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In this paper, the play model and the free energy model are applied to represent the hysteretic properties of non-oriented steel plates and compared. The ac symmetric B-H loops and PWM minor loops are represented by both methods and the results are compared with the measured ones. Small minor loops representation is found not complete with both methods. However, in play model, it can be easily improved by increasing the number of hysterons. In the spring model, the way to improve the minor loop representation accuracy is under discussion, whereas its identification is simpler than play model as less parameters are required.

The Multi-magnetic-valve structure is adopted in Magnetic Controlled Reactors (MCR) to reduce their current harmonics. However, the reactance can't be precisely calculated for its complicated structure. In this paper, an improved method to calculate its inductance is presented and the simulation analysis based on finite element method (FEM) verified its validity. The analysis results demonstrate that the length and the number of magnetic valves have a great impact on the inductance of MCR.

Due to the leakage flux effect, the nonuniform magnetic flux distribution would weaken the biasing ability of PMs in a permanent-magnet-biased fault current limiter. To improve the biasing ability of PMs and reduce the cost, a novel small-section permanent-magnet-biased fault current limiter is proposed by this paper. Firstly, the principle and the optimal small-section structure are introduced. To validate the impact of small section on the biasing ability of PMs, various FEA simulation and optimization study are performed in Ansoft. The simulation and optimization results verify that the small section can improve the biasing ability of PMs and reduce the cost.

Eddy current loss of NdFeB permanent magnets (PMs) are widely analyzed in permanent magnet motors. And it's necessary to analyze this issue in saturated core fault current limiter (SCFCL). This digest discusses the coupled 2-D finite element analysis (FEA) of the SCFCL and 3-D analytical model of PMs to evaluate the eddy current loss of PMs in a SCFCL. The comparison between result from coupled method and that from 3-D FEA verifies the applicability of the coupled method in analyzing eddy current loss of PMs in SCFCL.

In allusion to the difficulties in the optimal gear capacity design of the superconducting controllable reactor (SCR), a novel design optimization method of SCR is proposed in this paper combining field-circuit coupling finite element method (FEM) and Immune Algorithm (IA). Field-circuit coupling finite element method is realized in ANSYS and immune algorithm is embedded in ANSYS by ANSYS Parameter Design Language (APDL). The proposed method and the conventional method will make a detailed comparison. Finally, a 380V/30 KVar SCR prototype is fabricated, and detailed experiments are done.

To reduce the size and requirement of DC biasing capacity of saturated-core fault current limiter, a novel hybrid compact saturated-core fault current limiter (HCFCL) is proposed by this paper. The three-limb structure with Permanent magnets can reduce the size and DC biasing capacity. Firstly, the principle of HCFCL is introduced. To validate the performance, various FEA simulations with the 3D nonlinear field-circuit coupling transient analysis are carried out in Ansoft. And a 220V/10A prototype of HCFCL is designed and tested. The simulation and experimental results verify the effectiveness and excellent performance of proposed structure.

In the ordinary saturable magnetically controlled reactors inserted in the legs with magnetic valves of smaller cross-sectional areas (VMCR), the flux concentrates in the legs due to the valves so the iron loss and noise are increased. In this paper, to reduce the iron loss and noise of VMCR, the structure of the valves is improved by using 3D nonlinear magnetostatic field analysis taking account of the laminated structure and the anisotropy of iron cores. It is shown that the iron losses can be reduced by about 30% improving the valve structure.

This paper proposes a model order reduction (MOR) technique based on the proper orthogonal decomposition method, to speed up nonlinear magnetostatic analysis of inverter-driven electrical machines. In this method, a set of solutions of the original problem is obtained at relatively large intervals, covering the whole cycle. The solutions, known as snapshots, are then used for the linearization as well as the order reduction of the matrices at the intervals. The reduced linearized matrices are then interpolated for time instance within the strides, supplemented with initial guess obtained by interpolating the snapshots. The method enormously reduces the number of matrix projections. Furthermore, it limits the number of the Newton-Raphson iteration to one. The results of applying the method on the magnetostatic analysis of interior permanent magnet motor shows that the method is several time faster than the conventional MOR with almost the same accuracy.

In this paper, a novel hybrid saturated-core fault current limiter (HSFCL) is proposed considering the reliability of permanent magnets (PMs). For the HSFCL, a hybrid PMs/DC coil is designed to saturate the core and a fault limiting reactor is used to guarantee the fault clipping performance. The method of electromagnetic coupling is used to analyze the HSFCL based on ANSYS Maxwell. Simulation results have demonstrated that the HSFCL is efficient in fault clipping and stability enhancement of PMs.

This digest proposed a model of superconducting controllable reactor and calculates its reactance based on finite element method. In order to ensure the safe operation of superconducting reactor, the digest devises a control system for superconducting windings based on S7-200 PLC after analyzing the DC component and overvoltage of superconducting winding and puts forward an optimal control strategy. A 380V/30kVar SCR was fabricated for experiments and the experimental results show the correctness of this method and the feasibility of the control device.

In this paper, a simple structure of L and T shaped butt joints composed of anisotropic and isotropic block cores is proposed. The iron loss of a three-phase reactor having the proposed joints is compared with that having ordinary joints composed of anisotropic block cores only. It is shown that the iron loss can be reduced by applying the proposed joints because the flux distribution becomes more uniform.

Excess loss evaluation in SiFe electrical steel sheets is important for accurate iron loss prediction of electrical machines, especially under high frequencies. In this paper, a numerical excess loss estimation method of SiFe sheets considering the domain wall bowing caused by pinning sites is proposed. An equivalent magnetic field representing the pinning effect is implemented into a general nonlinear eddy current finite element analysis. The hysteresis and eddy current losses are calculated using the flux and eddy current distributions obtained from the proposed analysis directly. The proposed method is applied to two different grades SiFe sheets first. The calculated iron losses under various frequencies in one sheet are compared with catalogue data and less than 2% deviation can be achieved.