What is the principle of FOC?

At present, whether it is in the field of industrial automation, the field of automobiles, or the field of household appliances, various terminal markets have put forward higher requirements for BLDC motor control performance. They not only require the motor to achieve high-efficiency and multi-functional control, but also require the motor to achieve low-noise and low-vibration control while pursuing high speed. With 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 successively launched BLDC motor driver chips and solutions, which are not inferior to the driver chips of international manufacturers in terms of performance, and are more cost-effective. In terms of technical support, 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 has a high-speed dynamic response. At present, it has gradually replaced the traditional control method 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 the information such as the position of the motor rotor, the motor speed, and the current size as the feedback input. The controller performs dynamic adjustment according to the error between the feedback amount and the target value, and finally outputs a three-phase sine wave to drive the motor to rotate.

03. Sensored FOC/Sensorless FOC?

For sensored FOC, since 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 motor phase current 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 the control goals of high efficiency, low vibration, low noise and high response speed to the greatest extent, so it has gradually become the mainstream trend of the industry and is mostly used in fan applications.

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 magnetic orientation control is adopted in the solutions of humidifiers, air purifiers, fans, hair dryers, hand dryers and 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 in the industry for decades, making the products developed by the silicon-based power stable and reliable, including emerging technologies in the industry, and full of new era elements. In addition, Si-based Power has the ability to rapidly develop and produce samples in a short period of 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 research and development 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, helping customers in the fierce market competition. Stand out and stay ahead.