**ABSTRACT:**

This paper focuses on designing a disturbance observer-based control (DOBC) system for PMSM drives. The cascade structure of the discrete-time PI-PI control system with tracking anti-windup scheme has been designed for both loops. In this study, high order disturbance observer (HODO) based control is used to improve the speed tracking performance of the control system for the PMSM prototyping kit regardless of the disturbance and unmodelled dynamics. The motion equation was modified in the HODO in which torque losses due to the drug resulting from the time-varying flux, hysteresis, and friction have been taken into account to estimate the total disturbance. The HODO does not require the derivatives of the disturbance to be zero, like in the traditional ones.

**PMSM**

It demonstrates its ability to estimate along with a load torque the high order disturbances caused by a cogging torque and a high-frequency electromagnetic noise in the PMSM system. In the real-time experiments, the proposed algorithm with HODO achieves less speed errors and faster response comparing with the baseline controller. The performances with proposed and baseline control have been evaluated under mechanical speed and load torque variation cases. The experimental results have proved the feasibility of the proposed control scheme. The proposed disturbance observer-based control system was implemented with a Lucas-Nuelle 300 W PMSM prototyping kit.

**KEYWORDS:**

- Disturbance observer based control
- High-order disturbance observer
- PI controller
- PMSM
- Cascaded PI-PI
- Load torque observer

**SOFTWARE:** MATLAB/SIMULINK

**BLOCK DIAGRAM:**

Figure 1. Proposed Dobc Based Control Method Structure.

**EXPECTED SIMULATION RESULTS:**

Figure 2. Experimental Results Of The Proposed Hodo Based Pi With Novel Anti-Windup Scheme For Case 1. (A) Mechanical Speed Response Of Pmsm; (B) Mechanical Speed Error; (C) Estimated Load Torque Disturbance.

Figure 3. Dq-Axis Currents Of The Proposed Hodo Based Pi With Novel Anti-Windup Scheme For Case 1. (A)Ids And Its Desired Value Idsd; (B) Iqs And Its Desired Value Iqsd

Figure 4. Dq-Axis Voltages Under Proposed Hodo Based Pi With Novel Anti-Windup Scheme For Case 1. (A) Control Input On Q-Axis Vqs; (B) Control Input On D-Axis Vds.

Figure 5. Experimental Results Of The Proposed Hodo Based Pi With Novel Anti-Windup Scheme For Case 2. (A) Mechanical Speed Response Of Pmsm; (B) Mechanical Speed Error; (C) Estimated Load Torque Disturbance.

Figure 6. Dq-Axis Currents Of The Proposed Hodo Based Pi With Novel Anti-Windup Scheme For Case 2. (A) Ids And Its Desired Value Idsd; (B) Iqs And Its Desired Value Iqsd.

Figure 7. Dq-Axis Voltages Under The Proposed Hodo Based Pi With Novel Anti-Windup Scheme For Case 2. (A) Control Input On Q-Axis Vqs; (B) Control Input On D-Axis Vds.

Figure 8. Experimental Results Of The Baseline Control For Case 1. (A) Mechanical Speed Response Of Pmsm; (B) Mechanical Speed Error.

Figure 9. Dq-Axis Currents Of Baseline Control For Case 1. (A) Ids And Its Desired Value Idsd; (B) Iqs And Its Desired Value Iqsd.

Figure 10. Dq-Axis Voltages Of The Baseline Control For Case 1. (A) Control Input On Q-Axis Vqs; (B) Control Input On D-Axis Vds.

Figure 11. Experimental Results Of The Baseline Control For Case 2. (A) Mechanical Speed Response Of Pmsm; (B) Mechanical Speed Error.

**CONCLUSION:**

In this paper, disturbance observer based control for the PMSM prototyping kit is proposed. The cascade structure of discrete-time PI-PI control system equipped with tracking anti-windup scheme has been utilized for both loops. As the total disturbance estimation with HODO is based on the accurate prediction of the mechanical speed, the detailed motion equation of the PMSM has been derived. The motion equation in the proposed HODO includes terms associated with torque losses due to drag resulting from time-varying flux, friction, and hysteresis.

**HIGH FREQUENCY**

It has demonstrated its ability to improve the speed tracking performance under the external disturbance and unmodelled dynamics associated with a cogging torque and a high-frequency electromagnetic noise in the PMSM system. The estimated total disturbance is compensated in the speed controller. A zero steady-state errors have been achieved in the real time experiment. The mechanical speed errors were minimized in both operation scenarios. The performances of the proposed and baseline control algorithms have been evaluated under mechanical speed and load torque variations. The performance of the novel control system has shown better robustness to the external disturbances.

**REFERENCES:**

[1] T. D. Do, H. H. Choi, and J.-W. Jung, “Nonlinear optimal DTC design and stability analysis for interior permanent magnet synchronous motor drives,” *IEEE/ASME Trans. Mechatronics*, vol. 20, no. 6, pp. 2716_2725, Dec. 2015.

[2] T. D. Do, Y. N. Do, and P. D. Dai, “A robust suboptimal control system design of chaotic PMSMs,” *Electr. Eng.*, vol. 100, no. 3, pp. 1455_1466, Sep. 2018.

[3] B. Sarsembayev, K. Suleimenov, B. Mirzagalikova, and T. D. Do, “SDRE- based integral sliding mode control for wind energy conversion systems,” *IEEE Access*, vol. 8, pp. 51100_51113, 2020.

[4] T. D. Do, “Optimal control design for chaos suppression of PM synchronous motors,” in *Proc. 2nd Int. Conf. Control Sci. Syst. Eng. (ICCSSE)*, Jul. 2016, pp. 88_92.

[5] J.-W. Jung, V. Q. Leu, T. D. Do, E.-K. Kim, and H. H. Choi, “Adaptive PID speed control design for permanent magnet synchronous motor drives,” *IEEE Trans. Power Electron.*, vol. 30, no. 2, pp. 900_908, Feb. 2015.