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PS7411-PROJECT WORK(PHASE-II)

PRESENTED BY UNDER THE GUIDENCE OF

I.MOSES (950313411009) Ms.M.G.POORNA KALA ME.,

ME-POWER SYSTEM ENGINEERING ASSISTANT PROFESSOR,

DEPARTMENT OF EEE.

IMPROVEMENT OF POWER QUALITY IN DISTRIBUTIOIN SIDE USING MULTI

CONVERTER UPQC (MC-UPQC)

19/06/2015POWER QUALITY IMPROVEMENT USING MC-UPQC

9043857452 [email protected]

POWER QUALITY IMPROVEMENT USING MC-UPQC

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OUT LINE

AbstractObjectiveIntroductionExisting systemProposed systemLiterature reviewProblem formationTest SystemSimulation ResultReference

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ABSTRACT

This thesis is to develop a model of multi converter UPQC for enhancement of power quality under various operating conditions.

Multi converter Unified power quality conditioner (MC-UPQC) is

a custom power device which mitigates voltage and current related PQ issues in the power distribution systems.

Unified Power Quality Conditioner (MC-UPQC) that consists of

shunt and series voltage source converters connected back to back and deals with load current and supply voltage imperfections.

This proposed topology also Having voltage source converter consist series and shunt feeders lines to applied adjacent feeders to compensate supply voltage and load current imperfection on other feeders. 19/06/2015


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OBJECTIVE

To Mitigate the major power quality problems at load side of power system.

To enhancement of power quality in high power distribution network.

To Compensation of voltage and current issues of multi bus or multi feeder system.

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INTRODUCTION

Electric equipment made with semiconductor devices appears to be as sensitive and polluting as ever.

Non-linear devices, such as power electronics converters, increase overall reactive power demanded by the equivalent load and inject harmonic currents into the distribution grid.

It is well known that the reactive power demand causes a drop in the feeder voltage and increases the losses.

The presence of harmonic currents can cause additional losses and voltage waveform distortions, and so cause poor power quality.

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CONT…

One modern solution that deals with both load current and supply voltage imperfections is the MC- Unified Power Quality Conditioner (MC-UPQC).

The idea can be theoretically extended to multibus/multifeeder systems by adding more series VSC.

Such a solution can compensate for different power quality phenomena, such as: sags, swells,voltage imbalance, flicker, harmonics and reactive currents.

This system in both feeders by sharing power compensation capabilities between two adjacent feeders

• MC-UPQC-link voltage requirement for the shunt and series active filters is not the same.

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EXISTING SYSTEM

The three phase three wire Single UPQC is used to modified UPQC topology to maintain voltage rating of dc-link capacitor largely influences the compensation performance of an active filter.

FACTS devices are only used only for Transmission system.

Cascaded multi converter based inverter used to design UPQC.

Shunt & Series Active power filter (DVR And DSTATCOM) Used to design MC-UPQC the VSC connected only One feeder bus in series with distribution network.

Nonlinear loads and unbalanced loads have degraded the power quality (PQ) in the power distribution network

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PROPOSED SYSTEM

This MC-UPQC designed controller is connected to a source in

order to compensate voltage and current in the two feeders.

multilevel converter (MC) for power quality improvement of a distribution.

In a multi-bus, three independent feeders distribution system, the load reactive power and current harmonics of one feeder are compensated using MC as shunt compensator.

In the other two feeders the voltage harmonics, voltage sag/swell and interruptions are compensated as series VSC compensators.

To overcome this PQ problems using the PWM generator in MC-UPQC unified power quality conditioner (UPQC) in load system

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BLOCK DIAGRAM

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Conti….

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LITERATURE REVIEW

S. V. R. Kumar and S. S. Nagaraju “Simulation of DSTATCOM and DVR in power systems,” ARPN J. Eng. Appl. Sci., vol. 2, no. 3, pp. 7–13, Jun. 2007.

Power quality has become an important issue in recent times when many utilities around the world find very difficult to meet energy demands which leads to load shedding and power quality problem.

The power-quality problems which these compensator address include voltage sags/swells, load voltage harmonic distortions, and unbalancing

Tap changing transformer is takes care of a limited range of voltage sag.

Needs routine maintenance of its parts Uneconomical size and requires frequent replacement of

transformer oil

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CONT…

S. Srikanthan and M. K. Mishra, “DC capacitor voltage equalization in neutral

clamped inverters for MC-UPQC application,” IEEE Trans. Ind. Electron., vol. 57, no. 8, pp. 2768–2775, Aug. 2010.

Multilevel neutral point clamped (NPC) inverter systems are increasingly used in load compensation applications.

Resulting in degradation of tracking performance of the voltage source inverter

However, the most significant problem associated with these compensators is the capacitor voltage imbalances and drift due to dc components.

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CONT….

• M. K. Mishra and K. Karthikeyan, “Design and analysis of voltage source converter for active compensators to compensate unbalanced and non-

linear loads,” in Proc. IPEC, 2007, pp. 649–654.

A proper design of the voltage source inverter used for the load compensation is very essential to achieve good steady state and dynamic performance.

The proposed method can be extended to design the voltage source inverter of configuration and non-linear loads.

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PROBLEM FORMATION

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Structure of MC-UPQC

•Two feeders connected to two different substations supply the loads L1 and L2. The MC-UPQC is connected to two buses BUS1 and BUS2 with voltages of and , respectively. The shunt part of the MC-UPQC is also connected to load .

•A transient can occur when a load is either connected or disconnected to from the MC-UPQC or a voltage sag/swell on the supply side occurs.

•The design of the series capacitor and the other VSC parameters have significant effect on the performance of the compensator


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CONT….Proble

mEffects

Over voltage

Overstress insulation

Under voltage

Excessive motor current

Unbalance

Motor heating

Neutral-ground voltage

Digital device malfunction

Sag Variable speed drive &computer trip-out

Swell Overstress insulation

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PROBLEM SOLUTION

•DESIGN OF VSC PARAMETERS

•Design of Series Active Filter VSC Parameters •Design of Vdcfor the Proposed VSC Topology


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Conti…

CIRCUIT DIAGRAM


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BLOCKS/PARAMETER INPUT RANGE

Parameter Feeder

Supply voltage 25e3

Load resistance 2e-3*(2*pi*60)/50

Load inductance 95.5

Snupper resistance 1e5

Filter resistance 0.4

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TEST SYSTEM USING BREAKER SWITCHES



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Design of VSI parameter Using cascaded 3level mulitilevel inverter using IGBT


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SUB SYSTEM OF AN VSC GATE PULSE SIGNAL


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MATLAB SIMULINK MODEL OF SINGLE UPQC INVERTER WITH LOAD


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MATLAB SIMULINK MODEL OF MC-UPQC


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BUS1 VOLTAGE ,COMPENSATING VOLTAGE AND LOAD VOLTAGE

VOLTAGE SOURCE CONVERTER OUTPUTS


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UNBALANCED HARMONICS VOLTAGE AT SINGLE FEEDER

SERIES VOLTAGE OF MC-UPQC

TOTAL HARMONIC RATIO

CONCLUSIONIn the thesis, the main objectives for the utilization of the studied

Equipment have been to reducing the distortion level occurring in the

Cases of harmonics generating loads in distribution networks and

Highly improving the power quality of the system.

This MC-UPQC proposed topology is capable of Fully protecting critical and sensitive loads against distortions.

Power transfer between two adjacent feeders for sag/swell and interruption compensation.


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FUTURE SCOPE The More advanced controllers such as fuzzy

controller, artificial neutral network, instantaneous power theory.

It can also be used with MC-UPQC to make the system more effective and Effectiveness.

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REFERENCE

M. Bollen, Understanding Power Quality Problems: Voltage Sags and Interruptions. New York: IEEE Press, 2008

B. Singh and J. Solanki, “Load compensation for diesel generator-based

isolated generation system employing DSTATCOM,” IEEE Trans. Ind.

Electron., vol. 47, no. 1, pp. 238–244, Jan./Feb. 2011.

R. Stala, “Application of balancing circuit for dc-link voltages balance in

a single-phase diode-clamped inverter with two three-level legs,” IEEE

Trans. Ind. Electron., vol. 58, no. 9, pp. 4185–4195, Sep. 2011.

Yash Pal, A. Swarup, and Bhim Singh, “A Review of Compensating Type Custom Power Devices for multi converter Power Quality Improvement” 2008 Joint International Conference on Power System Technology (POWERCON) and IEEE Power India Conference New Delhi.

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THANK YOU!!!!

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