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This paper presents work related to management of active and reactive power exchange between a distributed generation (DG) source and the grid to which it is connected; for improved utilization of electricity generated by the DG source such as solar energy. This is based on the recently introduced Availability Based Tariff (ABT) concept for the consumer loads, where conventional power grid is available...
Fuel-cell, PV, wind power etc. alternative energy sources are gaining popularity now-a-days because they are reusable energy sources. To feed the alternating power to utility, a grid-tied inverter is necessary as an interfacing equipment. There are many strategies to control the grid tied inverters. In this paper, to control the output current of the grid tied inverters, unified constant-frequency...
Recent developments to address the stability of small power systems, such as AC & DC microgrids include the use of advanced techniques that apply to Markov Jump Linear Systems (MJLSs). The system is considered to oscillate between discrete, finite operating modes, and can be represented as a Stochastic Hybrid System (SHS). Analytical solutions in terms of the moments of the power system dynamic...
This paper provides detailed and complete models of the large-scale transmission-connected PV plants which have considered the dynamics of maximum power point tracking (MPPT). These models are based on the WECC's generic PV system models whose circuit and control modes are modified to build our new PV models. In terms of the circuit, the detailed inner-loop current control model is adopted for the...
This paper presents a single-stage three-level Neutral Point Clamped (NPC) inverter for connection to the electrical power grid, with integrated Maximum Power Point Tracking (MPPT) algorithm to extract the maximum power available from solar photovoltaic (PV) panels. This single-stage topology is more compact than the traditional topology, it was chosen because with the proper control strategy. It...
This paper presents a hybrid Phased Locked Loop (PLL) algorithm for 500kW–1MW grid-connected Centralized inverters for large Photovoltaic (PV) power plants. Proposed Hybrid PLL with ZCD enables faster synchronization during inverter start-up and can be used in high power master-slave based centralized inverters which are being used in large PV power plant. Three phase PLL structures such as Synchronous...
The paper deals with the modeling of a current controlled (CC) Distributed Generator (DG), connected to the distributed system and investigates the performance of over current relay installed in distribution line. In the grid connected mode, DG operates in constant current mode and supplies the current which is in phase with the grid current. During the occurrence of Single Line to Ground Fault (SLG...
In this paper, the control of single-phase current source inverter-based grid tie photovoltaic (PV) system is addressed. An intermediate DC/DC buck converter interfaces the PV source and the DC-AC inverter. A complete control structure for the single-phase PV system is presented. In source side, a Perturb and Observe algorithm is used to match the maximum power available in the PV panels. In grid...
A fast power flow control algorithm for a grid tie Photovoltaic inverter is presented here. The proposed method has the merits of design simplicity. The algorithm is fast and has the virtue of quick response to the change of required power output for the PV inverter. Current mode asynchronous sigma delta modulation is implemented to ease the controlled sensitivity to the grid current distortion. This...
In this paper a structure for high-speed incrementing/decrementing accumulator is proposed based on even and odd unit cells. Step of accumulation can be chosen among ±2n levels where n = 0, 1, 2, 3, … through a control digital word. A 10-bit accumulator is divided into two 5-bit accumulators where each one is realized in carry-ripple adder/subtractor structure. Basic cells are highly improved in number...
In recent years, there has been a rapid increase in the number of photovoltaic (PV) three phase inverter systems being to grid connected. Keeping the highly quality waveform and low harmonic distortion of the current waveform during abnormal condition is one of the most challenging. To achieve this target, a current control technique is carefully considered. This paper present a simple method to compensate...
In this paper, a single-phase self-synchronized inverter with current limiting capability without a dedicated synchronization unit is presented. It offers an approach for power systems to control distributed renewable energy sources. The proposed system has the capability to synchronize itself with the utility grid before connection and track the grid frequency after connection without a phase-locked...
a low-power all-digital PLL (ADPLL) is proposed for the 2.4G wireless communication applications. A new scheme is proposed for noise reduction of the quantization noise that is caused by the metastability between reference clock and the DCO output clock (CKV). The ADPLL is designed and fabricated in 0.65µm CMOS process, the whole digital block area is 0.065 mm2(include TDC).
This paper proposes a control scheme for a 3- level NPC inverter used in a grid connected PV system. The proposed scheme is useful in such way that the active and reactive power can be controlled separately. Such a scheme is applied in the rotating reference frame. The transformation of three-phase quantities (voltage and current) in to rotating reference frame is done by using Clarke and Park transformations...
Synchronization is an important issue in the control of grid connected inverters and most of the algorithms use the phase measurement of the component of the voltage of the grid with the classical corrector PI. In this article, we use a new synchronization of the phase-locked loop (PLL) with a PI controller commissioned by the fuzzy logic. The gains of the PI controller are changed using the algorithm...
In this paper, a fast-synchronization between grid and inverter based on virtual synchronous converter (VSCon) technique is achieved in single-phase inverter. Consequently, this technique is designed and simulated in Matlab/Simulink platform to perceive the significances during variation of grid load parameters. The VSCon is implemented for inverter output control that has a behavior of grid voltage...
The operation of grid side converters (GSC) is significant in its robust control design. Phase locked loop (PLL) algorithm is introduced to acquire synchronization and perfect operation of GSC. The control design depends on rapid and exact tracking of phase angle of grid voltage. The task of PLL is crucial condition, since grid connected system is to operate the power system under grid fault conditions...
This paper proposes single-phase power conditioning system which is capable of connecting a microgrid to an utility grid seamlessly through slew-rate control. The power conditioning system is composed of a single-phase phase-locked loop using an inverse Park transformation to detect the grid phase, a phase synchronizer using the slew-rate control, and isolated bidirectional inverter which transfers...
In this paper we propose the structure and the functioning of a photovoltaic (PV) connected to the electric distribution and transmission network, equipped with the malfunction detection blocks. The studies that were carried focused on the injection of a power of 16 KW, produced by a PV panel field, on the electrical network of medium voltage (25 KV). In order to the reliability of the injection system...
Now a day's, renewable energy sources become a substitute source of energy to reduce environment pollution and meet future energy demand. But integration of renewable energy sources to utility grid is a critical process as far as stability and power quality of the system is concerned. For proper synchronization current controlled Pulse width modulated voltage source inverter are generally used. The...
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