ROHM motor control solution
With the inverter control of inverters more and more used in the application of many white goods such as air conditioners, washing machines, refrigerators, etc., ROHM's control scheme evolved from the original BD620X series, process improvement to BD6201X+BM6202/ 3 (withstand voltage 600V, 1.5A/2.5A IPM), developed to the highly integrated BM620X series (integrated drive and IPM), BM622X series and so on. At the same time, with the rise of the industry 4.0, drones, intelligent robots, automotive electronics and other markets, ROHM also introduced the corresponding control chip, such as the car-level isolated GateDriver, brushed DC motor drive control chip with programmable SPI interface. The fast-reacting three-phase has a position/non-position dedicated control scheme.
Select the motor according to the implementation function
Motor control is widely used in various industries, and the trends are different. However, for all industries, the main driving force recently is efficiency. Motor design and inverter design and control are constantly improving.
Removing or at least reducing the magnetic parts of the synchronous motor is also the focus of the industry. This can be achieved with synchronous reluctance motors, which are basically permanent magnet synchronous motors (PMSM) without magnetic components. Since there is no magnetic part, it is difficult to control, and the benefit is to reduce the cost and improve the efficiency in the full load range.
A major trend in the automotive and consumer products is integration. For example, combine a FET driver and an MCU/DSP in a single package. This reduces the PCB area and makes it easy to mount the board to the back of the motor.
The key to the selection depends on what function the design is to achieve, what tasks the motor has to perform in the system, how much power is limited, whether it is powered by AC or battery, and what the desired size (shape factor) is.
BLDC and PMSM motors are popular, mainly because of their small size and large output torque. As PMSM runs more smoothly, quieter, and more efficiently, replacing BLDC has become a trend. Therefore, almost all motors in automobiles will use sensorless field oriented control (FOC) or PMSM.
