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Supraharmonic phenomena related to Compact Fluorescent Lamps (CFL) in single operation are described through this article by means of circuit simulation. Simulations are carried out using a typical CFL circuit without any Power Factor Corrector stage. The corresponding electronic ballast is simulated in LTSpice® using a BJT Half Bridge Resonant Inverter configuration. Supraharmonic phenomena show...
An inverter control strategy which can suppress harmonic and circulation is proposed for the paralleled multi-inverter system with non-linear loads in islanded microgrid in this paper. The proposed strategy does not require any active or reactive power calculations. Instead, a phase-locked loop (PLL) is used. The virtual impedance is set to contain the virtual negative impedance, the fundamental virtual...
Power grid is a weak grid with internal impedance for grid-connected PV generation system. The grid impedance has serious impact on system stability and power quality for PV grid-connected system. To study the interaction between grid-connected inverter and weak grid, the Norton equivalent output impedance model and state space representation of the PV grid-connected system is established in this...
Recently, the wireless EV chargers have been spotlighted because of safe, and easy use apparatus. Proposed has been a newly developed large-gap wireless power transfer EV charger which can communicate control signal to a power feeding from a secondary side with no communication equipment. The SEPP inverter WPT apparatus is designed for large-gap loose-coupling condition by characteristic-impedance...
A new topology of stepped impedance filters in substrate integrated waveguide (SIW) technology is presented in this paper. The filters are based on the reduction of the effective dielectric permittivity on certain waveguide sections which are below cutoff in the pass-band of the filter. Two different techniques for reducing the substrate permittivity have been analyzed and compared. In the first one,...
In this paper, we propose low electromagnetic interference (EMI) high-k tightly-coupled resonant magnetic field (TCR-HMF) charger. The high coupling coefficient, k, between Tx and Rx coils is essential for increasing power transfer efficiency (PTE) and reducing size of proposed TCR-HMF charger. As the k increase, the mutual inductance also increases. Moreover, the larger mutual inductance results...
This paper presents a comparative analysis of different shoot through control schemes employed in Z-source inverters. Z-source inverter provides a single stage power conversion topology which can give both voltage buck and boost properties. This paper also gives an insight on the working of Z-source inverter by utilization of shoot through forbidden states. These states are utilized by implementing...
Parallel connection of inverter modules is a solution to increase reliability, efficiency and redundancy of inverters in Micro-Grid system. Proper load sharing among parallel inverters is a key point. The circulating current among the inverters can greatly reduce the efficiency or even cause instability of the system. In this paper, a control strategy for improving the load sharing performance in...
Photovoltaic (PV) energy is one of the most important energy resource since it is clean, pollution free and inexhaustible. The number of installed PV power plants is steadily increasing worldwide. This poses new challenges to solar inverters to stabilize the electric grid. New control strategies must be developed to fulfil the requirements of the grid operators.
In this paper a comparison between grid-feeding and grid-supporting inverters is shown based on simulation and measurement of inverter output impedances. The output impedance of a grid-feeding inverter with current control shows capacitive behavior compared to inductive behavior of a grid-supporting inverter with voltage control.
This paper proposes a technique to perform the multifunctional use of current controlled voltage source inverters used primarily as interface between renewable energy sources and the grid utility. The strategy adopted doesn't demand sensing the grid current neither the load current. Instead, the reference signal for compensation purpose is obtained by filtering the harmonics components of the voltage...
Electrical power demand have grown rapidly over the years which results in power system congestion, depletion of fossil fuels and increased environmental hazards. Further existing power system generations are inadequate for the exponential demand growth. Environmental risks and depleting fossil fuels created a pocket for renewable energy based distributed generations that are cleaner, and renewable...
Since the concept that, inverters can controlled to behave like a synchronous generator "Virtual Synchronous Generator" has been proposed, the virtual synchronous generator started to become the mainstream control of distributed generators connected distributed system. This concept simulates the frequency and voltage regulation of synchronous generator to improve the overall stability in...
In this paper a CMOS Doherty Power Amplifier operating at 2 GHz frequency is presented. The Doherty power amplifier (DPA) maximizes the power amplifier efficiency and simultaneously maintains amplifier linearity for signals having high Peak to Average Power Ratios (pAPR). The proposed design is simulated in 180nm CMOS technology. The design consists of two sub-power amplifiers, a 3dB Coupler, and...
The estimation of grid impedance can be used to improve the control performance of the grid-connected inverter in distributed power generation systems and to achieve islanding detection simultaneously. Particle swarm optimization(PSO) algorithm has been widely studied in parameter identification since it converges fast and has few parameters to be set. The paper proposes a grid impedance estimation...
The renewable energy sources like wind, solar, and fuel cell sources has widely used in the smart gird to reduce the power loss in the conventional central generation. However, these sources usually operated at low output voltage levels. This paper proposes single phase bidirectional inverter is used for voltage regulation which gives less voltage ripple. Proposed quasi - Y source converter has many...
The objective of this paper is to provide a method for steady-state short-circuit analysis in power networks with distributed energy resources (DERs). For this purpose, we suggest an approach that takes into account the impact of current controlled DERs in the fault analysis. The current controlled DER has some characteristics that we should consider–1) DER's large filter inductance and 2) the limit...
Recent developments in high frequency inductive wireless power transfer (WPT) mean that the technology has reached a point where powering small autonomous drones has become feasible. Fundamentally, drones can only carry very limited payloads and thus require light-weight WPT receiver solutions. The key to achieving light weight is operating the WPT system at high frequency: this allows both the coils...
The impedance source inverter family has become one of the most interesting alternatives for wind and photo-voltaic energies applications which require high conversion ratio. The main drawback of these inverters is related to the modulation signal which must be used to control the output current and voltage conversion ratio simultaneously. To deal with this problem several modulation techniques and...
Resonance is a common problem of power quality in the renewable energy power generation system, and its suppression strategy is closely related to the safe and stable operation of the grid connected with the renewable energy. In this paper, the generation mechanism and related influencing factors of resonance are analysed at first by analysing the specific resonance problem of photovoltaic power station...
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