STUDY ON EFFECT OF UPFC DEVICE IN ELECTRICAL TRANSMISSION SYSTEM: POWER FLOW ASSESSMENT

Transcription

1 STUDY ON EFFECT OF DECE N ELECTRCAL TRANSMSSON SYSTEM: OWER FLOW ASSESSMENT 1 CH. CHENGAAH, 2 R..S. SATYANARAYANA & 3 G.. MARUTHESWAR Department of Electrical and Electronics Engineering, Sri enkateswara Uniersity College of Engineering, Sri enkateswara Uniersity, Tirupati517502, A., ndia. chinthapudi_ch@rediffmail.com Abstract The power transfer capability of electric transmission lines are usually limited by large signals ability. Economic factors such as the high cost of long lines and reenue from the deliery of additional power gies strong intensie to explore all economically and technically feasible means of raising the stability limit. On the other hand, the deelopment of effectie ways to use transmission systems at their maximum thermal capability. Fast progression in the field of power electronics has already started to influence the power industry. This is one direct out come of the concept of FACTS aspects, which has become feasible due to the improement realized in power electronic deices in principle the FACTS deices should proide fast control of actie and reactie power through a transmission line. The is a member of the FACTS family with ery attractie features. This deice can independently control many parameters. This deice offers an alternatie mean to mitigate transmission system oscillations. t is an important question is the selection of the input signals and the adopted control strategy for this deice in order to damp power oscillations in an effectie and robust manner. The parameters can be controlled in order to achiee the maximal desire effect in soling first swing stability problem. This problem appears for bulky power transmission systems with long transmission lines. n this paper a MATLAB Simulink Model is considered with deice to ealuate the performance of Electrical Transmission System of 22 k and 33k lines. n the simulation study, the facilitates the real time control and dynamic compensation of AC transmission system. The dynamic simulation is carried out in conjunction with the NR power flow solution sequence. The updated oltages at each NR iteratie step are interpreted as dynamic ariables. The releant ariables are input to the controllers. Key words: model, Flow Analysis (NR load flow method), MATLAB / SMULNK.. NTRODUCTON n competitie electricity markets the most important component is Transmission system/ network and it seres as the key mechanism for generators to compete in the supply to reach large users. With the restructuring in power supply industry and open access the importance of controllers for achieing Flexible AC Transmission systems (FACTS) is increasing. Comprehensie FACTS Controller referred to as the Unified Flow Controller (). t utilizes the synchronous oltage sources to proide comprehensie control of power flow in transmission systems [1]. nstalling the can improe power transfer capability. The is an adanced power system deice capable of proiding simultaneous control of nstantaneous speed of response oltage magnitude, actie and reactie power flows in an adaptie fashion. t has Extended functionality Capability to control oltage, line impedance and phase angle in the power system network Enhanced power transfer capability Ability to decrease generation cost Ability to improe security and stability Applicability for power flow control, loop flow control, load sharing among parallel corridors [2 3]. n this paper, the deelopment of a comprehensie method for steady state power flow analysis of a transmission system with Simulink Model to ealuate the performance of a single electrical transmission line system has been focused. This deice offers an alternatie mean to mitigate transmission system oscillations. t is an important question is the selection of the input signals and the adopted control strategy for this deice in order to damp power oscillations in an effectie and robust manner. The parameters can be controlled in order to achiee the maximal desire effect in soling first swing stability problem. This problem appears for bulky power transmission systems with long transmission lines. Dynamic simulation of the controllers will remoe the assumption that the specified control objecties hae been achieed in the steady state model. The new model for power flow analysis is based on the explicit dynamic simulation of both the shunt conerter and series conerter controllers. The dynamic simulation is carried out in conjunction with the NR power flow solution sequence. The updated oltages at each NR iteratie step are interpreted as dynamic ariables. The releant ariables are input to the controllers. The response of the controllers to the inputs, subject to the limits and priority specified in the controllers, are the oltage sources associated with shunt and series conerters. The oltage sources are input to power network at locations for the subsequent NR iteration. The constraint solution problem encountered in preious steady state nternational Journal of Electrical and Electronics Engineering (JEEE), SSN (RNT): ol1 ss4,

2 i Study on Effect of Deice n Electrical Transmission System: Flow Assessment model in which there are interactions among the equations representing the control objecties and inequality constraints representing the operating limits is aoided completely. The relatie priority in control is inherently taken in to account in the new formulation ia the direct simulation in a dynamical form of the controllers. The oerall simulation can be considered to be a hybrid one in which dynamic simulation based model of the is combined with the NR power flow method for power network. The applications of the simulation technique are those in power systems planning and design where s are proposed. This deice offers an alternatie means to mitigate power system oscillations. Thus an important question is the selection of the input signal and the adopted control strategy for these deices in order to damp power oscillations in an effectie and robust manner. This paper work shows that is an effectie deice to improe the power flow in transmission system by incorporating in transmission line. Since it is a solid state controller which can be used to control actie and reactie power flow in a transmission line. n the simulation study, the facilitates the real time control and dynamic compensation of AC transmission system [45]. t proides the necessary functional flexibility required for soling the problems faced by the utility industry. The could be considered as comprehensie real and reactie power compensation capable of independently controlling oltage profile as well as the real and reactie powers in the line.. METHODOLOGY performance assessment depends on data collection capabilities and performance metrics to ensure continued grid adequacy and security. The testing of single line transmission system without deice in MATLAB / SMULNK model has been discussed in the following sections. A. Simulink model of 22kTransmission line system of 22k Line is shown in Fig.1. The model is simulated and corresponding results of oltage magnitude, real and reactie power flows in the line are shown in Figs.2and 3 respectiely E,30 mh 22 K 30mH ct e mh oltage Measurement Actie & Reactie The concept of the control system, in a transmission line is taken to implement the use of. The two modes that is the power flow control mode and oltage injection mode is simulated in simulink model to see the effect of [678] on a transmission line. t is carried out to erify the utility of deice. The could be considered as comprehensie real and reactie power compensation capable of independently controlling oltage profile as well as the real and reactie powers in the line. The corresponding simulation models with and without are deeloped in MATLAB / SMULNK [9 10] enironment for the following cases.. TESTNG OF 22K AND 33K TRANSMSSON LNE SYSTEM WTHOUT DECE. Fig.1. Simulink Model of 22k Transmission Line. p q The basic function of the electric power system is to supply electrical energy to consumers as economical as possible with an acceptable leel of reliability. An efficient transmission system is expected to hae the optimum capability to proide the transfer of electrical energy between the point of supply and the point of deliery. Transmission line Fig.2. oltage magnitude of 33 k Transmission Line nternational Journal of Electrical and Electronics Engineering (JEEE), SSN (RNT): ol1 ss4,

3 i i Study on Effect of Deice n Electrical Transmission System: Flow Assessment Fig.6. Real and Reactie power flows of 33 k Line. Fig.3 Real and Reactie power flows of 22 k Line. By obsering the aboe wae forms, at steady state time t = 0.02sec the oltage magnitude is k, the real power is 93.69MW and the reactie power is 57.53MAr. B. Simulink model of 33k Transmission line system of 33k, Line is shown in Fig.4. The model is simulated and corresponding results of oltage magnitude, real and reactie power flows in line are shown in Figs.5 and 6 respectiely E,45mH 33 K 45 mh c t e mh oltage Measurement Actie & Reactie Fig.4. Simulink model of 33k Transmission Line p q By obsering the aboe wae forms, at steady state time t = 0.02sec the oltage magnitude is k, the real power is 1.40MW and the reactie power is MAr.. TESTNG OF 22K AND 33 K TRANSMSSON LNE SYSTEM WTH DECE. With the deelopment of power systems especially the opening of electric energy markets, it becomes more and more important to control the power flow along the transmission line, thus to meet the need of power transfer. On the other hand the fast deelopment of power electronic technology has made a promising part for future power system needs. This deice is an adance power system deice capable of proiding simultaneous control of oltage magnitude, actie and reactie power flows in an adaptie fashion [10]. The following section is discussing the testing of transmission line with deice with MATLAB / SMULNK model enironment [1112]. A. Simulink model of 22 k Transmission Line system of 22k Line is shown in Fig.7. The model is simulated and corresponding results of oltage magnitude, real and reactie power flows in line are shown in Fig s 8 and 9espectiely E,30mH 30mH ct1 1 2 LT e 22 K 1 2 LT 2 1 O1 2 O2 oltage Measurement 1 1 Actie & Reac tie mh Fig.5. oltage magnitude of 33 k Transmission Line. Fig.7. Simulink Model of 22k Transmission Line. 22 p q22 nternational Journal of Electrical and Electronics Engineering (JEEE), SSN (RNT): ol1 ss4,

4 Study on Effect of Deice n Electrical Transmission System: Flow Assessment Fig.8. oltage magnitude of 22 k Transmission Line. Fig.10. Simulink Model of 33 k Transmission Line. Fig.11 oltage magnitude of 33 k Transmission Line. Fig.12 Real and Reactie power flows of 33 k Line. Fig.9. Real and Reactie power flows of 22 k Line. By obsering the aboe wae forms, at steady state time t = 0.02sec the oltage magnitude is 21.23k, the real power is 98.15MW and the reactie power is MAr B. Simulink model of 33k Transmission Line The simulation model of Single line Transmission system of 33k, Line is shown in Fig 10. The model is simulated and corresponding results of oltage magnitude, real and reactie power flows in line are shown in Fig s 11 and 12 respectiely. By obsering the aboe wae forms, at steady state time t = 0.02sec the oltage magnitude is32.5 k, the real power is 1.77MW and the reactie power is 99.5 MAr respectiely. Here, comparing Fig.2 with that of Fig. 8, we can obsere that at the same steady state time the magnitude of peak oltage is improed from k to k and by comparing Fig.3 with that of Fig.9, we can obsere that at the same steady state time the magnitude of real power is improed from 93.69MW to 98.15MW and the reactie power is improed from 57.53MAr to 61.64MAr for 22k transmission line. nternational Journal of Electrical and Electronics Engineering (JEEE), SSN (RNT): ol1 ss4,

5 Study on Effect of Deice n Electrical Transmission System: Flow Assessment Similarly comparing Fig.5 with that of Fig. 11, we can obsere that with the same steady state time the magnitude of peak oltage is improed from 31.04k to 32.50kand by comparing Fig.6 with that of Fig12, we can obsere that with the same steady state time the magnitude of real power is improed from 1.77MW to 99.50MAr. The oltages, real power and the reactie powers with compensation hae been improed when compared to normal circuit. The scheme proides a way to transfer real power between sensitie loads in indiidual line through the common dc link this compensates by improing the real power from the dc link. Therefore when a fault occurs in the line, the in the line acts to compensate is by taking the real power from the common dc link. The initial drop is due to the sudden power change in line 22k, and initially this power is supplied by 33k line. t takes certain time to react to the power change. The real power needed by the 22k feeder to compensate the oltage collapse is exactly equal to the real power deliered by the 33k feeder. From the output waeforms, of all the oltage magnitudes and power flows are clearly obsered that the magnitude of the maximum real power of 22 k feeder is improed by controlling circuit by supplying the real power from 33k feeder ice ersa, which is practically possible, so the power flows and oltage profile has been improed. The summary of the results are tabulated in Table.1. Table.1 Summary of 6.6k and 22 k lines with and Without as shown in table 4.1 arameters oltage magnitude(k ) Real (MW) Reactie (MAr). CONCLUSONS 22k Line Witho ut With UF C k Line Witho ut With UF C n the simulation study, MATLAB/ SMULNK model is used to simulate the model of rectifier and inerter based connected with transmission lines i.e. 22k and 33k. This work gies control and performance of the used for power quality improement and to obtain the steady state time, objecties are achieable by control settings of the controllers. Simulation results show the effectieness of to control the real and reactie powers as well as oltage magnitude. t is found that there is an improement in the real power and reactie power and oltage magnitude through the transmission line when is introduced. The concept proides a powerful tool for the cost effectie utilization of indiidual transmission lines by facilitating the independent control of both the real and reactie power flow. There is an improement in both oltage and power profiles, through the transmission line when is incorporated in the system. FUTURE SCOE The model can be reduce the harmonics and ability to control real and reactie powers. The heating in the transformers is reducing by using multileel response. This is due to the reduction in the harmonics. So That the simulation results are inline with the predictions. REFERENCES 1. M.H Haque, C.M.Yam, A simple method of soling the controlled load flow problem of a power system in the presence of, electrical power system research 65(2003) pp Narain G.Hingorani Laszlo Gyugyi Understanding FACTS EEE ress, L.Gyugyi, Unified Flow Control concept for flexible AC transmission system, EEE proc 139(4) (July 1992) K.R adiyar, senior member and A M Kul karni, control design and simulation of Unified Flow Controller, EEE Trans. On Del., ol. 13, no. 4, October 1998, pp: MATLAB software / matlabcentral. 6. W.L Fang, H.W.Ngan : Control settings of through a robust load flow calculations EE roc. On Gen, Trans and Dist ol.146. No.4, July N.G Hingorani G. Gyugyi Lazlo Understanding FACTS: Concepts & technology of flexible AC Transmission Systems SBN ( ). 8. Z. Huang et al., Application of in interconnected power systems modeling, interface, control strategy and case study, EEE Trans. Syst., ol. 15, no. 2, pp , May Sen, K.K. and A.J.F. Keri, Comparison of field results and digital simulation results of oltagesourced conerterbased FACTS controller. EEE Trans. Del., 18(1): T.T.Nguyen and.l. Nguyen, Dynamic Model of Unified power Flow Controllers in load flow analysis, EEE /06, Sen, K.K. and A.J.F. Keri, Comparison of field results and digital simulation results of oltagesourced Conerterbased FACTS controller. EEE Trans. Del., 18(1): S. Muthukrishna and A. Nirmalkumar, Enhancement of power quality in 14 bus system using.research Journal of Applied sciences, Engineers and Technology 2(4). Maxwell scientific organization, 2010 nternational Journal of Electrical and Electronics Engineering (JEEE), SSN (RNT): ol1 ss4,