I. Three Major Development Directions of DC Brushless Motor Control Solutions
1. Chips are developing towards high integration. Motor drive control chips have evolved from completely discrete components to integrated operational amplifiers and comparators, integrated pre-drivers, integrated power supplies and MOSFETs, and now to fully integrated modules. This demonstrates that high integration is a core development trend in chips.
2. The development of control algorithms towards SoC hardware: Looking at the development path of motor control algorithms from both performance and complexity perspectives, it has progressed from the initial 120-degree square wave control to sensored SVPWM, then to sensored FOC, and finally to sensorless FOC control algorithms. These control algorithms are becoming increasingly complex, raising the development threshold. To facilitate users' access to the latest and optimal control solutions, hardware-based implementation of motor control algorithms to lower the development barrier is an inevitable trend. Early pure software development using MCUs was quickly replaced by intelligent integrated hardware. From ASIC-based square wave algorithms, to ASIC-based sine wave algorithms, integrated MDUs, Cordic, etc., to the final ASIC-based sensorless FOC algorithms, a series of changes have achieved a sharp transformation in the hardware-based implementation of motor control algorithms in SoCs. PeakG Technology launched the industry's first fully integrated FOC chips, the FT8213 and FT8215; these chips feature built-in Rdson 1Ω driver MOS, highly integrated components required for motor control, fewer external components, low noise, low motor torque ripple, and built-in EFUSE, allowing configuration of customer motor parameters, starting and speed control methods, etc.
3. The trend of DC brushless motors towards ultra-high speed is driven by two factors. On the one hand, continuous technological advancements give products more possibilities; on the other hand, changes in market demand determine the direction of technology. When operating the sensorless FOC algorithm, the maximum electrical cycle of DC brushless motors has increased from 300Hz to 4500Hz. Peak G Technology's sensorless FOC solution for vacuum cleaners has reached an electrical speed of 264,000 rpm, while the sensorless square wave solution for model aircraft has reached an electrical speed of 780,000 rpm. It is evident that high speed and even ultra-high speed will inevitably become an irreversible technological trend in the future.
II. What are the advantages of brushless DC motors?
1. It has good external characteristics and can output large torque at low speeds, which allows it to provide large starting torque;
2. Wide speed range; can operate at full power at any speed;
3. Its high efficiency and strong overload capacity enable it to perform excellently in drive systems;
4. It has good regenerative braking effect because its rotor is made of permanent magnet material, and the motor can enter generator mode during braking;
5. Small size and high power density;
6. It features no mechanical commutator and a fully enclosed structure, preventing dust from entering the motor and ensuring high reliability.
7. Compared to asynchronous motors, the drive control is simpler.
