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The technological advances of intelligent electric substations have significantly improved the operational performance of power utilities by incorporating advanced monitoring and control functionalities. The data traffic patterns in substation communication network (SCN) need to be better understood to improve the SCN performance against different forms of cyber-attacks. To this end, this study presents a fractional auto-regressive integrated moving average (FARIMA)-based threshold model to characterise the SCN traffic flow based on the IEC 61850 protocol and carry out anomaly detection. The performance of the proposed anomaly detection solution is assessed and validated through numerical analysis under the condition of the cyber storm based on the collected SCN data traffic from a real 110 kV substation, and the numerical results clearly confirmed its effectiveness.

The industrial control system (ICS) is facing increasing threats in underline communication infrastructure. The mathematical model of communication network traffic in ICS plays a crucial part in the precaution of the cyberattacks. To this end, this paper proposes an integrated prediction approach using learning rate exponential decay (ED-LSTM) method and fuzzy information granulation. The proposed prediction approach is designed to characterize the traffic patterns of ICS for both point and interval prediction. The traffic pattern prediction is essential to characterize the operation behaviors and unique traits in ICS. The experiments and numerical results demonstrate that the proposed integrated prediction approach outperforms the other prediction models in both point prediction and interval prediction.

The working principle of the outer stator magnetic gear (MG) integrated permanent magnet (PM) motor is analyzed theoretically. The influence of the ferromagnetic pieces parameters of the outer stator MG integrated PM motor on electromagnetic torque of the ferromagnetic modulation ring rotor is analyzed by FEM simulation, and the optimal width of the ferromagnetic pieces is determined. By setting up imaginary coils at the boundary between each stator PM with different magnetizing directions and on the two air gaps sides of each non magnetic portion in the ferromagnetic modulation ring, the change law of flux linkage on the imaginary coils when the motor is unloaded and loaded is analyzed by simulation. The change law of induced electromotive force (EMF) and the trend of eddy current loss in each PM and non magnetic portion can be further obtained. The loss of each component in the motor obtained by simulation shows that the eddy current loss of the outer stator MG integrated PM motor is mainly concentrated in PMs and non magnetic portions of the ferromagnetic modulation ring. In the design and manufacture of such motors, effective countermeasures and technical measures must be taken to reduce the eddy current loss under the premise of ensuring the mechanical strength of the motor, so that the motor can be applied in engineering.

In applications like robot joint and medical instruments with limitations for space and mass, frameless motor is an ideal choice as it doesn’t contain shell, bearing, etc. In view of frameless PMSM with 39 slots and 12 poles, a method adopting 6 sets of three-phase winding for phase division and arranging coils in wave winding is proposed in this paper. Specifically, three-phase winding in every set is differently divided by approximate 60° phase belt, so that composite electromotive forces (EMFs) attached to same phase in different sets are not coincide but adjacent. Then embed double-layer short-pitch distributed wave winding of each set of three-phase winding according to this phase division and successively connect coils belonging to same phase in series. In this way, not only deviations in amplitude and phase among three-phase fundamental EMF caused by single set of winding can be reduced, but also higher winding factor can be obtained. Additionally, it can also save the copper wire and make the winding end shorter to achieve lighter weight and higher efficiency. Theoretical analysis about EMF and magnetomotive force (MMF) in this paper showed the validity of this design, while simulation results proved that the frameless PMSM has excellent electromagnetic performance. Prototype machine also shows that the arrangement of copper wires is very uniform and there is no more additional winding end.

A 96kW traction permanent magnet synchronous motor(PMSM) is designed by means of finite element analysis(FEA) of electromagnetic field according to the traction and working characteristics of the locomotive. Due to the adverse installation environment, the temperature rise, strength and other characteristics of the motor should be simulated and analyzed accurately during the design process. In this paper, the electromagnetic characteristics are obtained through the FEA of electromagnetic field. And on the basis of the electromagnetic field, fluid field, thermal field, rotor strength and so on, the multi-physics field of the traction motor is analyzed. The simulation results provide a basis for motor design and verify its rationality. This paper proves the correctness of the simulation analysis and design method of traction permanent magnet (PM) motor, and lays a certain foundation for the subsequent design of traction motor for rail vehicles.

In order to improve the problem of safe commutation and high voltage spikes in the converter commutation process, a decoupling-unipolar phase-shifted modulation strategy was proposed; In order to improve the conversion efficiency and reduce the voltage stress on the switch, the topological structure of the cycle-changing high frequency link converter is adopted. Because the leakage inductance of the transformer is in series resonance with the parasitic capacitance of the switch tube, resulting in voltage spikes and voltage oscillations at both ends of the switch tube, the resonant inductor and the clamp diode are introduced; Compared with the traditional modulation method, this modulation improves the efficiency of the converter and realizes zero voltage switching(ZVS) of all switch tubes in the topology. The correctness and feasibility of the method are verified by simulation and experiments.