KR20050097528A - Motor control system and method with adaptive current profile - Google Patents

Abstract

Subject to user or system selection, one of the motor control schemes is accessed from the memory (56) by a controller (44) for implementation. The controller (44) generates control signals that are applied to energization circuitry (42) for supplying current to the phase windings (38) with a particular current waveform profile in accordance with the selected motor control scheme. The controller (44) has an input terminal (47) for receiving a user initiated torque command signal representing a desired motor torque. Each motor control scheme provides motor driving current that corresponds to torque command signals received at the controller input terminal.

Description

Motor control system and method with adaptive current profile {MOTOR CONTROL SYSTEM AND METHOD WITH ADAPTIVE CURRENT PROFILE}

This application is filed on April 5, 2001, all assigned with this application, US Concurrent Application No. 09 / 826,423, filed April 5, 2001, and US Concurrent Application, filed on April 5, 2001, Maslov et al. No. 09 / 966,102 to Maslov et al, filed 09 / 826,422, filed Oct. 1, 2001, application number 09 / 993,596 to Pyntikov et al, filed November 27, 2001, June 2002 Application No. 10 / 173,610 of Maslov et al, filed 19, Application No. 10 / 290,537, filed November 8, 2002, and Application of Maslov et al, filed January 29, 2003 Includes information related to No. 10 / 353,075.

The contents disclosed in these applications are incorporated herein by reference.

The present invention relates to the control of electric motors, and more particularly to the implementation of each of a plurality of motor control methods affecting the associated stator current waveform profiles.

The above-mentioned concurrent patent applications are those developed for effectively driving an electric motor. Electrically controlled pulsed energization of the motor windings allows the motor characteristics to operate more flexibly. By controlling the pulse width, duty cycle, and alternating application of energy sources to the appropriate stator windings, greater functional variability can be obtained. The use of permanent magnets in connection with such windings is beneficial in limited current consumption.

In vehicle drive environments where power availability for traction motors is limited to on-board supply, high torque with minimal power consumption while maintaining high efficiency under all conditions for traction motor operation It is highly desirable to derive the output. The structural arrangements of the motor disclosed in the co-pending applications serve these purposes. As described in these applications, the electromagnet core segments can be configured in the form of an annular ring of isolated magnetically permanent structures to increase magnetic flux density. Isolation of the electromagnet core segments allows concentration of individual magnetic flux in the magnet cores while minimizing the magnetic flux loss or unfavorable transformer interface effects that occur while interacting with other electromagnet members.

U. S. Application Serial No. 10 / 173,610 mentioned above discloses a control system for a multiphase motor that compensates for changes in individual phase circuit elements. High levels of precision control are achieved by using each phase control loop to fit its corresponding winding and structure. The alternating excitation for each phase winding is controlled by a controller that generates a signal in accordance with the parameters associated with each stator phase component and the selected drive algorithm. Phase windings are excited using a sinusoidal waveform of current for high efficiency operation. The control system changes the output current to correspond to the user's torque command input and accurately track.

The sinusoidal waveform profile obtained with this rectification method can extend battery life through efficient operation. However, a torque capability exceeding the torque capability that can be obtained from the control method that is most effective in the vehicle driving operation may be required. Typically, the power supply is rated as a maximum current discharge rate such as 10.0 amps. If the system user requests a torque command associated with this maximum current draw, the motor torque output for the sinusoidal current waveform profile is limited to approximately 54.0 Nm, for example, in a motor of the structure as described above. In application to vehicle driving, torque input commands are associated with commands for speed changes by the user. In a typical drive operation, the user's torque requirements apply to a wide range of variability with very little long-term predictability, which may be possible. The driver may require much higher acceleration or greater speed than the system can accommodate sinusoidal waveforms at full torque. Steeply rising slopes or heavy vehicle loads or similar driving conditions may impose other limits on the available speed and acceleration. Other applications that do not apply to a vehicle may have similar high torque demands.

Therefore, at the user's request, there is a need to still provide increased torque output for a vehicle motor control system that can operate with high efficiency. The above mentioned 10 / 290,537 application addresses this need by providing a number of useful motor control methods, each of which can provide a unique current waveform profile for driving the motor. One of the motor control methods can be selected by the user to obtain a current waveform profile with a large ability to meet the operating purposes. For example, one control method may be selected to achieve high efficiency operation, such as a sinusoidal waveform, while the other control method may be selected to provide high torque, although operating efficiency is low. The choice among the motor control methods can be made according to the needs or purposes of the user regarding torque and efficiency at specific times or other factors such as low torque ripple and noise. The selected motor control method will be performed to generate a control signal to generate a motor excitation current having an associated waveform profile.

For example, in application to vehicle towing, user profile selection provides the flexibility of driving the vehicle to adjust motion to meet the objectives. For example, if a user wants to reach a destination within a minimum amount of time, a high torque profile can be selected and maintained to provide maximum speed and acceleration capability throughout the journey. However, if a greater concern is to preserve the embedded energy source for relatively long trips, the high efficiency profile throughout the trip allows for the user's choice of a high torque profile at several points on a limited basis. Can be selected. See application 10 / 290,537 for a more detailed description of the illustrated waveforms, particularly those having high efficiency sine waves and high torque square wave shapes.

However, various conditions and change requirements for vehicle operation may require a change in profile much more frequently or faster than the driver may or may not want to maintain speed. The driver's torque requirements can be adequately met by choosing a high efficiency profile mode except for relatively temporary cases such as traffic conditions, elevation angles and the like. In such cases, the driver may not be able to adequately respond to the changing conditions to obtain an optimum gain for the change in the selection from the high efficiency profile to the high torque profile. When the high torque requirements are reduced, switching to the high efficiency profile may be delayed until the user realizes that the high torque profile is no longer needed, thereby allowing unnecessary current to be drawn from the battery. Therefore, it is desirable to use the high torque mode only when much higher torque is required than the torque available in the high efficiency mode.

The above-mentioned pending Maslov et al (Atty. Docket 57357-041) application discloses a system in which a motor control method is automatically selected on a dynamic basis to provide an appropriate excitation current waveform profile. The system responds to a user's input signal indicative of a torque request. User input signals are constantly detected and the system's ability to meet torque demands is monitored so that the appropriate motor control method is selected. The system's ability to meet torque demands is a function of motor speed, which is also constantly detected to facilitate torque demand monitoring. The high efficiency motor control method is implemented when the corresponding current waveform profile can meet the torque demand. The high torque motor control method is only performed when an increased torque demand is needed.

While such a system is suitable to provide an appropriate stator current waveform to meet system torque demands, other conditions that the driver is not aware of may reverse the implementation of the high torque motor control method. Events not directly related to the torque generating capability can generate an indication that the high efficiency mode is suitable even while high torque is required. For example, the battery supply voltage may reach a low threshold level indicating an urgent need for battery recharging or replacement. High efficiency profile mode delays these requirements. As another example, by increasing the heat, the motor can be operated under severe load conditions. The motor temperature may reach a level that indicates the need for low current draw and hence the first choice for implementing a high efficiency profile mode of operation. Other external conditions may also be an element that selects at least one from a plurality of different stator current waveform profiles.

Thus, there is a need for a more adaptive system in which the motor control method is automatically selected based on a plurality of conditions to provide an appropriate excitation current waveform profile.

The invention is illustrated by the accompanying drawings as examples and not by way of limitation, like reference numerals refer to like elements.

1 is an embodiment showing the rotor and stator elements in a configuration that may be employed in the present invention.

2 is a block diagram of a motor control system according to the present invention.

3 is a block diagram illustrating a torque controller methodology for use in the control system of FIG.

4 is a flowchart for explaining the operation of the profile selection function according to the present invention;

The present invention fulfills this need by providing a plurality of motor control methods for driving the motor, each of which can generate a unique motor excitation current waveform profile. One or more conditions from the outside on the motor are continuously sensed throughout the operation of the motor. These conditions relate to motor operation other than directly sensed motor functions such as position, speed and current feedback parameters. One of the motor control methods is automatically selected on a dynamic basis to supply the motor stator current excitation with the appropriate current waveform profile. The choice of motor control method is made in accordance with criteria relating to the torque requirements as well as the conditions to be monitored. The present invention therefore provides additional advantages for motors having ferromagnetically independent stator electromagnets.

The motor control methods may include a high efficiency motor control method that provides a current waveform profile for a relatively optimal operating efficiency and a high torque motor control method that provides a current waveform profile for a relatively high operating torque response. The system responds to a user signal that establishes a torque command request. The torque demand and the system's ability to meet that torque demand are monitored and the appropriate motor control method is selected accordingly. The high efficiency motor control method is implemented when the corresponding current waveform profile can meet the torque demand. If the torque demand exceeds the system's torque capability when operating in high efficiency mode, the high torque motor method is implemented in the absence of opposing signals generated by sensing conditions from the outside.

Another advantage of the present invention is that one or more system operating conditions are monitored and compared to criteria where the use of specific waveform profiles is required. The motor temperature can be monitored and compared to a specific temperature threshold higher than the high efficiency motor control method selected and implemented. The power supply voltage can be monitored and compared with the supply voltage threshold level. If the monitored voltage is lower than this threshold, a high efficiency motor control method is selected and executed. If any of these thresholds are met, the high torque motor control method is not selected regardless of the monitored torque conditions.

A further advantage of the present invention is that the user is given the choice of freeing automatic profile selection by entering a manual selection. For example, in application to a vehicle, the driver may choose to employ a high torque mode during operation so that the destination can be reached as soon as possible.

The invention can be clarified in a control system for a multiphase motor having a permanent magnet rotor and a plurality of stator phase components, each stator phase component having a phase winding formed on the core element. Preferably, each of the stator core elements has a separate ferromagnetic material such that it is not in direct contact with the other core elements, whereby each stator phase component forms an independent electromagnet unit. Stator excitation current is provided by direct current power supply through a circuit coupled to the controller. The controller can access data from the profile memory, which stores any of a plurality of motor control methods for executing the stator excitation current having the corresponding waveform profile. Using the accessed data, the controller generates a control signal applied to an excitation circuit for supplying current to the phase windings using a specific current waveform profile according to the selected motor control method. Each motor control method supplies a motor drive current corresponding to torque command signals received at the controller input terminal. The excitation circuit may have a plurality of controllable switches having control terminals coupled to the controller via pulse width modulation, as disclosed in the '041 Maslov application mentioned above.

The controller responds dynamically to one or more monitored conditions that affect the choice of motor control methods. Stored motor control methods are determined for current waveform profiles and, when accessed, incorporated into the operation of the controller. The user input coupled to the controller provides a torque command signal, which begins with the torque command. The controller is preferably provided with additional inputs including feedback signals on motor operation such as speed, rotor position, stator current and others and signals indicating conditions from the outside such as temperature and supply voltage levels. If the sensed motor temperature exceeds the temperature threshold or the sensed power supply voltage level is lower than the voltage level threshold, data for the high efficiency motor control method is accessed from the memory for motor control execution.

In the absence of these conditions, the data for the torque motor control method is accessed when the torque demand exceeds the torque threshold and the data for the high efficiency motor control method is accessed when the torque request does not exceed the torque threshold. The torque threshold is set depending on the torque output capability of the motor for high efficiency motor control operation. As the torque output capability depends on the speed, the torque threshold becomes variable. Based on the received input signals, the controller derives the motor torque requests and the control voltages necessary to meet those torque requirements on a real time basis. If the voltage required to maintain sinusoidal profile mode exceeds the power supply voltage, the controller selects a high torque profile mode operation to access data from the profile memory. In addition to repeating real-time calculations for profile selection, a lookup table may be stored in memory that correlates the profile selection with the torque request input and the monitored speed.

Additional advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, in which preferred embodiments of the invention are shown and described as a description of the best method contemplated for carrying out the invention. As will be realized, the present invention is capable of different embodiments, and its several details are capable of various modifications without departing from the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature, and not as restrictive.

Although the present invention can be used with a variety of other permanent magnet motors, the present invention applies to motors such as those disclosed in co-pending application Ser. No. 09 / 826,422 to Maslov et al. 1 is therefore an embodiment showing the rotor and stator elements disclosed in the application, the disclosure of which is incorporated herein. The rotor member 20 is an annular ring structure with permanent magnets 21 distributed substantially evenly along a cylindrical back plate 24. Permanent magnets are rotor poles with alternating polarity of the magnet along the inner periphery of the annular ring. The rotor surrounds the stator member 30, and the rotor and stator members are separated by an annular radial air gap. The stator 30 has a plurality of electromagnet core segments of uniform structure evenly distributed along the air gap. Each core segment has a generally U-shaped magnet structure 36 which forms two poles with surfaces 32 facing the air gap. Although the core segment may be configured to receive a single winding formed on the portion connecting the pole pairs, the legs of the pole pairs are wound around the winding 38. Each stator electromagnet core structure is separated from adjacent stator core elements and magnetically isolated. The stator elements 36 are protected by a permanent support structure which is not magnetic by forming an annular ring structure. This structure eliminates leakage radiation of stray transformer magnetic flux resulting from adjacent stator pole groups. The stator electromagnets thus become separate units, each having stator phases. The concept of the present invention, described in more detail below, can also be applied to other permanent magnet motor structures including a single stator core that supports all phase windings.

2 is a block diagram of a motor control system according to the present invention. The plurality of multiphase motor stator phase windings 38 are alternately supplied with voltage by a drive current supplied through the hybrid power block 42 from a direct current (dc) power source 40 such as a battery. The power block 42 may have electrical switch sets coupled with the controller 44 via a pulse width modulation converter and gate drivers. Each phase winding is connected to a switching bridge having control terminals connected to receive pulse modulated output voltages from a controller. Optionally, the switching bridge and gate driver components can be replaced with amplifiers connected to the controller output voltage. For a more detailed description of the winding power circuit, see application 10 / 290,537, supra.

The current in each phase winding is sensed by each one of the plurality of current sensors 45 whose outputs are supplied to the controller 44. The controller may have a plurality of inputs for this purpose or, optionally, signals from current sensors may be multiplexed and connected to a single controller input. Rotor position and speed sensor 46 provides rotor position and speed feedback signals to the controller. The sensor may comprise a known resolver, encoder or equivalent to them and a speed approximator that converts the position signals into speed signals in a known manner. The controller is connected to the source 40 by a main power supply bus. The controller is also supplied with user inputs including a torque request signal 47 and a profile select input 48 and other inputs 49 received from sensed external conditions such as motor temperature and battery voltage.

The combination to the controller is the program RAM memory 50, the program ROM 52, the data RAM 54 and the profile memory 56. These described units merely represent a known storage arrangement that allows the controller to access stored RAM data and program data. The profile memory 56 is shown separately in the figure for the purpose of illustrating the inventive concept. The profile memory may have a ROM in which a portion of the motor control method programs for instructing motor current waveform profiles obtained through the execution of related control methods are stored. The profile memory data may be stored in the form of a profile function library and a lookup table. Profile memory data structures may be in the form of real-time computation and optimization paths. Alternatively or additionally, a unit may be provided for computing values while the motor is running in real time.

In a vehicle drive application, torque request input 47 represents the torque required by the driver's throttle. The increase in the throttle indicates a command to increase the speed, which can be realized by increasing the torque. Optionally, this may indicate a command to increase torque to keep the speed of the vehicle the same under heavy load conditions, such as uphill driving. In operation, the control system torque tracking function must maintain a steady state torque operation for any given torque request entered through various external conditions such as drive conditions, load gradients, terrain, etc. In response, the driver's throttle commands must be accepted. The way in which the control system responds to the torque input requests depends on the particular motor control method executed. Multiple motor control methods can be used to obtain an appropriate response. Each control method affects a specific motor current waveform profile with unique characteristics in terms of efficiency, torque capacity, response capability, power loss, and the like.

3 is a block diagram illustrating a motor control method utilized in the simultaneous continuous application 10 / 173,610 described previously. For a detailed description of the operation, refer to the application. To produce the desired phase currents, the following per-phase voltage control is applied to the driver for the phase windings.

FIG. 3 is represented generally by the reference numeral 60 and represents a methodology for the controller to derive these voltage components using the torque request input and signals received from phase current sensors, position sensors and speed sensors in real time. . The function block 70 represents the formula and addition for the above components for obtaining the control voltage in real time. Respective functional blocks 62, 64, 66, 68, 72, 74, and 76, shown as inputs to block 70, provide a variety of components for the components obtained from real-time inputs or parameter constants received by the controller. Indicates the occurrence of components. Block 62 represents a precise torque tracking function, which is the desired current trajectory for each phase selected according to the following equation.

Where I _di is the desired current trajectory for each phase, τ _d is the requested torque command of the user, Ns is the total number of phase turns, K _τi is the torque transfer coefficient for each phase, and θ _i represents the rotor position with respect to the i-th phase. The magnitude of each phase current depends on the value of each phase of the torque transmission coefficient K _{tau i} .

In operation, the controller 44 continuously outputs the control signals _Vi (t) to the hybrid power block in the order set in the controller for each excitation for each phase winding. Each successive control signal V _i (t) is related to a specific current sensed at the corresponding phase winding, immediately detected rotor position and speed, and in particular the preset model parameters K _ei and K for each phase. related to _{τ i} . The operation described in FIG. 3 is performed continuously in real time. The equation shown in block 62 in this motor control method supplies the desired current component for the tracking torque output control signal _Vi (t) to the sinusoidal profile. The sinusoidal current trajectory I _sin (t) is generated from the following equation.

Where I _m is the magnitude of the phase current, N _r is the number of permanent magnet pairs, and θ _i is the signal measured for each phase rotor position. As described in the co-pending application Maslov et al applications (10 / 290,537 and '041) mentioned above, this sinusoidal waveform profile provides effective motor operation.

Even at the expense of some of the efficiency achievable with a sinusoidal waveform protocol, other equations for block 62 can be used with the torque tracking function of FIG. 3 to obtain different current waveform profiles to clarify other operational aspects. For higher torque operation, the equation of block 62 shown in FIG. 3 can be replaced by an equation that produces a square wave current waveform trajectory I _sq (t) as follows.

Here sgn (X) stands for the standard signing function, which is defined as 1 if X> 0, 0 if X = 0, and -1 if X <0. For a more detailed description comparing the efficiency and torque characteristics of two different current waveform profiles obtained by the motor control methods described above, see also Simlov et al. Applications (10 / 290,537 and '041).

Profile memory 56 stores data used by the controller to obtain current values that satisfy the equation illustrated above. For the square wave profile, the equation L _i dI _di / dt may be stored in advance. The data can be stored as a lookup table in the profile function library, and each motor control method has a corresponding lookup table. For a specific combination of torque demand value and rotor position for the corresponding motor control method, each entry in the lookup table represents a current value as shown by the output of block 62 in FIG. If the control method in which the sine waveform is generated is selected, the corresponding profile memory data is accessed. The square wave profile memory data is accessed when the corresponding control method is selected. Optionally, the profile memory can store data for each profile for which the desired current value I _di is computed repeatedly by the controller in real time. Although equations for sine and square wave waveforms have been set above for illustrative purposes, profiles of other waveforms, such as sawtooth waves, may be utilized for other operational purposes.

The selection of the profile data can be made automatically by the controller as appropriate while the motor is running. Optionally, the user may select an operation mode corresponding to one of the profiles by inputting a profile selection signal to the controller input 48. The profile selection operation is described with reference to the flow chart shown in FIG. The descriptions show that the profile memory stores data for executing a high efficiency profile motor control method, such as a control method for generating a sine motor current waveform, and for executing a high torque profile, such as a control method for generating a square wave motor current waveform. It relates to a particular embodiment of storing. This embodiment is described as data only to allow other profiles to be stored in the profile memory and to be accessed under operating conditions to ensure that other current waveforms are appropriate.

If no profile selection signal is detected by the controller, the automatic profile selection mode is executed. In step 100, the controller detects whether a user profile selection signal has been received at input 48 to determine whether automatic mode should be implemented. If the determination in step 100 is negative, the controller determines in step 102 whether the received profile selection signal is a high torque profile selection. If not, the controller accesses the profile memory at step 104 and exports data from the high efficiency profile lookup table after some reasonable delay. The exported data produces the desired current value I _di and sensed rotor position levels for instantaneous values of the torque demand. Instead, as a decision in step 102, if a high torque profile is selected, in step 106 the corresponding lookup table is accessed and the appropriate value I _di for that table is obtained. The process returns from step 104 and 106 to step 100 to determine whether a received user profile selection still exists and whether the nature of such selection continues in the manner described above. The operation in steps 104 and 106 occurs after the selection in step 102 for a sufficiently long time to overcome the temporary effect on the profile change. Thus, the appropriate delay for the return of the process to step 100 can be extended for the number of consecutive feedback samplings.

 If no user profile selection input signal is present and the system is not switched off, the controller determines in step 100 whether the waveform profile can be automatically selected. In step 108, the controller compares the sensed battery voltage received as a signal at input 49 and compares the voltage level with a predetermined voltage threshold level. If the battery voltage is below the threshold level, after a suitable delay in step 110 the controller selects the high efficiency mode and accesses the profile memory to retrieve data from the high efficiency profile lookup table. If it is necessary to switch between motor control methods, a delay is appropriate. During operation in this mode, the process returns to step 108 at regular intervals to continue the comparison of the sampled battery voltage and voltage threshold level. If the battery voltage is determined to be higher than the threshold level in step 108, the controller compares the sensed motor temperature received as a signal at input 49 and determines whether it exceeds the preset temperature level in step 112. . If it is determined in step 112 that the temperature is high, a high efficiency mode is indicated and the process returns to step 110. If the motor temperature is in an acceptable range of levels, the process may, in high efficiency mode implementation, determine whether the torque capacity of the motor for the current motor speed is sufficient to meet the requirements imposed by the user's torque input request. Proceed to step 114, which is determined by the controller. Concurrent applicant Maslov et at. As more fully disclosed in the application '041, the motor torque capacity is determined by comparing the required controller output voltage with the power supply voltage. The torque requirements can be satisfied if the obtained control voltages generated in association with the value Vi (t) of the controller from the output of the block 70 do not exceed the voltage level of the power supply. The comparison, as well as the calculation of the required voltage, can be performed in real time by the controller for each input sampling. Optionally, the lookup table can be accessed so that torque capacity is correlated with torque demand and motor speed.

If it is determined in step 114 that the torque capacity is sufficient, proceed to step 110 to continue to operate as a high efficiency profile or to switch from another control method with an appropriate delay to select a high efficiency motor control method and profile for execution. Access the corresponding data from the memory. If at step 114 the controller determines that the high efficiency motor operation method does not meet the torque demand, the next time the controller is moderately delayed to some extent, the high torque motor control method is selected and data is exported from the profile memory. While operating in the high torque mode, the process returns to step 100 at regular intervals to continue the determination of profile selection.

It is evident from the foregoing that the motor control system of the present invention is adaptable to the needs of the user as well as conditions from the outside which the user does not recognize. The system allows operation at high torque capacity only when there is a need to handle extreme demands and when external motor conditions are adequate. In this disclosure only a few examples of the preferred embodiments of the present invention and many of their uses have been shown and described. The present invention can be used in various other combinations and environments and variations and modifications are possible within the scope of the invention as described herein. For example, various other current waveform profiles may be utilized. Thus, the profile memory can store a plurality of profiles that can be accessed by the controller in response to specific profile selection commands. In another variation, the determination of torque capability determination may be made for the voltage actually supplied with each controller input sampling rather than the nominal supply voltage.

Claims (19)

A method of controlling a motor having a plurality of stator windings coupled to a controller, the method comprising: Storing a plurality of motor control methods in which each stored motor control method affects each stator current waveform profile; Generating control signals responsive to a motor operating function to excite the stator winding using a current waveform profile corresponding to a first motor control method of the motor control methods; Monitoring conditions from the outside to the motor; Detecting whether the monitored condition at the monitoring step meets or exceeds a threshold; Selecting a second motor control method from the stored motor control methods in response to the sensing step; And Generating motor control signals in accordance with the motor control method selected in the selection step to excite the stator winding using a current waveform profile corresponding to the second motor control method. The method of claim 1 wherein the stored motor control methods A motor control method comprising an efficiency motor control method providing a current waveform profile for a relatively optimum operating efficiency and a high torque motor control method providing a current waveform profile for a relatively high operating torque response. The method of claim 2, And wherein said relatively optimal operating efficiency current waveform profile has a substantially sinusoidal waveform and said relatively maximum torque response current waveform profile has a substantially square waveform. The method of claim 3, wherein Wherein the monitored condition is a motor temperature and the selecting step includes selecting the efficiency motor control method when the monitored motor temperature exceeds a temperature threshold. The method of claim 3, wherein Wherein the monitored condition is a motor supply voltage and the selecting step includes selecting the efficiency motor control method when the monitored supply voltage is below a voltage threshold level. The method of claim 3, wherein The monitoring step further includes continuously monitoring a plurality of conditions including motor temperature and motor supply voltage; And said selecting step includes selecting said efficiency motor control method when said sensing step detects that a monitored motor temperature exceeds a temperature threshold or said monitored supply voltage is below a voltage threshold level. The method of claim 6, Inputting a user signal to the controller; The monitoring step further comprises a monitoring torque request; The selecting step is to control the torque motor when the sensing step exceeds the torque threshold when there is no reaching of the temperature threshold for the monitored motor temperature or the voltage threshold level for the monitored supply voltage. A motor control method comprising selecting a method. The method of claim 1, wherein the motor A stator having a plurality of ferromagnetically independent electromagnets, each electromagnet having one of the windings wound thereon; And A motor control method comprising a permanent magnet rotor. A motor having a plurality of stator windings; An excitation circuit for providing an excitation current from a power supply to said stator windings; A controller coupled with the excitation circuit; Coupled to the controller, having a plurality of different motor control methods stored therein, each method comprising: storage means for affecting each one of the plurality of motor stator excitation current waveform profiles when applied by the controller; And Condition detecting means coupled to the controller for detecting a condition from at least one external to the motor, The controller dynamically responds to condition sensing means for accessing the motor control methods from the storage means to excite the motor stator windings using corresponding current waveform profiles according to a criterion associated with the sensed conditions. . The method of claim 9, The stored motor control methods include an efficiency motor control method providing a current waveform profile for a relatively optimum operating efficiency and a torque motor control method providing a current waveform profile for a relatively high operating torque response. The method of claim 10, Wherein the relatively optimal operating efficiency current waveform profile has a substantially sinusoidal waveform and the relatively maximum torque response current waveform profile has a substantially square waveform. The method of claim 10, The condition detecting means has a motor temperature sensor, The efficiency motor control method is accessed when the sensed motor temperature exceeds a temperature threshold. The method of claim 10, The condition detecting means has a voltage level detector; The efficiency motor control method is accessed when the sensed power supply voltage level is lower than the voltage level threshold. The method of claim 10, And means for deriving a user torque command coupled to the controller and deriving a motor torque request therefrom; The torque motor control method is accessed when the torque request exceeds the torque threshold and the efficiency motor control method is accessed when the torque request does not exceed the torque threshold. The method of claim 13, The condition detecting means further comprises a motor temperature sensor; Regardless of the torque demand, the efficient motor control method is accessed when the sensed motor temperature exceeds a temperature threshold. The method of claim 13, The condition detecting means has a voltage level detector; Regardless of the torque demand, the efficiency motor control method is accessed when the sensed power supply voltage level is lower than a voltage level threshold. The method of claim 14, The condition detecting means further comprises a motor temperature sensor and a voltage level detector, and irrespective of the torque demand, the efficient motor control method may include the detected motor temperature exceeding a temperature threshold or the detected power supply voltage level being voltage level threshold. Motor control system accessed when lower than value. The method of claim 17, Further comprising a user profile selection input to the controller; The controller is responsive to receipt of a command at the user profile selection input to access a corresponding motor control method and to ignore the sensed motor temperature and sensed power supply voltage. The method of claim 11, wherein the motor A stator having a plurality of ferromagnetically independent electromagnets, each electromagnet having one of the windings wound thereon; And Motor control system with permanent magnet rotor.