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This paper presents a maximum efficiency point tracking algorithm for Wireless Power Transfer (WPT) to match the load impedance to that of the source impedance. Conventionally, the load is considered only resistive in the literature. In most of the applications the battery is the end load and the equivalent circuit of battery consists of resistive and reactive elements. Therefore, to improve the overall...
In this paper, a hybrid control of IPT system is proposed in limited operating frequency range according to coupling coefficients. The coupling coefficient k and self-inductance of pad vary according to misalignment and vertical distance condition in inductive power transfer (IPT) system. Those variation cause change of output voltage and zero phase angle (ZPA) frequency. Proposed method enables the...
This paper proposes the new multiple feedback loop control inverters parallel system based on distributed control and droop control which consists of two sets of three-phase inverters with current and voltage double loop, droop loop and current outer loop of distributed control to control the inverter modules. The control method combines droop control with distributed control. This control method...
In this paper, the static stability of droop control for a multiple grid-connected-inverter system is analyzed. The equations of droop coefficient to power capacity are derived. However, inverters based on conventional droop control have no inertia support for the power system. Therefore, a modified strategy adding virtual synchronous generator control to the conventional static droop approach is...
The wide application of distributed generations (DGs) and microgrids (MGs) infuses new vitality into the voltage control of the inverter, which represents a traditional power electronic research area. In this paper, a self-synchronized resonance voltage control algorithm is proposed to satisfy the requirement of an inverter's seamless switching from grid-connected (GC) mode to stand-alone (SA) mode,...
Power systems are under a huge transformation because of the growing penetration of renewable sources. In this sense, microgrids may become a reality, since local sources and manageable loads and batteries may help the system to be self-sustainable under emergency conditions. This paper proposes a three phase power flow for microgrids which considers the droop method. Hence, frequency and voltage...
The paper proposes a control strategy for managing the load associated to the HVAC system of a building. The idea is to use the thermal energy stored into the building to contribute to frequency response during emergency conditions and improve islanding transition. The frequency dynamics of a Microgrid, following a disturbance on the main grid, can be improved using load response. A test network model...
The increased integration of distributed energy sources into microgrids presents a major challenge in voltage and frequency stability of the microgrids, especially in islanded conditions. Microgrid control is typically classified into a three-level hierarchical control involving primary, secondary, and tertiary control, where primary and secondary levels are related to the operation of a microgrid...
Frequency control of AC systems using Voltage Source Converter (VSC) HVDC links is of growing importance as interconnectors and links to offshore generation replace conventional synchronous generators in many countries. This paper investigates the use of local system feedback and advanced droop control to achieve frequency stabilization for a two-area test system.
The operation of diesel engine generator sets (gensets) with light loading leads to deterioration in the engine performance and efficiency. This problem is intensified in no-storage hydrokinetic-diesel systems since the genset is usually oversized to make-up for the potential shortage of renewable energy. In this paper, a new power sharing control strategy has been developed which minimizes this issue...
The recent amendment to the IEEE Standard for Interconnecting Distributed Resources with Electric Power Systems (IEEE Std. 1547a-2014) is unleashing the application of advanced inverter functionalities to help mitigate voltage regulation problems commonly encountered in areas with high levels of PV penetration. This paper describes the experimental testing of some of the important autonomous functionalities...
Virtual synchronous machine (VSM) can be used in micro-grids (MGs) for supporting virtual inertia to mitigate frequency fluctuations in the system. The performance of VSM depends on the performance of the current controlled voltage source inverter. Generally used proportional-integral (PI) controller has limited transient performance in current control. Adaptive dynamic programming (ADP) controller...
High penetration of Converter-Interfaced Generation (CIG) presents challenges because there exists no or very little mechanical coupling between CIGs and the power grid. During transients, the operational constraints of the inverters may be exceeded to the point of damaging the inverters or causing the shutdown of the inverters (LVRT logic). This paper proposes a Dynamic State Estimation (DSE) enabled...
Now-a-days Variable Frequency Drives (VFDs) became popular due to the advantage of energy saving. Earlier, DC motors were used in variable speed applications which require good dynamic response, even though they have problems related to commutation. With the advancement in power electronics, dynamic response is no more a problem with induction motor. This paper demonstrates three speed control methods...
This paper investigates transient performance of inverter-based microgrids in terms of the resistive power losses incurred in regulating frequency under persistent stochastic disturbances. We model the inverters as second-order oscillators and compare two algorithms for frequency regulation: the standard frequency droop controller and a distributed proportional-integral (PI) controller. The transient...
With the use of large amount of distributed generation(DG), the control strategy of inverter has become a hot area of research, which plays an important role in the microgrid stability. A control strategy combined droop control with PI control is proposed, in which the frequency and amplitude of output voltage is generate according to active and reactive power and the error between the output current...
The LC hybrid active power filter (LC-HAPF) is able to compensate reactive power and harmonics with operating voltage lower than the grid voltage. The quasi proportional-resonant (PR) controller could reduce the current tracking error by increasing the open loop gain at the selected frequency. Multiple PR controllers have been adopted for improving harmonic compensation in LCL filter coupled grid-connected...
The Distributed power supply has an increasing influence on the stability of the micro-grid. Virtual synchronous generator technology can improve the stability of power grid with large inertia of synchronous generator. This paper describes the principle of virtual synchronous generator technology, as well as a detailed description of the control strategy of power frequency control and excitation control...
MicroGrids (MGs) include spatially distributed generation (DG) systems and loads that may require operating autonomously in islanded mode. The operation of islanded MGs can benefit from consensus theory and practice, which are the foundations of distributed control. One of the main features of consensus strategies is that they rely on a cooperative scheme where inverters are required to communicate...
The photovoltaic (PV) grid-connected power generation has become an important direction of energy development. A grid-connected inverter is the key equipment in the PV grid-connected system. The efficiency and performance of the PV grid-connected inverter mainly depend on its topology and control technology. The PI controller has good dynamic and steady-state performance, which is widely used in the...
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