Computerized Expert System for Lighting Grids - wseas

Proceedings of the 7th WSEAS International Conference on CIRCUITS, SYSTEMS, ELECTRONICS, CONTROL and SIGNAL PROCESSING (CSECS'08)

Computerized Expert System for Lighting Grids COSTIN CEPISCA Faculty of Electrical Engineering Politehnica University of Bucharest Splaiul Independentei 313, s.6, Bucharest ROMANIA [email protected] http://www.electro.pub.ro HORIA ANDREI Faculty of Electrical Engineering University Valahia of Targoviste ROMANIA [email protected] SORIN DAN GRIGORESCU Faculty of Electrical Engineering Politehnica University of Bucharest ROMANIA [email protected] MIRCEA PERPELEA University of Pitesti ROMANIA [email protected] LAURENTIU STANCU Amiras C&L Impex SRL Targoviste ROMANIA [email protected] VALENTIN DOGARU ULIERU Faculty of Electrical Engineering University Valahia of Targoviste ROMANIA [email protected] Abstract: - An important equipment of a lighting system is the switch on point, which ensures the correct supply of the lamps on an hour interval imposed by the beneficiary and thus also provides the energy economy. The paper proposes an expert system which uses the programmable automat ALPHA XL and which leads an automat system for switch on points in public lighting systems. It is presented the hardware and software implemented application and the performances analysis of the proposed system. Key-Words: - lighting system, switch point, expert system, programmable automat.

1 Introduction

The new intelligent equipments presented in this paper, to increase the efficiency of the public lighting [6]-[9], include more functions: switch on/off depending on the local lighting state; the possibility of switch on/off

The present switches on points of lighting grids have no automated systems, starting to function and disconnecting, most often, at the manual action [1]-[5].

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depending on the functioning preliminary schedule; the knowledge from distance of the functioning state of the respective electric network, the signaling at the appearance of some possible defects; the possibility of remote controlling the switch on/off commands; the knowledge possibility from a central point of the energetic consumptions in each switch on point and the state of the respective network, especially that the measured quantities are most often non-sinusoidal; the possibility of establishing economic functioning regimes, inclusive at voltages lower than nominal voltages; the endowment with a distance transmitting device of the command and measuring information: radio, wireless etc. These new functions can be implemented using hardware and software specialized elements, such as programmable automats ALPHA XL. The programmable automat (PLC) is a device which allows the control and the automation of the working regimes of several electrical equipments. The PLC receives signals through the agency of its inputs, processes them after an established program and transmits signals to its outputs. The specialized program is realized with a programming soft. Through the program, we can command the inputs and outputs as we wish; we can measure times and perform calculus operations. The main characteristics of a PLC are: the maximum number of inputs/outputs, the memory capacity and the calculus speed. The compact programmable automats are defined through the next system characteristics: • programming with the same software package, regardless of the number of inputs/outputs; • possibilities of local and distant extension; • integrated interface for communication; • removable terminal blocks, with screws; • compact gauge. Through the agency of the menu and only with the help of the buttons on the apparatus, the command scheme can be introduced directly as a scheme of connections with contacts and relay coils. The introduction can be alternatively made using ALPHA XL and a PC. On the MFD screen or on the PC, the active states from the command scheme can be immediately observed and thus precious time is saved.

- the lighting switch on/off are possible in the centralized or decentralized variant; - the lighting switch on and switch off are possible in the centralized or decentralized variant through the impulse relay function; - the lighting switch off command can be realized through the agency of the clock delay, which facilitates the centralized disconnection of the lighting and the energy economy; - a base device can control up to 12 independent lighting groups. Special commands for lighting can be realized, such as centralized lighting for maintenance activities and automatic commutation for reduced lighting; - the montage of these devices in the plug board charts for the modular equipment is facilitated by the 45 mm frontal dimension and the width which is 4,6,8 and 12 multiplied with the modular step.

Fig.1. Programmable automat ALPHA XL In figure 1 is presented the configuration of this device, chosen to equip the switch on point. Among the technical characteristics which make it useful in our application we name: - applications in the domain between discreet components and systems with PLCs; - models with d.c. 24Vcc supply or a.c. 100-240Vac; - software resources even for complex applications; strong set of predefined functions, including PID, SPD, PWM, mathematic calculus; - 10-24 I/O, extension possibility with digital or analogical modules, thermo element signal adaptors; - for the models with d.c. supply the first 8 inputs can be used also as analogical inputs in the range 0…10 V with a resolution of 9 bits / 500 values in the measuring range; - memory for maximum 200 block functions. ALPHA XL combines all the advantages of a PLC system in a very compact casing and ensures a reduction of the cost price regarding the occupied surface, the relays and the contactors. Up to 64 functions can be processed by a program.

2 Using the PLC to control the lighting systems Regarding the use of this programmable automat for the lighting control, we can make the following appreciations:

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Each of the valid functions (time, numerator, analog processing converter, calendar/clock, etc.) can be used in all of the programs, every time when needed. ALPHA XL includes a tripling of the program capacity up to 200 functions and a big screen, extension options and a second communication block, 15 new functions suited to the instruction set, including mathematical operations, PWM and SMS messages functions. The easy operating and the legible screen are two big advantages of ALPHA XL, offering in the same time graphics from the moving bar and text on screen. The three levels of password protection prevent unauthorized access to the processed parameters and data, which can be changed directly through 8 key functions. ALPHA XL is equipped with a communication interface and with the possibility of ensuring an automatic control through a GSM modem. Additionally, it’s possible to send SMS texts to a mobile phone, e-mail to a PC or fax. The extended analogical modules increase the applications level. With these modules it’s possible to generate voltage or current signals and to measure temperature. The I/O points of the slave devices are electronically recorded through the bus connection or the PLC program introducing the master into the network. All the controllers from the ALPHA series can be programmed with the soft MS Windows AL PCS/WIN. This software is very easy to use and doesn’t need the user to have experience. The programming of ALPHA is easy and is made placing the different elements of the program into a graphic programming environment.

- Disconnecting the lighting in situations commanded by the Civil Protection and the predefined command of an alarming siren (with a certain sound clock); - Disconnecting the lighting in function of the arisen failures (over and sub voltage, over and sub current), to identify the abnormal working of the installation (bus interruptions, energy thieveries); - Protection sensitizing depending on the chosen supply variants: directly, converter, autotransformer; - Metering the consumed energy (meter of impulses taken from an administration system); - Supervising the temperature and sending this value at the control point (with the help of a temperature transducer).

3 Hardware and software configuration of PLC for controlling the switch on point of public lighting systems To configure the programmable automat ALPHA XL for the application related to the control of switch on points in public lighting, [10], we take into account the next requirements: - Connecting the automat consumer, depending on the lighting state, through the agency of a solar radiation transducer or through manual command; - Connecting the lighting network using an hour program, depending on the day from the week; - Supplying the network through the agency of voltage/ frequency converter; - Supplying the lighting through the agency of an autotransformer, in order decrease the lighting intensity between certain hours (the reduction of the luminous flux);

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Fig.2. Programming scheme.

3.1 Inputs and outputs assignations The assignation of the inputs and the outputs are presented below. Inputs: I01 – Automation supply switch (network operating) – digital, I02 - Luminous intensity transducer (0-10 V)analogical, I03- Automatic functioning switch depending on digital light sensor, I04 – Automation functioning switch depending on programming clock – digital, I05 – Civil Alarm signal input – digital, I06 - Current transducer signal input – (0-10V) analogical, I07-Voltage transducer signal input (0-10V) analogical, I08Temperature transducer signal input (0-10V)-analogical,

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I09- Energy meter signal input (0-10V) - digital, I10Automation functioning switch with frequency converter– digital, I11-Automation– digital. Outputs: O01- Temperature (0-10V) –analogical, O02- Lighting command – digital, O04 – Civil defense siren – digital, O05 – Autotransformer servomotor – digital, O06Converter command ( 0-10 V) – analogical, O07– Output for impulses proportional with consumed energy – digital, O08 – Cabin fan command – digital. The programming scheme and the utilization interface are presented in figure 2, respectively in figure 3.

Fig. 4. The system state. The “Disconnect” function is activated through the application of a digital system at the I05 input. In this state, the automat commands the public lighting disconnection (if the conditions were fulfilled). The digital signal enters in the loop B 25, conditioning depending on the command key), B 26 (signal negation), generating a signal in B 28 (“and” logic), disconnecting the lighting contactor. The display is presented in figure 5.

Fig. 5. The display is activated. The supervising of the failures (voltage and current) is made with the functional blocks B32 and B33 which take over the analogical information from the inputs I06 and I07 through the agency of B31 and B32. These states are shown in figure 6, respectively in figure 7.

Fig.3. Utilization interface.

3.2 Program work algorithm The input functions I01, I02, and I03 give the general validation conditions for the lighting command O 02.[11] The input analogical signal, received from the twilight transducer is compared with the values imposed in the lighting controller B 15 and B 16. Depending on this comparison the automat will decide if it’s the moment to command the connection of the public lighting. The system state is visualized on the display screen B 17 and B 20 (B 17 indicates the “lighting turned on” state and B 20 indicates the “lighting turned off” state). The two displays are conditioned by the Boolean function B 18, like in figure 4.

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Fig. 6. The functional blocks B32 and B33.

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which the luminous intensity will reduce (between what hours and what days), shown in figure 11.

Fig. 7. The functional blocks B31. The visualization of the voltage and current protection state is made through the optic blocks B 31 and B 32, is show in figure 8.

Fig. 9. The failure.

Fig. 8. The integrated signal of voltage and current. Depending on the chosen automation variant: through the autotransformer or through the converter, the current and voltage protections automatically modify their working parameters. The failure, figure 9, is shown on the B 23 display. When the converter works, the input signals integrate in blocks B06 and B07, through the agency of the amplifiers B04 and B05. The resulted signal integrates in blocks B 08 and B 09. The failure is shown on the B 22 display. The failure signals are totalized through the “OR” logic in the functional block B10 - figure 10. When the autotransformer works, the input signals integrate in the B12 and B13 blocks, through the agency of the amplifiers B64 and B11. The resulted signal integrates in blocks B19 and B21. The automation working in the autotransformer variant is realized when at the I11 input a digital signal is applied, signal which is also found at the terminals of B 02. The autotransformer is operated by the digital output O 05, commanded by the B 02 “AND” block. The working takes place when all the three signals are simultaneously applied from I 11, I 01 and the programming clock B 03. With the help of this clock we can program the period in

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Fig. 10. The functional blocks B10.

Fig. 11 The set of time switch.

The automation functioning with the help of the frequency converter is realized when at the I 10 input a digital signal is applied and when the system is in operating state (I01 is supplied). The signal from I10 is applied to the integrator blocks B52 and B55 which also take over the analogical information from

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[2] S. D. Grigorescu, C. Cepisca, I. Stancu, A. Ionescu , Light Equipment from ELIPSA - a Modern Solution, Related to ICE Standards, for Electronic Ignition and Supply of Discharge Lamps, Electric Lighting International Show’98, Bucharest, april,1998, pp. 25 [3] Andrei,H, Spinei, F, Cepisca, C, A new method to determine the relative variation in electric power systems, Revue Roumaine des Sciences Techniques, Serie Electrotechnique et Energetique, tome 46, 4, pp.445, Bucarest, 2001. [4] Tetri, E., Halonen L. Future trends of energy efficient lighting, Proceedings of the 26th session of the CIE, Beijing, China, 4-11 July 2007. pp. 45-48. [5] Farahmandpour, I. Nasseri, H. Houri Jafari, Analysis of Ultimate Energy Consumption by Sector in Iran, Proceedings of the 3rd IASME / WSEAS International Conference on ENERGY & ENVIRONMENT (EE'08), Cambridge, UK, February 23-25, 2008 pp,151-158 [6] Jitka Mohelnikova, Electric Energy Savings and Light Guides, Proceedings of the 3rd IASME / WSEAS International Conference on ENERGY& ENVIRONMENT (EE'08), Cambridge, UK, February 23-25, 2008, pp.470-474 [7] Andrei,H, Cepisca,C, Chicco,F, Spinei,F, Equilibrium State of the Electric Circuits, A Minimum Dissipated Power , WSEAS TRANSACTIONS ON SYSTEMS, Issue 12, vol.4, December 2005 pp.2284-2290 [8] Cepisca,C, Andrei,H, Grigorescu,S.D., Modern solutions for reducing the lighting consumption by using a computerized expert system, Proceeedings of the 6th International Symposium ATEE, nov. 2008, Bucharest, pp.86-91. [9] Faranda,R, Fumagalli,K, A study on Daylighting for energy saving, 7th WSEAS International Conference on Application of Electrical Engineering (AEE’08), Trondheim, Norway, July 2-4, 2008 [10] Grigore,O, Inge Gavat, Corina Grigore, M, Cotescu, An Adaptive Lighting System Using the Simulated Annealing Algorithm, 8th WSEAS International Conference on SIMULATION, MODELLING and OPTIMIZATION, Santander, Cantabria, Spain, Sept., 2008, pp.142-147 [11] C. Cepisca, S .D. Grigorescu, M. Covrig, H. Andrei, Abbout the Efficiency of the Real Time Sequence FFT Computing, Proc. IEEE Workshop on Design and Diagnostics of Electronic Circuits and Systems, April 11-13, 2007, Krakovia, pp. 211-214.

the I02 input. The system state is visualized on the B56 display, figure 12.

Fig.12. The functional blocks B56.

4 CONCLUSIONS From the electrical energy consumer categories, with an important weight, circa 10% is owned by the public lighting. An important equipment of a lighting system is the switch on point, which ensures the correct supply of the lamps on an hour interval imposed by the beneficiary and thus also provides the energy economy. The new intelligent equipments used in this paper to increase the efficiency of the public lighting must include more functions: switch on/off depending on the local lighting state; the possibility of switch on/off depending on the functioning preliminary schedule; the knowledge from distance of the functioning state of the respective electric network, the signaling at the appearance of some possible defects; the possibility of remote controlling the switch on/off commands; the knowledge possibility from a central point of the energetic consumptions in each switch on point and the state of the respective network, especially that the measured quantities are most often non-sinusoidal; the possibility of establishing economic functioning regimes, inclusive at voltages lower than nominal voltages; the endowment with a distance transmitting device of the command and measuring information: radio, wireless etc. These new functions can be implemented using hardware and software specialized elements, such as programmable automats ALPHA XL. References: [1] Gordon KL, R Foster, and T McGowan, Lighting for Tomorrow: What have we learned and what about the day after tomorrow?, 2006 ACEEE Summer Study on Energy Efficiency in Buildings, ed. John and Ron Judkoff, p. 439. American Council for an EnergyEfficient Economy , Washington, DC.

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