At present, whether it is in the field of industrial automation, automobiles, or household appliances, various end markets have put forward higher requirements for the control performance of BLDC motors. They not only require the motor to be able to achieve high efficiency and multi-functional control, but also require the motor to achieve low noise and low vibration control effects while pursuing high speed. Under the ever-increasing high-standard performance requirements, more and more high-performance BLDC motor drive control chips have emerged under the two opportunities of high market demand and high performance standards. Many domestic manufacturers have launched BLDC motor driver chips and solutions one after another. Compared with international manufacturers’ driver chips in terms of performance, they are also more cost-effective. Domestic manufacturers can also give customers more support in a timely manner. .
01 What is FOC?
FOC (Field-Oriented Control), that is, field-oriented control, also known as vector frequency conversion, is currently the best choice for efficient control of brushless DC motors (BLDC) and permanent magnet synchronous motors (PMSM).
FOC precisely controls the magnitude and direction of the magnetic field, making the motor torque stable, low noise, high efficiency, and high-speed dynamic response. At present, it has gradually replaced traditional control methods in many applications, and has attracted much attention in the motion control industry.
02 What is the principle of FOC?
The FOC control first needs to obtain information such as the position of the motor rotor, motor speed, and current as feedback input. It needs to collect the phase current of the motor, and perform a series of mathematical transformations and estimation algorithms on it to obtain the feedback amount of decoupled and easy-to-use control. The controller dynamically adjusts according to the error between the feedback value and the target value, and finally outputs a three-phase sine wave to drive the motor to rotate.
FOC typical control block diagram
03 Sensor FOC/Sensorless FOC?
- For FOC with sensors, because the encoder can feed back the position information of the motor rotor, the control is simple, but it often requires higher control performance.
- For sensorless FOC, it is necessary to collect the phase current of the motor in the control and use the position estimation algorithm to calculate the rotor position, so the control is difficult. However, the wiring is simple, the cost is low, and the reliability is high. It can achieve control goals such as high efficiency, low vibration, low noise, and high response speed to the greatest extent. Therefore, it has gradually become the mainstream trend of the industry and is mostly used in fan applications.
Silicon-based power——Expert in micro power system
04 Silicon-based power three-phase non-inductive FOC control technology
In order to achieve the best product application effect, silicon-based power adopts different motor control technologies according to the characteristics of different products. FOC is used in solutions for humidifiers, air purifiers, fans, hair dryers, hand dryers and many other application scenarios, and the sine wave control method is used to solve the noise problem caused by square wave control while starting smoothly. By decomposing the motor stator current into excitation current and torque current, the accuracy of motor speed control can be greatly improved. The silicon-based power R&D team has top experts who have been cultivating in the industry for decades, making the products developed by silicon-based stable and reliable, containing emerging technologies in the industry, and full of elements of the new era. In addition, silicon-based power has the ability to quickly develop and produce samples in a short time. According to customer requirements, the process from scheme design to sample production can be completed in as little as two weeks. At the same time, Siji Power provides personalized customer service, conducts in-depth R&D and customization according to customer needs, provides the highest quality and most suitable high-end motor system solutions and high-quality, positive feedback service experience, and helps customers in the fierce market competition. Stand out and stay ahead.