Motor Drive major advantages:
- Elimination of wearing components
- Reduction in operating forces
- Substantial reduction of the noise level during operation
- increased reliability
The motor-drive mechanism is mainly composed of the ac/dc power supply, energy buffer capacitors, converter, and control unit and motor,shown in right Fig.
The capacitors are the energy buffering units. Large transient current is required during the operation of a CB. The energy required is provided by the capacitors. Thus, the impact on the power supply is minimized.
The converter is composed of IPM.
The stator current is measured by hall sensors. Motor speed and rotor position are measured by the optical encoder installed in the shaft. PMSM are used in many applications that require rapid torque response and high-performance operation.
The vector control method is used to control the PMSM. The basic idea of the vector control algorithm is to decompose a stator current into a magnetic field-generating component and a torque generating component. Both components can be separately controlled like a dc machine.
The speed and torque of PMSM are separately controlled.
In left pic show a HV CB with motor drive mechanism by ABB company
