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POWER SYSTEM 2018

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Speed control of solar water pumping with indirect vector control technique

Abstract:

This paper deals with a solar based indirect vector controlled induction motor drive(IMD) for water pumping system. The speed of IMD is estimated by taking stator current and rotor flux as a state variable. It consists of a solar photovoltaic (PV) array, boost converter, voltage source inverter (VSI) and a motor-pump assembly. In spite of atmospheric variation, maximum power point tracker (MPPT) based upon an incremental and conductance (I&C) algorithm tracks maximum power from solar PV array. The proposed system is designed and simulated in MATLAB/Simulink platform and speed control of IMD is demonstrated through simulated results.

MATLAB implementation of standalone hybrid wind-solar power generation with and without dump power control

Abstract:

In this paper unique approach for standalone hybrid model power generation system is been developed using MATLAB simulink. While implementing this technique advance power control technique which used a four power sources, solar, wind, diesel generator and storage battery is demonstrated which is generally not use in commercial power system. Serious efforts has been put while completing this project for active, reactive and dump power control. The illustrated results in MATLAB shows magnitude and phases of output voltages are regulated if proposed system in implemented. The major advantage of using this system is different generation sources can be easily interconnected. In India there is huge potential for the conventional power generation using wind and sun, if proposed system is incorporated interconnection will be very easy, it will definitely contribute to the global environment.

Modeling and simulation of interleaved boost converter with MPPT for fuel cell application

Abstract:

In recent years, fuel cell is the most promising renewable power sources because of its high stability, low energy consumed, very low emission and high efficiency. In addition to that, it can be utilized as various applications such a transportation, residential building and in electronics appliances. In order to extract the maximum efficiency from fuel cell a DC-DC converter is highly essential. However, among various types of boost converter interleaved boost converter (IBC) has low ripple current, reduce electromagnetic emission, high efficiency and more reliable. In this paper a comparative studies of input ripple current, output voltage and current by using fuel cell connected to IBC with and without maximum power point tracking (MPPT) in MATLAB/SIMULINK environment.

Phase Current Reconstruction for the Grid-Side Converter with Four-Switch Three-Phase Topology in a DFIG-WT

Abstract:

To increase the reliability of a doubly-fed induction generator-based wind turbine (DFIG-WT), this paper proposes a fault-tolerant four-switch three-phase (FSTP) grid-side converter (GSC) with phase current reconstruction strategy. The proposed strategy is effective when the semiconductor open-circuit fault and phase current sensor failure occur simultaneously, which is a kind of hybrid fault. Only one current sensor is applied for measuring the currents flowing between the AC and DC sides of the GSC, and the phase current information can be derived by combining this information with the switching states of FSTP GSC. In the proposed current reconstruction strategy, only two scenarios of duty ratio allocation are needed to be considered. In addition, the space vector pulse width modulation (SVPWM) technique is simplified by obtaining the unified expressions for the duty ratios for the remaining four switches in GSC, and sector identification is removed. Besides, voltage balancing on the DC bus is achieved. Furthermore, the limitation of the proposed current reconstruction strategy is presented, and the dead zones for SVPWM techniques in both a six-switch three-phase (SSTP) and FSTP converters are analyzed. Simulations are carried out in Matlab/Simulink to verify the proposed hybrid fault-tolerant strategy for the GSC in a 1.5MW DFIG-WT.

MPPT for wind power system with switched reluctance generator

Abstract:

Based on the principle of switched reluctance wind generator and its power output characteristics, a direct rotational speed disturbance maximum wind tracking method is proposed. Through the relationship between power and speed changes, the method uses a variable step size climbing search algorithm to adjust the maximum output power of switched reluctance wind generator. Comparing with the direct power disturbance maximum wind tracking method, the method which proposed avoid the instability which caused by the slow reducing of output power, and still have a high algorithm rapidity. A simulation model of wind power system is established. The results of simulation indicate that the proposed method can quickly achieve maximum wind power tracking with good static and dynamic characteristics under the condition of stable wind speed and variable wind speed.

Usage of smart inverter Q-V droop functionality for irradiance variation induced voltage fluctuation reduction considering system uncertainty

Abstract:

Frequent changes in primary voltage can be a significant power quality concern on distribution systems. The main cause of these voltage fluctuations is rapid changes in loads on a system. However, there are other phenomena apart from load variation which can also create voltage fluctuations. One of these is the variation in output level of distributed energy resources (DERs). Photovoltaic based DERs for instance, have an inherent uncertainty in their output level due to the naturally occurring intermittency of irradiance levels. This uncertain injection pattern can create a significant impact on the number of voltage fluctuation events experienced on a distribution feeder. A study of this phenomenon is of utmost importance to help distribution engineers understand the potential effects of solar irradiance ramp events which can cause voltage fluctuation and further to consider possible mitigation steps. In this paper, a high-resolution irradiance dataset is analyzed with a probabilistic approach to find the extremes of these uncertain events. In addition, voltage sensitive load modeling is used for higher accuracy. Moreover, the analysis is performed on each phase separately to capture the varied effects due to load imbalance. The analysis is then repeated using reduced primary voltage to observe the impact on the system when it is operated under a conservation by voltage reduction (CVR) scheme at peak demand. The entire analysis is performed in a quasi-static time series simulation platform using OpenDSS and MATLAB. Finally, smart inverter Q-V droop functionality is used to assess its effectiveness in reducing the number of voltage fluctuation events.

Hybrid power system with integration of wind, battery and solar PV system

Abstract:

This paper presents a renewable energy hybrid power system based on photovoltaic (PV) and wind, and equipped with Cuk DC-DC converter, three phase inverter and LC filter. The wind and PV energy are suitable for hybrid system because they are environmental friendly and widely available in India. However, the hybrid power system that solely depends on the intermittent renewable energy sources generates a fluctuating output voltage that leads to damage to the machines operating on a stable supply. The modeling of the hybrid system with Cuk converter, three phase inverter and LC filter are done using MATLAB Simulink. Blocks such as wind model, photovoltaic model, Cuk converter, inverter and LC filter are built separately before combining into a complete DC voltage hybrid system with main grid of power system. Different irradiance value and varying wind speed are the input parameters for the project simulation. The results show that hybrid system has better reliability in terms of output voltage generation as compared to standalone system. In addition, Cuk DC-DC converter, three phase universal bridge based inverter and LC filter that are installed in the hybrid system are able to reduce the fluctuation output voltage.

Hybrid wind solar system for efficient power generation

Abstract:

The most popular renewable energy technology is Hybrid Power System consisting of wind and solar energy sources because the system is reliable and complimentary in nature. Wind / PV Hybrid system is commonly used in Distributed generation (DG). This paper proposes a new solution for improved voltage stability with quality power output. In this system voltage out from wind energy conversion system(WECS) and Photo voltaic panels are given to separate DC DC converters, independently controlled and connected to a common DC bus and from there it is inverted. In the proposed controller the voltage stability is obtained by applying adaptive Honey Bee Optimization (HBO) algorithm along with a PI controller. The implementation of the proposed method is done by using Simulink platform. The performance of the suggested co ordinate control system is analyzed by comparing the computer simulation results with and with out using controllers and it shows that the proposed system is more efficient.

Solar-wind hybrid energy system using MPPT

Abstract:

Energy demand is ever increasing in the world, searching for fossil fuel is done on priority basis. These fuels are not sustainable, they pollute the environment. Shortage of fossil fuels resources and adverse environment affects made use of Renewable Energy Sources (RES) as Solar energy and Wind energy essential. Solar energy and Wind energy are natural resources which are not depleted by use and are more popular. Availability and ease to obtain electric power made Solar and Wind power as alternative energy sources. Solar energy and Wind energy combined to form Solar-Wind Hybrid Power System (SWHPS), which will enhance the qualities of each other and another. To reduce the power demand on the conventional power generation sector, the optimized utilization of these natural resources is essential to produce power. Various methodologies are in practice for generation of power using Solar-Wind Hybrid System with Maximum Power Point Tracking (MPPT). Constant voltage method is used for maximum power transfer. This method should have some key features to increase the stability and efficiency.

Stator current internal model control for MPPT of PMSG-based wind turbines

Abstract:

Wind energy conversion systems based on fully-rated power converters have had increasing application in the last couple years, mainly the based on permanent magnet synchronous generator with back-to-back converters one. For this scheme, the machine-side converter is responsible for accomplishing the maximum power point tracking, while the grid-side converter is responsible for controlling the active and the reactive powers delivered to the grid. Conventionally, the controllers for these converters are based on proportional-integral loops. However, the robustness of this kind of controller towards external disturbance and large parametric uncertainties has not been tested. In this work, this assessment is provided and it presents an alternative to the machine-side converter control. The proposed control is designed to meet the reference of machine stator currents and, aiming to obtain improved robustness, it is based on state feedback including an internal model of error. The proposed control performance is compared to the conventional control through simulations in Matlab/Simulink.

A novel grid integration scheme for the hybrid electric power generation using solar and wind energy resources

Abstract:

In this paper is reported a novel grid integration scheme for a hybrid electric power generation scheme using Photovoltaic power generation and induction generator based wind power generation. The proposed scheme adopts Fuzzy Logic Control (FLC) for the Maximum Power Point Tracking (MPPT) of the wind turbine driven induction generator and the incremental conductance based MPPT for the solar PV system. The power from the wind source and the photo voltaic source are brought to a common DC link and a DC to AC three phase inverter is used to upload power into the grid and a novel control scheme is adopted for sinusoidal current injection at the point of grid integration. The first novelty of the proposed system is that a variable frequency drive is used to run the induction generator at different synchronous speeds for power generation over a wide wind speed range. The additional novelty of the proposed scheme is that a direct Clark transformation and a set of two PI controllers are used to control the grid integration inverter enabling it to drive grid current with THD levels much less than the allowable limits.

A new topology for hybrid wind-solar generation system for isolated loads

Abstract:

This paper proposes a new topology for hybrid wind-solar generation system for isolated loads. The main focus is to reduce the size of battery for critical loads and supply non-critical loads directly from the stator side of DFIG. DFIG is controlled from rotor side with back to back connected PWM converters. Vector control scheme is being used in synchronously rotating reference frame for Rotor side converter (RSC) and Load side converter (LSC) does not require any special control scheme resulting in the lesser complex control circuitry. Reactive power demand for critical, non-critical loads and induction machine will be supplied from DC link capacitor. DC link voltage will be maintained as constant by DC-DC converter, connected to control battery charging and discharging. Since there are three possible options at DC link (wind, solar & battery backup), the size of battery will be lesser. The proposed scheme is modelled, simulated and analysed in MATLAB.

Improvement of maximum power point tracking for a new wind power system

Abstract:

Implementation of maximum power point tracking (MPPT) control is of great help to improve the efficiency of variable-speed wind turbine below the rated wind velocity. Theoretically, once the MPPT control is activated, the operating point will eventually reach the theoretical maximum point precisely. But the actual operating point cannot be controlled to reach the target value due to the losses of new system, which consists of planetary gear, generator and auxiliary motor. This study presents a way to roughly estimate iron loss in auxiliary motor, using bisection method to obtain iron loss without so many detailed parameters needed and compensate it in the torque MPPT control loop. Finally, the theoretical analysis method is verified by simulation and experiment results.

A study & analysis of fuzzy based P&O MPPT scheme in PMSG based wind turbine

Abstract:

With the advent of need of renewable energy resources, wind energy proves out to be a vital category of the resource. It is a bright and efficient non conventional source of energy. It can be used as constant and variable wind speeds operation. With continued development in this field advanced technologies and supervision examined, which helps the wind turbine to operate at its optimal position. Major researchers have focused on maximum power extraction from the generator using the different maximum power point tracking (MPPT) techniques. While in this article the objective is to present the comparison of classical Perturb & Observe algorithm (P&O) and fuzzy based Perturb & Observe algorithm and analysis of power oscillations and computational time. This paper based on a simulation study of the proposed standalone system which is done using SIMULATION in MATLAB.

Mitigation of grid voltage disturbances using quasi-Z-source based dynamic voltage restorer

Abstract:

Power quality has become a matter of great concern for all energy stakeholders, whether they are network operators, suppliers, producers, or end users. One of the main power quality issues affecting sensitive equipment and loads are short-time voltage variations (disturbances) called voltage sags and swells. This paper focuses on the compensation of voltage disturbances using a novel quasi-Z-Source (qZS) based dynamic voltage restorer (DVR) solution. The proposed DVR is controlled by using a multi-constraint model predictive control (MPC) approach, which regulates the injection of the required compensation voltage in series and synchronism with the grid during the voltage disturbances events. Moreover, as it is mandatory to ensure proper operation of the qZS inverter, the proposed MPC ensures the control of the qZS capacitor voltage at its reference value. Theoretical analysis and simulation results are given to show the high performance of the proposed solution.

Dual P-Q Theory based Energy Optimized Dynamic Voltage Restorer for Power Quality Improvement in Distribution System

Abstract:

This paper deals with the protection of critical loads from voltage related power quality issues using Dynamic Voltage Restorer (DVR). A generalized control algorithm based on Instantaneous Space Phasor (ISP) and dual P-Q theory has been proposed to generate the instantaneous reference voltages to compensate the load voltages with direct power flow control. The proposed algorithm adapts energy optimized series voltage compensation, which results in a reduction of energy storage requirement. The proposed DVR control scheme can support the load from voltage related power quality issues irrespective of the load current profile. Each leg of the three-phase three-leg split capacitor inverter is used to inject series compensation voltage in respective phases of the system. Model-based computer simulation studies and real-time experimental results validate the effectiveness of the proposed control algorithm.

Design of dual optimal UPFC based PI controller to damp low frequency oscillation in power system

Abstract:

In this work a new UPFC based dual PI controller is presented, whose gains are tuned by Improved GWO technique. The controller is used to damp low frequency oscillation in the power system. The disturbance considered is step rise in input mechanical power to generator. The ITAE criterion is selected for optimization problem. Standard popular techniques PSO & DE are also employed to tune dual PI controller parameters. In dual PI controller, simultaneously two actions of UPFC are performed, which are modulation index of series (mB) and phase angle of shunt (ôe) converter to damp power system oscillations. From system response and eigen values, it is observed that dual PI controller shows better result than conventional PI controller. Also IGWO technique provides much better result as compared to PSO & DE technique to design dual controller.

Research on an Improved Hybrid Unified Power Flow Controller

Abstract:

An improved hybrid unified power flow controller (IHUPFC) is developed in this paper to control power flow and increase utilization rate of the existing transmission lines. The IHUPFC is composed of an improved “Sen” transformer (IST) and a small capacity UPFC. After a detail introduction of the structure and voltage regulation performance of the IST, this paper derives the capacity relationship between the IST and the UPFC. Then this paper introduces the technology of IHUPFC in power flow regulation and transmission capability improvement. Besides, the advantages of the IHUPFC in performance and structure are analyzed. The IST has simpler structure and larger power flow control area than “Sen” transformer and the IHUPFC provides a continuous active and reactive power flow control. Simulation and experiment studies are used to verify the practicability and superiority of the IHUPFC.

Power quality improvement by using modular multilevel cascade converter based STATCOM

Abstract:

Quantity of the output power delivered from the utilities has become major concern of the modern industries for the last decade. The power quality associated problems are voltage sag, flicker, voltage imbalance, interruption and harmonics problems which results in the malfunctutioning of equipment’s in the industries by affecting the microprocessor based loads, sensitive electric components which are highly sensitive to voltage level fluctuation. The power consumed by the heavy load creates unsymmetrical currents which results in reduced power quality in the electrical grid. The stimulating functions of Flexible AC Transmission system (FACTS) estimate the critical clearing time, voltage regulation, steady state power flow and oscillation damping control. The main objective of this paper is the application of modular multilevel cascade (MMC) converter based Static synchronous Compensator (STATCOM) for reactive-power control and improved power quality. The complete simulation of this system is performed in the MATLAB software and the PI control is used for the controlling.

Research on STATCOM for reactive power flow control and voltage stability in microgrid

Abstract:

Static Synchronous Compensator (STATCOM) is a kind of parallel reactive power compensation equipment in FACTS system. To study the reactive power regulation of STATCOM in microgrid, the relationship between reactive power flow and voltage in microgrid is analyzed theoretically in this paper. The direct current control is used to control the reactive power exchange between the microgrid and distribution network based on a given reference voltage. Then the simulation research on reactive power flow control of a microgrid system connected STATCOM is carried out. The simulation results show that the voltage at PCC point will be unstable under the two conditions. STATCOM can effectively maintain the voltage balance of PCC point in the microgrid access to the grid and meet the requirements of flexible regulation and stable operation of microgrid.

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