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In this paper, a novel hybrid current balancing method for multi-channel LED drive based on quasi-two-stage converter is proposed. In presented structure, each output modules includes two LED strings and can achieve internal current balancing easily through its current balancing capacitor. The current regulators are used to balance the currents among the output modules. By applying the partial power...
Traditional LED drivers generally use electrolytic capacitor as the storage element which will restrict the lifetime and power density of drivers. In this paper, an electrolytic capacitor-less LED driver which pluses an auxiliary winding in the transformer and an additional full-bridge circuit to Flyback converter is proposed. It not only eliminates the electrolytic capacitor to extend the lifetime,...
This paper describes a four quadrants converter system for the international fusion tokamak device (ITER) which is now under construction in the south of France. The ITER poloidal field (PF) converter system is thyristor-based and rated for 82 MVA, providing up to ±1.05 kV/± 55 kA dc power to the superconducting magnets to generate a controlled rotating magnetic field for nuclear fusion reactions...
Modern high-frequency induction heating technology puts forward higher requirements for load matching of the induction heating power supply. LLC resonant load circuit can replace the traditional induction heating load matching transformer, and increase power density. This paper analyzes the load matching characteristics of LLC load resonant circuit in high frequency induction heating power supply,...
Ripple current at twice the output frequency exists at dc side in single phase inverter due to the instantaneous power imbalance between input and output power. Neutral-point voltage waveform control method is proposed in this paper to eliminate the ripple current in E-capless full-bridge inverter. With the proposed method, the pulsation power is controlled to only flow through ac capacitors and the...
In cascade AC systems, the impedance interaction between the source module and the load module may cause overall system instability. The generalized Nyquist stability criterion can be applied to characterize the stability of cascade three-phase AC systems. But it is usually very complicated and cannot directly reveal effective control strategy to alleviate the interaction problem. Based on three-phase...
This paper addresses the optimal design of leakage inductance of the high-frequency transformer in dual active bidirectional converter stages of cascaded bidirectional converters. By the analyzing realization condition of zero-voltage-switching and the method to reduce reactive power under controlling of single phase shifting control strategy, the optimized circuit parameters are selected. An experimental...
Electric vehicles (EV) offer promise as an effective solution to environmental problems. One of the keys to their successful diffusion is the provision of adequate battery charging infrastructure. In order to create a charging infrastructure by installing equipment in such as locations as carports in private homes, the wireless battery charging system is very suitable. EVs can be used in smart house...
Full-wave rectifier with center-tapped transformer is a popular and competitive topology for power supply with high power density. Main transformer and output inductor are two large size components and have great roles on the power supply's form factor. From the view of volume and height in a real product, a new integrated magnetic structure is proposed in this paper. The proposed structure has four...
This paper presents an analysis and comparison of magnetics structures in a tapped boost converter for LED applications. The magnetic structure is a coupled inductor which is analyzed in a conventional wire-wound core as well as in a planar structure for different interleaving winding arrangements. The analysis is performed in terms of leakage inductance, winding capacitance and winding loss. Efficiency...
The electromagnetic interference (EMI) filter plays an important role in the EMI noise suppression. As the development of the switch mode power supply (SMPS), the power density of the SMPS improves every year. As a result the distance between components becomes smaller and smaller. The near-field magnetic coupling between components becomes larger and larger. However there are fewer studies about...
Conventional Wireless Power Transfer (WPT) has limitation due to the contradiction between the power transfer efficiency (PTE) and power transmission distance. A novel network called Wireless Power Transfer Network (WPTN) is proposed to help overcome the limitation, and power is efficiently transferred from a transfer node to a receive node via relay nodes over a relatively long transmission distance...
Deep analysis on the magnetic near-field leakage around the induction heating cooker was performed. The factors, such as pan materials, pan sizes and pan offsets, on the magnetic field leakages were analyzed by FEM simulations. Also, the paper puts forward the method for suppressing magnetic leakage using shielding conductor and analyzes the shielding effect on the near-field magnetic leakage with...
Inverter control technology is the core technology of Photovoltaic power generation system. In this paper, an improved deadbeat control strategy for Photovoltaic grid-connected inverter was proposed and implemented in TMS320F2812 system. DC input voltage, output current and grid voltage are introduced in the improved deadbeat control strategy for getting the duty value, which is used to control the...
Permanent magnet synchronous motor (PMSM) are favored in traction drives of rail vehicles for their high efficiency of operation. Traction inverters always operate at reduced switching frequency to minimize the losses in semiconductor devices. To restrain the motor current harmonics, off-lined calculated optimal synchronous pulse patterns can be used. This paper presents a closed-loop control of permanent...
For grid-tied inverters, islanding occurs when the grid is disconnected but the inverters are still energizing the local loads. When the inverter output active and reactive power match the local loads, the inverter output voltage and frequency will keep the same values as before. Islanding poses a hazard to maintenance workers and equipment. To detect islanding, a disturbance signal is usually added...
When the network voltage is unbalanced, reactive component under synchronous rotating coordinate system will contain twice frequency AC component, which influences phase-locked precision. In order to accurately lock phase, notch filter is added to the Soft Phase-locked Loop(SPLL). This paper focuses on the research of the PLL system containing notch filter. Based on the consideration of stability...
A hybrid rotor position observer with online rotor flux identification was proposed for interior permanent magnet synchronous motor (IPMSM) sensorless drive system. To achieve wide-speed-range operation, rotor position was estimated using pulsating high frequency injection (HFI) at low-speed-range and model reference adaptive system (MRAS) based method at high-speed-range. The hybrid position observer...
In order to improve the performance and the stability of the sensorless vector control system for permanent magnet synchronous motor, H∞ speed observer of permanent magnet synchronous motor based on Immune Algorithm (IA) is proposed in this paper. The H∞ speed observer is used instead of speed sensor to implement the speed identification for permanent magnet synchronous motor. The problem that the...
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