Second-order generalized integrator (SOGI) based phase-locked loops (PLLs) are widely used for grid synchronization in single-phase grid-connected power converters. Previously, the estimated frequency of PLL stage is fed back to front-end SOGI block make SOGI-PLLs frequency-adaptive, which increases implementation complexity, and makes tuning sensitive, thus reducing stability margins. Alternatively, a frequency-fixed SOGI-based (briefly called FFSOGI-PLL) proposed ensure simple this letter....

In this paper, a new open-loop architecture with good dynamic performance and strong harmonic rejection capability is proposed for single-phase grid synchronization under distorted conditions. Different from previous algorithms based on the phase-locked loop technique, method to estimate frequency phase angle of voltage in an manner so that fast response enhanced system stability can be achieved. First, estimation algorithm introduced ideal condition. Then, it extended voltages through...

In this paper, a new critical-conduction-mode (CRM)-based modulation is proposed for three-phase inverters. With modulation, soft switching achieved and the efficiency of inverter improved, especially high frequency operation with SiC MOSFET. string PV applications, by operating at above 300 kHz, power density estimated to be least three times higher than commercial products, while peak about 99%. Good performance verified simulation analysis. The results are also experimentally on 25 kW...

A fast voltage detection method to assist with the low-voltage ride-through operation of grid-tied renewable energy generation systems is proposed in this study. It designed detect every phase voltage, so that it can be applied both three-phase and single-phase applications. The whole approach consists two stages, pre-filtering stage stage. In stage, a cascaded delayed signal cancellation (CDSC) module low-pass filter are connected series low-order harmonics high-frequency noises. For...

This paper presents an effective method, which can address the existing dc-link double-line-frequency voltage ripples in single-phase grid-connected PV inverters, to improve current. The instantaneous power pulsations at grid side cause fluctuations of systems. A PI controller is generally used regulate and its output generate current reference. Since cannot effectively attenuate components, generated reference suffers from harmonic components. As a consequent, actual injected also contains...

In this paper, a novel critical-conduction-mode (CRM)-based soft-switching modulation is applied into three-phase rectifier application. With modulation, zero-voltage-switching (ZVS) soft switching turn-on achieved and the efficiency of improved, especially for high frequency operation with SiC MOSFETs, whose energy large while turn-off negligible. electric vehicle (EV) charging station applications, by operating at above 300 kHz frequency, system power density estimated to be least five...

To meet the electricity demand for fieldwork applications where grid is unavailable, a mobile power generation station driven by wind, solar and diesel presented in this paper. Different from conventional solutions sole source, proposed approach utilizes wind as main sources while used back-up. With reasonable capacity configuration, design highly increases service time reduces dependence on traditional sources. Therefore, solution suitable long-term application remote areas. Finally,...

This study presents a fast reactive current detection (RCD) method based on closed-loop resonant filter for single-phase grid-connected inverters. The developed filter-based RCD (CLRF-RCD) technique with shorter time delay can enhance the dynamic performance of detection, which is beneficial achieving faster compensation and/or power regulation in systems. optimal design CLRF-RCD presented detail, together comparison conventional second-order generalised integrator-based RCD. Finally,...

In this paper, a single-phase grid-connected inverter applying boost coupled inductor is proposed for photovoltaic (PV) generation system and PV grid connected systems to enhance integration of Single phase with Photovoltaic panel form independent embedded modules. DC 20V 40V boosted up 400V, successfully inverted AC 220V. This will efficiently convert solar energy into electrical comply the requirements local load, or connect converted grid. Simulations were conducted using PSIM software...

Droop control is widely used in distributed generators for relating their terminal parameters to power generation. These are usually assumed have enough capacities supplying the required power. This however not always true, especially with renewable sources no or insufficient storage. To deal this issue, an improved droop-based proposed single-phase two-stage PV inverters. With method, inverter can operate either MPPT mode dispatched when connected grid. Also, method be realizing operational...

The paper presents the developed 50 kW switched reluctance generator system included three-phase 6/4 structure exciting commutation power converter and MCS Intel80C196KC single chip microprocessor controller. comparison of two circuits is made. equations electric loading, rated average electromagnetic torque turn numbers coil in per stator pole are given. nonlinear mathematical models also presented. test results prototype described.

With the increase of multi-terminal flexible DC distribution network projects, medium-voltage circuit breaker, as key equipment to remove short-circuit fault, plays a role in operation reliability whole network. In order meet engineering needs network, 10kV hybrid breaker based on coupling negative voltage principle is developed this paper. Firstly, topology and working are introduced. Furthermore, design scheme components including fast mechanical switch, power electronic switch device...

This paper presents a new control strategy for distributed generations (DGs) in DC microgrid. The proposed technique is derived based on game theory and independent of the communication network. In presented paper, operation microgrid with non-communication structure regarded as non-cooperative game. With reasonable mechanisms, converges to stable equilibrium, known Nash equilibrium. Compared traditional droop control, approach eliminates trade-off between power sharing accuracy output...