View of MITIGATION OF VOLTAGE SAG AND SWELL IN DISTRIBUTION SYSTEM USING D-STATCOM

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MITIGATION OF VOLTAGE SAG AND SWELL IN DISTRIBUTION SYSTEM USING D-STATCOM

1MANISH PRAJAPATI , ²ANURAG TAMRAKAR

12Dept. of Electrical & Electronics Engg., SVN University Sagar (M.P.) [email protected]

Abstract - This paper exhibits the upgrade of voltage droops, symphonious bending and low power component utilizing Distribution Static Compensator (D- STATCOM) with LCL Passive Filter in dissemination framework. The model depends on the Voltage Source Converter (VSC) guideline. The D-STATCOM infuses a current into the framework to alleviate the voltage sags.LCL Passive Filter was then added to D-STATCOM to enhance consonant twisting and low power component. the execution of voltage-source converter-based shunt and arrangement compensators utilized for burden voltage control as a part of electrical force conveyance frameworks has been broke down and looked at, when a nonlinear burden is associated over the heap transport. A dispersion static compensator (DSTATCOM) as a shunt gadget.

Keyword D-STATCOM, Voltage Sags, Voltage Source Converter (VSC), LCL Passive Filter, Total harmonics Distortion (THD).

I. INTRODUCTION

The voltage related force quality (PQ) issues, for example, droops and swells, voltage plunges, symphonious twists because of nonlinear burdens and voltage unbalancing in electrical force conveyance frameworks, have been a noteworthy sympathy toward the voltage-delicate burdens [1]. Load voltage control utilizing VSC for various lattice associated applications has been as of late endeavored in [2]–[4]. With the expanded utilization of force gadgets in the customer items, the heaps are getting to be voltage delicate and nonlinear in nature. Contingent on the applications, these heaps are associated with the dissemination framework having differing voltage and force e. Likewise the spiral feeders of the conveyance framework to which these heaps are associated have differing length and short out current (SCC) levels. This relies on the area of the heap, conveyance framework size, and its voltage and volt-ampere (VA) evaluations. This prompts the wide varieties in the Thevenin‟s equal feeder impedance looking from the heap side. In the event that the heap is associated toward the end of the long feeder and has little short out current worth, it is known as a powerless air conditioning supply framework (or non-solid source) [5]. These feeders have huge line impedance relying on their length and short out current worth [6]. Thus, if the heap is associated near the feeder, it is alluded to as solid air conditioning supply framework (or hardened source). The line impedance of these feeders is little or irrelevant. An expanding interest for high caliber, solid electrical power and expanding number of bending burdens may prompts an expanded familiarity with force quality both by clients and utilities. The most well-known force quality issues

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in r.m.s voltage size happens [4]. It is frequently set just by two parameters, profundity/greatness and term. The voltage droops greatness is extended from 10% to 90% of ostensible voltage and with term from a large portion of a cycle to 1 min. Voltage hangs is brought about by a deficiency in the utility framework, a flaw inside the clients office or an expansive increment of the heap present, such as beginning an engine or transformer invigorating [2,3].Voltage lists are a standout amongst the most happening force quality issues. For an industry voltage droops happen all the more frequently and cause serious issues and temperate misfortunes. Utilities regularly concentrate on unsettling influences from end-client hardware as the primary force quality issues [5]. Consonant streams in circulation framework can bring about symphonious contortion, low power component and extra misfortunes and additionally warming in the electrical hardware. It additionally can bring about vibration and commotion in machines and breakdown of the delicate hardware.

The improvement of force hardware gadgets, for example, Flexible AC Transmission System(FACTS) and traditions power gadgets have presented and developing branch of innovation furnishing the force framework with adaptable new control abilities [1].There are diverse approaches to upgrade power quality issues in transmission and conveyance frameworks. Among these, the D- STATCOM is a standout amongst the best gadgets. Another PWM-based control plan has been actualized to control the electronic valves in the DSTATCOM. The D-STATCOM has extra ability to maintain responsive current at low voltage, and can be produced as a voltage and recurrence support by supplanting capacitors with batteries as vitality stockpiling. In this paper, the arrangement and outline of the DSTATCOM with LCL Passive Filter are broke down. It is associated in shunt or parallel to the 11 kV test dispersion framework. It likewise is configuration to upgrade the force quality, for example, voltage lists, symphonious mutilation and low power component in dispersion framework.

II. DISTRIBUTION STATIC COMPENSATOR (D-STATCOM)

A D-STATCOM consists of a two-level VSC, a dc energy storage device, controller and a coupling transformer connected in shunt to the distribution network.

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Figure1. Schematic diagram of a D-STATCOM A. Voltage Source Converter (VSC)

A voltage-source converter is a force electronic gadget that associated in shunt or parallel to the framework. It can produce a sinusoidal voltage with any required size, recurrence and stage point. The VSC used to either totally supplant the voltage or to infuse the „missing voltage‟. The „missing voltage‟ is the distinction between the ostensible voltage and the real. It likewise changes over the DC voltage crosswise over capacity gadgets into an arrangement of three stage AC yield voltages [8, 9]. Moreover, D-STATCOM is additionally skilled to create or retains responsive force. On the off chance that the yield voltage of the VSC is more prominent than AC transport terminal voltages, D-STATCOM is said to be in capacitive mode. Along these lines, it will remunerate the receptive force through AC framework and controls missing voltages. These voltages are in stage and combined with the AC framework through the reactance of coupling transformers.

Reasonable conformity of the stage and size of the DSTATCOM yield voltages permits effectives control of dynamic and responsive force trades between D- STATCOM and AC system.[9]B. Controller

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Figure 2 shows the block diagram of Controller system.

The controller framework is mostly a portion of circulation framework.

Figure2.Block Diagram of Controller System Proportional-fundamental controller (PI Controller) is a criticism controller which drives the framework to be controlled with a weighted whole of the mistake signal (distinction between the yield and wanted set point) and the vital of that quality. For this situation, PI controller will handle the blunder sign to zero. The heap r.m.s voltage is taken back to the reference voltage by contrasting the reference voltage and the r.m.s voltages that had been measured at the heap point. It additionally is utilized to control the stream of receptive force from the DC capacitor stockpiling circuit. PWM generator is the gadget that creates the Sinusoidal PWM waveform or sign. To work PWM generator, the edge is summed with the stage point of the parity supply voltages similarly at 120 degrees. Along these lines, it can create the craved synchronizing signal that required. PWM generator additionally got the mistake signal point from PI controller. The regulated sign is looked at against a triangle signal keeping in mind the end goal to create the exchanging signals for VSC valves.

III. METHODOLOGY

To enhance the performance of distribution system, DSTATCOM was connected to the distribution system. DSTATCOM was designed using MATLAB simulink.

Figure6 below shows the flowchart for the methodology:

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Fig 1 Flow Chart (Methodology)

IV. RESULTS AND CONCLUSION

To create distortion in the distribution system, different types of fault such as Three Phase to Ground (TPG), Double Line to Ground (DLG), Line to Line (LL), and

Single Line to Ground (SLG) are injected.

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Figure 2 .Input Line Voltage.

Figure 3.Line Voltage RMSE Response.

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Figure 4 : D-STATCOM current Response without Hormonics.

V. CONCLUSION

The reproduction results demonstrate that the voltage hangs can be relieve by embeddings D-STATCOM to the dispersion framework. By adding LCL Passive channel to D-STATCOM, the THD decreased inside the IEEE STD 519-1992. The force considers additionally build near solidarity. Hence, it can be inferred that by including D-STATCOM with LCL channel the force quality is progressed.

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