## 1 Introduction  
The stator core loss of permanent magnet synchronous machines (PMSMs) is closely related to the magnetic field in the core that changes with time and space, and it is difficult to obtain an accurate calculation process. The Bertotti loss separation model is a commonly used calculation model for stator core loss [1]. According to the physical causes of core loss, it is decomposed into hysteresis loss, eddy current loss and additional loss, and the proposed General calculation model of loss. This model is currently recognized as the more accurate loss model. [PERSON] of the University of Technology Sydney and others took permanent magnet brushless DC motors as a research object and proposed accurate circular rotating magnetization loss calculation models and elliptical rotating magnetization loss calculation models suitable for iron loss calculations [2]. This calculation model requires loss coefficients under rotating magnetization and alternating magnetization. However, the loss factor under circular rotating magnetization is difficult to obtain, which restricts the application of this method. On this basis, [PERSON] of Southeast University and others proposed an orthogonal decomposition loss calculation model, which equates the rotating magnetization loss as the linear superposition of two orthogonal alternating magnetization losses. This method has undergone a large number of experiments and measurements. The error of the value is kept within 10%, with high accuracy [3]. With the development of power electronic devices and high-power devices, inverter control technologies such as Pulse Width Modulation (PWM) and Space Vector Pulse Width Modulation (SVPWM) have become more widely used in motor control. The analysis of the influence of frequency and time harmonics on core loss is particularly important. [PERSON] et al., based on the non-sinusoidal time harmonics generated by the PWM inverter, established an improved calculation model for the additional core loss and permanent magnet eddy current loss caused by high-frequency non-sinusoidal time harmonics. The influence of inverter parameters (switching frequency and modulation ratio) on core loss was studied [4; 5; 6; 7]. [PERSON] et al. respectively carried out the core loss and permanent magnet eddy current loss obtained by the frequency domain loss calculation model considering only the sinusoidal distributed magnetic field, and the time domain loss calculation model considering PWM non-sinusoidal harmonics, rotating magnetization, and local hysteresis loops. The results showed that the high-order current harmonics generated by PWM greatly increase the core loss of the motor and the eddy current loss of the permanent magnet, and the segmented structure of the permanent magnet could effectively reduce the eddy current loss [8]. In [9], [PERSON] and others used finite element co-simulation to simulate the core loss, copper loss, and eddy current loss of the V-type interior PMSM (IPMSM) under SVPWM control, and analyzed the influence of the SVPWM carrier ratio and modulation ratio on the motor loss. In [10; 11], [PERSON] et al. took a 5.5 kW motor as an example, and then established the SVPWM control model of the motor, and simulated the output voltage waveforms at different operating points of the motor, and then analyzed the different carrier frequencies and carrier frequencies of the motor using finite element simulation. The change rule of stator and rotor core flux density under modulation ratio and its influence on loss density, but the Simulink simulation model in this method does not consider the influence of the magnetic saturation effect on electromagnetic parameters. In [12; 13], [PERSON] et al. compared the core loss of amorphous alloy PMSMs produced under different power supply modes (including sine wave power supply, direct torque control, and vector control). The study showed that compared with vector control, moment control could produce greater core loss and permanent magnet eddy current loss.