Purpose - The purpose of the paper is to evaluate theoretically and experimentally the static and dynamic characteristics of a single-phase claw-pole motor using soft magnetic composite (SMC) for the stator core. Design/methodology/approach - On the basis of the static characteristics, which are measured and obtained from a series of 3D FE magnetostatic solutions, the dynamic characteristics are simulated according to a proposed control strategy. The same strategy is tested in dSpace control environment. Apart from the evaluation of the prototype SMC motor, some study has been made in order to improve the existing motor design. Findings - The static characteristics of the single-phase claw-pole motor have been modelled in 3D FE magnetostatic solver, where the rotor position and stator current have been changed. The characteristics compare well with the measurements, while the discrepancy with the cogging torque waveform needs further analyses and experiments to explain the real magnetization pattern of the plastic bounded ferrite magnet-ring and the influence of magnetic hysteresis. The 3D FE magnetostatic optimization routine shows the maximum quantities for magnetic coupling and static core loss. Furthermore it is used to obtain the improved pole distribution so that the resting position of the unexcited motor co-aligns at the position of the maximum electromagnetical torque. This is achieved by changing the angular width of claw-poles. The specific output of the maximum coupling torque from the single-phase claw-pole motor can be increased from the recent 0.1 to 0.6 Nm/kg at a temperature rise of 60 degrees. The simulations of dynamical characteristics show a good correlation with the experiments where the same control system in Simulink is applied to the prototype via dSpace. It is practically easier to implement a simple control strategy for the direct current controlled voltage source inverter. A more advantageous control system needs to be applied for the sampled current controller. Research limitations/implications - The influence of the magnetization of a multi-pole magnet ring is not considered while computing the static characteristics in 3D FE magnetostatic solver. Practical implications - The evaluation of the realistic magnetization pattern in the magnet aggravates the proper theoretical evaluation of static characteristics. Originality/value - The design of a small size powder core motor is faced with the complexity of evaluating properly the static characteristics, while the magnetization pattern is not exactly known. The broad search here is for an efficient tool to visualize the output of the 3D FE optimization for an improved design.
- Annan elektroteknik och elektronik