Overview of FOC motor drive

    A large number of motor control applications have been continuously seeking ways to improve efficiency while reducing system costs. As a result, Field Oriented Control (FOC) has attracted attention in the motion control industry and has gradually replaced traditional control methods in many applications. At present, FOC technology has been perfectly matched with BLDC motors. With the acceleration of MCU localization process, non-inductive FOC will gradually become popular.

    FOC, also known as vector frequency conversion, can accurately control the size and direction of the magnetic field, making the motor torque stable, low noise, high efficiency, and has high-speed dynamic response. Therefore, in recent years, FOC has been widely popular in the market for low-cost, brushless motor applications. At present, FOC has gradually replaced traditional control methods in many applications and is highly favored in the motion control industry. Motor control has always been a non focus area for electronic engineers, and many developers are unable to easily design necessary control circuits due to a lack of experience or professional knowledge.

    However, although electronic control has long been the weakness of Chinese electronic engineers, Chinese enterprises are not immersed in the research and development of traditional AC motors because of the difficulties in control technology. In recent years, the research and development of FOC motors has been constantly promoted. Air conditioners, UAVs, robots, medical equipment, CNC machine tools and other fields have been widely used in FOC technology, and the market penetration of FOC motors has increased year by year.

    FOC requires complex mathematical algorithms, which may not be familiar to ordinary designers. Therefore, in the past, designers often relied on complex digital signal processing (DSP) chips to achieve sensorless FOC.

    And currently, regarding FOC technology, although multiple chip manufacturers have developed chips specifically for motor control and applied their chips to implement relevant algorithms for FOC motor control, their FOC motor control algorithms are not fully open source, but only provide a function API for users to use. Some domestic chip manufacturers also integrate modules related to FOC control into the chip using hardware. Users only need to configure some relevant registers to use FOC algorithm to control the motor. And some companies have indeed applied the above methods to corresponding projects. However, there are no manufacturers on the current market that truly achieve open-source FOC algorithms. The vast majority of engineers do not understand the FOC motor control algorithm, nor are they able to independently write relevant code. They are only limited to minor repairs to the original non core code to complete project development.

    The purpose of our online work this time is to completely solve the bottleneck above, so that everyone can no longer only call the relevant function API interface. All of our code does not call any library functions, so that everyone can truly learn how to write the code in the FOC algorithm themselves and know the meaning of each code. I will also lead everyone to derive all the theories of relevant algorithms, such as SVPWM algorithm, sliding mode observer algorithm, etc., so that everyone can know both the nature and the reason behind it.