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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 number of mobile device users increases every year. Each mobile device is usually equipped with a Li-ion battery having voltage that varies from a minimum of 2.7V to a maximum of 4.2V. Therefore, as the battery voltage decreases with time, a DC-DC converter is required for a regulated supply lower or higher than the battery voltage. A simple buck converter is not suited for this case, since step-up...
This paper presents an Active Disturbance Rejection Control (ADRC) technology and PI-fuzzy compound technology method for Active Power Filter (APF). The ADRC consists of Tracking Differentiator (TD), Extended State Observer (ESO) and Nonlinear State Error Feedback law (NLSEF). This control method makes full use of the error driven control law, the modern control theory and the nonlinear feedback control...
Due to low cost and high efficiency, the AC-DC single-stage LED driver has been used to realize power factor correction and DC-DC constant current output. But there usually exists the problem of larger twice line frequency output ripple, which is one of the important factors to affect LED optical properties and lifetime. A suitable kind of LED driver that a single-stage modified Flyback power factor...
The problem of interfacing a Photovoltaic Generator (PVG) with an electrical three phase grid is addressed in the presence of nonlinear loads. The connection of the PVG to the power grid is done in two stages with both a DC/DC converter and DC/AC multilevel inverter. This latter is based on a Neutral Point Converter (NPC) operating simultaneously as an interfacing system and as a shunt active power...
This paper presents a flexible active power line conditioner (FAPLC) that works for reactive power or harmonic current compensation with load balancing and single-phase sag compensation as its additional functions. It injects single-phase current to heavy-load phase and draw currents from other two light-load phases for unbalanced loads condition. In type B fault, it only injects required reactive...
Nowadays distributed generation systems such as photovoltaic power generation systems and wind power generation systems have been on the increase. The increase of distributed generation systems causes the reverse power flow and the voltage rise in power distribution systems. By the way, the leading currents by the installed compensation capacitors cause the voltage rise and increase of the power loss...
Focus on the ripple of the output voltage of switched reluctance generator (SRG), an optimized controller of turn-on and turn-off angle basing on fuzzy logic is designed. The effect of turn-on and turn-off angle on system's performance is studied after introducing the working principle of SRG. Considering the ripple of output voltage and the difference between the real voltage and the reference voltage,...
The purpose of this work is to present a complete nonlinear analysis of the DC/DC Non-isolated Ćuk Converter in conjunction with a photovoltaic cell fractal model. Beginning with eigenvalues location and then using Lyapunov analysis to demonstrate stability, it is studied the input to state stability, input to output stability and finally passivity of the system. Then feedback controllers are designed:...
The buck-boost inverter can be easily used to construct a multi-input converter due to its inherent symmetrical and extendable differential structure. This paper proposed a multi-input converter derived from the buck-boost inverter to interface different input sources. When two pure DC voltages are chosen as the references for the two output capacitor voltages, the proposed converter will operate...
This paper presents the control method of an LCL filter implemented for a three-phase, voltage-source, grid-connected inverter for not only offering better attenuation of switching harmonics but also for highly damping the resonance. A discrete-time deadbeat current controller with tuned state-feedback gains is proposed to realize the time optimum responses with high control accuracy. In addition,...
In this paper a single phase grid-connected photovoltaic converter with maximum power point tracking algorithm is presented. This system is characterized by high efficiency and good output quality parameters of electrical energy. The implemented output inverter operates in current tracking controller mode. The output current (current of grid) is almost sinusoidal and the reactive power is equal to...
This paper is focused on the optimal design of the controllers in an active filtering and regeneration system for DC railway traction substation. The control algorithm of the system is based on the indirect current control method and uses two closed loops with PI controllers: an outer one for the DC voltage control and the other for the grid current control. In order to perform the energy regeneration...
Modular Multi-level converters are the most discussed topic in the field of HVDC for AC to DC conversions. In this paper it is shown that modular multi-level converters with series connected H-bridges have the capability to convert 3-phase AC to single phase AC. Additionally M2C with full bridge modules has many degrees of freedoms in terms of frequency and voltage levels. In addition, it does not...
This paper presents a novel digital deadbeat + repetitive control (DBRC) strategy for output voltage regulation of pulsed power resonant converters used in high energy physics applications. The proposed converter contains three individual series resonant parallel loaded (SRPL) converter arms, which effectively mitigate the influence of resonant tank unbalances on the converter operation. The deadbeat...
The use of series connected capacitors for high voltage applications has been proven to be beneficial for voltage stress reduction across power semiconductors. In a 3-phase grid any asymmetry in the value of the series capacitance may lead to significant variations in the voltage seen across the low voltage converter. This paper investigates the effects of an unbalanced set of series connected capacitors...
In this paper a novel unified modelling and control procedure for Back-to-Back converters is introduced. The proposed procedure captures in a single state-space model detailed converter dynamics of both LCL filters and DC-capacitor. A linear multivariable approach has been identified as the most suitable control strategy for taking full advantage of the unified model. A state-feedback controller has...
Due to the increasing adoption of domestic photovoltaic (PV) systems, the use of technologies such as on-load tap changer (OLTC)-fitted transformers, capacitor banks, and remote monitoring are being considered to mitigate voltage issues, particularly in European-style low voltage (LV) networks. Depending on the control strategy, however, the effects on customer voltages and control actions (e.g.,...
This paper presents an approach for obtaining a dynamic model of a Modular Multilevel Converter (MMC) where all state variables settle at a constant point of equilibrium during steady-state operation. The resulting model can be expressed as a steady-state time-invariant (SSTI) state-space model, which can be linearized for assessment of small-signal stability by eigenvalue analysis or can be utilized...
This paper presents a high-efficiency non-isolated synchronous buck-boost DC-DC switching converter. The circuit is made to operate in Discontinuous Conduction Mode (DCM)of operation for minimum inductor value, to reduce size and cost of the converter. A snubber capacitor is used across the switch to minimize turn-off loss. The power dissipation through snubber capacitor and inductor is minimized...
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