PowerPoint Presentation: A SEMINAR ON PRACTICAL TRAINING TAKEN AT POWER LINE CARRIER COMMUNICATION RAJASTHAN RAJYA VIDHUT PRASARAN NIGAM LIMITED PLCC-I HEERAPURA POWER HOUSE 220KV, JAIPUR SUBMITTED BY: RAJESH KUMAR E&C (FINAL YEAR) R.I.E.T ,JAIPUR INTRODUCTION OF R.S.E.B.: INTRODUCTION OF R.S.E.B. * RSEB started from 1 July 1957 It is a big organisation and it function under provision electricity act The aim of RSEB is to supply electricity to entire Rajasthan state in most economical way The target of board is to distribut energy in new areas as possible PowerPoint Presentation: For betterment and profit, privatization of RSEB has been done recently . It has been divided in five main parts, they are 1) Electricity production authority: RRVUNL 2) Electricity transmission authority: RRVVNL 3) Distribution authority for Jaipur: JVVNL 4) Distribution authority for Jodhpur: JDVVNL 5) Distribution authority for Ajmer: AVVNL CONTENTS: CONTENTS INTRODUCTION OF PLCC GENERAL DISCRIPTION OF PLCC PARTS OF EQUIPMENTS SPECIFICATIONS FACILITY AVAILABLE ARE BASIC PRINCIPLE OF PLCC CONSTRUCTION OF PLCC TYPES OF COUPLING WAVETRAPS BATTERY CHARGER ADVANTAGES AND DISADVANTAGES OF PLCC CONCLUSION INTRODUCTION OF PLCC: INTRODUCTION OF PLCC POWER LINE CARRIER COMMUNICATION Power line carrier communication has been found to be the most economical and reliable method for communication medium and long distance in a power distance. PowerPoint Presentation: FFor sending speech or other signals from point to point in an interconnected power grid. Some of them are as between: . Public Telephone Network. .Direct Lines 3.Radio Circuitsower .Power Line Carrier Communication(PLCC ) PowerPoint Presentation: GENERAL DESCRIPTION OF PLCC EQUIPMENTS (ETI) The multipurpose equipment type ETI-21 and ETI-22 transmit simultaneously speech and multiplexed tele-operation signals in SSB technique over high voltage lines of cables. The transmitted intelligence is suitable for: Telephony Tele-operations : - Telemetry - Remote control - Remote analogue metering - Tele-printer Tele-protection signals for : - High voltage power equipment - High voltage power lines While the telephone and Tele operations facilities are typically used for economic control and supervision of energy network. The ETI series offers a complete range of variation made possible by a combination of tiers and plug-in PCB. Parts of the Equipment : Parts of the Equipment The equipment is built on three main parts:- Low frequency multiplex signal Carrier frequency signal Power supply unit FACILITY AVAILABLE ARE: FACILITY AVAILABLE ARE The four wire duplex speech from remote location. Duplex Tele Operational Channel, from remote location. Duplex Signaling Channel from remote location. Possibilities for input and output connections of tele operation signals from PLCC equipments. Operational service telephone from parent PLC equipment to opposite PLC station. CONSTRUCTION: CONSTRUCTION 1-It is built in MODULE ELECTRONICS SYSTEM(MES) 2-There are two type of ETI Equipment: a:ETI-21, b:ETI-22 ETI-21 use for 3wire,double channle ETI-22 use for 4 wire,double channle 3-PLCC Equuipments associated with protection signaling and electronics trunk-dialing unit for telephone subscribers MODE OF OPERATION: MODE OF OPERATION PLCC Unit Provide Five type of operation: 1:TELEPHONE FACILITES 2:COMPRESSOR & EXPANDER 3:EMERGENCY CALL 4:SIGNAL BOOSTING 5:SUPERVISION & ALARMS GENERAL MODULATION PRINCIPLE: GENERAL MODULATION PRINCIPLE SINGLE SIDE BAND TRANSMISSION CARRIER FREQUENCY IS SPACED ON A 4-KHZ I.F. FIXED AT 16-KHZ FULL DUPLEX MODE IS USED LOWER SIDE BAND IS USED THROUGHOUT ALL COMMUNICATION SPECIFICATIONS OF PLCC: SPECIFICATIONS OF PLCC 1) GENERAL - Carrier frequency range :- 40 to 512 KHZ Useful AF band :- 300 to 3,700 KHZ 2) TRNSMITTER R.F.TRANSMITTING POWER; -peak envelope power:- 25w -side band power :- 15w PowerPoint Presentation: -I.F. CARRIER FRIQUENCY : 16 KHZ -PILOT TONE : 3600 KHZ -TEST TONE : 1000 KHZ -DUMMY LODE : 20 OHMS 3)POWER SUPPLY -DC SUPPLY : 24 V -CAPACITY : 800 AH - POWER CONSUMPTION :< 80 W PowerPoint Presentation: BASIC PRINCIPLE OF PLCC In PLCC the higher mechanical strength and insulation level of high voltage power lines result in increased reliability of communication and lower attenuation over long-distance. Since telephone communication system can not be directly connected to the high voltage lines, suitably designed coupling devices have to be employed. Coupling devices consists of high voltage capacitors in conjunction with suitable line matching units(LMU’s) for line impedance matching to that of the co-axial cable connecting the unit to the PLC transmit-receive equipment. Carrier currents used for communication have to be prevented from entering the power equipment used in GSS as this would result in high attenuation of even complete loss of communication signals when earthed at isolator. PowerPoint Presentation: To prevent loss of communication signals, wave traps or line traps are employed. These consist of suitably designed choke coils connected in series with the line, which offer negligible impedance to RF carrier currents. Wave traps also usually have one or more suitably designed capacitors connected in parallel with the choke coils so as to resonate at carrier frequencies and thus offer even higher impedance to the flow of RF currents. The RF is prevented from entering the stations bus(yard) and the power frequency is blocked of coupling capacitor . PowerPoint Presentation: The basic arrangement of connecting the WT and coupling capacitor in PLCC communication is shown in the figure below – PowerPoint Presentation: TYPES OF COUPLING PowerPoint Presentation: (a ) PHASE TO GROUND COUPLING PowerPoint Presentation: (b) PHASE TO PHASE COUPLING PowerPoint Presentation: (c) PHASE TO PHASE COUPLING PowerPoint Presentation: (d) INTERLINE OR INTER CIRCUIT COUPLING WAVE TRAP: WAVE TRAP PowerPoint Presentation: WAVE TRAPS Wave traps – (WT ’ s) are used between the transmission line and the power stations to avoid carrier power dislocation in the power plant and cross talk with other power line carrier circuits connected to the same power station. WT ’ s also ensure proper operating conditions and signal levels at the PLCC transmit receive equipment irrespective of switching conditions of the power circuits and equipment in the station. A wave trap must satisfy the following requirements: 1) It must block the carrier currents. By blocking, we mean that the track should attenuate the H.F. signals by at least 8 to 10 dB. 2) It must carry the power frequency current safely during normal operation as well as during short circuit fault conditions . LIGHTNING ARRESTER: LIGHTNING ARRESTER The ground wires running over the towers provides an adequate protection against lighting called L.A. It reduced the induced electrostatic or electromagnetic voltage. A good light arrester must pass the following properties: 1:It should not absorb any current during normal operation, but during over voltage surge it must provide an easy way to the earth. 2:After the over voltage discharge, it must be capable of interrupting the normal frequency of current from flowing to ground as soon as voltages reaches below break down value . DIAGRAM OF L.A.: DIAGRAM OF L.A. TUNING CAPACITOR: TUNING CAPACITOR Used are high voltage, high stability mica capacitors with low losses For lower voltage class of tuning units with impulse test voltage rating upto 40 KV polystyrene capacitors are used For higher voltage class of tuning units with impulse test voltage rating upto 150 KV, capacitors with mineral oil impregnated paper die electric are used DIAGRAM OF TUNING CAPACITOR: DIAGRAM OF TUNING CAPACITOR THE DRAIN COIL: THE DRAIN COIL The drainage coils has a pondered iron core serves to ground the power frequency charging to appear in the output of the unit. The coarse voltage arrester consists of an air gap, which sparks over at about 2 KV and protects the matching unit against line surges. Firstly it isolates the communication equipment for the power line. Secondly it serves to match the characteristic impedance of the power line 400-600 ohms to that of the co-axial vacuum arrester, which sparks, is over at about 250 v is provided for giving additional protection to the communication equipment. PowerPoint Presentation: BATTERY CHARGER PLCC (Power Line Carrier Communication) works on rectified AC or main. When supply goes off, we use BATTERY CHARGER for proper functioning of PLCC, which provides supply to the PLCC equipment for uninterrupted working. It provides DC to the panel by battery of 48V. In this type 24 batteries are connected in series and individually per battery has approximately 2V capacity. Battery charger mainly consists of 4 sections – 1. Float charger 2. Boost charger section 3. Control section 4. Alarm section TECHNICAL SPECIFICATIONS: TECHNICAL SPECIFICATIONS NORMAL INPUT :415 V AC 3-PHASE INPUT VARIATION : +/- 20% FLOAT CHARGER : DC OUTPUT :50 V OUTPUT CURRENT :20 TO 40 AMP RIPPLE : +/- 1% EFFICIENCY : >70% PowerPoint Presentation: BOOST CHARGER DC output - 43.2 to 67.2 V Output current - 25-70 Amps. Over load - 10% Efficiency - >80% FLOT CHARGER: FLOT CHARGER BOOST CHARGER: BOOST CHARGER PowerPoint Presentation: ADVANTAGES & DISADVANTAGES OF PLCC PowerPoint Presentation: ADVANTAGES 2 1. No separate wires are needed for communication purposes, as the power lines themselves carry power as well as communication signals. Hence the cost is less. 2 Power lines have appreciably higher mechanical strength compared with ordinary lines. They would normally remain unaffected under the conditions, which might seriously damage telephone lines. 3. Power lines usually provide the shortest route between the power stations. 4. Power lines have large cross-sectional area resulting in very low resistance per unit length. Consequently carrier signals suffer much less attenuation than when they travel on telephone lines of equal lengths. 5. Power lines are well insulated to provide only negligible leakage between conductors and ground even in adverse weather conditions 6. Largest spacing between conductors reduces capacitance, which results in smaller attenuation at high frequencies. The large spacing also reduces the cross talk to a considerable extent. PowerPoint Presentation: DISADVANTAGES 1. Proper care has to be taken to guard carrier equipment and persons using them against high voltages and currents on the lines. 2. Reflections are produced on spur lines connected to high voltage lines. This increases attenuation and creates problem. 3. High voltage lines have transformer connections, attenuate carrier currents. Sub-station equipments adversely affect the carrier currents. 4. Noise introduced by power lines is far more than in case of telephone lines. This is due to the noise generated by discharge across insulators, corona and switching processes. It is obvious that an effective power lines carrier system must overcome these difficulties. PowerPoint Presentation: CONCLUSION A practical training for a period of 45 days provided me with an in-depth knowledge about POWER LINE CARRIER COMMUNICATION (PLCC). THANK YOU: THANK YOU QUERIES ?: QUERIES ?