Hi Pratheesh,
To limit power in a PMSM vector control system without adding another PI controller, you can directly limit the DC current based on power calculations. Here's what you can try:
- Determine the electrical power based on speed reference and torque command. Adjust for flux weakening if applicable.
- Calculate the maximum allowable DC current (I_{DC_{max}}) using the maximum power limit (P_{max}) and the DC link voltage (V_{DC}).
- Before setting I_d and I_q references, ensure the estimated I_{DC} won't exceed I_{DC_{max}}. If it does, scale down I_d and I_q references to keep I_{DC} within limits.
- Use a scaling factor based on the ratio of I_{DC_{max}} to the estimated I_{DC} from your current references. Adjust I_d and I_q accordingly to maintain the power within desired limits.
This would avoid the need for an additional PI controller by directly managing the power demand through current limiting, making it suitable for systems with limited computational resources.
