Search

Magnetic field sensors, such as Hall current sensors, are widely used in permanent-magnet synchronous motors drive system. For the purpose of reducing cost and volume, the phase current reconstruction method is used in the motor drive system with only one current sensor. In this paper, a novel phase current reconstruction method is introduced. By arranging the single current sensor at a novel position, the proposed method is able to sample current in two zero voltage vectors. Then, a novel dc drift error mitigation method is proposed to eliminate the dc drift error in the Hall current sensor, which can influence the motor drive performance. The Clarke coordinate transformation is modified to decouple the dc drift error in the α–β-axis current components. Then, a notch filter is adapted to estimate the dc drift component of the current sampling results, which can compensate the dc drift error in the Hall current sensor. The proposed method is validated by both simulation and experiments. [ABSTRACT FROM AUTHOR]

This paper proposes a novel Continuous Quantum Immune Clonal Optimization algorithm for thermal optimization on a 117 kW high-speed permanent-magnet generator (HSPMG). The proposed algorithm mixes the Quantum-Computation into the Immune-Cloning-Algorithm and causes better population diversity, higher global searching ability, and faster convergence which is approved by simulation results. Then, the improved algorithm is applied to seek an optimized slot groove and improve HSPMG thermal performance, where the 3-D fluid-thermal coupling analyses are processed with a multiobjective optimal group composed of the highest temperature and temperature difference. Both the proposed algorithm and the obtained conclusions are of significances in the design and optimization of the cooling system in electric machines. [ABSTRACT FROM AUTHOR]

This paper proposes a novel permanent magnet planar motor with moving multilayer orthogonal overlapping windings. This novel motor topology can achieve a five-degrees-of-freedom drive using two sets of $x$ -direction windings and two sets of $y$ -direction windings in a coreless configuration. The orthogonal multilayer construction guarantees a high utilization of the magnetic field and realizes decoupling between the $x$ -direction thrust and the $y$ -direction thrust. The topology and operating principle of the planar motor are introduced in this paper. The analytical modeling of the motor is established based on the equivalent current method, and the expressions of forces are derived. The force characteristics of the two-layer and three-layer winding topologies are compared, and the design guidelines of a planar motor are proposed. The analytical and 3-D finite-element model results are validated with the experimental results of a tested prototype. [ABSTRACT FROM AUTHOR]

A 30 kVA, 96000 r/min, air-cooled high-speed permanent-magnet generator (HSPMG) is investigated in this paper. Considering effects on both the magnetic circuit and heat transfer paths comprehensively, the stator slot notch in this HSPMG is optimized. First, using the time-stepping finite-element method, the transient electromagnetic fields of HSPMG are numerically calculated, and the electromagnetic losses in different components are obtained. Then, after the determination of other mechanical losses in such a machine, a 3-D fluid–thermal coupling calculation model is established, and the working temperature distribution in the HSPMG is studied. Thus, the electromagnetic–fluid–thermal coupling analysis method on the HSPMG is proposed, and the use of the influences of machine notch height on machine magnetic circuit and cooling air flowing path are investigated. Meanwhile, both the electromagnetic performance and the temperature distribution in HSPMG with different stator notch height are studied, and a series of analytical equations is deduced to describe the variations of machine performances with stator notch. Using the proposed unbalance relative weighting method, the notch height is optimized to enhance the performance of HSPMG. The obtained conclusion could provide reference for HSPMG electromagnetic calculation, cooling system design, and optimization design. [ABSTRACT FROM AUTHOR]