Direct Torque Control Simulation for Induction Motors

Direct Torque Control (DTC) for induction motors represents a high-performance motor control strategy that directly regulates motor flux and torque, eliminating the complex coordinate transformations and regulator designs required in traditional vector control methods. This paper presents a DTC simulation solution developed in Matlab 7.0 environment, with testing validation confirming its effectiveness through numerical simulation and algorithm verification.

Fundamental Principles of Direct Torque Control The core concept of DTC involves using hysteresis controllers to directly manage the motor's flux magnitude and electromagnetic torque. Compared to conventional vector control, DTC eliminates current loop regulation and coordinate transformation, significantly simplifying the algorithm structure. Implementation advantages include rapid dynamic response and strong robustness, making it particularly suitable for high-performance drive systems such as electric vehicles and industrial servo applications where real-time control efficiency is critical.

Key Aspects of Matlab Simulation Implementation In the Matlab 7.0 environment, establishing a DTC simulation model for induction motors typically involves these essential modules: Motor Model: Utilizes dynamic equations of induction motors, commonly employing stator flux and torque as state variables with differential equation implementation using ode solvers. Hysteresis Control Module: Sets hysteresis bandwidth for flux and torque, generating switching signals by comparing actual values with reference values through relational operators and conditional statements. Voltage Vector Selection: Based on hysteresis outputs and stator flux position, selects appropriate voltage vectors to drive the inverter using lookup tables or switching logic algorithms. Speed Loop Regulation (Optional): For closed-loop speed control, an external PI regulator generates torque reference values through proportional-integral computation with anti-windup protection.

Simulation Testing and Optimization During simulation testing, focus on flux and torque tracking performance, along with ripple characteristics in steady-state conditions. Optimization approaches include adjusting hysteresis bandwidth, improving voltage vector selection strategies, or implementing Space Vector Modulation (SVM-DTC) to reduce harmonics. Proper configuration of simulation step sizes and solver parameters ensures balanced accuracy and computational efficiency through appropriate numerical integration methods.

Conclusion Matlab simulation provides an efficient platform for DTC algorithm validation. This solution has demonstrated feasibility through comprehensive testing and is suitable for both educational purposes in motor control and engineering pre-research. Future work may incorporate Hardware-in-the-Loop (HIL) testing to bridge simulation results with practical applications through real-time interface implementation.