C.Madhu sudhakar : 122B5A0204

B.Yedukondalu : 122B5A0203

V.Vinod Kumar yadav : 122B5A0208

k.Deepika : 112B1A0204

Under the guidance of

Mr.J.Srinu naik , M.tech.

Head of the EEE Department.

Presented by

Project first review01/04/2015

Abstract

This project addresses the automatic generation control of deregulated multi area power system including one of the most important renewable energy resource viz. wind power plant.

Generation rate constraint (GRC) is considered in all the GENCOs separately.

By using Integral square error technique it can be optimize the gains of various integral controllers.

Effect of changing DPM on dynamic responses is studied, following a step load perturbation.

Project Objectives

The main objectives of this project are:

To study the effect of changing DPM on the dynamic responses of the system.

To study the effect of GRC on system’s dynamic responses.

INTRODUCTION

Automatic generation control (AGC) or load frequency controlinvolves the problems of transient load perturbations that make thefrequency and tie line power to deviate from their nominal values.

These perturbations effect to the mismatch in generation of powersystem and overall load demand.

But these are the most important parameters of power system thatare needed to be controlled to their nominal values even after thedisturbances

Hear AGC can used to control secondary side.

WHAT DOES AGC MEAN?

Process that controls the limits of the frequency and voltage variations.

The mismatching between the generation and load demand, If the frequency is swinging.

Purpose of AGC

To maintain power balance in the system.

Make sure that system frequency is constant (not change by load).

To maintain each unit's generation at the most economic value.

Wind power plant

Conventional power plants like thermal, hydro, nuclear etc.pose a threat to the environment and lead to the globalwarming due to harmful gas emissions.

So, it is of great importance to include cleaner sources ofpower into the power system like solar power, wind poweretc.

Solar power plant have low energy conversion efficiency andare more expensive than wind power plants.

In wind power plant, Wind speed varies with time

The output power of wind generators depends on the wind speed at that time.

The output power of wind turbine Pw is calculated as:

Pw = 0, Vs < Vi and Vs > Vo

Pw = Pwr*[(Vs-Vi) / (Vr-Vi)], Vs ≥ Vi and Vs ≤ Vr

Pw = Pwr, Vs ≥ Vr and Vs ≤ Vo

Where,

Vi = cut-in wind speed

Vr = rated wind speed

Vo = cut-out wind speed

Pwr = rated power output of wind turbine

Their values are taken as 5, 15, 45 m/s respectively.

DISCO Participation Matrix (DPM)

In an open market scenario a DISCO is free to purchasepower from any GENCO either in its own area or in otherarea according to its convenience.

A contract between a GENCO and DISCO for purchase ofpower is known as “bilateral transaction” and should beapproved by independent system operator. As there aremultiple GENCOs and DISCOs in every area severalcombinations of GENCO-DISCO contracts are possible.

A DISCO participation matrix which is popularly known asDPM is used for representing a set of GENCO-DISCOcontracts in the power system for the ease of visualization.

Number of rows and number of column in a DPM is same asthat of number of GENCOs and number of DISCOs in thesystem.

Contract Participation Factor (CPF)

Each element of DPM matrix is known as contractparticipation factor (CPF) that represents the fraction of totalload demand of a DISCO committed by a GENCO.

For example nth column element of mth row of a DPM i.e.cpfmn denotes the fraction of total load demand of nth DISCOsupplied by mth GENCO. Hence, sum of each column ofDPM matrix should be unity.

DPM of a power system with P number of GENCO and Qnumber of DISCO can be given as

EFFECT OF DPM

In deregulated environment, DPM is chosen on the basis ofopen market strategy .

So it becomes important to see the effect of changing DPMon the dynamic responses of the system involving windpower plant. Also, controllers are to be optimized fordifferent DPMs, using ISE technique.

Table I shows the optimized values of integral controller gainsand electric governor parameters for the following two DPMs

DPM Matrices of two areas

The capability of smart grid power generation or ISOoperations w.r.t economical , cost and load flowanalysis are known as generation rate constraint.

This constraint includes:

Active power

Reactive power

Voltage

Frequency

Generation Rate Constraint

It is more realistic to add the physical constraints in thepower system, One such constraint is GRC.

Shows the comparison of dynamic responses with andwithout GRC for deregulated wind integrated powersystems.

It is clearly seen that the responses become poorer in termsof overshoots and undershoots and settling time. But it is themore practical way to include GRC into the power system.

Effect of GRC

Simulation diagram

Dynamic responses comparison for sets of DPMs

Dynamic responses comparison in terms of GRC

CONCLUSION

Frequency is one of the most important parameter todetermine the stability of a system.

To improve the overall dynamic performance in thepresence of the plant parameters changes and systemnon linearities, the conventional integral controllerbased AGC problem has been formulated.

Wind power plant is included in the system for takingcare of continously increasing load demands and in theview of depleting conventional energy resources.

Transient responses hardly vary and becomes poorerfor varying DPM and GRC in terms of peak deviations(overshoots and undershoots) and settling time.

Any Queries