motor based on the calculated DC bridge voltage.

[0050] In some embodiments, the motor includes a permanent magnet synchronous motor. In some embodiments, the motor is associated with a steering system of a vehicle. In some embodiments, the steering system includes a steer-by-wire steering system. In some embodiments, the motor is associated with a steering wheel actuator of the steering system. In some embodiments, the motor is associated with a wheel actuator of the steering system. In some embodiments, the controller is also configured to calculate the DC bridge voltage based on the amplitude of an inverter closed-loop PI regulator command. In some embodiments, the controller is also configured to calculate the DC bridge voltage using feedforward calculation. In some embodiments, the controller is configured to selectively control the motor by increasing or decreasing the DC bridge voltage relative to the nominal input battery voltage.

[0051] The foregoing discussion is intended to illustrate the principles and various embodiments of this disclosure. Once the foregoing disclosure is fully understood, many variations and modifications will become apparent to those skilled in the art. The appended claims are intended to be construed as covering all such variations and modifications.

[0052] The word “example” is used herein to mean something used as an example, illustration, or description. Any aspect or design described herein as an “example” is not necessarily to be construed as being more preferred or advantageous than other aspects or designs. Rather, the use of the word “example” is intended to present a concept in a specific manner. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise stated or clearly apparent from the context, “X comprises A or B” is intended to mean any natural inclusion. That is, if X comprises A; X comprises B; or X comprises both A and B, then “X comprises A or B” is satisfied in any of the foregoing cases. Additionally, the article “a / an” used in this application and the appended claims should generally be interpreted as meaning “one or more” unless otherwise stated or clearly apparent from the context to the singular form. Furthermore, unless so described, the use of the terms “implementation” or “an embodiment” throughout the document is not intended to refer to the same embodiment or implementation.

[0053] The systems, algorithms, methods, and instructions described herein can be implemented in hardware, software, or any combination thereof. Hardware may include, for example, a computer, intellectual property (IP) core, application-specific integrated circuit (ASIC), programmable logic array, optical processor, programmable logic controller, microcode, microcontroller, server, microprocessor, digital signal processor, or any other suitable circuit. In the claims, the term "processor" should be understood to include any of the foregoing hardware, individually or in combination. The terms "signal" and "data" are used interchangeably.

[0054] As used herein, the term "module" can include a packaged functional hardware unit designed for use with other components, a set of instructions executable by a controller (e.g., a processor executing software or firmware), processing circuitry configured to perform a specific function, and a self-contained hardware or software component that interfaces with a larger system. For example, a module can include an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), circuitry, digital logic circuitry, analog circuitry, a combination of discrete circuitry, gate circuits, and other types of hardware, or combinations thereof. In other embodiments, a module can include a memory storing instructions executable by a controller to implement the features of the module.

[0055] Furthermore, in one respect, for example, the system described herein can be implemented using a general-purpose computer or general-purpose processor with a computer program that, when executed, implements any of the corresponding methods, algorithms, and / or instructions described herein. Additionally or alternatively, for example, a special-purpose computer / processor may be utilized, which may contain additional hardware for implementing any of the methods, algorithms, or instructions described herein.

[0056] Furthermore, all or part of the embodiments of this disclosure may take the form of a computer program product accessible from, for example, a computer-usable or computer-readable medium. A computer-usable or computer-readable medium may be, for example, any means capable of tangibly containing, storing, conveying, or transmitting a program for use by or in conjunction with any processor. The medium may be, for example, an electrical, magnetic, optical, electromagnetic, or semiconductor device. Other suitable media may also be used.

[0057] The above embodiments, implementations, and aspects have been described to allow for easy understanding of this disclosure and do not limit it. Rather, this disclosure is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which should be interpreted in the broadest possible sense to cover all such modifications and equivalent structures permitted by law.

Claims

1. A method comprising: For the motor, the modulation index is set to a predetermined value; Based on the predetermined value of the modulation index, the bridge voltage is calculated for the output voltage command; as well as The motor is selectively controlled based on the bridge voltage.

2. The method according to claim 1, wherein, The motor includes a permanent magnet synchronous motor.

3. The method according to claim 1, wherein, The motor is associated with the vehicle's steering system.

4. The method according to claim 3, wherein, The steering system includes a steer-by-wire system.

5. The method according to claim 4, wherein, The motor is associated with the steering wheel actuator of the steering system.

6. The method according to claim 4, wherein, The motor is associated with the wheel actuator of the steering system.

7. The method according to claim 1, wherein, Calculating the bridge voltage includes calculating the bridge voltage based on the output voltage amplitude associated with the output voltage command.

8. The method according to claim 1, wherein, Calculating the bridge voltage involves using the motor feedforward model equation to calculate the bridge voltage.

9. The method according to claim 1, wherein, The modulation index value is configured to control the current harmonic performance of the motor.

10. The method according to claim 1, wherein, Selectively controlling the motor based on the bridge voltage includes using at least one voltage reference using a feedforward motor model equation.

11. The method according to claim 10, wherein, The at least one voltage reference is calculated using the output of the inverter feedback proportional-integral regulator.

12. A system comprising: The controller is configured as follows: For the motor, the modulation index is set to a predetermined value; Based on the predetermined value of the modulation index, the bridge voltage is calculated for the output voltage command; and The motor is selectively controlled based on the bridge voltage.

13. The system according to claim 12, wherein, The motor includes a permanent magnet synchronous motor.

14. The system according to claim 12, wherein, The motor is associated with the vehicle's steering system.

15. The system according to claim 14, wherein, The steering system includes a steer-by-wire system.

16. The system according to claim 15, wherein, The motor is associated with the steering wheel actuator of the steering system.

17. The system according to claim 15, wherein, The motor is associated with the wheel actuator of the steering system.

18. The system according to claim 12, wherein, The controller is also configured to calculate the bridge voltage based on the output voltage amplitude associated with the output voltage command.

19. The system according to claim 12, wherein, The controller is also configured to use a feedforward motor model equation to calculate the bridge voltage.

20. The system according to claim 12, wherein, The controller is also configured to use at least one voltage reference to selectively control the motor based on the bridge voltage.

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