Motor Control Brushless (BLDC motor)

Introduction

Brushless DC motors (BLDC) combine the speed regulation advantages of DC motors with the reliability of AC motors, making them ideal for high-efficiency, high-precision applications. Unlike brushed motors, BLDC motors rely on electronic commutation instead of mechanical brushes, ensuring long lifespan, low maintenance, and minimal electromagnetic interference.

Core definition

DC motors that use electronic commutation instead of traditional brushes/commutators, combining the speed regulation advantages of DC motors with the structural reliability of AC motors, are widely used in high-precision and high-efficiency scenarios.

Key control elements

• Commutation logic: It relies on position sensors (such as Hall elements, encoders) or sensorless algorithms (such as back electromotive force method) to obtain the rotor position, triggering the inverter to switch the stator winding current to achieve continuous rotation.

• Drive circuit: The core is a three-phase full-bridge inverter (composed of IGBT/MOSFET), which receives control signals and regulates the winding voltage/current.

• Control strategies: Common ones include "six-step commutation" (suitable for medium and low-speed, low-cost scenarios) and "Vector control (FOC)" (suitable for high-precision, high-dynamic response scenarios, such as servo systems).

• Core advantages: No brush wear, long service life; No electric sparks, low electromagnetic interference; High efficiency (usually 85%-95%), low power consumption; It has a wide speed range and high control accuracy.

• Typical applications: New energy vehicles (drive/steering), unmanned aerial vehicles (propellers), household appliances (air conditioning compressors/washing machines), industrial servo systems, medical devices, etc.

• The main challenge: The complexity of the control circuit is higher than that of brushed motors, and a dedicated controller is required. The sensorless solution is prone to inaccurate positioning at low speeds or during startup, and the algorithm needs to be optimized.

Why Baoquan Zhijie

With expertise in IGBTs Module, MOSFET Module, and power module design, Baoquan Zhijie delivers advanced BLDC motor control solutions that achieve high efficiency, precision, and reliability for automotive, industrial, and consumer applications.