Electrical network as the energy conservation has become the focus of attention, the world of motor design efficiency has become an interesting problem. Motor drive products with the trend of the development of the industry, to help designers to improve energy efficiency, reducing energy consumption, improve reliability and reduce the number of components, etc. , play a positive role in realize energy saving. Motor market development trend after one hundred years of development, application fields of the motor has a very wide range. Motor drive products covering areas such as automotive and industrial applications, it is a microcosm of motor main trends in the market. First is the trend of electrification, the car manufacturing business integration of energy-efficient motor instead of traditional internal combustion engine power, usually using brushless dc (刷)Alternative belt and gear motor drive, used for auxiliary components under the hood, such as pump, valve, heating and air conditioning, fan, etc. Due to the BLDC motor has very excellent performance motors, also begin to enter traditionally use a brushless dc (BDC)Other applications of motor scheme. Another trend is the application rate promotion to increase the number of the installation of the motor assembly, such as electric heating ventilation and air conditioning (HVAC)Gas valve control (It is mainly used for brush dc and unipolar stepper motor)Are applied in lower-end cars HVAC system. BLDC motor in the application of industrial and telecommunications motors is becoming more and more popular. Typical applications include fan, blower, pump and compressor. BLDC motor can effect comparing ac motor or motors switched reluctance motor is higher. BLDC motor can realize low cost variable speed motors, especially sensor commutation algorithm was used to integrate, able to dispense external sensors. Energy saving trend of new requirements on the application of the motor drive energy costs are usually motor of the most important part of the whole life cycle cost. Therefore, the use of more efficient motor can save a lot of energy. Energy saving trend of the motor drive new requirements include several aspects, first, the efficiency is decided by motor technology and structure of the selected, so the can choose converts electrical energy into mechanical energy ratio up to the top of the motor. Next, want to choose to drive to minimize power consumption and efficient drive circuit. Third, motor driver intelligence through ascension to realize optimization of energy consumption. In addition, some applications also require system does not use a brush motor (Use step or brushless dc motor); While the use of sensorless commutation (Do not use the potentiometer or hall sensors feedback), embedded motion control algorithm (Used for low power applications)Mentioned, the efficiency is highest, to reduce the audible noise, improve the electromagnetic interference (EMC)Performance, etc. In addition, there are some applications need to drive circuit and motor is adjacent to deploy on the electromechanical actuator, and through the bus (LIN, I2C, etc. )To connect to the central control unit.