TWI280723B - Method and system for determining a rotor angle in a drive control for a motor - Google Patents

Abstract

A method of determining a rotor angle in a drive control for a motor, comprising the steps of (a) determining a rotor magnetic flux in the motor; (b) estimating the rotor angle on the basis of the rotor magnetic flux; and (c) correcting the estimated rotor angle on the basis of reactive power input to the motor. Step (a) may include the step of non-ideal integration of stator voltage and current values. Step (b) may include the step of correcting phase errors caused by said non-ideal integration via a PLL circuit with phase compensation (F). Step (c) may include the steps of (1) calculating a first reactive power input value as 1:5*We*(C_Lq*I*1) and a second reactive power input value as 1.5*(Vq*id-Vd*iq); (2) determining a difference between said first and second reactive power input values; and (3) applying said difference to the rotor angle estimated in step (b) to obtain a corrected rotor angle. At higher motor frequencies, the estimated rotor angle is based on the rotor magnetic flux. At lower frequencies, it is based on a predetermined motor load model which is used in conjunction with a start-up sequencing logic circuit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the control of a motor drive machine, and more particularly to a rotor angle estimation technique for a permanent 5 magnet synchronous motor (pMSM) drive machine, particularly for PMSM by stationary Estimation of the rotor angle at start-up. tPrevious chair; j Background of the invention Rotor position information is usually required for stable operation of a permanent magnet with a sinusoidal current excitation. In the past, the encoders mounted on the motor shaft have been subjected to the position of the joint, the bay rotor, or indirectly via the voltage and current based feedback by the estimation of the deductive rule to obtain the continuous rotor position indirectly. The latter is preferred because of the lower system cost and operating costs of the latter. However, most passive motor estimation schemes (based on measured voltage and power /4 estimates) are complex and require precise knowledge of motor parameters such as resistance and inductance. These parameters are particularly variable for stator resistance as a function of temperature. In this way, the rotor angle estimation is inaccurate, and the control stability problem is caused, the torque per ampere is reduced, and the efficiency of the Ma Lai is inferior. The patent application Serial No. 10/294,201 describes a method in which the rotor angle 2 is estimated by a phase-locked loop (PLL), the phase-locked loop is locked to the motor flux, and in particular the normally operating mode is locked to the motor flux. Ren Ting observed that there were additional problems when starting the motor. Under the condition of zero speed or low speed (<1〇=), due to the low amplitude of the motor after the MF), it is difficult to accurately estimate the motor electric history. For most of the non-sensors (no main 1280723 axis, 'flat horse suppression) control drive, based on bemf tracking rotor angle usually low, , ) failed. Therefore, the sensor controls the permanent magnet motor driver to require some sort of starting device. In most cases, the motor is opened in a thin open loop (without any feedback). Once the motor speed is increased (typical > 1〇%), the drive is switched to a closed loop (using current and / or voltage feedback) control. However, during the switching from the open loop mode to the closed loop mode, torque and current ripple may occur due to the mode shift. It is therefore desirable to provide a rotor angle estimation scheme that provides maximum torque performance per amp without the need to accurately understand stator resistance or other motor parameters. It is further desirable to provide a solution to estimate the rotor angle at start-up, thereby providing a strong start of the motor and reducing torque ripple during motor starting. SUMMARY OF THE INVENTION The present invention provides a novel method for novelly estimating rotor angle information for permanent magnet parental motor control having a sinusoidal back EMF. The rotor angle is estimated by a phase-locked loop (with phase-rank difference compensation) that receives the rotor flux estimate. The rotor flux is derived from the stator voltage (actual voltage or command voltage), current, resistance and inductance. The rotor angle estimation error (the stator resistance change due to temperature) is then removed using a novel angular error corrector. Such angular error correctors are based on reactive power compensation and are insensitive to resistance changes. In addition, the diagonal corrector reference module requires only one inductance parameter. In order to provide a strong start during motor start-up and reduce torque ripple 1280723, the present invention uses the aforementioned PLL in conjunction with newly developed start-up logic. Start the logic, including starting the sort minus the mechanical mode. The material elements can be made very early, for the reason that the elements utilize the same PLL integrator used to estimate the rotor angle using the 10/294,201 patent. The 5 pieces of flux information are used by the PLL to seal the rotor angle to track the rotor angle. A simple mechanical mode is used by the PLL for the open loop to predict the rotor angle. This startup sequence logic is used to provide a robust and smooth transition from open loop control mode to closed loop control mode during motor start-up. The rotor angle estimation deduction method for sensorless control of such a PM motor includes one or more of the following example characteristics. (1) The flux estimator has feedforward inductance compensation. The vector pLL is locked to the flux estimate. A non-ideal flux estimator in combination with flux pLL is used to estimate the rotor angle. (2) The phase compensation circuit (F) is included in pll to estimate the phase error introduced by the non-ideal flux 15 estimator. (3) Based on the compensation scheme of the reactive power, the sensitivity of the rotor angle estimation method to the change of the stator resistance can be removed. (4) Start the sequencer and load mode combined with the vector pll operation to achieve a strong start and a smooth ramp rise. 20 Other features and advantages of the present invention will become more apparent from the following description of the embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a PMSM control system including a first specific example of the present invention. 1280723 Figure 2 is a detailed block diagram showing the rotor angle estimator of Figure 1. Fig. 3 is a circuit diagram of a rotor flux estimator associated with the sketch of Fig. 2. Figure 4 is a further detailed view showing the rotor angle corrector of Figure 1. Figure 5 is a line graph showing the relationship between the error of the reactive power 5 and the rotor angular error in terms of motor rated power. Fig. 6 is a block diagram showing a second specific example of the rotor angle estimator. Fig. 7 is a block diagram showing a third specific example of the rotor angle estimator. Figure 8 shows further details of the rotor angle estimator of Figure 7. [Embodiment 3] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is described herein with respect to a motor control deductive rule for firmware implementation. However, the scope of the present invention encompasses any combination of hardware, firmware and software that has been foreseen within the skill of the art. A block diagram of the first specific example of the control method is shown in FIG. The d-axis is 15 to calibrate the direction of the rotor's magnetic axis (reference usage habits). The following are the definitions of each quantity listed in Figure 1. 1280723 id* Shiztong current command iq* torque current command id flux current feedback iq torque current feedback ia, ib phase current Rtr_Ang estimated rotor angle C_Rs stator per phase resistance Del_Ang from angle corrector Compensation angle Vab, Vbc line voltage feedback Vd flux-axis voltage feedback Vq torque · shaft voltage feedback We inverter fundamental frequency The details of the rotor angle estimation block of Figure 1 are shown in Figure 2. The input Flx_A and Flx_B are the rotor flux, and the rotor flux is obtained by the unbalance of the voltage back enlf. The voltage emf is formed by the stator current, voltage, resistance and inductance, as shown in Fig. 3. In the figure, Tf represents the time constant of a non-ideal integrator. Note that the inputs (V_A, V_B, 1_8, and I_B) of the flux estimator in Figure 3 are simply 3-phase (ia, ib, Vab, Vbc) to 2-phase conversion signals. ° The rotor angle estimator (Fig. 2) utilizes a novel flux-locked loop system. The frequency feedforward circuit F compensates for the phase error caused by the non-ideal integration of the stator voltage. Figure 3 is used to obtain the magnetic flux. The phase error produced by the non-ideal integral is fully compensated by circuit F. Then the 'estimation error due to the resistance is compensated by the rotor angle corrector system 1280723'. Figure 4 illustrates the following. The rotor angle corrector circuit details of Fig. 1 are shown in Fig. 4. When estimating the rotor angle of _ (the fifth (five) matches the actual rotor angle, the reference value of the reactive power (9) wheeled motor is equal to: 1.5*We*(C Lq*I*I+Flx—M*id+(C—Ld-C— Ld)*id*id) Note that for permanent magnet surface mount (PMSM) motors, the air gap reluctance is the same for the d-axis and q-axis. Thus id=〇 and Ld=Lq. Therefore, the aforementioned reference invalid power equation can be Reduced to: 1.5*We*(C_Lq*I*I) The internal motor reactive power (Q) is expressed only by voltage and current, and can be obtained as follows: Q=L5*(Vq*id-Vd*iq) : C—Ld - d-axis inductance C_Lq - q-axis inductance I - stator current amplitude

Flx_M - equivalent flux linkage of the rotor magnet Q-terminal reactive power, and

We(omegae) - Stator fundamental frequency Since C_Ld=C_Lq, only one inductance parameter (Lq or Ld) can achieve rotor angle correction. Lq is used in this case. Of course, the invention is also suitable for use with other types of motors, such as internal permanent magnet motors, where Ld is not equal to Lq, as is known to those skilled in the art. If the estimated rotor angle matches the actual rotor angle, then the following will be satisfied. 10 1280723 Series: (Vq*id-Vd*iq)-We*C—Lq*I*I=0 So Q and (We*C_Lq*I *i) (Inverted power error between the vertical axis of Figure 5) can be used to offset any rotor angular error (horizontal axis of Figure 5), thus maintaining a maximum torque of 5 amps per amp, even if the resistance parameter used by the flux estimator The same is true for errors (Figure 3). The rotor angle estimation block according to the second specific example of the present invention is shown in Fig. 6. The system can be simplified by estimating the upper square in the M〇d-2 7Γ block of the system of Figure 2. 10 The third specific example is shown in Fig. 7. The system of Figure 6 has been modified again. In the first specific example and the second specific example, the two input terminals of the PI (proportional integer) regulator are tied together. One receives the Pll-Err output from Demod-Flux. In this specific example, the second input of the PI regulator receives the separate individual output of the start block "ί§' - an input female receives the Pll Err from Demod_Flux. Further details of the 15 start mode and its interface to the PLL angle tracking mode are shown in Figure 8. In Figure 8:

Rtr an Ang - estimated rotor angle

Flx_A - Estimated alpha flux

Fix a Β - Estimated 10,000 flux

Pll-Err - PLL error signal

Trq - estimated motor torque

We - Inverter Fundamental Frequency Figure 6 shows the same PLL (Figure 2), and block F moves to the path of the pLL. This provides a convenient interface to the boot module. Moving to block f does not affect the 20 1280723 PLL function because the main function of block F is to estimate the phase shift (Rtr_Ang) of the resulting rotor angle. The PI block of Figure 2 is expanded in Figure 8 to show the P-path and I-path of the interface to the boot module. Figure 8 shows the interface between the boot module and the pll module. 5 When the motor BEMF is small (<1〇%), the fidelity signal Flx_A&Flx__B (obtained from the estimated motor voltage or the measured motor voltage calculation) is inferior, resulting in an inaccuracy of the error correction signal (Pll_Err). In order to solve this problem, P11-Err is generated by a simple motor mode (load mode of Fig. 8) during the initial startup. The load mode is only used for a short period of time at startup. When the motor frequency 10 (We) reaches a certain threshold, the fidelity of F1x_a & F1x_b is improved, and then the calculation of P11_Err can be obtained from the number of Fix-A and Flx-B. In Fig. 8, during the start of the motor, the switches Sw1 and Sw2 are tied to their upper positions. The start sequencer is in its parked state and the input to the PI regulator is zero. In the parked state, the initial motor angle is captured (using any common technique such as DC current capture) and the initial motor angle is initialized. After the berth is completed, Sw2 is closed, and Swl is still in its upper position (open loop mode). The integrator input of the ρι regulator is fed by a simple load mode, consisting of two gain multipliers (Kt&K〇. The Kt path is the motor acceleration torque mode, and the Kt path is fed back by the load torque current (iq)). Feed. The Kf path is the friction torque mode, which is fed by the frequency (). In the case of the motor, the acceleration torque is much larger than the friction torque during the motor start. In this case, the use of the Kf path can be deleted. When the absolute motor frequency exceeds a certain threshold (usually 1% of the rated frequency), the switch Swl is closed and the closed loop mode is activated. 12 1280723 Although specific examples have been described The present invention is susceptible to various other modifications and adaptations and other uses. The invention is therefore not limited by the specific disclosure herein. L. BRIEF DESCRIPTION OF THE DRAWINGS 3 5 FIG. 1 is a block diagram showing the present invention. The PMSM control system of the first specific example. Fig. 2 is a detailed block diagram showing the rotor angle estimator of Fig. 1. Fig. 3 is a circuit diagram of the rotor flux estimator associated with the sketch of Fig. 2. For further detail, the rotor angle corrector of Figure 1 is shown. 10 Figure 5 is a line diagram showing the relationship between the reactive power error and the rotor angular error in terms of motor rated power. Figure 6 is a block diagram. A second specific example of the rotor angle estimator is shown. Fig. 7 is a block diagram showing a third specific example of the rotor angle estimator. Fig. 8 shows further details of the rotor angle estimator of Fig. 7. 15 - [Main components Explanation of symbols] 1.. .Rtr-Ang, estimated rotor angle 2...We, inverter fundamental frequency 3.. .Flx-A, estimated oc magnetic flux 4.. .F1X-B, estimated Beta flux 13

Claims (1)

1280723---1 repair (more) depends on j ......... mm ιιι „,, 鸣································ 〇.% 1 - A method for determining the rotor angle in a drive controller of a motor, the method comprising the steps of: ^ 5 phantom based on the rotor flux in the motor to estimate the rotor angle; and b) based on the motor The invalid power input is used to correct the estimated rotor angle; wherein the step (4) further comprises the step (al): estimating the rotor angle according to a predetermined motor load model in combination with the start sequencer during the motor start period. The method of claim 1, wherein the load model is representative of a motor acceleration torque. 3. The method of claim 2, wherein the model is responsive to a negative 15 load torque current feedback (iq). The method of claim 2, wherein the load model is representative of friction torque. 5. The method of claim 4, wherein the model is responsive to the motor frequency (We). Patent application scope The method of item 1, wherein the step (al) ends at an adjustable percentage of the rated motor frequency. 7. The method of claim 6, wherein the adjustable percentage is about 10%. The method of the first aspect of the patent scope, wherein the step (al) is performed in the open circuit mode of 12 1280723 牴 10 genus, and ends in the open circuit mode to the closed circuit mode. (9) The method for determining the rotor angle in the drive controller of the motor comprises the following steps: determining the rotor flux of the motor; and b) based on the rotor between the motors, starting from the macro X and starting the motor Period sub-angle: Start the sort 11 with ^, and estimate the turn of 10 15 20 = the invalid power input of the motor to correct the estimated score step = the step (4) butterfly value and the non-ideal product 10_ Representation of the ninth item of the patent application, the torque is added. The load model is the motor u. For example, the method of applying the patent range (4), the torque current feedback (10). 回应 Responding to the negative U·such as the scope of patent application 1 item torque Table, method, and the load model are friction A such as Shen t# 姆 _12 slave frequency (We). (d) in response to Ma K as in the patent application scope item 9, wherein the adjustable rated motor Percentage of frequency. 糸 Ends with α as in the method of U of the patent application, about 10% of rated motor power. /, " ') Ends at 15 1280723 ^ Month repair (more) is being replaced; 10.26 16. The method of claim 9, wherein the step (b) is performed in an open loop mode and ends in an open loop mode transition to a closed loop mode. 17. The method of claim 9, wherein the step (a) further comprises the step of correcting the phase error caused by the unintended integration through the phase compensation (F) PLL circuit. 18. A system for determining a rotor angle in a drive controller of a motor, the system comprising: 10 15 20 a first circuit that estimates a rotor angle based on a rotor flux in the motor; and a second A circuit that corrects the estimated rotor angle based on an invalid power input of the motor; wherein the first circuit estimates the rotor angle in conjunction with a start sequencer in accordance with a predetermined motor load model during motor startup. 19. The system of claim 18, wherein the load model is representative of motor acceleration torque. 20. The system of claim 19, wherein the model is responsive to load torque current feedback (iq). 21. The system of claim 19, wherein the load model is representative of friction torque. 22. The system of claim 21, wherein the model is responsive to the frequency of the motor (We). 23. The system of claim 18, wherein the estimating step ends with an adjustable nominal motor frequency percentage. 16 1280723 - i n strict (more), 24. The system of claim 23, wherein the estimating step ends at about 10% of the rated motor voltage. 25. The system of claim 18, wherein the estimating step is performed in an open loop mode and ends in an open loop mode transition to a closed 5 loop mode. 26. A system for determining a rotor angle in a drive controller of a motor, the system comprising: a) a first circuit for measuring rotor flux of the motor; and b) a second circuit for The rotor flux in the motor, 10 and during motor startup, estimating the rotor angle in accordance with a predetermined motor load model in conjunction with the start sequence Is; and correcting the estimated rotor angle based on the motor's reactive power input; The first circuit performs a non-ideal integration of the stator voltage value and the current value. 15 27. The system of claim 26, wherein the load model is representative of motor acceleration torque. A system as claimed in claim 27, wherein the model is responsive to load torque current feedback (iq). 29. The system of claim 27, wherein the load model is representative of friction 2 转矩 torque. 3. A system as claimed in claim 29, wherein the model is responsive to the frequency of the motor (We). 31. The system of claim 26, wherein the estimating step ends with an adjustable nominal motor frequency percentage. 17 Ι28〇71ϊ]26Ώ 32. The system of claim 31, wherein the estimating step ends at about 10% of the rated motor voltage. 33. The system of claim 26, wherein the estimating step is performed in an open 5 10 15 20 loop mode and ends in an open loop mode transition to a closed loop mode. 34. The system of claim 26, wherein the second circuit is calibrated by a PLL circuit with phase compensation (F) to correct the phase error caused by the non-ideal integration. 35. The method of claim 1, wherein the correcting step is performed by: calculating a first-invalid power input value and a second invalid power input value; determining the H-th reactive material input The association between the values; and applying the _ to the estimated rotor angle in the stipulated money to obtain the corrected rotor angle. 36. The method of claim 1, wherein the estimating step comprises a non-ideal Μίν of the stator voltage value and the current value, a step of accumulating the knives, and correcting through a pll circuit having a phase complement (F) The step of phase error. (10) Caused by the ideal integral 37. As in the method of claim 9, the wheel is calibrated to correct the estimated rotor: the reactive power of the motor is implemented: the step of calculating an nth is performed by the following actions铋 power wheeling value and a second helmet power wheeling value; determining the first 盥 second..., 联; and applying the correlation between the riding power input values to obtain a corrected rotor angle. ,) Estimated rotor angle, 38. If the method of claim 9 is applied, "t step (b) contains one of the phase compensation (F) by replacing the money with 18 2 repair (more) A PLL circuit to correct the phase error caused by non-ideal integration. 39. The system of claim 18, wherein the second circuit corrects the estimated rotor angle based on the reactive power input of the motor by: calculating a first invalid power input value and a second An invalid power input value; determining an association between the first and second invalid power input values; and applying the association to the estimated rotor angle in the estimating step to thereby obtain a corrected rotor angle. 40. The system of claim 18, wherein the first circuit performs a non-ideal integration of a stator voltage value and a current value, and wherein the second circuit is calibrated by a PLL circuit having phase compensation (F) Phase error caused by ideal integration. 41. The system of claim 26, wherein the estimated rotor angle is corrected based on the reactive power input of the motor in the following manner: calculating a first invalid power input value and a second invalid power input value Determining an association between the first and second invalid power input values; and applying the association to the estimated rotor angle in step (b) to obtain a corrected rotor angle. 42. The system of claim 26, wherein the second circuit corrects a phase error due to non-ideal integration through a PLL circuit having phase compensation (F). 43. The method of claim 3, wherein the model uses a predetermined gain multiplier for the load torque current feedback. 44. The method of claim 5, wherein the model is for the motor frequency 19 The 26th repair (more) is being replaced with 丨 "'"丨· III _·ι 丨丨 rate using a predetermined gain multiplier. 45. The system of claim 20, wherein the model uses a predetermined gain multiplier for the load torque current feedback. 46. The system of claim 22, wherein the model uses a predetermined gain multiplier for the motor frequency. 20