Brushless DC Motor Dual Closed-Loop Control Simulation

Dual closed-loop simulation for brushless DC motors represents a critical research area in motor control, fundamentally achieving precise control through two feedback loops. The speed loop (outer loop) regulates motor rotational speed, while the current loop (inner loop) dynamically tracks phase currents. Their coordinated operation significantly enhances system response speed and disturbance rejection capabilities. During simulation modeling, constructing the motor's mathematical model is essential—typically described using state-space equations to characterize electromagnetic and mechanical properties. The Park transformation converts three-phase coordinates to a rotating reference frame, simplifying control algorithm design. The speed loop generally employs a PI controller to convert speed error into current references, while the current loop utilizes Space Vector Pulse Width Modulation (SVPWM) technology for rapid current tracking. Special attention must be paid to bandwidth matching between loops during simulation—the current loop's response speed is typically designed 5-10 times faster than the speed loop to prevent inter-loop interference. Modern simulation tools like MATLAB/Simulink enable modular construction with visual parameter adjustment capabilities, facilitating observation of key indicators like speed overshoot and current harmonics. This simulation methodology not only validates control algorithm effectiveness but also predicts motor behavior under various operating conditions, providing crucial theoretical support for practical hardware implementation. Key implementation aspects include: using transfer functions for controller design, implementing Clarke/Park transformations through coordinate conversion blocks, and configuring SVPWM modules with proper switching frequency and voltage vector sequencing.