13892 
Wireless Synchronous Transfer of Power and Reverse Signals 
전력전자학회 
20190717 
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Wireless power transfer via coupled magnetic resonances has been a hot research topic in recent years. In addition, the number of related devices has also been increasing. However, reverse signals transfer is often required in addition to wireless power transfer. The structure of the circuit for a wireless power transfer system via coupled magnetic resonances is analyzed. The advantages and disadvantages of both parallel compensation and series compensation are listed. Then the compensation characteristics of the inductor, capacitor and resistor were studied and an appropriate compensation method was selected. The reverse signals can be transferred by controlling the compensation of the resistor. In addition, it can be demodulated by extracting the change of the primary current. A 3.3 MHz resonant frequency with a 100 kHz reverse signals transfer system platform was established in the laboratory. Experimental results demonstrate that wireless power and reverse signals can be transferred synchronously. 
13891 
Design and Implementation of Instantaneous Power Estimation Algorithm for Unified Power Conditioner 
전력전자학회 
20190717 
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This paper discusses a simple control approach for a Unified Power Conditioner (UPC) system to achieve power quality compensation at the point of common coupling in distribution systems. The proposed Instantaneous Power Estimation Algorithm(IPEA) for shunt and series active power filters uses a simple mathematical concept that reduces the complexity in the design of the controller. The performance of a UPC is verified with a system subjected to voltage distortions, sags/swells and unbalanced loads using MATLAB/SIMULINK. The simulation study shows that a UPC with the proposed control algorithm can effectively compensate for voltage and current harmonics, unbalance and reactive power. The control algorithm is experimentally implemented using dSPACE DS1104 and its effectiveness has been verified. 
13890 
ThreePhase Current Balancing Strategy with Distributed Static Series Compensators 
전력전자학회 
20190717 
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This paper proposes a threephase current balancing strategy in a power transmission system employing distributed static series compensators (DSSCs). With the proposed variable quadrature voltage injection method, the DSSC emulates either an inductive or a capacitive impedance into the transmission line, and the magnitudes of the phase currents are balanced. Hence, the phase imbalances in the power transmission system are significantly reduced. As a result, the power transfer capability of the transmission lines can be improved. The operational principle of the DSSCs, the hardware structure and the control algorithm are described in detail. Finally, the theoretical analyses and the proposed strategy are experimentally verified through a scaled down transmission system with DSSC prototypes. 
13889 
Analytical Calculation of Air Gap Magnetic Field Distribution in Magnetic Geared Motors 
전력전자학회 
20190717 
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Magnetic geared motors are driven using the same operating principle as conventional synchronous motors in which a magnetic gear is embedded. The magnetic geared motor is structurally similar to a magnetic gear. However, by applying currents to the stator coil, the highspeed rotor is rotated by a magnetic field and the lowspeed rotor is rotated according to the gear ratio. In this paper, the operational principle of a magnetic geared motor and the magnetic flux density in its inner and outer air gaps are described. Then the magnetic flux density in the two air gaps is used to express a method for calculating the electrical and mechanical output. Results obtained with the analytical calculation method are compared with those of the finite element analysis. Finally, a prototype is used to verify the results of the analytical calculation and FEA. 
13888 
Performance Improvement in SinglePhase Electric Spring Control 
전력전자학회 
20190717 
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These objectives are the stabilization of the voltage across the critical load (CL) of a power system, and the achievement of a specific functionality similar to the pure compensation of reactive power or the correction of the power factor. However, existing control systems implementing the control do not cope with nonideal operating conditions, such as line voltage distortions, and exhibit a somewhat sluggish regulation of the CL voltage. This paper starts by analyzing the dynamics of an ES power system in terms of its poles and zeros. After that, a reduced secondorder model of the dynamics is formulated to avoid a notch filter in the pole assignment. A repetitive control for an ES power system is then designed to meet the two above mentioned objectives. Experimental tests carried out on a laboratory setup demonstrate the effectiveness of the proposed control system in significantly improving the ES power system performance, while reaching the two objectives. In particular, the tests outline the large mitigation of harmonics in the CL voltage under line voltage distortions and its fast stabilization action. 
13887 
SynRM Driving CVT System Using an ARGOPNN with MPSO Control System 
전력전자학회 
20190717 
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Due to nonlinearsynthetic uncertainty including the total unknown nonlinear load torque, the total parameter variation and the fixed load torque, a synchronous reluctance motor (SynRM) driving a continuously variable transmission (CVT) system causes a lot of nonlinear effects. Linear control methods make it hard to achieve good control performance. To increase the control performance and reduce the influence of nonlinear timesynthetic uncertainty, an admixed recurrent Gegenbauer orthogonal polynomials neural network (ARGOPNN) with a modified particle swarm optimization (MPSO) control system is proposed to achieve better control performance. The ARGOPNN with a MPSO control system is composed of an observer controller, a recurrent Gegenbauer orthogonal polynomial neural network (RGOPNN) controller and a remunerated controller. To insure the stability of the control system, the RGOPNN controller with an adaptive law and the remunerated controller with a reckoned law are derived according to the Lyapunov stability theorem. In addition, the two learning rates of the weights in the RGOPNN are regulating by using the MPSO algorithm to enhance convergence. Finally, three types of experimental results with comparative studies are presented to confirm the usefulness of the proposed ARGOPNN with a MPSO control system. 
13886 
Hybrid Phase Excitation Method for Improving Efficiency of 7Phase BLDC Motors for Ship Propulsion Systems 
전력전자학회 
20190717 
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This paper proposes a hybrid phase windings excitation method for improving the efficiency of a 7phase brushless DC(BLDC) motor in the electric propulsion system of a ship. The electrical losses of a BLDC motor system depend on the operating region and the number of excited phase windings (2phase, 4phase or general 6phase windings). In this paper the operating region and torque/speed characteristics according to the motor rotation speed and propeller load are analyzed for a number of excitation methods. In addition, it analyzes the electrical losses of the system under each of the excitation methods in the entire operating region of the motor. In every sampling time, the proposed control method calculates the electrical loss of the system for each of the excitation methods and operates a 7phase BLDC motor by selecting the excitation method that results a decreased electrical loss at the operating speed. The usefulness of the proposed control algorithm is verified through experimental results. 
13885 
Simplified Rotor and Stator Resistance Estimation Method Based on Direct Rotor Flux Identification 
전력전자학회 
20190717 
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Since parameter mismatch seriously impacts the efficiency and stability of induction motor drives, it is important to accurately estimate the rotor and stator resistance. This paper introduces a method to directly calculate the rotor flux that is independent of stator and rotor resistance and electrical angle. It is based on obtaining the rotor and stator resistance using the model reference adaptive system (MRAS) method. The method has a lower computation burden and less adaptation time when compared with other rotor resistance estimation methods. This paper builds three coordinate frames to analyze the rotor flux error and rotor resistance error. A number of implementation issues are also considered. 
13884 
Finite Element Analysis and Dynamics Simulation of Mechanical FluxVarying PM Machines with AutoRotary PMs 
전력전자학회 
20190717 
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A new type of autorotary PM mechanical fluxvarying PM machine (ARPMMFVPMM) is proposed in this paper, which can overcome the problem where the airgap magnetic field of a PM machine is difficult to freely adjust. The topology structures of the machine and the mechanical fluxadjusting device are given. In addition, the operation principle of fluxadjusting is analyzed in detail. Furthermore, the deformation of a spring with the speed variation is obtained by virtual prototype technology. Electromagnetic characteristics including the flux distribution, air gap flux density, flux linkage, electromagneticmagneticforce(EMF), and flux weakening ability are computed by 2D finite element method (FEM). Results show that the machine has some advantages such as the good field control ability. 
13883 
PulseWidth Modulation Strategy for Common Mode Voltage Elimination with Reduced Common Mode Voltage Spikes in Multilevel Inverters with Extension to OverModulation Mode 
전력전자학회 
20190717 
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This paper presents a pulsewidth modulation strategy to eliminate the common mode voltage (CMV) with reduced CMV spikes in multilevel inverters since a high CMV magnitude and its fast variations dv/dt result in bearing failure of motors, overvoltage at motor terminals, and electromagnetic interference (EMI). The proposed method only utilizes the zero CMV states in a space vector diagram and it is implemented by a carrierbased pulsewidth modulation (CBPWM) method. This method is generalized for odd number levels of inverters including neutralpointclamped (NPC) and cascaded Hbridge inverters. Then it is extended to the overmodulation mode. The overmodulation mode is implemented by using the twolimit trajectory principle to maintain linear control and to avoid lookup tables. Even though the CMV is eliminated, CMV spikes that can cause EMI and bearing current problems still exist due to the deadtime effect. As a result, the deadtime effect is analyzed. By taking the deadtime effect into consideration, the proposed method is capable of reducing CMV spikes. Simulation and experimental results verify the effectiveness of the proposed strategy. 