College Papers

COMPANY PROFILE Triton Valves was established in 1975 by their visionary founder M

COMPANY PROFILE
Triton Valves was established in 1975 by their visionary founder M.V.Gokarn. Triton began manufacturing valves for the tyre and inner tube industry in 1978 and emerged a market leader in India. With the growth of automobile industry in India, Triton grew to be India’s largest manufacturer of tyre valves. With the advent of tubeless tyres, Triton began manufacturing tubeless tyre valves and evolved from a Tier 2 to a Tier 1 supplier for the automobile industry. With a strong focus on product quality and R ; D, Triton has evolved into a precision manufacturer and supplier of valves and components to a diverse range of customers and industries from air conditioning and hydraulics to aerospace, mining, defence and industrial HVAC ; R.

The headquarters is in Bengaluru India and the manufacturing facilities and R ; D Center are located in Mysuru. They also operate warehouses in Bengaluru, Chennai and Delhi in order to serve their customers with Just-In-Time deliveries. All the facilities conform to IATF 16949, ISO 14001 and BS OHSAS 18001 standards.
The 11300 sq mts, manufacturing facility is located at Mysore, 140 kms South-West of Bangalore in Southern India. Every month they turn out a huge number of high precision valves and cores which find their way into tyres of all sizes of vehicles from motorcycles and scooters to heavy-duty trucks and even aircrafts. The products conform to internationally accepted standards such as The Tire and Rim Association, the European Tyre and Rim Technical Organization and the Japan Automobile Tyre Manufacturers’ Association.

INTRODUCTION
Triton Valves Ltd. Mysuru, is India’s largest manufacturers of automotive tyre tube valves, valve cores and its accessories. For almost over three decades they have been developing and manufacturing high precision products that are delivered to meet the diverse requirements of the customers around the world. Their reputation for quality, delivery and customer service have earned them the trust of various customers such as Apollo Tyres, Bridgestone India, CEAT Tyres, JK tyres, MRF Tyres, Mahindra ; Mahindra, Tata Motors, TVS – Srichakra Tyres and Wheels India.

They are working on improving the testing procedures and including new tests for their valves to assure that only the best valves reach their customers. One such on-going project of Triton valves is Design of a Centrifugal Testing Machine, which helps to dynamically test the valves for leakages in the most unfavourable conditions that a valve will be used in.

PROBLEM STATEMENT
2125667106889400To validate the quality of the valves, a dynamic test for leakage is required to ensure its proper working in environment with different temperatures and with wheels running at different speeds. Designing of a Centrifugal testing machine is required to conduct the dynamic test.
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132651537465Figure 2.1: Speed and Temperature Characteristics of the test.

0Figure 2.1: Speed and Temperature Characteristics of the test.

OBJECTIVES
To design the electrical circuit for the Centrifugal Testing Machine.

To write a ladder program for a PLC to control the working of the Centrifugal Testing Machine.

LITERATURE SURVEY
In “Speed Control of Induction Motor Using PLC and SCADA System” by Ayman Seksak Elsaid, Wael A. Mohamed, Salah Ghazy Ramadan, monitoring the speed of three phase induction motor using a SCADA system is done. The control system is designed based on the most advanced technology which gives a high amount of flexibility and efficiency using PLC and VFD.

In “A New Electronically Monitored Centrifuge for the Analysis of Plant Growth in Simulated Hypergravity” by M. J. A. Nava, T. Russomano, M. A. dos Santos, L. B. Poehls, a new design for a centrifuge simulating hypergravity used for plant experiments is implemented. It represents a more robust and completely redesigned equipment based on a previous centrifuge project by the MicroG Centre. Distinct experiments using plants have been performed in order to validate the centrifuge.

COMPONENTS OF THE CIRCUIT
34607531686500center3871925Figure 4.1 : Schematic layout of the circuit of test machine.

Figure 4.1 : Schematic layout of the circuit of test machine.

Schematic layout of the circuit of test machine

Components of the circuit
Drive:

A Variable Frequency Drive is used for applications wherein speed control is required due to load changes, where the speed needs to be increased or decreased accordingly. Operating VFD with inverters, offers a wide range of advantages:
Prevents inrush current, as the inverter increases the frequency from 0 Hz instead of delivering a surge current of 50 Hz at motor start-up.

Any required degree of soft start and braking can be obtained by specifying the time for acceleration and deceleration.
For the requirement of different delivery rate for conveying liquid or gases, the motor need not work in its full capacity, leading to savings on energy.

The speed of the motor is controlled by varying the supply frequency. The product of the supply frequency and air-gap flux is directly proportional to the voltage induced in the stator. Neglecting stator drop, the terminal voltage is considered proportional to product of frequency and flux. V1 ? f.?.

The effects of change in supply frequency without change in terminal voltage:
1. Reduction of supply frequency without change in terminal voltage will cause an increase in the air gap flux, thereby saturating the motor. Thus it will increase the magnetizing current, core loss and stator copper loss and will tend to cause distortion in line current and voltage and will produce high-pitch noise.

2. Increase in the supply frequency without terminal voltage change will cause decrease in flux, thus leading to reduction of motor’s torque capability.

The basic working principle behind VFD operation requires understanding the three basic sections of the VFD: the rectifier, dc bus, and inverter. A VFD in this circuit helps to achieve the desired speed for the shaft. Change in the frequency helps to change the speed of the 3 phase induction motor. The motor is coupled with the shaft via a pulley. Variable speed is required to simulate the varying speeds of the vehicle, which can have an effect on the performance of the valves, since the valves flex due to the centrifugal force. The valves are required to be leak-proof even when they tend to flex at higher speeds of the wheels.

Technical specifications
Brand : ABB/Siemens
Rated power : (3ph, 415V, 50 Hz) 7.5 hpRated current : 13 amps
Acceleration/Deceleration time (min): 10 secs.

3 phase induction motor:

Induction motors are commonly used motors for various equipment in various industries. Due to the simple design, low-cost and low maintenance, and the ease of directly being connected to an AC power source they are popular. The two main electrical components of an induction motor are:
Rotor (Squirrel-cage rotor and Wound rotor)
Stator
The air-gap between the rotor and the stator ranges from 0.4mm to 4mm depending on the power of the motor.

A flux is generated in the stator magnetic circuit when AC current is applied in the stator armature. This flux induces an emf in the conducting bars of rotor as they are “cut” by the flux while the magnet is being moved (E = BVL (Faraday’s Law)). Due to the induced emf, a current flows in the rotor circuit, which in turn produces a force, (F = BIL) can be changed to the torque as the output.

Induction motors are simple, rugged, low-priced. They run at a constant speed from zero to full-load. The speed is frequency-dependant and these motors do not easily adapt to speed control. Thus variable frequency drives are used to control speed of these motors.
Technical specifications
Brand : RotomotiveRated power : (3ph, 415V, 50 Hz) 5.5 kW – 7.5 hpRated speed : 2925 rpm
Size : 132 S
Efficiency at full-load : 86.5%
Rated current : 10.3 amps
Rated torque : 18 Nm

SMPS:

The switched mode power supply converts the input supply is drawn from the ac mains which is rectified and filtered using a capacitor at the rectifier output. The unregulated dc voltage which is the output of the rectifier, is then fed to a high frequency chopper. Most of the choppers used in SMPS circuits have an intermediate high frequency ac conversion stage to facilitate the voltage scaling and isolation by using a high frequency transformer. In linear power supplies with input voltage drawn from ac mains, the mains voltage is first stepped down to the desired magnitude using a mains frequency transformer, and later rectification and filtering. The high frequency transformer used in a SMPS circuit is much smaller in size and weight compared to the low frequency transformer of the linear power supply circuit.

The ‘Switched Mode Power Supply’ gets its name from the dc-to-dc switching converter for conversion from unregulated dc input voltage to regulated dc output voltage. The employed switch is turned ‘ON’ and ‘OFF’ (switching action) at a high frequency. The switch is in saturation mode with negligible voltage drop across the collector and emitter terminals during ‘ON’ mode and the switch is in cut-off mode with negligible current through the collector and emitter terminals in ‘OFF’ mode. The voltage-regulating switch, always remains in the active region, in a linear regulator circuit,.
The available unregulated input voltage, which is either ac or dc, is converted to a regulated dc output voltage by switched mode power supply. In SMPS with input supply drawn from the ac mains, the input voltage is first rectified and filtered using a capacitor at the rectifier output. The unregulated dc voltage across the capacitor is then fed to a high frequency dc-to-dc converter. Most of the dc-to-dc converters used in SMPS circuits have an intermediate high frequency ac conversion stage to facilitate the use of a high frequency transformer for voltage scaling and isolation.

Technical specifications
Brand : Omron

Environmental Chamber:

Environmental Chamber is used to test specimen at varying temperature. Simulation and stimulation are two fundamental forms of environmental testing. Simulation imitates the conditions a product would undergo during its normal use, such as environmental conditions. The temperature, humidity, and vibrations, do not exceed the values under which the product is intended to be used. Thus referred to as ‘test to pass’. Once the product passes the simulation test, it is ready to be used by the consumer. Stimulation is used to discover a product’s weaknesses and limits, often stressing a product to the point where it tends to fail or fails. For example, the temperature would gradually increase in an attempt to find the highest temperature at which the product is still operating and the point at which the product gets damaged. Stimulation is also referred to as accelerated testing.

The Environmental chamber is used as the test chamber where the wheel will be mounted for testing. Variable temperature is used to simulate the varying temperature of the weather. The fabricated wheel or the regular tyre is used as per the test specified by the customer. The fabricated wheel accommodates 6 valves, thus helps to test all the 6 valves at once, whereas the tyre will accommodate only 1 valve and will be used to simulate the exact conditions of the tyre and valve while driving a car.

Technical specifications
Brand : Envisys Environmental Chamber
Temperature
Range: -70°C to 150°C
Fluctuation: ± 1°C
Rate of change:
Heating: 4ºC/min
Cooling: 3ºC/min
Resolution: 0.1°C
Humidity: Relative humidity of 10 – 95%
Noise level: 65 dB
Cooling system: Water cooling system
PLC :

A PLC (Programmable Logic Controller) is a special form of microprocessor-based controller that uses memory that can be programmed, to store instructions and to implement logical functions, sequencing functions, timing and counting functions also arithmetic functions in order to be able control machines and processes.
It is designed to be operated by engineers with ease, requiring a very limited knowledge of computers and computing languages. They are designed so that every user with little knowledge of programming can set up or change the programs. The designers of the PLC have pre-programmed it in such a way that the program for controlling processes can be set up using a simple, rather intuitive form of language.
The term logic is used because programming is primarily concerned with implementing logic and switching operations; for example, if X or Y are positive, then Z is switched on; if X and Y are positive, then O is switched on. The PLC controls the input devices (such as sensors, switches etc.) and output devices (such as drives, valves, etc.) present in the system. A sequence of instructions is entered into the memory of the PLC by the programmer. This set of sequence of instructions is called as a program. The monitoring of the inputs and outputs according to the sequence of the program is done by the controller according to the control rules of the program.
For a wide range of control systems, the basic controller of the PLC can be used, which is an added advantage. To modify the way a control system follows the control rules, the operator should add a different set of instructions, or modify the present program. The need to rewire is prevented since the chnge in the PLC program takes care of it. Thus resulting in a flexible, less expensive system that can be used to control the systems, which vary quite widely in their nature and complexity. PLCs are similar to computers, but whereas computers are optimized for calculation and display tasks, PLCs are optimized for control tasks and the industrial environment.

Thus PLCs:
• Are designed to withstand the harsh conditions of the industrial environments like vibrations, temperature, humidity, and noise.

center59726300• Have availability of interfacing for inputs and outputs inside the controller.

Typically a PLC system has the basic functional components of processor unit, memory, power supply unit, input/output interface section, communications interface, and the programming device. Figure 1.4 shows the basic arrangement.

The processor unit or central processing unit (CPU) is the unit containing the microprocessor. This unit interprets the input signals and carries out the control actions according to the program stored in its memory, communicating the decisions as action signals to the outputs.

The power supply unit is needed to convert the mains AC voltage to the low DC voltage (5 V) necessary for the processor and the circuits in the input and output interface modules.

The programming device is used to enter the required program into the memory of the processor. The program is developed in the device and then transferred to the memory unit of the PLC.

The memory unit is where the program containing the control actions to be exercised by the microprocessor is stored and where the data is stored from the input for processing and for the output.
The input and output sections are where the processor receives information from external devices and communicates information to external devices. The inputs might thus be from switches, sensors. The outputs might be to motor starter coils, solenoid valves, or similar things.

The communications interface is used to receive and transmit data on communication networks from or to other remote PLCs (Figure 1.6). It is concerned with such actions as device verification, data acquisition, synchronization between user applications, and connection management.

Advantages of PLC include cost-effective controlling for complex systems, flexible and can be applied to control other systems faster and with ease, computational abilities allow control that is more sophisticated, programming is made easier by troubleshooting aids and reduce downtime reliable components make these likely to operate for years before failure.

Technical specifications
Brand : Siemens S7
CPU : 1214C
Signal module : 1232 AQ
Expansion module : SM 1223

HMI:
HMI is the acronym for Human Machine Interface. The visual representation of a control system and real time data acquisition is provided by an HMI. For the successful design of a good HMI screen system five primary areas are considered. They are:
Situation Awareness
Using Colour Effectively
Interpreting the data
Depicting Device State
HMI Display Organization
Situation awareness relates to the objectives and desired goals of a specific process, function or work. Designers and engineers form mental models of the process or function in their heads. The designer designs the flow of thw program based on the perception of how or what the operator might select to reach his goals. Only by understanding the user’s goals on Situation Awareness, the information and program that is presented will have meaning. By having a centralized control center that is extremely user-friendly, an HMI can increase the productivity of the industry.

Applying SA terminology to HMI Graphics:
Level 1 SA – P;ID representation with Live numbers
Level 2 SA – Provide the operator with the relevant information they require to understand how the plant is operating
Level 3 SA – Provide trending data so that the operator can extrapolate the plant’s performance to the future
Level 2 and Level 3 SA reinforces the operators’ mental model of the plant or process
In this project HMI is used to help the operator to select the speeds, time durations, temperature ranges/settings, humidity settings of the tests to be performed.

Technical specifications
Brand : RedlionPanel : 7″ graphite
Sensors:
The sensors used in the circuit are Pressure sensor, Proximity sensor, Thermocouple, Encoder, Humidity sensor and TPMS.

The Pressure sensor is used to measure the pressure of the test chamber.

The Proximity sensor is used to measure the angle of flexing of the valves during the test. The max. flexing angle of the valve during the test is 25º.

The Thermocouple is used to measure and control the temperature inside the test chamber.

The Humidity sensor is used to set the humidity level inside the test chamber.

TPMS is used to monitor the parameters of the tyre such as pressure, temperature and acceleration.

METHODOLOGY
Flow-Chart
3462655571500
The flow of control in Ladder Program written in the PLC will be as per the flow-chart, as shown above.

The Algorithm for the Ladder Program is as follows:
Switch on the Power supply and press the ‘START’ button on the HMI Screen.

If the door of the test chamber is closed, the next screen will appear in the HMI. Else an ‘ALARM 1’ is switched ON indicating that the door is open.

The temperature inside the chamber is set to 25º Celsius, to allow the user to mount the wheel inside the chamber without much difficulty.

Once the chamber temperature is set to 25º Celsius, the opening of the chamber door is enabled. The wheel with the valve to be tested is mounted on the shaft and the door is closed.
If the door of the test chamber is closed, the next screen will appear in the HMI. Else an ‘ALARM 1’ is switched ON indicating that the door is open.

Active screen appears in the HMI, where it allows the user to input the values of the parameters of the test such as temperature to be maintained inside the chamber, acceleration and deceleration time, desired speed, cycle time, period of duration of the test. Press ‘OK’ once all the values are entered.

The temperature inside the chamber is set to the specified value in a specified time.

The test starts and the values of the parameters are displayed on the HMI screen. If any fault is encountered once the test starts and the motor stops running then ‘ALARM 2’ is switched ON indicating that the test has failed or stopped.
Once the test is completed, the indication of completion is shown on the HMI screen. Then the temperature of the chamber is set to 25º Celsius, to allow the user to remove the wheel inside the chamber without much difficulty.

The door is enabled to be open.

ELECTRICAL LAYOUT OF INTEGRATION

Figure 6.1 : Proposed Electrical Layout for Integration of Motor along with
VFD to the Environmental Chamber.

Figure 6.1 : Electrical layout of test chamber.

Figure 6.1 : Electrical layout of test chamber

Figure 6.1 : Electrical layout of heat exchanger circuit.

Figure 6.1 : Electrical layout of motor and VFD integration.
Figure 6.1 : Electrical layout of heater circuit of chamber.

Figure 6.1 : Electrical layout of safety switch and window and door heater circuit.

Figure 6.1 :Electrical layout of connection to PLC output interface.

Figure 6.1 : Electrical layout of connections to SMPS.

Figure 6.1 : Electrical layout of fault indicator circuit.

Figure 6.1 : Electrical layout of safety circuit.

Figure 6.1 : Electrical layout of valve connections.

Figure 6.1 : Electrical layout of PLC connections.

Figure 6.1 : Electrical layout of PLC expansion module connections.

Figure 6.1 : Electrical layout of PID connections.

Figure 6.1 : Interfacing layout.

BILL OF MATERIALS
Description Specification Brand Quantity
Surge Protector VAL MS 320/3 + 1-FM Phoenix 1
Mains Switch 25A 4 Pole Salzer1
MPCB 3VU1340-1MG00 (1-1.6A) Siemens 2
MPCB 3VU1340-1MM00 (10-16A) Siemens 3
MCB 5SX41107RC (1 Pole 10A) Siemens 4
MCB 5SX41047RC (1 Pole 4A) Siemens 2
Fan Motor Ext.Shaft 1/2 hp 3 Phase 420mm Stark 2
Basket Fan 4e-300-B 1-Phase Blowing Type Favelle1
Induction Motor 7.5hp 2 Pole Foot Mount Rotomotive1
Encoder 100PPR 24V TTL Output Delta/Autonics1
Panel Cooling Fan 4″ dia 230VAC Darshan Industries 1
VFD 7.5 hp 3 Phase ABB 1
Thermostat 50-300 DegCElcon/Jumo1
On Delay Timer 3RP15 25-1AP30 8K Siemens 1
Step Down Transformer Pri 415×2, sec 230VX1-300VA STD 1
HMI 7″ Graphite Redlion1
Modular Controller
CSMSTRLE Redlion1
PID Module CSPID2 Redlion1
PLC with CPU CPU1214C Siemens 1
PLC Expansion SM1223 Siemens 1
Emergency Switch with NC 3SB52 03-0UC01 Siemens 1
Door Limit Switch 3SE3-100-1E Siemens 1
Description Specification Brand Quantity
Power Supply S8VK-C12024 Omron 1
Power Contactor 3TF-30-10-AM0 Siemens 4
Power Contactor 3TF-31-10-AM0 Siemens 2
Input Power Safety Switch K8AK-PM2 Omron 1
Change Over Relay+BaseAC/AC Omron 4
Change Over Relay+BaseAC/DC Omron 2
Solid State Relay 40A DC ERI 4
Solid State Relay 16A AC ERI 1
Temperature Sensor 3X75mm SS Class A PT-100 5M T Duplex 1
Humidity Sensor HMM100 Visala1
Thermocouple T-Type -62 To 125 Deg C Duplex 1
Thermocouple T-Type -62 To 125 Deg C 1/4″BSP Duplex 1
Temperature Sensor 3X75mm SS Class A PT-100 5M T Duplex 1
Indicator 22.5mm dia Red Flasher Idea 1

PROPOSED PLC LADDER PROGRAM FOR
center57785000 MOTOR AND VFD INTEGRATION.

Figure 7.1 : Network 1
On pressing the ‘P1’ button ON, the output ‘Q1’ is made high is latched, thus keeping it ON.

If ‘Q1’ is high and if the chamber door is sensed to be closed, then the ‘Ready’ button on the HMI screen is made high. If the chamber door is sensed to be open, the ‘Alarm’ is set ON.

If the ‘Ready’ button is high, then on clicking the ‘Enter’ button on the HMI screen, output ‘Q2’ is made high.

Once ‘Q2’ is high, the parameters of the test to be conducted are entered on the HMI screen and the ‘OK’ button on the HMI screen is clicked. The output ‘Q3’ is made high once the thermocouple senses that the desired temperature is set inside the test chamber.

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Figure 7.2 : Network 2.

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Figure 7.3 : Network 2 (continued).

ADVANTAGES

CONCLUSION
The project is in its fabrication stage. Some changes are bound to be present the final electrical design since a single circuit will be present for both the test chamber along with the integration. Also fine tuning of the PLC ladder program has to be done while focusing on the expected outputs from the machine.

This testing machine will simulate the dynamic conditions of the wheel along with the valve to ensure that the valves tested in this machine are capable to withstand extreme road conditions, as valve is the safety product which is a part of the tyre.

REFERENCES
1 “Speed Control of Induction Motor Using PLC and SCADA System” by Ayman Seksak Elsaid, Wael A. Mohamed, Salah Ghazy Ramadan.

2 “A New Electronically Monitored Centrifuge for the Analysis of Plant Growth in Simulated Hypergravity” by M. J. A. Nava, T. Russomano, M. A. dos Santos, L. B. Poehls.

3 “Introduction to PLC” by Industrial control system.
4 “DC to DC Converters” by EE IIT Kharagpur.