Yaser_qudaih4

Implementation of Fuzzy Logic Controller on ECS Applications to Reduce CO2 Emission Yaser Qudaih*, Graduate School of Science and Technology, Kumamoto University Takashi Hiyama, Graduate School of Science and Technology, Kumamoto University Abstract- Conventional controllers such as PID, shows flexible ways to deal with electrical equipments; however, intelligent controllers show more powerful techniques to deal with such systems. In this paper a combination of PI and Fuzzy Logic Controllers have been implemented in order to make the Energy Capacitor System (ECS) working efficiently in power distribution system where uncontrollable renewable energy sources have been used. Results show quite big improvement in the real power that supply to the system from a bigger infinite-bus system. Carbon Dioxide (CO2) reduction as a target behind building such systems has been considered and discussed in such a way to use the largest amount of energy produced by the renewable energy sources without affecting the system performance negatively which results in CO2 emission to be reduced.

on such system, in addition to simplicity of simulations. Therefore a ring three-phase instantaneous model has been implemented using Matlab/Simulink environment. The single line diagram is shown in Fig.1.

Index Terms- CO2 Minimization, ECS, Fuzzy logic controller, Power distribution system.

I. INTRODUCTION

S

INCE the studies started to take into account the minimization of CO2 in the atmosphere, the renewable energy sources were incrementally implemented and rapidly occupying an important and huge place in power systems, namely, distributed generations (DG) can be found in most of the recently built and developed distribution systems. The performance of those systems is affected by the penetration of the DG. Reliability, performance and also stability of the system are the main topics following the new technology implementations, thus the Energy Capacitor Systems as a new technology of saving energy is participating and involving in solving such matters [1]. Conventional and intelligent controllers present where the ECS present, which is supposed to be relatively small in size for economical reasons. Such matters have been discussed in this paper in order to achieve the target of CO2 reduction using the ECS technology to keep the distribution system performed well in the presence of wind energy and photovoltaic energy systems. Finding the suitable measures to evaluate the minimization of CO2 emission in atmosphere is a continuous job to be started from this research paper, where an example of increasing power generated from wind has been illustrated. According to [2], the amount of CO2 emitted is the product of the amount of fossil fuel consumed and the amount of CO2 emitted per unit quantity of that fuel.

Fig. 1. Single line diagram shows the connection the DG units to the system

A. DG penetration Diesel generator, wind turbine, and photovoltaic systems are connected to represent the effect of DG penetration. Three-phase current injection method is used to connect the DG to the distribution network. B. ECS Energy Capacitor System (ECS) consists of capacitors and power electronics. It is used as an energy storage system. The capacitor part of the ECS is a group of electric double layer capacitors of increased energy density. Similar to PV and other elements, the AC side of the three-phase instantaneous model is considered in this paper. Charging and discharging operation of the ECS is utilized for Load Following Operation control and for Automatic Generation Control as well. Fig. 2 shows the charging and discharging operation.

II. SYSTEM DESCRIPTION Medium tension Power Distribution System with a threephase representation was the most suitable system to be a target for this paper. The reason behind that was the flexibility of reconfiguring the system and detecting the effect of the DG

Fig. 2. Charging/Discharging operation of the ECS with the DG support

Keeping the charging/discharging operation in the specified range vitally depends on the diesel generator support and using the suitable controllers. The charging and discharging level of the ECS was specified from 0.9 kWh to 3 kWh and the rating power is ± 1.5 MW in the case study of this paper.

To evaluate the CO2 emission, Table I illustrates an example of using more clean energy extracted from wind and compensates the lack of energy caused by reducing the diesel usage. TABLE I TOTAL ENERGY PRODUCED BY THE NON-RENEWABLE ENERGY SOURCES WITH TWO DIFFERENT LEVELS OF WIND ENERGY GENERATION

III. CONTROL STRATEGY Both the ECS and the diesel generator are coordinated with each others by using the suitable combination of Fuzzy logic and PI controllers in order to regulate the power supplying the system from the infinite-bus. Controllers at every stage of the system are shown in Fig. 3, where P is the real power from the infinite-bus system, Pecs is the power modulation of the ECS,E is the stored energy and DPset is the control signal to the diesel unit.

Total Energy Generated by Diesel (Wh)

Total Energy Received from Infinite-bus system (Wh)

wind unit, 1MW rating power

72.1

0.15

wind unit, 2MW rating power

48.5

-0.25

wind unit, 1MW rating power

69.442

3.129

wind unit, 2MW rating power

34.72

14.1

Simulation time=100s

With ECS

With out ECS

The amount of CO2 emission will be reduced following the reduction of using the diesel which is fossil fuel to about 35% according to the above table, which is equivalent to a total emission saving of CO2 as follow:

Fig 3. Implementation PI and Fuzzy logic controllers

The well regulated real power output has been shown in the result and compared with the conventional case when the coordination process between the ECS and the diesel unit is not possible. IV. RESULTS Tow kinds of results have been found. First to show the efficient usage ECS with PI and Fuzzy logic controllers in regulating the real power by absorbing the fluctuations caused by the renewable energy sources, that illustrated in Fig.4. Second results show the overall energy efficiency of the system after increasing the wind energy delivered to the system in order to reduce the amount of CO2 emission. Table I, shows the detailed result of energy generated by the conventional power sources such as diesel unit and infinitebus source.

Emission saving (tons CO2) = renewable energy generated (Wh)× emission factor(kgCO2/Wh) ×0.001

Related to the example in this paper the emission saving= 23.7×0.00043×0.001=0.0000102 (tones CO2) in case of one unit wind of 1000kw rating power and 47.4×0.00043×0.001= 0.0000204 (tones CO2) in case of double sized wind turbine. That is similar to the example given by Carbon Trust [3], with the assumption that additional emissions caused by the renewable technology transport and manufacture are ignored and should be considered by the applicant. If considering the PV implementation in the system and according to [4], PV systems, especially grid-connected systems, can contribute significantly in the mitigation of CO2 emission. V. CONCLUSION CO2 emission can be minimized by using more clean sources such as wind. The system performance kept good in the presence of the ECS with the suitable controllers. VI. REFERENCES [1]

[2] [3] Fig 4. (a): Received power with ECS, PI and Fuzzy logic controllers’ implementation. (b): Received power without ECS implementation.

[4]

Y. Qudaih, and T. Hiyama, “Reconfiguration of Power Distribution System Using Multi Agent and Hierarchical Based Load Following Operation with Energy Capacitor System,” in Proc. The 8th international power engineering conference (IPEC2007)- Singapore, pp. 263-267. Martin M. Halmann, and Meyer Steinberg. “Green House Gas Carbon Dioxide Mitigation,” Book, Published by CRC press, 1999. Carbon Trust website, http://www.carbontrust.co.uk Available in 10 November, 2008. Alsema E.A. “Energy Requirements and CO2 Mitigation Potential of PV Systems.” BNL/NREL Workshop "PV and the Environment 1998", Keystone, CO, 1998.