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For high power rectifiers, due to the limit restriction of the switching loss, operating at low switching frequency is necessary. In this paper, an effective approach is proposed to restrain grid harmonic current and DC-link pulsating voltage. A discrete-time domain of the complex vector current regulator combined with a synchronized PWM modulation strategies at low switching frequency are employed...
In this paper, comparisons between two permanent-magnet-free (PM-free) machines, namely a wound-field flux-switching machine (WFFSM) and a switched reluctance machine (SRM), covering skewed-rotor and straight-rotor structures are conducted. The topologies and operation principles of the WFFSM are illustrated firstly. Then, the effects of rotor skewing angle on static characteristics, e.g., open-circuit...
In order to improve performance of switched reluctance motor (SRM) at high speed, a new hybrid asymmetric and buck-boost fronted converter for SRM with active boost voltage capability is proposed. Different from existing converters with boosting voltage, the proposed converter has an active regulation ability of boosting voltage, in which voltage level is independent from switching and dwell angels...
In order to improve the power quality of wind power generation system, a direct power control (DPC) strategy of open-winding brushless doubly-fed generator (BDFG) system based on dual converters is presented in this paper. The control method is divided into two parts: the grid side converter control and the machine side converter control. In terms of the grid side converter, a model predictive-based...
According to controllability theory of nonlinear coordinated control with multi-agent, this paper proposes a coordinative optimization method based on the model predictive control (MPC) to achieve the coordination control of energy allocation. Between the micro sources with the incremental cost of consistency algorithm for leader-follower, using an interactive algorithm to achieve the exact optimal...
The evaporative cooling system for wind power generator inclines at an angle of 3∼5 degrees. Due to the special structure, it forms a liquid-gas two-phase self-circulation. Two-phase flow self-circulating system is a typical nonlinear dynamic system. So it is important to study the nonlinear characteristics. In this paper, the nonlinear characteristics were studied through theoretical analysis and...
This paper presents a mid-voltage experimental voltage generator used for the testing mainly of distribution power equipment, high-power drives and renewable power generation. It utilizes thyristor-controlled zigzag transformer as its primary circuit. Based on the analysis of the operation mechanism, the voltage equations are derived and control strategy is proposed. This power electronic zigzag transformer...
Paper introduces a coaxial magnetic gearbox with a new high-speed rotor configuration. The proposed configuration optimizes magnet volume and employs cage rotor bars in the high-speed rotor. The resulting proposed gear improves torque performance at overload condition, and utilises 5% less magnet volume in the high-speed rotor.
The maintenance cost of 8200 series electric locomotive operating in Korea is rising due to aging and lack of original technology. 8200 series electric locomotive have two auxiliary power systems. The auxiliary power system supplies power to the passenger cars. So it is related to the safety and reliability. There are many parts of the auxiliary power system. Among that, The PWM modules are very important...
The numerical prediction of the main state of the equipment is the first step in the prognostic and health management (PHM) study. Temperature is one of the most important health indicators of segment — powered linear motor. A nonlinear autoregressive with exogenous input neural network (NARXNN) model is trained to predict the temperature of the segment-powered linear motor. Based on the single —...
In view of the appearance of asymmetrical operation condition in the air-cooled turbo-generator, the negative sequent current is caused in stator windings, which may endanger the stability of the turbo-generator. With the 2-D and 3-D direct coupled transient electromagnetic field, the end region electromagnetic field distribution with the rated condition and single-phase earth fault condition is studied...
The low-efficiency design method of traditional motor usually needs a long time, so Cloud Computing is introduced for the traditional FEM and BP neural network to reduce the time consuming. In this paper, the electromagnetic axial torque of permanent magnet synchronous motor (PMSM) is used as calculation case. The utilizing Cloud Computing curtails approximately 4 times hour to calculate this case...
A saturation map for the non-uniform magnetic saturation of a V-shaped interior permanent magnet rotor is formulated in this paper. This saturation map is used in conjunction with the magnetic equivalent circuit theory to propose an analytical method for accurate computation of the airgap permanent magnet flux density for interior permanent magnet rotors. Unlike the conventional methods, the proposed...
The position and speed detection of maglev train is critical to train control system. The common methods of speed measurement include speed sensor measurement and speed sensorless measurement. The use of sensorless method can significantly reduce costs and it's not influenced by various environmental factors. In this paper, a high frequency pulsating voltage injection method is proposed for the PMLSM,...
In this paper, a new control strategy for seamless mode transfer of grid-connected single-phase inverter is proposed. Generally, power flow between DC side and AC side is controlled by current reference of grid-connected inverter in d-q synchronous rotating frame. Therefore, it is general to reverse the current reference if the direction of power flow is changed. However, it causes a rapid change...
We constructed a charge and discharge system for effective utilization of an electric storage device composed of batteries. We verified the system operation by simulation analysis and actual measurement. The simulation analysis showed that it is useful to alternately use two secondary batteries as the lithium ion battery (LIB). From the measurement of 60 cycles, the use of secondary batteries under...
In order to increase the output power density and maintainability of the conventional driving system in electric vehicle, the research on magnetic gears is being carried out variously all over the world. In this paper, the design technique of the magnetic-geared permanent magnet synchronous motor(MG-PMSM) is first studied for the application of the MG-PMSM structurally integrated with magnetic gear...
This paper presents a method to shed off the least important loads in a microgrid operated at constant frequency under the contingency of inadequate power generation. Different from conventional frequency deviation based load shedding, this paper discusses in detail how to shed off load based on the voltage deviation. The key issue is to differentiate whether the voltage deviation is due to sudden...
A teaching example is built in Simulink, and then, based on the communication between Matlab and LabVIEW, a teaching virtual platform in LabVIEW is realized. This platform is about a wind power generation system and used mainly for the Renewable Energy Sources course of the undergraduate students of electrical engineering major. Compared with Simulink simulation teaching, the virtual platform adopts...
Since air-gap magnetic fields of brushless doubly-fed machine (BDFM) are produced by two stator windings of different pole pairs, the spatial harmonic contents of the BDFM are higher than conventional induction machines and have a considerable effect on the machine performance. To reduce the contents of main slot harmonics, the harmonic components of airgap magnetic field for the BDFM are analyzed...
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