US 11,689,143 B2
Electric motor control method and device, system, and electric vehicle
Xiong Zheng, Ningde (CN); Xianxi Pan, Ningde (CN); Zhimin Dan, Ningde (CN); and Hong Wang, Ningde (CN)
Assigned to CONTEMPORARY AMPEREX TECHNOLOGY CO., LIMITED, Ningde (CN)
Filed by CONTEMPORARY AMPEREX TECHNOLOGY CO., LIMITED, Ningde (CN)
Filed on Jul. 6, 2022, as Appl. No. 17/858,862.
Application 17/858,862 is a continuation of application No. PCT/CN2021/114600, filed on Aug. 25, 2021.
Prior Publication US 2023/0064607 A1, Mar. 2, 2023
Int. Cl. H02P 27/08 (2006.01); H02M 7/5395 (2006.01)
CPC H02P 27/08 (2013.01) [H02M 7/5395 (2013.01); H02K 2213/03 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An electric motor control method performed by a controller, the method comprising:
obtaining an input power and an output power of an electric motor;
determining a loss power based on the input power and the output power;
determining a target d-axis current of the electric motor, wherein the target d-axis current is calculated by a calculation module based on the loss power, the calculation module comprises a tracking differentiator, and the calculation module operates in the controller; and
determining a duty ratio based on the target d-axis current and a preset q-axis current, and inputting the duty ratio into an inverter so that the inverter drives, based on the duty ratio, the electric motor to operate.