Method for controlling electric machine, electric machine controller and electric machine system

Abstract

The invention relates to a method for controlling a motor, a motor controller and a motor system. According to some embodiments, the method for controlling an electric machine includes: applying a first reference torque generating current parameter to the electric machine in a stationary state during a start-up mode; generating a demand torque generation voltage parameter based on the first reference torque generation current parameter; determining a feedback torque generation current parameter based on the measured motor current in the stationary state; determining a phase resistance measurement of the electric machine based on the demand torque generation voltage parameter and the feedback torque generation current parameter; and controlling the motor in a speed control mode based on the phase resistance measurement.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to motor control, and more particularly to a method for controlling a motor, a motor controller, and a motor system. BACKGROUND

[0002] Permanent magnet synchronous machines (PMSMs) are used in consumer and industrial motor applications due to their higher reliability and smaller size compared to other types of electric machines. In order to achieve high efficiency and low vibration and noise, field oriented control (FOC) techniques are commonly used for consumer and industrial PMSM control of fans, pumps, compressors, gear motors, etc. SUMMARY

[0003] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0004] According to some embodiments, a method for controlling a motor includes applying a first reference torque generation current parameter to the motor in a stationary state during a start-up mode, generating a demand torque generation voltage parameter based on the first reference torque generation current parameter, determining a feedback torque generation current parameter based on a measured motor current in the stationary state, determining a phase resistance measurement of the motor based on the demand torque generation voltage parameter and the feedback torque generation current parameter, and controlling the motor in a speed control mode based on the phase resistance measurement.

[0005] According to some embodiments, a motor controller includes a first controller configured to apply a first reference torque generation current parameter to the motor in a stationary state in a start-up mode, a second controller configured to generate a demand torque generation voltage parameter based on the first reference torque generation current parameter during the start-up mode, and a feedback unit configured to receive three-phase motor current measurements in response to the demand torque generation voltage parameter and to transform the three-phase motor current measurements to determine a feedback torque generation current parameter, wherein the first controller is configured to determine a phase resistance measurement of the motor based on the demand torque generation voltage parameter and the feedback torque generation current parameter, and the second controller is configured to control the motor in a speed control mode based on the phase resistance measurement.

[0006] According to some embodiments, a system comprises: a motor; a current sensing unit connected to the motor and configured to measure motor current and generate motor current measurements; and a motor controller comprising: a first controller configured to apply a first reference torque generating current parameter to the motor in a start-up mode; a second controller configured to generate a demand torque generating voltage parameter based on the first reference torque generating current parameter during the start-up mode; and a feedback unit configured to receive the motor current measurements in response to the demand torque generating voltage parameter and to transform the motor current measurements to generate a feedback torque generating current parameter, wherein the motor is stationary during the start-up mode, the first controller is configured to determine a phase resistance measurement of the motor based on the demand torque generating voltage parameter and the feedback torque generating current parameter, and the second controller is configured to control the motor in a speed control mode based on the phase resistance measurement.

[0007] According to some embodiments, a system for controlling a motor comprises: means for applying a first reference torque generating current parameter to the motor in a stationary state during a start-up mode, means for generating a demand torque generating voltage parameter based on the first reference torque generating current parameter, means for determining a feedback torque generating current parameter based on a measured motor current in the stationary state, means for determining a phase resistance measurement of the motor based on the demand torque generating voltage parameter and the feedback torque generating current parameter, and means for controlling the motor in a speed control mode based on the phase resistance measurement.

[0008] To the accomplishment of the foregoing and related aspects and advantages, the following description and appended drawings set forth certain illustrative aspects and implementations. These are indicative of but a few of the various ways in which one or more aspects can be employed. Other aspects, advantages, and novel features of the disclosure will become apparent from the following detailed description when considered in conjunction with the annexed drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic diagram of a motor controller according to some embodiments.

[0010] Figure 2 is a diagram illustrating a permanent magnet synchronous motor (PMSM) rotating orthogonal coordinate system according to some embodiments.

[0011] Figure 3 is a diagram illustrating a start-up mode of a motor according to some embodiments.

[0012] Figure 4 is a schematic diagram of an implementation of an estimator unit according to some embodiments.

[0013] Figure 5A method of controlling a motor is shown in accordance with some embodiments.

[0014] Figure 6 An exemplary computer readable medium is shown in accordance with some embodiments. DETAILED DESCRIPTION

[0015] The claimed subject matter is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It can be evident, however, that the claimed subject matter can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the claimed subject matter.

[0016] In addition to motor control functions, processing time of the microcontroller used in the motor controller is shared to provide user interfaces and other functions. Providing motor control without computationally intensive techniques, such as transforms requiring quadratic equations, allows more functionality to be provided in a system with reduced complexity, lower cost microcontrollers.

[0017] Field Oriented Control (FOC) is a variable speed control method for three-phase alternating current (AC) electric motors that utilizes fast control response throughout the motor speed range to improve power efficiency. Various implementations of structures, components, and techniques for providing three-phase AC motor control are discussed herein. Structures, components, and techniques are discussed with reference to an example three-phase permanent magnet synchronous motor (PMSM) device and control system. However, the present application is not intended to be limited in this regard, but rather the discussion is meant to be illustrative and explanatory. The discussed techniques and devices can be applied to other motor designs, control structures, etc. (e.g., single and three-phase variable frequency drives, digital phase converters, three-phase and single-phase motors, induction motors, regenerative drives, etc.) and remain within the scope of the present disclosure.

[0018] Figure 1 is a schematic diagram of a motor system 100 in accordance with some embodiments. The motor system 100 includes a motor controller 101 employing a sensorless topology that uses an estimator unit 102 to estimate rotor position and rotor speed to support FOC techniques for controlling a motor 104. In some embodiments, the motor controller 101 estimates motor resistance parameters R s .

[0019] Rotor speed indicates motor speed. To implement FOC control, motor controller 101 uses a Park transform and an inverse Park transform to convert between a D-Q rotor-fixed reference frame, defined by a torque-generating component Q and a flux-generating component D, and an a- b stationary reference frame.

[0020] The Park transform converts the orthogonal stationary reference frame currents to flux-generating currents and torque-generating currents using the following equations:

[0021] and

[0022]

[0023] The inverse Park transform converts back from the rotating reference frame to the stationary reference frame using the following equations:

[0024] and

[0025] V β = V q cos (0) + V d sin (0).

[0026] The Clarke transform converts between a three-phase reference frame, defined by V, U, and W components, and an a-b stationary reference frame using the following equations:

[0027] and

[0028]

[0029] Figure 2 FIG. 200 is a diagram 200 showing PMSM rotating orthogonal coordinate systems according to some embodiments. The a-b stationary reference frame signals are sinusoidal signals at steady state, while the D-Q rotor-fixed reference frame signals are nearly constant at steady state. In the three-phase reference frame, the A, B, and C components are 120° apart and are stationary. In the a-b stationary reference frame, the components are electrically orthogonal and are stationary. In the D-Q rotor-fixed reference frame, the components are electrically orthogonal and are rotating. For the purposes of this description, it is assumed that motor 104 rotates in the positive direction, i.e., counterclockwise, so the angle and angular velocity are positive. For a motor 104 rotating in the negative direction, i.e., clockwise, the signs of the angle and angular velocity can change. The coordinate systems can be referenced to the stator and / or rotor of motor 104. For example, the D-Q rotor-fixed reference frame is fixed to the rotor, and the components of the D-Q coordinate system rotate together. The direct axis of the D-Q rotor-fixed reference frame is oriented in the direction from the rotor permanent magnet south pole (S) to the north pole (N). The quadrature axis of the D-Q rotor-fixed reference frame is perpendicular to the rotor flux (e.g., perpendicular to the rotor).

[0030] The three-phase sinusoidal current I of the motor stator winding A I B and I C Three non-rotating pulsating magnetic fields are generated at 120° intervals in directions A, B, and C, respectively, thus producing a rotating magnetic field (stator flux space vector). A I B and I C The vectors are added together to obtain the space vector of the current. For a vector with ω i In a rotating motor, the magnitude of the current space vector can be amplified or reduced without changing its direction.

[0031] In the stationary α-β reference frame, the space vector of the rotating stator flux represents the rotating stator flux. The three-phase stator phase voltages V, spaced 120° apart... A V B and V C The vector addition defines the rotating voltage space vector. The rotating rotor permanent magnet generates a rotating rotor flux space vector. The magnitude and direction of the aforementioned rotating space vector can be represented by radial coordinates and polar angles in a polar coordinate system. Techniques for transformation between reference frames are known in the art.

[0032] Reference Figure 1 The motor controller 101 includes a start controller 106 that provides open-loop parameters during the start-up mode of the motor 104 and a speed controller 108 that provides closed-loop control during the speed control mode of the motor 104. The start controller 106 controls switches 110 and 112 to select between start-up mode and speed control mode operation. Switch 110 selects between the start controller 106 and the speed controller 108 to provide I... qref Signal. Switch 112 selects between the output of the start controller 106 and the estimator unit 102 to provide the estimated rotor position.

[0033] During speed control mode, speed controller 108 receives a reference speed ω representing the desired rotational speed of motor 104. ref and the estimated rotor speed from estimator unit 102 As input. In some embodiments, the speed controller 108 is a proportional-integral (PI) controller that operates to drive the error between the inputs to zero. q Controller 114 receives I from switch 110 qref Signal and feedback torque generation current parameters (I q In some implementations, I q Controller 114 is a proportional-integral (PI) controller that operates to drive the error between its inputs to zero.d Controller 116 receives as inputs a reference flux generating current parameter (I dref ) and a feedback flux generating current parameter (I d ). In some embodiments, I d controller 116 is a proportional-integral (PI) controller that operates to drive an error between its inputs to zero. I q controller 114 outputs a demand torque generating voltage parameter V q , and I d controller 116 outputs a demand flux generating voltage parameter V d . By providing a value of I dref that is zero, the flux generating component I d is controlled to zero. A negative value of I dref may be used to control the flux generating component I d to achieve flux weakening control, extending the operating speed range of motor 104, or a positive value of I dref may be used to control the flux generating component I d to achieve flux enhancement control.

[0034] Motor controller 101 includes a park's transformation unit 120, an inverse park's transformation unit 122, and a Clarke's transformation unit 124 to convert between reference frames. Park's transformation unit 120 transforms an a-β stationary reference frame to a D-Q rotor fixed reference frame. Inverse park's transformation unit 122 transforms the D-Q rotor fixed reference frame to an a-β fixed reference frame. Clarke's transformation unit 124 transforms a three-phase reference frame to an a-β stationary reference frame.

[0035] Inverse park's transformation unit 122 receives a demand torque generating voltage parameter V q from I q controller 114, and a demand flux generating voltage parameter V d from I d controller 116, and generates stationary coordinate system voltage parameters V α , V β as inputs to a space vector modulator 126. The magnitude and angle of the voltage vector defined by V α and V β provide a reference voltage to space vector modulator 126 to control a pulse width modulation (PWM) unit 128 to generate three-phase sinusoidal waveform output signals that drive an inverter 130. The output signals of inverter 130 drive the phases of motor 104. In some embodiments, inverter 130 includes a three-phase two-level voltage inverter.

[0036] The current sensing unit 132 senses phase currents of the motor 104. In some embodiments, the current sensing unit 132 includes three shunt resistors associated with the three legs of the inverter 130 to sense the current of each phase of the motor 104. In some embodiments, two shunt resistors are used to sense the current of two phases of the motor 104. The current from the third phase of the motor 104 can be calculated based on the relationship I A +I B +I C = 0. In some embodiments, a single shunt resistor is inserted into the DC link of the inverter 130 to sense the DC link current, and three-phase current reconstruction is used to obtain current information for each phase of the motor 104.

[0037] An analog-to-digital converter (ADC) 134 receives the sensed voltages from the current sensing unit 132 to generate digital inputs for a current calculation unit 136. The current calculation unit 136 generates phase current measurement parameters I A , I B , and I C . The phase current measurement parameters are provided to a Clarke transformation unit 124 to generate alpha-beta stationary reference frame feedback current parameters I α , I β . The stationary reference frame feedback current parameters are provided to a Park transformation unit 120 to generate a feedback torque generation current parameter I q and a feedback flux generation current parameter I d . The current calculation unit 136, the Clarke transformation unit 124, and the Park transformation unit 120 include a feedback unit 138 for generating the feedback torque generation current parameter I q and the feedback flux generation current parameter I d .

[0038] The estimator unit 102 uses data in the alpha-beta stationary reference frame to estimate rotor position and rotor speed In a surface permanent magnet synchronous motor (SPMSM), efficiency is improved by controlling the flux generation current I d to zero.

[0039] The dynamic D-Q axis voltage equations for a PMSM are:

[0040]

[0041] where:

[0042] V d - flux generation voltage

[0043] V q - torque generation voltage

[0044] R s - motor phase resistance

[0045] L d - synchronous inductance of motor winding in d-axis

[0046] L q - synchronous inductance of motor winding in q-axis

[0047] I q - torque generation current

[0048] I d - flux generation current

[0049] k e - back-emf constant

[0050] In some embodiments, the start-up controller 106 estimates the motor phase resistance R s In some embodiments, the synchronous inductance parameters L q and L d are motor specification table reference values.

[0051] Figure 3 is a diagram 300 illustrating a start-up mode of the motor 104 according to some embodiments. The start-up mode is controlled by the start-up controller 106. During start-up, the switches 110, 112 are connected to the start-up controller 106. During speed control mode, the switch 110 is connected to the speed controller 108, and the switch 112 is connected to the estimator unit 102.

[0052] The start-up controller 106 generates a reference torque generation current I qref and a reference rotor position The reference torque generation current I qref from the start-up controller 106 is provided to the I q controller 114 by the switch 110. The output of the I q controller 114 is provided to a low pass filter 114F to generate V q-LPF . The reference rotor position from the start-up controller 106 is provided to the park unit 120 and the inverse park unit 122 by the switch 112. The motor current generated in response to the reference torque generation current I qref from the start-up controller 106 is sensed by the current sensing unit 132, converted to a digital value by the ADC 134, converted to a phase current by the current computation unit 136, converted to a stationary reference frame current by the Clarke unit 124, and converted to a D-Q rotor fixed reference frame current by the park unit 120. The I q output of the park unit 120 is provided to a low pass filter 120F to generate Iq-LPF .

[0053] exist Figure 3 In the middle, the electric velocity ω e As shown by curve 302, and the reference torque generating current I qref As shown by curve 304, stage 1 is the orientation stage. In stage 1, the start controller 106 sets an initial electrical angle setpoint of 90 degrees and applies a current I in a ramp manner. qref To move motor 104 to the rotor position The setpoint. Phase 2 is the stable phase, in which motor 104 does not move (ω). e =0), and after achieving the initial electrical angle of motor 104, the controller 106 is activated to provide a steady-state value I. qref Phase 3 is the asynchronous drive phase that begins when the electric motor starts rotating, such as the electric speed (ω). e As shown in the addition, in stage 4, the speed control mode operation is initiated by configuring switch 110 to select speed controller 108 and switch 112 to select estimator unit 102.

[0054] In some embodiments, the start controller 106 measures the phase resistance R during phase 2 when the motor 104 is stationary. s Because the electric velocity (ω) e Since the current is zero, the back electromotive force is zero. The current measured by the current sensing unit 132 is the steady-state current. d Controller 116 and I q The output voltage of controller 114 is a square wave signal with high-frequency alternating current, resulting in ripple in the phase current, and therefore the current derivative is not zero. Low-pass filters 114F and 120F remove the ripple to provide V q-LPF and I q-LPF If the feedback magnetic flux from the Parker transformer unit 120 generates a current I... d If provided to a low-pass filter, it will have a value of zero. Therefore, due to ω e =0, I d-LPF =0, and Therefore, equations 1 and 2 can be simplified to:

[0055] V d =0 and (3)

[0056] V q-LPF =R s I q-LPF (4)

[0057] The phase resistance in Equation 4 is:

[0058]

[0059] In some embodiments, the start-up controller 106 makes multiple resistance measurements during phase 2 and averages the results. In some embodiments, the motor controller 101 controls the motor 104 based on the measured phase resistance R s by the I q controller 114 and the I d controller 116 controls the integral gain parameter of the current loop based on the measured phase resistance R s according to the following equation:

[0060] K I = ω c R s (6)

[0061] The transfer function of the current control loop is a first order LPF with a cut-off frequency of ω c . In some embodiments, the cut-off frequency ω c is set to approximately three times the maximum motor speed to obtain a good trade-off between dynamic response and sensitivity to measurement noise. The motor controller 101 sets the integral gain parameter of the I s controller 114 or the I q controller 116 based on the measured phase resistance R d .

[0062] Figure 4 is a schematic diagram of an embodiment of the estimator unit 102 according to some embodiments. In some embodiments, the estimator unit 102 is a sliding mode estimator that uses motor parameters such as the α-β reference frame currents I α and I β , the α-β reference frame voltages V α and V β , the measured phase resistance R s and the synchronous inductance parameters L q and L d to estimate the motor speed and position. The estimator unit 102 determines the stator back-EMF parameters based on the α-β reference frame voltages and currents according to the following equations:

[0063] and

[0064] where

[0065] L s is the stator inductance parameter, which for surface-mounted PMSMs is equal to the synchronous inductance parameter (L s = L q = L d ), and for interior-mounted PMSMs is equal to the average of the synchronous inductance parameters (Ls = 1 / 2 (L q + L d )).

[0066] In some embodiments, the estimator unit 102 comprises: a Park transform unit 402; filters 404, 406 connected to the Park transform unit 402; a sign unit 408 connected to the filter 406; multiplication units 410 connected to the filter 404 and the sign unit 408; a subtraction unit 412 connected to the filter 406 and the multiplication units 410; an integrator 414 connected to the Park transform unit 402; and multiplication units 416 connected to the subtraction unit 412 and the integrator 414. The output of the Park transform unit 402 is the D-Q frame back-EMF parameters:

[0067] and

[0068]

[0069] In some embodiments, the filters 404 and 406 are low-pass filters that generate filtered D-Q frame back-EMF parameters E df and E qf . The sign unit 408 determines the sign (+ / -) of the filtered Q back-EMF parameter E qf . The sign unit 408, multiplication units 410, 416 and the subtraction unit 412 generate the estimated speed according to the following equation:

[0070]

[0071] The integrator 414 estimates the rotor position based on the estimated rotor speed:

[0072]

[0073] In some embodiments, different update frequencies are used for different loops in the motor controller 101. For example, the speed controller 108 is updated at intervals such as 1 ms, 2 ms, 5 ms, etc. The d controller 116, the I q controller 114, the estimator unit 102 and the low-pass filters 114F, 120F operate at a high frequency update frequency such as 4 KHz, 8 KHz, 16 KHz, etc.

[0074] Figure 5 A method 500 of controlling the motor 104 according to some embodiments is shown. At 502, the motor 104 enters a start-up state, e.g., phase 1 to phase 3 in Figure 3 . At 504, the start-up controller 106 determines whether the motor 104 is in a steady phase, e.g., phase 4 in Figure 3Phase 2. The start controller 106 cycles through the steady-state phase to record the phase resistance R. s The N measured values. The loop count N can be reset at 502. If the loop count is less than N at 508, the controller 106 is activated at 510 to output V from low-pass filters 114F and 120F. q-LPF and I q-LPF The digital values ​​are converted to analog values ​​respectively. This conversion operation is the reverse of the operation of the ADC 134, which converts analog values ​​to digital values, and depends on the dynamic range used for the digital values. At 512, the start controller 106 calculates V. q-LPF The cumulative value, and at 514, the controller 106 is started to calculate I. q-LPF The cumulative value. In some implementations, the cumulative value represents the average value. In some implementations, the cumulative value is a vector of values. The cycle count increments at 516.

[0075] If the count is reached at 508, then controller 106 is activated to calculate the phase resistance R at 518. s At 520, the motor controller 101 bases its decisions on the measured phase resistance R. s To control motor 104. In some embodiments, controlling motor 104 may include setting up as described in Equation 6 by I q Controller 114 or I d The controller 116 controls the integral gain parameter of the current loop to generate the drive signal for the motor 104. In some embodiments, controlling the motor 104 may include based on the measured phase resistance R. s To estimate rotor speed and position, such as Figure 4 As shown, the estimate is provided to the speed controller 108 to control I. q Controller 114.

[0076] Furthermore, some of the disclosed techniques can be easily implemented in software using object-oriented or object-based software development environments that provide portable source code, which can be used on various computer or workstation platforms. Alternatively, the disclosed techniques and / or arrangements can be implemented partially or entirely in hardware using standard logic circuits or VLSI designs. In some embodiments, motor 104, inverter 130, current sensing unit 132, and ADC 134 are implemented in hardware, and... Figure 1 The remaining units are implemented in software. However, other combinations of hardware, firmware, or software can also be considered.

[0077] Moreover, the disclosed processes can be readily implemented in software that can be stored on a computer-readable storage medium, executed on a programmed general- purpose computer, a special-purpose computer, a microprocessor, or the like. In these instances, the arrangements and processes described can be implemented as program instructions 504 stored on a computer- readable storage medium 506, such as a memory storage device, that are executed by a programmable computer under the control of a computer program 508. The program instructions 504 can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language. The program instructions 504 can be converted to a binary, machine language, or other interpretable format by a compiler, assembler, or interpreter. The program instructions 504 can be executed by a computer, such as a general-purpose computer, a special-purpose computer, a microprocessor, or the like. The program instructions 504 can be executed by a computer to cause the computer to perform the arrangements and processes described. Or CGI scripts, resources residing on servers or computer workstations, routines embedded in special- purpose communication devices or computer programs, etc. The arrangements and / or processes can also be implemented by physically incorporating the arrangements and / or processes into a software and / or hardware system, such as the hardware and software system of a testing / modeling device.

[0078] Figure 6 An exemplary embodiment of a computer-readable medium 602 according to some embodiments 600 is shown. One or more embodiments are directed to a computer-readable medium comprising processor-executable instructions configured to implement one or more of the techniques presented herein. Embodiments 600 include a non-transitory computer-readable medium 602 (e.g., a CD-R, DVD-R, flash drive, diskette, etc.) having computer-readable data 604 encoded thereon. The computer-readable data 604, in turn, includes a set of processor-executable computer instructions 606 configured to facilitate operations in accordance with one or more principles set forth herein when executed by a computing device 608 including a reader 610 to read the processor-executable computer instructions 606 and a processor 612 to execute the processor-executable computer instructions 606. In some embodiments, the processor-executable computer instructions 606, when executed, are configured to facilitate performance of a method 614, such as at least some of the methods described previously. In some embodiments, the processor-executable computer instructions 606, when executed, are configured to facilitate implementation of a system, such as at least some of the systems described previously. Numerous such computer-readable media, configured to operate according to the techniques presented herein, can be designed and fabricated by persons of ordinary skill in the art.

[0079] The term "computer-readable medium" can include communication media. Communication media typically embodies computer-readable instructions or other data in a "modulated data signal" such as a carrier wave or other transport mechanism and includes any information delivery media. The term "modulated data signal" can include a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal.

[0080] According to some embodiments, a method for controlling an electric machine includes applying a first reference torque generation current parameter to the electric machine in a stationary state during a start-up mode, generating a demand torque generation voltage parameter based on the first reference torque generation current parameter, determining a feedback torque generation current parameter based on a measured electric machine current in the stationary state, determining a phase resistance measurement of the electric machine based on the demand torque generation voltage parameter and the feedback torque generation current parameter, and controlling the electric machine in a speed control mode based on the phase resistance measurement.

[0081] According to some embodiments, applying the first reference torque generation current parameter to the electric machine includes setting an electrical angular position setpoint of the electric machine to 90 degrees, and applying the first reference torque generation current parameter to the electric machine to move the electric machine to the electrical angular position setpoint.

[0082] According to some embodiments, determining the phase resistance measurement includes dividing the demand torque generation voltage parameter by the feedback torque generation current parameter.

[0083] According to some embodiments, generating the demand torque generation voltage parameter based on the first reference torque generation current parameter includes generating the demand torque generation voltage parameter in a controller, and controlling the electric machine includes configuring a gain parameter of the controller based on the phase resistance measurement.

[0084] According to some embodiments, controlling the electric machine includes configuring a gain parameter of the controller based on the phase resistance measurement, and generating a drive signal for the electric machine in the speed control mode using the controller configured with the gain parameter.

[0085] According to some embodiments, controlling the electric machine includes estimating an electric machine speed and an electric machine position based on the phase resistance measurement, and generating a drive signal for the electric machine in the speed control mode based on the electric machine position and the electric machine speed.

[0086] According to some embodiments, the method includes iterating the generation of the phase resistance measurement in the stationary state.

[0087] According to some embodiments, determining the phase resistance measurement includes generating a filtered value of the demand torque generation voltage parameter, converting the filtered value of the demand torque generation voltage parameter to an analog demand torque generation voltage parameter, generating a filtered value of the feedback torque generation current parameter, converting the filtered value of the feedback torque generation current parameter to an analog feedback torque generation current parameter, and determining the phase resistance measurement based on the analog demand torque generation voltage parameter and the analog feedback torque generation current parameter.

[0088] According to some embodiments, a motor controller comprises: a first controller configured to apply a first reference torque generation current parameter to a motor in a stationary state in a start-up mode; a second controller configured to generate a demand torque generation voltage parameter based on the first reference torque generation current parameter during the start-up mode; and a feedback unit configured to receive three-phase motor current measurements in response to the demand torque generation voltage parameter and to transform the three-phase motor current measurements to determine a feedback torque generation current parameter, wherein the first controller is configured to determine a phase resistance measurement of the motor based on the demand torque generation voltage parameter and the feedback torque generation current parameter, and the second controller is configured to control the motor in a speed control mode based on the phase resistance measurement.

[0089] According to some embodiments, the first controller is configured to set an electrical angle position setpoint of the motor to 90 degrees and to apply the first reference torque generation current parameter to the motor to move the motor to the electrical angle position setpoint.

[0090] According to some embodiments, the first controller is configured to determine the phase resistance measurement by dividing the demand torque generation voltage parameter by the feedback torque generation current parameter.

[0091] According to some embodiments, the second controller is configured to employ a gain parameter configured based on the phase resistance measurement in the speed control mode.

[0092] According to some embodiments, the motor controller comprises a third controller configured to generate a demand flux generation voltage parameter for driving the motor based on a reference flux generation current parameter using a gain parameter configured based on the phase resistance measurement.

[0093] According to some embodiments, the motor controller comprises an estimator unit configured to estimate a motor speed and a motor position in the speed control mode based on the phase resistance measurement; and a third controller configured to generate a second reference torque generation current parameter for the second controller in the speed control mode based on the motor position and the motor speed.

[0094] According to some embodiments, the first controller is configured to iterate the generation of the phase resistance measurement in the start-up mode.

[0095] According to some embodiments, the motor controller comprises: a first low pass filter configured to generate a filtered value of a demand torque generation voltage parameter; and a second low pass filter configured to generate a filtered value of a feedback torque generation current parameter, wherein the first controller is configured to: convert the filtered value of the demand torque generation voltage parameter to an analog demand torque generation voltage parameter, convert the filtered value of the feedback torque generation current parameter to an analog feedback torque generation current parameter, and determine a phase resistance measurement based on the analog demand torque generation voltage parameter and the analog feedback torque generation current parameter.

[0096] According to some embodiments, a system comprises: a motor; a current sensing unit connected to the motor and configured to measure a motor current and generate a motor current measurement; and a motor controller comprising: a first controller configured to apply a first reference torque generation current parameter to the motor in a start-up mode; a second controller configured to generate a demand torque generation voltage parameter based on the first reference torque generation current parameter during the start-up mode; and a feedback unit configured to receive the motor current measurement in response to the demand torque generation voltage parameter and transform the motor current measurement to generate a feedback torque generation current parameter, wherein the motor is stationary during the start-up mode, the first controller is configured to determine a phase resistance measurement of the motor based on the demand torque generation voltage parameter and the feedback torque generation current parameter, and the second controller is configured to control the motor in a speed control mode based on the phase resistance measurement.

[0097] According to some embodiments, the second controller is configured to employ a gain parameter configured based on the phase resistance measurement in the speed control mode.

[0098] According to some embodiments, the system comprises a third controller configured to generate a demand flux generation voltage parameter for driving the motor based on a reference flux generation current parameter using a gain parameter configured based on the phase resistance measurement.

[0099] According to some embodiments, the system comprises an estimator unit configured to estimate a motor speed and a motor position in the speed control mode based on the phase resistance measurement; and a third controller configured to generate a second reference torque generation current parameter for the second controller in the speed control mode based on the motor position and the motor speed.

[0100] According to some embodiments, a system for controlling an electric machine comprises means for applying a first reference torque generating current parameter to the electric machine in a stationary state during a start-up mode, means for generating a demand torque generating voltage parameter based on the first reference torque generating current parameter, means for determining a feedback torque generating current parameter based on a measured electric machine current in the stationary state, means for determining a phase resistance measurement of the electric machine based on the demand torque generating voltage parameter and the feedback torque generating current parameter, and means for controlling the electric machine in a speed control mode based on the phase resistance measurement.

[0101] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing at least some of the claims.

[0102] Various operations of embodiments are provided herein. The order in which some or all of the operations are described should not be construed as a requirement. Alternative ordering is possible and can be understood by those of ordinary skill in the art. Further, some or all of the operations can not be necessary in some embodiments. Additionally, the order in which some or all of the operations are described does not necessarily correspond to the order in which the operations are performed.

[0103] Further, "exemplary" is used herein to mean serving as an example, instance, illustration, etc., and not necessarily as advantageous. As used in this application, "or" is intended to mean an inclusive "or" rather than an exclusive "or". In addition, the use of "a" or "an" is intended to mean "one or more" unless otherwise indicated. Further, the use of "at least one" is intended to mean "one or more" unless otherwise indicated. Also, the use of relative terms such as "first", "second", etc. is intended to be illustrative and not necessarily indicative of a time aspect, spatial aspect, order of execution, etc. Rather, such terms are used merely as labels to distinguish between different elements, items, etc. For example, a first element and a second element can correspond to two different elements or two identical elements or the same element.

[0104] Moreover, although this disclosure has been largely described with respect to one or more implementations, various alternatives, modifications, and equivalents can be used. Such equivalents include, but are not limited to, equivalents in structure, functionality, and / or operation. Substantial equivalents are defined to include not only components that are identical, but also components that have similar structure, function, and / or operation. It will be apparent to those skilled in the art after understanding the disclosure that various changes and modifications can be made.

Claims

1. A method for controlling an electric machine, comprising: applying a first reference torque generation current parameter to an electric machine in a stationary state during a start-up mode; generating a demand torque generation voltage parameter based on the first reference torque generation current parameter; determining a feedback torque generation current parameter based on a measured electric machine current in the stationary state; determining a phase resistance measurement of the electric machine based on the demand torque generation voltage parameter and the feedback torque generation current parameter; and controlling the electric machine in a speed control mode based on the phase resistance measurement. applying the first reference torque generation current parameter to the electric machine comprises:

2. The method of claim 1, wherein, setting an electrical angular position setpoint of the electric machine to 90 degrees; and applying the first reference torque generation current parameter to the electric machine to move the electric machine to the electrical angular position setpoint. determining the phase resistance measurement comprises:

3. The method of claim 1, wherein, dividing the demand torque generation voltage parameter by the feedback torque generation current parameter.

4. The method of claim 1, wherein: generating the demand torque generation voltage parameter based on the first reference torque generation current parameter comprises: generating the demand torque generation voltage parameter in a controller; and controlling the electric machine comprises: configuring a gain parameter of the controller based on the phase resistance measurement. controlling the electric machine comprises:

5. The method of claim 1, wherein, configuring a gain parameter of a controller based on the phase resistance measurement; and generating a drive signal for the electric machine in the speed control mode using the controller configured with the gain parameter. controlling the electric machine comprises:

6. The method of claim 1, wherein, estimating an electric machine speed and an electric machine position based on the phase resistance measurement; and generating a drive signal for the electric machine in the speed control mode based on the electric machine position and the electric machine speed.

7. The method of claim 1, comprising: iterating the generation of the phase resistance measurement in the stationary state. determining the phase resistance measurement comprises:

8. The method of claim 1, wherein, generating a filtered value of the demand torque generation voltage parameter; converting the filtered value of the demand torque generation voltage parameter to an analog demand torque generation voltage parameter; generating a filtered value of the feedback torque generation current parameter; converting the filtered value of the feedback torque generation current parameter to an analog feedback torque generation current parameter; and determining the phase resistance measurement based on the analog demand torque generation voltage parameter and the analog feedback torque generation current parameter.

9. An electric machine controller, comprising: a first controller configured to apply a first reference torque generation current parameter to an electric machine in a stationary state in a start-up mode; a second controller configured to generate a demand torque generation voltage parameter based on the first reference torque generation current parameter during the start-up mode; and a feedback unit configured to receive three-phase electric machine current measurements in response to the demand torque generation voltage parameter and to transform the three-phase electric machine current measurements to determine a feedback torque generation current parameter, wherein: ​ ​ the first controller is configured to determine a phase resistance measurement of the electric machine based on the demand torque generation voltage parameter and the feedback torque generation current parameter; and the second controller is configured to control the electric machine in a speed control mode based on the phase resistance measurement.

10. The electric machine controller of claim 9, wherein: the first controller is configured to: set an electrical angular position setpoint of the electric machine to 90 degrees; and apply the first reference torque generation current parameter to the electric machine to move the electric machine to the electrical angular position setpoint.

11. The electric machine controller of claim 9, wherein: the first controller is configured to determine the phase resistance measurement by dividing the demand torque generation voltage parameter by the feedback torque generation current parameter.

12. The electric machine controller of claim 9, wherein: the second controller is configured to employ a gain parameter configured based on the phase resistance measurement in the speed control mode.

13. The electric machine controller of claim 9, comprising: a third controller configured to generate a demand flux generation voltage parameter for driving the electric machine based on a reference flux generation current parameter using a gain parameter configured based on the phase resistance measurement.

14. The electric machine controller of claim 9, comprising: an estimator unit configured to estimate an electric machine speed and an electric machine position in the speed control mode based on the phase resistance measurement; and a third controller configured to generate a second reference torque generation current parameter for the second controller in the speed control mode based on the electric machine position and the electric machine speed.

15. The electric machine controller of claim 9, wherein: the first controller is configured to iterate the generation of the phase resistance measurement in the start-up mode.

16. The electric machine controller of claim 9, comprising: a first low pass filter configured to generate a filtered value of the demand torque generation voltage parameter; and a second low pass filter configured to generate a filtered value of the feedback torque generation current parameter, wherein: the first controller is configured to: convert the filtered value of the demand torque generation voltage parameter to an analog demand torque generation voltage parameter; convert the filtered value of the feedback torque generation current parameter to an analog feedback torque generation current parameter; and determine the phase resistance measurement based on the analog demand torque generation voltage parameter and the analog feedback torque generation current parameter.

17. An electric machine system, comprising: an electric machine; a current sensing unit connected to the electric machine and configured to measure an electric machine current and generate an electric machine current measurement; and an electric machine controller, comprising: a first controller configured to apply a first reference torque generation current parameter to the electric machine in a start-up mode; a second controller configured to generate a demand torque generation voltage parameter based on the first reference torque generation current parameter during the start-up mode; and a third controller configured to generate a demand flux generation voltage parameter for driving the electric machine based on a reference flux generation current parameter using a gain parameter configured based on the phase resistance measurement. a feedback unit configured to receive the motor current measurements in response to the demand torque generating voltage parameter and transform the motor current measurements to generate a feedback torque generating current parameter, wherein: the motor is stationary during the start-up mode; the first controller is configured to determine a phase resistance measurement of the motor based on the demand torque generating voltage parameter and the feedback torque generating current parameter; and the second controller is configured to control the motor in a speed control mode based on the phase resistance measurement.

18. The motor system of claim 17, wherein: the second controller is configured to employ a gain parameter configured based on the phase resistance measurement in the speed control mode.

19. The motor system of claim 17, comprising: a third controller configured to generate a demand flux generating voltage parameter for driving the motor based on a reference flux generating current parameter using a gain parameter configured based on the phase resistance measurement.

20. The motor system of claim 17, comprising: an estimator unit configured to estimate a motor speed and a motor position in the speed control mode based on the phase resistance measurement; and a third controller configured to generate a second reference torque generating current parameter for the second controller in the speed control mode based on the motor position and the motor speed. ​

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