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This paper presents a random space vector pulse width modulation (SVPWM) strategy for a three-phase voltage source inverter based on Field Programmable Gate Array (FPGA). It is more flexible and faster to realize randomization algorithm in FPGA than digital signal processor (DSP). What's more, it is easily extensible for multiphase driving systems with FPGA. Models in Simulink and an experiment platform...
The introduction of aluminum shielding incurs eddy current effect, which weakens the self-inductance of transceiver coils. Simulation and experiments are carried out to find optimal shielding position to realize efficient and fast charging.
This paper presents a novel semiconductor switch test platform for power converter optimization which allows to test power semiconductors under different switching current waveforms. As switching current has a major influence on the switching behavior of power semiconductors and thus on switching losses. Compared with conventional double pulse test circuit which can only test power semiconductors...
The model of mismatched transceiver coils in wireless power transfer system is proposed in this paper. System transmission efficiency and transferred power are analyzed against coupling coefficient. The mismatched charging scenario and ways to achieve optimal charging are investigated based on theoretical analysis and validated by experiment results.
This paper considers the minimizing of eddy current losses of PM motor through the proper choice of the magnet material, rotor magnet design and the comparison analysis between with and without rotor segmentation. Through 3D analysis and the experiment, it is shown that the magnet segmentation has the effectiveness of eddy current loss reduction especially for the variation of load condition.
In Constant speed constant frequency (CSCF) AC power supply system, generator output constant frequency and constant voltage AC power by connecting engine with constant speed transmission device (CSD). However, CSCF has many disadvantages, such as complex structure, heavy weight, high cost and low energy conversion efficiency. By eliminating CSD in CSCF and taking output voltage and output frequency...
Chip resistors are widely used in switching mode power supply (SMPS). The output voltage sampling circuit of PFC is usually composed of several series-connected chip resistors. When fully-immersed evaporative cooling is applied to SMPS, a rise of PFC output voltage occurs after a period of operation, which is caused by resistance increase of the chip resistor applied to voltage sampling circuit. This...
In order to design electrical devices using coil or conductive media, an analysis of precise eddy current distributions is necessary. However, the distribution of eddy current inside a conductive media is somewhat complicated. In this paper, the eddy current distributions by finite element analysis inside a conductive media is analyzed. Based on the eddy current distributions of this paper, several...
In this paper, two dual random space vector pulse-width modulation (RSVPWM) methods, Random Switching Period-Random Zero Vector Timing SVPWM (RSP-RZVT-SVPWM) and Variable Daley-Random Zero Vector Timing SVPWM (VD-RZVT-SVPWM), are proposed to apply in five-phase inverters. The proposed RSVPWM methods can decrease the amplitudes of high harmonics and spread harmonics concentrated around switching frequency...
This paper discusses the dead-time effect of dual bridge series resonant DC/DC converter (DBSRC). The phase-shift modulation is usually adopted in DBSRC. However, the phase-shift angle is usually small, and voltage polarity reversal (VPR) may occur in dead-time, which may deteriorate EMI/EMC and increase loss. This paper analyzes the commutation of DBSRC when VPR occurs and proposes a method to eliminate...
The vacuum interrupter(VI) is the core of vacuum circuit breakers and the design of contact structure plays a vital role in improving vacuum switch current breaking capability. In this paper, a three-dimensional model of cup-shaped axial magnetic contact with core structure has been established. And the effects of different slotted depth and angle on axial magnetic field(AMF) distribution of arc center...
For evaluate the thermal behavior of a permanent magnet motor under different types of losses and various loss distributions, a simplified thermal circuit is proposed. The result shows that, the model presented in the companion paper is suitable to use in machine design with certain accuracy.
The paper presents a method of the series arc fault for DC systems. The aim of the study is to find some current characteristics, which can be significant for the purpose of arc detection. The validity of the proposed method is testified by analyzing the arc fault current signal. The low voltage series DC arc study is carried out on the currents waveforms acquired during some tests on electric appliances...
A novel 6/13-pole axial field flux-switching permanent magnet (AFFSPM) machine has the advantages of compact structure, large torque density, high efficiency and good fault tolerance. In order to reduce the influence of load mutation and the variation of system parameter on the control system of AFFSPM machine, and to improve the stability of drive system, the control method of AFFSPM machine is researched...
In this paper, considering the change rate of the load, a frequency division control is optimized to improve the control accuracy of hybrid energy storage, compared to the traditional frequency division control. Firstly, the optimal control strategy is designed based on the first power allocation and the second power allocation. Secondly, the model is applied in residential area to avoid the peak...
Permanent magnet synchronous machines (PMSMs) equipped with dual three-phase (DTP) fractional-slot overlapping windings (FSOWs) are characterized by stator modularization, low rotor losses and easy manufacturing. However, the overlapping between the adjacent phase windings may cause poor magnetic insulation in PMSMs, which is undesirable in fault-tolerant applications. This paper proposes a type of...
The Hall-sensor-controlled brushless dc (BLDC) motors have been widely used in a myriad of industrial and commercial applications due to their simplicity and low cost; meanwhile the fault-tolerant operation of Hall sensor drives is receiving renewed attention in recent literature. This paper proposes an innovative fast fault diagnosis (FFD) method for analyzing different fault cases and reconstructing...
The DC circuit breaker technology is one of the key technologies to build multi-terminal DC transmission network. Active DC vacuum circuit breaker (DCVCB) has become the research object. Based on the continuous transition model(CTM) and variable-step 4th-order Runge-Kutta method, sheath development stage during the post-arc dielectric recovery has been simulated and analyzed. Then the influence of...
For the vacuum arc, the parameters of the interelectrode plasma have influences on the electrode process. It is necessary to obtain the parameters and characteristics of the plasma by simulating the plasma among the electrodes. In this paper, based on the analysis of the existing vacuum arc model, combined with the characteristics of vacuum arc fault under different interrupting conditions, the effects...
With the R&D of high voltage direct current (HVDC) transmission, HVDC circuit breaker as the protection equipment has been widely applied in the power system. In this paper, the HVDC vacuum circuit breaker (VCB) based on artificial zero mode has been analyzed, and the genetic algorithm (GA) has been used to optimize the parameters of DC VCB. Moreover, an optimization design method of converting...
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