SMART STREET LIGHT SYSTEM VIT University, Vellore Aditya Khandelwal VVM Dileep 3 rd Year, B.Tech Electrical and Electronics Engineering Guided By S. Meikandasivam Associate Professor School of Electrical Engineering, VIT University
Abstract The project aims to describe a method for modifying street light illumination by using sensors at minimum electrical energy consumption. When presence is detected, all surrounding street lights glow at their brightest mode, else they stay in the dim mode.led bulbs shall be implemented as they are better than conventional incandescent bulbs in every way. This shall reduce heat emissions, power consumption, maintenance and replacement costs, and carbon dioxide emissions. Coupled with SSLS (Smart Street Light System), massive energy-savings are envisioned. Also, a demonstration with a real-time proto type model involving costs and implementation procedure has been developed.
Contents Abstract... 1 Introduction... 3 Block Diagram... 4 Explanation of Concept... 4 Components Used... 5 IR Sensors... 5 Battery Eliminator... 6 Arduino... 7 Relay... 8 Step Down Transformer... 9 Prototype...10 Energy Savings...11 Conclusion...14 References...15
Introduction Streetlights are an integral part of any developing locality. They are present on all major roadways and in the suburbs too. Every day, streetlights are powered from sunset to sunrise at full strength, even when there is no one around. On a global scale, millions of dollars are spent each day on these street lights to provide the required electrical energy. The maintenance and replacement costs of conventional incandescent bulbs are immense. They consume a lot of electric power to function and their heat emissions are also quite high. All of this contributes to greater demand of electricity production and consequently, more carbon dioxide emissions from powerhouses. So, along with unnecessary light pollution, this practice causes damage to our planet too. A simple and effective solution to this would be dimming the lights during off peak hours. Whenever presence is detected, the lights around it will glow at the normal (bright) mode. This would save a lot of energy and also reduce cost of operation of the streetlights. The concept was implemented on VIT University (Vellore Campus) street lamps to calculate the energy consumption and savings. The duration of the street lights is from 6:00PM to 6:00AM. During this period the average population on the streets is very low and hence the concept can been implemented effectively. So, most of the time, the street lights are on a dim mode and go into bright mode only if there is presence detected. Additionally, a table top prototype has been constructed to display the concept s functioning. The components used for the real-life implementation are substituted appropriately to recreate the ambience.
Block Diagram Fig. 1 Block Diagram Explanation of Concept The present system employs power delivery via a single phase line to the streetlight. The proposed system involves five more components to regulate the power delivery. An Infra-Red Proximity Sensor at the base of the street light detects presence in a small area around the street light. The data from the sensor is sent to the Arduino which forms brain of the circuit. The Arduino then commands a two channel relay to switch between 110V (dim) and 230V (bright) modes depending upon the requirement. The relay, thus, controls the brightness of the street light. A step down transformer powered by the single phase line is used to generate 110 V. A battery eliminator, also powered by the single phase line, is used to supply 5V inputs to the sensors and Arduino.
Components Used IR Sensors An infrared sensor is an electronic instrument that is used to sense certain characteristics of its surroundings by either emitting and/or detecting infrared radiation. It is also capable of measuring heat of an object and detecting motion. Infrared waves are not visible to the human eye.in the electromagnetic spectrum, infrared radiation is the region having wavelengths longer than visible light wavelengths, but shorter than microwaves. The infrared region is approximately demarcated from 0.75 to 1000µm. Infrared technology is found in many of our everyday products. For example, a television has an IR detector for interpreting the signal from the remote control. Key benefits of infrared sensors include low power requirements, simple circuitry, and their portable feature. IR (infrared) sensors detect infrared light. The IR light is transformed into an electric current, and this is detected by a voltage or amperage detector.a property of light-emitting diodes (LEDs) is that they produce a certain wavelength of light when an electric current is applied, but they also produce a current when they are subjected to the same wavelength s light. A pair of IR LEDs can be used as motion detectors. The first IR LED is wired to emit IR waves and the second LED is wired to transmit a signal when it receives an IR input. When an object comes within range of the emittingled, it reflects the IR back to the receiving LED and produces a signal. This signal can be used to open sliding doors, turn on a light or set off an alarm. [1] Fig 2. Infra-Red Sensor
Battery Eliminator A battery eliminator is a device powered by an electrical source (other than a battery), which then converts the source to a suitable DC voltage; that may be used by a second device designed to be powered by batteries. A battery eliminator eliminates the need to replace batteries but may remove the advantage of portability. A battery eliminator is also effective in replacing obsolete battery designs. A Batter Eliminating Circuit (BEC) is typically just a voltage regulator which converts the 12V or higher voltage of the main battery down to the (typically) 5V required by the radio control receiver. These voltage regulators are cheap off-the-shelf electronic components. They generally have three terminals, an input voltage, a 0V reference pin, and the output voltage. [2] Fig 3. Circuit of a Battery Eliminator The capacitors either side of the regulator smooth out any ripples in the voltages. The capacitor to the right is an integral part of the regulator's feedback circuit.
Arduino Arduino is a single-board microcontroller, intended to make the application of interactive objects or environments more accessible. The hardware consists of an open-source hardware board designed around an 8-bit Atmel AVR microcontroller, or a 32-bit Atmel ARM. Current models feature a USB interface, 6 analog input pins, as well as 14 digital I/O pins which allows the user to attach various extension boards. The Arduino board exposes most of the microcontroller's I/O pins for use by other circuits. The Diecimila, Duemilanove, and current Uno provide 14 digital I/O pins, six of which can produce pulsewidth modulated signals, and six analog inputs. The Arduino integrated development environment (IDE) is a cross-platform application written in Java, and is derived from the IDE for the Processing programming language and the Wiring projects. It is designed to introduce programming to artists and other newcomers unfamiliar with software development. It includes a code editor with features such as syntax highlighting, brace matching, and automatic indentation, and is also capable of compiling and uploading programs to the board with a single click. A program or code written for Arduino is called a "sketch". Arduino programs are written in C or C++. The Arduino IDE comes with a software library called "Wiring" from the original Wiring project, which makes many common input/output operations much easier. [3] Fig 4. Arduino UNO
Relay Relays are switches that open and close circuits electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. As relay diagrams show, when a relay contact is normally open (NO), there is an open contact when the relay is not energized. When a relay contact is Normally Closed (NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to the contacts will change their state. Relays are generally used to switch smaller currents in a control circuit and do not usually control power consuming devices except for small motors and solenoids that draw low currents. Nonetheless, relays can "control" larger voltages and amperes by having an amplifying effect because a small voltage applied to a relays coil can result in a large voltage being switched by the contacts. Protective relays can prevent equipment damage by detecting electrical abnormalities, including overcurrent, undercurrent, overloads and reverse currents. In addition, relays are also widely used to switch starting coils, heating elements, pilot lights and audible alarms. [4] Fig 5. A typical Relay circuit
Step Down Transformer A transformer is a device that changes (transforms) and alternating potential difference (voltage) from one value to another value be it smaller or greater using the principle of electromagnetic induction.a transformer consists of a soft iron coil with two coils wound around it which are not connected to one another. These coils can be wound either on separate limbs of the iron core or be arranged on top of each other. The coil to which the alternating voltage is supplied is called the primary coil or primary winding. When an alternating potential difference is supplied the resulting alternating current in the primary coil produces a changing magnetic field around it. This changing field induces an alternating current in the secondary coil. The size of the induced voltage resulting from the induced current in the secondary coil depends on the number of turns in the secondary coil. A step down transformer has less turns on the secondary coil that the primary coil. The induced voltage across the secondary coil is less the applied voltage across the primary coil or in other words the voltage is stepped-down. Transformers are very efficient. If it is assumed that a transformer is 100% efficient (and this is a safe assumption as transformers may be up to 99% efficient) then the power in the primary coil has to be equal to the power in the secondary coil, as per the law of conservation of energy. [5] Fig 6. Step Down Transformer
Prototype Fig 7. Front view of prototype Fig 8. Side view of prototype
Energy Savings By practical observation, data was collected regarding energy consumption of the street lamps in VIT. The energy consumption of 6 incandescent bulbs for 12 hours was found to be 1 kwh. The difference between the claimed energy consumption and the actual energy consumption is also shown here. Observation 12 hours 1 hour Theoretical Difference Error 1 For 6 bulbs For 1 bulb For 6 bulbs For 1 bulb As shown on product Measured- Theoretical Difference*100 Theoretical (in Wh) Energy Consumed 1000 166.67 83.33 13.89 9 4.89 54.32 The energy consumed by one bulb, as obtained from the previous tabulation is now used to extrapolate the energy consumption of 1 bulb in 1 year and 270 bulbs in 1 year. Supply from Mains 1 bulb 2 1 hour 12 hours (or 1 day) 1 week 1 month 1 year Energy consumed 13.889 166.67 1166.68 5000.04 60833.82 60.83 Cost per unit 0.83 304.17 5 1 hour Number of bulbs in VIT 270 12 hours (or 1 day) 1 week 1 month 1 year Watt-hour (Wh) 3750.03 45000.36 315002.52 1350010.80 16425131.40 Unit (kwh) 16425.13 37.50 82125.66
Also, the cost of the energy consumed is calculated. We can see that VIT University spends over INR 82,000 to illuminate its streets every night for a year. Now, the SSLS (Smart Street Light System) concept was implemented on these street lamps. The following is the data obtained regarding its energy consumption. Supply from Stepped Down source 1 bulb 3 1 hour 12 hours (or 1 day) 1 week 1 month 1 year Energy consumed 8 96 672 2880 35040 35.04 Cost per unit 0.48 175.2 5 1 hour Number of bulbs in VIT 270 12 hours (or 1 day) 1 week 1 month 1 year Watt-hour (Wh) 2160 25920 181440 777600 9460800 Unit (kwh) 9460.8 12.44 47304 Savings 4 Mains Stepped Down source 1 hour per day 11 hours per day (in INR) 365 hours per year 6843.80 Present cost 82125.66 4015 hours Cost using per year 43362.00 SSLS 50205.80 Savings per TOTAL 50205.80 year 31919.85
It is estimated that during the off-peak hours, the bulbs glow at maximum brightness for 1 hour and at dim mode for the rest of the 11 hours. A comprehensive cost calculation is shown below. We can see that SSLS (Smart Street Light Concept) has saved over INR 31,000 in just one year. This amount of saving can justify the initial investment costs as well. Thus, we can see that SSLS (Smart Street Light System) is effective ecologically and financially.
Conclusion The use of power electronics is increasing exponentially across various sectors of human life. The components used in the project, like Arduino, relays and sensors, are slowly becoming an indispensable part of our daily routines. So, it is only fitting that we use them to improve efficiency in every walk of life. Keeping in mind the urgent need for energy conservation, SSLS (Smart Street Light System) is an excellent and effective solution. It combines safe lighting protocols with consumption of minimal amount of power. The energy savings, as discussed before, are phenomenal. The future scope of this project expands into speed detection and customizable area of illumination. An additional component which would lead to better functioning of the concept would be the use of LED bulbs. Despite their high initial costs, they are a viable option as they drastically reduce the power consumption. Theywill aid in further saving of energy and reduction in operational costs.
References [1] http://www.ehow.com/how-does_5561845_do-ir-sensors-work.html#ixzz310syld6i [2] http://homepages.which.net/~paul.hills/emc/becbody.html [3] http://en.wikipedia.org/wiki/arduino [4] http://www.galco.com/comp/prod/relay.htm [5] http://www.passmyexams.co.uk/gcse/physics/transformers.html