1. The control structure is very simple. Traditional rotor field oriented vector control system needs four PI regulators and a single PWM regulator, while DTC control only needs a pair of hysteresis controllers and a speed PI regulator, which makes DTC have better dynamic performance.
2. The operation of DTC is carried out in stator stationary coordinate system, and the stator current does not need to be decomposed and set in rotating coordinate system. Therefore, complex coordinate transformation like vector control is not needed, which greatly simplifies the operation process, simplifies the structure of control system and improves the speed of control operation.
3. Direct torque control uses a pair of hysteresis comparators to directly control the stator flux and torque, instead of indirectly controlling the motor flux and torque by controlling the two components of stator current as vector control. It pursues the speed and accuracy of torque control, and does not purposefully pursue circular flux trajectory and sinusoidal current.
4. Direct Torque Control (DTC) uses space voltage vector, integrates the inverters and control strategies. According to the output of flux linkage and torque hysteresis comparator, the optimal control of on-off and on-off of the inverters'switching transistors is directly carried out, resulting in discrete PWM voltage output. Therefore, the traditional DTC system does not need a separate PWM modulator.
To sum up, direct torque control overcomes the complexity of vector control to a great extent. It calculates and controls the torque of AC motor directly in stator coordinate system by using space vector analysis method, uses stator magnetic field orientation, generates PWM signal by means of discrete two-point regulation, and directly controls the switching state of the inverters to obtain high torque. State performance is an AC speed regulation method with high dynamic performance.
Shenzhen Haibo Motor Drive Development Co., Ltd. is located in Shenzhen, the frontier city of high-tech technology and products in China. The company has devoted itself to the research and development of BLDC controller for many years. It has rich experience in R&D technology team, and has high R&D experience in the design and development of brushless driver controller.