Vector Control of Induction Motors

Vector control of induction motors is a high-performance speed regulation method that enables decoupled control of torque and flux similar to DC motors. In industrial applications, it overcomes the dynamic performance limitations of traditional V/F control.

Core Method Comparison MARS (Model Adaptive Reference System) establishes a model reference adaptive system for real-time adjustment of control parameters to accommodate motor parameter variations. This method demonstrates strong robustness to motor parameter changes, particularly maintaining good observation accuracy in low-speed regions. Implementation typically involves adaptive observers with parameter identification algorithms that continuously update d-q axis inductance and resistance values.

The i_sq closed-loop speed estimation method constructs a speed observation loop using q-axis current (torque current component), dynamically compensating slip frequency through PI regulators. This sensorless approach eliminates mechanical sensors but requires precise motor parameter matching. Code implementation often includes slip frequency calculation blocks and current regulator tuning for optimal dynamic response.

Dual-Mode Operation Characteristics Speed Sensor Mode: Relies on encoder feedback, suitable for high-precision applications requiring accurate position and speed detection Sensorless Mode: Estimates speed based on flux observers, enabling fault-tolerant operation during sensor failures through advanced estimation algorithms

Implementation Key Points Both control methods must address flux observation challenges at low speeds, typically employing compensated adaptive observers. Modern solutions often integrate high-frequency signal injection techniques to enhance control performance near zero speed, involving carrier signal superposition and demodulation algorithms for improved low-speed torque characteristics.