# US 12,005,794 B2 · System and method for damping of mechanical oscillaton of a rotor of an electric machine in a vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,794 B2 - Document ID: US12005794B2 - Status: Granted - Kind: B2 - Application number: 17/643,719 - Filed: 2021-12-10 - Published: 2023-02-02 - Granted: 2024-06-11 - Earliest claimed: 2021-07-30 - Assignees: Deere & Company - Applicants: Deere & Company - Inventors: Yujiang Wu; Christopher J. Tremel; Kent D. Wanner - Web page: https://patentgrep.com/patent/US12005794B2 ## CPC - B60L 53/20: characterised by converters located in the vehicle - H02P 23/04: specially adapted for damping motor oscillations, e.g. for reducing hunting - B60L 15/20: for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed - H02P 6/10: Arrangements for controlling torque ripple, e.g. providing reduced torque ripple - H02P 21/05: specially adapted for damping motor oscillations, e.g. for reducing hunting - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract An inverter system is configured to mitigate oscillation of a rotary system that drives a generator or electric machine. A torque damping module is configured to receive a commanded torque or an observed torque and to generate a commanded compensating torque to dampen any mechanical oscillation or resonance of the rotary system based on the observed rotational speed of the generator. The torque damping module further comprises a digital filter of order greater than one, a gain adjuster and a limiter. ## Claims ### Claim 1 An inverter system for mitigating oscillation of a rotary system that drives a generator, the rotary system comprising a driveshaft or shaft of a vehicle that is mechanically rotationally coupled to generator, the inverter system further comprising: a torque command generation module for receiving an observed torque or commanded torque from an operator of a vehicle that applies rotational energy to the shaft; a torque damping module for detecting the commanded torque applied to a rotor of a generator and generating a commanded compensating torque to dampen any mechanical oscillation or resonance of the generator and the rotary system based on the observed rotational speed of the generator; wherein in the torque damping module further comprises: a filter of order greater than one, wherein the filter has a bandpass or high-pass filter response of magnitude versus frequency, wherein the input to the filter comprises the observed rotational speed of the generator and wherein the output of the filter comprises an isolated oscillation or ripple of the observed rotational speed with a removed or attenuated DC offset in the compensating torque; a gain adjuster coupled to the output of the filter, the gain adjuster configured to determine a gain of the commanded compensating torque based on the isolated oscillation or ripple of the observed rotational speed; and a limiter for restricting the gain to a lower limit of the gain and an upper limit of the gain based on integration of the ripple of the observed rotational speed or proportional integral control of the ripple component of the observed speed. ### Claim 2 (depends on 1) The inverter system according to claim 1 further comprising: an energy storage device; an inverter is coupled between the generator and the energy storage device, the inverter associated with a data processing system comprising an electronic data processor and a data storage device that communicate via a data bus; a torque compensating module, storable in the data storage device, to provide a compensating torque to address, reduce, dampen or ameliorate torque variation or rotational speed or velocity fluctuation in the rotary system. ### Claim 3 (depends on 2) The inverter system according to claim 2 further comprising: a second inverter coupled to the energy storage device and configured to provide alternating current (AC) signals to control the electric machine or drive motor in a motoring mode, where the drive motor may be configured as a hub motor or another motor to drive a wheel of the implement, to control the electric machine with a torque compensating module to reduce fluctuation in torque associated with the rotor of the electric machine in engagement with the ground via implement wheels or tracks, alone or together with the contribution to such fluctuation in torque from the engagement with the vehicle ground of wheels or tracks. ### Claim 4 (depends on 1) The inverter system according to claim 1 wherein the rotary system comprises a power take-off shaft or driveshaft as the shaft, alone or together with a clutch. ### Claim 5 (depends on 1) The inverter system according to claim 1 further comprising: an internal combustion engine having an engine shaft; and where the rotary system comprises an input shaft, an output shaft, and a clutch to mechanically, rotationally couple or decouple an input shaft and an output shaft, where the input shaft is coupled to the engine shaft, where the output shaft is coupled to the generator. ### Claim 6 (depends on 3) The inverter system according to claim 3 wherein the power take-off shaft is arranged as an input shaft to a first rotatable portion of the clutch, an output shaft is associated with a second rotatable portion of the clutch, and if a threshold torque is met or exceeded the input shaft is temporarily, rotationally decoupled from the output shaft. ### Claim 7 (depends on 1) The inverter system according to claim 1 wherein the commanded compensating torque is applied to the generator in a generating mode. ### Claim 8 (depends on 1) The inverter system of claim 1 wherein gain adjuster multiplies the gain (ba) by the ripple of the observed rotational speed for each sampling interval or set of sampling intervals. ### Claim 9 (depends on 1) The inverter system according to claim 1 wherein a combination of the gain adjuster and the limiter comprises a proportional integral controller or a proportional integral differential controller that is configured to schedule the gain based on detecting whether the generator is operating in a first speed range or a second speed range that is different than the first speed range. ### Claim 10 (depends on 9) The inverter system according to claim 9 wherein the first speed range comprises a low speed range and wherein the second speed range comprises a high speed range. ### Claim 11 (depends on 1) The inverter system according to claim 1 wherein a combination of the gain adjuster and the limiter comprises a proportional integral controller or a proportional integral differential controller that is configured to schedule the gain based on detecting whether the generator is operating in a first torque range or a second torque range that is different than the first torque range. ### Claim 12 (depends on 9) The inverter system according to claim 9 wherein the first speed range comprises a low speed range and wherein the second speed range comprises a high speed range, where the first speed range is associated with a corresponding first gain or initial gain that is stable relative to one or more poles (on a left-side of first root locus diagram) and wherein a second speed range is associated with a corresponding second gain or revised gain that is stable relative to one or more poles (on the left-side of the second root locus diagram. ### Claim 13 (depends on 1) The inverter system according to claim 1 wherein the gain adjuster is configured to adjust the gain without resulting in a material DC offset in the commanded torque upon to the generator during compensation for torque fluctuation. ### Claim 14 A method for mitigating oscillation of a rotary system that drives an electric machine, the rotary system comprising a driveshaft or shaft of a vehicle that is mechanically, rotationally coupled to the electric machine, the inverter system further comprising: receiving or observing an observed or commanded torque; generating a commanded compensating torque to modify the commanded torque to dampen any mechanical oscillation or resonance of the electric machine and the rotary system based on the observed rotational speed of the electric machine; wherein in the torque damping module further comprises: applying, by a filter of order greater than one, a bandpass or high-pass filter response of magnitude versus frequency, wherein the input to the filter comprises the observed rotational speed of the electric machine and wherein the output of the filter comprises an isolated oscillation or ripple of the observed rotational speed with a removed or attenuated DC offset in the compensating torque; determining, by a gain adjuster, a gain of the commanded compensating torque based on the isolated oscillation or ripple of the observed rotational speed; and restricting, by a limiter, the gain to a lower limit of the gain and an upper limit of the gain based on integration of the ripple of the observed rotational speed or proportional integral control of the ripple component of the observed speed. ### Claim 15 (depends on 14) The method of claim 14 further comprising: providing alternating current (AC) signals to control the electric machine or drive motor in a motoring mode; controlling the electric machine with a torque compensating module to reduce fluctuation in torque associated with the rotor of the electric machine in engagement with the ground via implement wheels or tracks, alone or together with the contribution to such fluctuation in torque from the engagement with the vehicle ground of wheels or tracks. ### Claim 16 (depends on 15) The method according to claim 15 wherein the rotary system comprises a power take-off shaft or driveshaft as the shaft, alone or together with a clutch. ### Claim 17 (depends on 14) The method according to claim 14 further comprising: temporarily, rotationally decoupling the power-take-off shaft from an output shaft of a clutch if a threshold torque is met or exceeded. ### Claim 18 (depends on 14) The method according to claim 14 wherein the commanded compensating torque is applied to the electric machine as a generator in a generating mode. ### Claim 19 (depends on 14) The method according to claim 14 further comprising: multiplying the gain (ba) by the ripple of the observed rotational speed for each sampling interval or set of sampling intervals. ### Claim 20 (depends on 14) The method according to claim 14 further comprising: detecting whether a rotor of the electric machine is operating in a first speed range or a second speed range that is different than the first speed range; determining or scheduling the gain based on the detected speed range within the first speed range or the second speed range. ### Claim 21 (depends on 14) The method according to claim 14 wherein the first speed range comprises a low speed range and wherein the second speed range comprises a high speed range. ### Claim 22 (depends on 14) The method according to claim 14 further comprising: detecting whether a rotor of the electric machine is operating in a first torque range or a second torque range that is different than the first torque range; and determining or scheduling the gain based on detected torque range within the first torque range or the second torque range that is different than the first torque range. ### Claim 23 (depends on 18) The method according to claim 18 wherein the first speed range comprises a low speed range and wherein the second speed range comprises a high speed range, where the first speed range is associated with a corresponding first gain or initial gain that is stable relative to one or more poles (on a left-side of first root locus diagram) and wherein a second speed range is associated with a corresponding second gain or revised gain that is stable relative to one or more poles (on the left-side of the second root locus diagram. ### Claim 24 (depends on 14) The method according to claim 14 wherein the determining of the gain further comprises adjusting the gain without resulting in a material DC offset in the commanded torque for the electric machine.