US-12617288-B2 - Electric machine torque adjustment based on waveform multiples

Abstract

Methods, systems, and devices for electric machine torque adjustment based on waveform multiples are disclosed herein. One electric machine controller, arranged to direct pulsed operation of an electric machine, utilizes a pulse controller that calculates a first average measured torque from sensed torque values over a first time period and a second average measured torque from sensed torque values over a second time period, wherein the first and second time periods are different time periods.

Inventors

• Matthew Younkins
• Mark Wilcutts

Assignees

• TULA ETECHNOLOGY INC.

Dates

Publication Date

20260505

Application Date

20240223

Claims (20)

1. 1 . An electric machine controller arranged to direct pulsed operation of an electric machine, wherein the electric machine controller utilizes a pulse controller that calculates a first average measured torque from sensed torque values over a first time period and a second average measured torque from sensed torque values over a second time period, wherein the first and second time periods are different time periods; wherein the machine controller is configured to vary a first output level in accordance with variations in at least one of an operating speed, a torque, and a rotational speed times a number of poles of the electric machine.
2. 2 . The electric machine controller of claim 1 , wherein the pulse controller determines whether the electric machine is operating in a safe state based on the calculated first average measured torque and second average measured torque.
3. 3 . The electric machine controller of claim 1 , wherein the first average measured torque and second average measured torque are compared to a threshold to determine whether a safety process needs to be initiated.
4. 4 . The electric machine controller of claim 1 , wherein the first and second time periods overlap.
5. 5 . The electric machine controller of claim 1 , wherein a period between sequential first output level pulses is the waveform cycle, and the waveform cycle varies during operation of an electric machine.
6. 6 . The electric machine controller of claim 1 , wherein the waveform cycle varies as a function of a rotational speed of the electric machine.
7. 7 . An electric machine controller arranged to direct pulsed operation of an electric machine, wherein the electric machine controller utilizes a pulse controller that calculates an average torque based upon a time period that corresponds with a non-integer multiple of a waveform cycle or sub-cycle of a pulse waveform.
8. 8 . The electric machine controller of claim 7 , wherein first and second output levels are selected such that the electric machine has a higher energy conversion efficiency during the pulsed operation of the electric machine than the electric machine would have when operated at a third output level that would be required to drive the electric machine in a continuous manner to deliver the desired output.
9. 9 . The electric machine controller of claim 8 , wherein during the pulsed operation of the electric machine, the electric machine is turned off for at least portions of the times that the electric machine outputs zero torque.
10. 10 . The electric machine controller of claim 7 , wherein a period between beginnings of sequential first output level pulses is the waveform cycle, and the waveform cycle varies during operation of the electric machine.
11. 11 . The electric machine controller of claim 10 , wherein the waveform cycle varies as a function of a rotational speed of the electric machine.
12. 12 . A system comprising: an electric machine; a power converter; and an electric machine controller arranged to direct pulsed operation of an electric machine, wherein the electric machine controller utilizes a pulse controller that calculates a first average measured torque from sensed torque values over a first time period and a second average measured torque from sensed torque values over a second time period, wherein the first and second time periods are different time periods; and wherein a period between sequential first output level pulses is the waveform cycle, and the waveform cycle varies during operation of an electric machine.
13. 13 . The system of claim 12 , wherein the electric machine is operating as a motor and the power converter includes an inverter.
14. 14 . The system of claim 12 , wherein the electric machine is operating as a generator and the power converter includes a rectifier or inverter.
15. 15 . The system of claim 12 , wherein the electric machine is configured to operate as a motor/generator.
16. 16 . The system of claim 15 , wherein the pulse controller is configured to cause the electric machine to switch between first and second output levels at least 100 times per second.
17. 17 . The system of claim 12 , wherein the electric machine is selected from the group including: a synchronous reluctance machine, a permanent magnet synchronous reluctance machine; a hybrid permanent magnet synchronous reluctance machine; a switched reluctance machine; an externally excited AC synchronous machine; and a permanent magnet synchronous machine.
18. 18 . The system of claim 12 , wherein the electric machine is selected from the group including: an electrically excited DC electric machine; a permanent magnet DC electric machine; a series wound DC electric machine; a shunt DC electric machine; a brushless DC electric machine; a brushed DC electric machine; and a compound DC electric machine.
19. 19 . The system of claim 12 , wherein the electric machine is selected from the group including: an eddy current machine; an AC linear machine; an AC and DC mechanically commutated machine; and an axial flux machine.
20. 20 . A method, comprising: providing an electric machine controller arranged to direct pulsed operation of an electric machine; and calculating, using a pulse controller, an average torque; wherein the average torque is based upon a time period that corresponds with a non-integer multiple of a waveform cycle or sub-cycle of a pulse waveform.

Description

PRIORITY INFORMATION This application is a Continuation in Part of U.S. application Ser. No. 17/886,640, filed Aug. 12, 2022, which issues as U.S. Pat. No. 11,916,498 on Feb. 27, 2024, which claims the benefit of U.S. Provisional Application No. 63/241,888, filed on Sep. 8, 2021, the contents of which are included herein by reference. TECHNICAL FIELD The present disclosure relates to electric machine management methods, devices, and systems and, in particular, to electric machine torque adjustment based on waveform multiples BACKGROUND The phrase “electric machine” as used herein is intended to be broadly construed to include machines that operate as either or both electric motors and generators. When an electric machine is operating as a motor, it converts electrical energy into mechanical energy. When operating as a generator, the electric machine converts mechanical energy into electrical energy. Electric motors and generators are used in a wide variety of applications and under a wide variety of operating conditions. In general, many modern electric machines have relatively high energy conversion efficiencies. However, the energy conversion efficiency of most electric machines can vary considerably based on their operational load. Many applications require that the electric machine operate under a wide variety of different operating load conditions, which means that the electric machine when operating in a continuous manner often does not operate as efficiently as it is capable of. For example, for any given motor speed, the motor's efficiency tends to drop off somewhat when the motor's load is higher or lower than the most efficient load. In some performance areas, the motor's efficiency tends to drop relatively quickly. If the operating conditions could be controlled so that the motor is almost always operated at or near its most efficient point, the energy conversion efficiency of the motor would be quite good. It has been proposed that the electric machine be pulsed during operation to achieve a condition where it is operating in its most efficient point more often. When controlling a machine in pulsed operation, measurement or estimation of the torque output must be determined over a period of time. A conventional method to determine this torque output is to process measured or estimated torque as a function of time, for example, by averaging or using a digital filter of recent estimates or measurements of torque. When attempting to use these methods for an electric machine using pulsed operation, this can lead to inaccurate torque values as these methods can render inconsistent results. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram that diagrammatically illustrates an electric machine control architecture in accordance with embodiments of the present disclosure. FIG. 2 is a graph illustrating a pulsed drive signal for an electric machine that may be used with embodiments of the present disclosure. FIG. 3 is a flow chart illustrating a motor control scheme in accordance with embodiments of the present disclosure. FIG. 4 is a graph diagrammatically representing the desired power estimation methodology for pulsed power that may be used with embodiments of the present disclosure. FIG. 5 is a graph illustrating another pulsed drive signal methodology for an electric machine that may be used with embodiments of the present disclosure. DETAILED DESCRIPTION The present disclosure provides a better way to utilize pulsed electric machine management by averaging pulsed outputs at multiples of the pulsed waveform. This can be accomplished by implementing a new electric machine pulsed control methodology. Historical practices for electrical machine control have been developed for operation of motors subject to continuously variable torque control. For example, when electric machines are operated under a continuous power application scheme, if 100 Newton meters (Nm) of torque is desired to be delivered, the control system controlling the electric machine delivers 100 Nm's of electro-motive torque. However, in some implementations, advantages can be found to deliver larger amounts of torque over shorter time periods (pulsing torque delivery intermittently). This pulsing operation can be more efficient, and therefore, more desirable. In such situations, if the desired torque output is 100 Nm's of torque over a period of time and, if the most efficient torque production is at 200 Nm's, the control system will deliver 200 Nm's of torque during 50% of that time period, providing the same aggregate 100 Nm's over the time period, but doing so more efficiently than if 100 Nm's were provided for the entire time period. The 200 Nm torque deliveries can be delivered in pulses that are spaced out over time. For example, a time period can have twenty segments, where ten of the segments are at 200 Nm's and ten of the segments are at 0 Nm's (e.g., alternating 200 Nm, 0 Nm, 200 Nm, 0 Nm, . . . ). Other