A Single Phase Smart Grid Zero Steady State Error Connected

It is observed that the power factor is maintained closer to unity when the input voltage is reduced from 230V to 110Vrms. Figure 11 (a) and (b) shows the power factor correction of controller for various load condition such as 20% (60W) and 75% (230W). The power factor for the system is found to be 0.84 for light load condition and 0.99 for full load condition. The THD of input current at full load with predominant third and fifth harmonic components are shown in Figure 12(a) and (b).Third harmonics is found to be 4.8% and fifth harmonic component is 4.9% which are well within IEC 61000-3-2 standard during wide range of load variations. The variation in power factor with load is shown graphically in Figure 13(a). It can be inferred from the graph that improved resettable control operates at high power factor for all load condition whereas the conventional PI control has poor power factor under light load conditions. Figure 13(b) shows the comparison between the efficiency of the converter for varying load conditions with the conventional control method and the resettable integrator control. The converter’s efficiency is maintained at 92% for light load conditions and 96% for fully loaded condition with integrator control technique. Thus the improved resettable integrator controller provides a very simple and reliable solution for power factor correction and

The parameters of this controller (PI- 1) can be decreased during the voltage sag in order to improve the performance of the proposed method.

The DVR is one of the most common and effective solutions for protecting critical load against voltage sags [10] [11]. The DVR is a power electronic device used to inject three-phase voltages in series and in synchronism with the distribution feeder voltages in order to compensate for voltage sags. Moreover, it can be efficiently used to augment the fault ride through capability in wind applications. Detection time is an important factor in the voltage restitution process. Fast detection

It is of great importance in our industries to cut the cost of power controlling with high efficiency and PWM satisfies this criteria. Therefore, it is

HVDC transmission may also be selected for other technical benefits. HVDC can transfer power between separate AC networks. HVDC powerflow between separate AC systems can be automatically controlled to support either network during transient conditions, but without the risk that a major power system collapse in one network will lead to a collapse in the second. HVDC improves on system controllability, with at least one HVDC link embedded in an AC grid—in the deregulated environment, the controllability feature is particularly useful where control of energy trading is needed.

Firstly the hybrid HVDC transmission system configuration is given. Next MMC description is given and then the control strategies for the rectifier and inverter is presented. Finally the performance of system under steady state and transient conditions is discussed with the help of MATLAB results.

Abstract: Nowadays an Inverter is most commonly used device in almost every field. An inverter gives ac square wave output. The objective of this paper is to obtain a three-phase ac voltage output of 3-phase inverter in Simulation. An inverter receives dc supply as input and generates an ac output. The dc input of 3-phase inverter is obtained by constant dc source. The inverter circuit consists of six IGBTs which are used for conversion of dc to ac supply. Simulation of 3-phase inverter is done in MATLAB software.

What was once a novelty; energy is now the ultimate necessity for any modern country. A sustain power grid is what separates a solvent nation from a third world country. The scenario of one of the three power grids failing would cause chaos to that area but would be sustainable with the capabilities of the remaining grid systems (ESSP 2015). A major sustain loss of power grid across the United States would interrupt commerce of the food chain via manufacturing and delivery of product, water systems, federal, state and local line of communications which would paralyze law enforcement, civil unrest would spread across the nation.

In the grid new renewable resources are added to extract more power. This adds more power quality issues to grid connection. A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or a mis-operation of end user equipment. This paper investigates the use of a static synchronous compensator (STATCOM) is connected at a point of common coupling with Battery Energy Storage System(BESS)to overcome of a power quality issues of a wind farm equipped with variable speed wind turbines driving Double – Fed Induction Generators (DFIG). A physical control scheme, including four control loops: ac voltage, dc voltage, ac active current and ac reactive current controllers, is pre-specified for the STATCOM. A synthetic algorithm is proposed to embed these physical control loops in the output feedback path. The simulation results demonstrated that under various system disturbances, the proposed mode decoupling STATCOM is effective in regulating IG terminal voltage.

Abstract—This paper covers the need and use of power electronics in the application of renewable energy utilization. Covered in this paper is wind energy with variable speed drives and their controlling power electronics. Solar energy, specifically photovoltaics and their controlling power electronics. High-voltage direct current transmission lines and the power electronics that allow for this technology to exist.

Power electronic converters, especially DC/AC inverters have been extending their range of use in industrial application because they provide better system efficiency, reduced energy consumption and improved quality of power. The output voltage of inverter could be fixed or variable at a fixed or variable frequency and output waveforms are therefore made up of discrete values, producing fast transition rather than smooth ones [2]. The ability to

Balancing load of distribution feeders is significant for falling of power loss and mitigating power flow. As the loop power controller is implanting for the active power and reactive power flows by change in voltage ratio and phase shift. So that the balancing of the load distribution feeders can be achieved. However it can include photovoltaic power producing in feeder balancing load, as a Taipower distribution feeder consisting of two feeders with large amount of photovoltaic equipment considered. The balancing load can be determine in distribution feeders with photovoltaic set up by using the loop power controllers as the changing of solar energy and power loading of feeders. With implanting the control algorithm in MATLAB for loop power controller by changing the voltage ratio and phase shift connecting to the feeder the proper amount of active power and

A few recent papers [53]-[56] have demonstrated a virtual synchronous machine (VSM) concept, particularly for microgrid applications and usually for distributed generators utilizing the same ac-dc-ac conversion stages. The same concept applied on flywheel based energy storage is discussed in [57]. Given the similarities existed in the MEA power grid and motor controlled thermal storage, it is deemed feasible to implement the VSM concept in this research. A high-level description is shown in Fig. 3. For a synchronous machine in the rotating reference frame, the d-q voltage and current relationship is shown in (1a-b), where vg is the grid voltage, R is the stator resistance, M is the magnetizing, and Ld = Lq = L is assumed. On the other hand, the active front end (i.e., the hex-bridge converter connected to the gird) follows (2a-b) in d-q reference frame at ωc rotating speed, where Rg and Lg are grid tied resistance and inductance, and vc is the output voltage at the converter controlled by modulation index from the dc voltage bus []. The analogy between (1a-b) and (2a-b) is straightforward. By equating the first three terms and varying the modulation indices, md and mq, the active front end mimics the VSM proposed in [ZhongQC]. The purpose of the ac motor-tied inverter (i.e., the left hex-bridge converter in Fig. 3) is to main a constant 270 V dc bus by adjusting the motor speed and torque using conventional vector controls. Given the limited

This chapter explores the hardware setup of DFIG system. It also shows experimental results and the performance of this system under different types of controllers. The experimental work is divided into three parts. The first part is emulating the wind turbine characteristic using PMSM. The second part is implementing the GSC connected to the grid and maintaining its DC-link voltage constant under different disturbances. The final part is controlling the DFIG to extract power from the wind emulator and transfer it to the utility grid.

Abstract--Multilevel inverter finds its application in high voltage high power converters. Various topologies of multilevel inverter provides several advantages such as high efficiency, low voltage stress, low EMI, better waveform and improved THD. This paper presents the development of Xilinx FPGA as a control circuit for generation of the pulse width modulation (PWM) signal for the single-phase cascaded H-bridge multilevel inverter and modified H-bridge PWM multilevel inverter. The XILINX FPGA based modified multilevel PWM inverter was implemented by adding bi-directional switches to the conventional bridge topology. Xilinx System Generator/MATLAB software has been used for simulation and verification of the proposed circuit before implementation.