We are instrumental in offering our clients, quality industrial automation products. These industrial automation products are primarily used for plant automation and are carefully manufactured by us as per the specifications of our clients.
Servo Drives & Motors
Cut to length lines
Non Ferrous continuous casting
Pick and place
Unwind and rewind stands
Some Clients in Servo Application: Sutantra, ARAI, Tata Motor, Kinetic, Finolex, Ashok Leyland, TVS, Symec, Nuclear Fuel Complex.
Programmable logic control systems (plc) covers a large application area from relatively small applications such as machine tools, highly dynamic special purpose equipment to individual and complete integrated plant processes.
The functions covered are sequences, safety, timing, positioning, counting, alarm generation, closed loop control, definable dependant functionality, curve fitting, recipe loading, etc.
The information can be fed to the plc through a wide range of input modules both analog and digital. the range includes simple low voltage dc input modules to high end diagnostic modules with a variety of fault indications and even with integrated safety levels, high speed counters and interrupt modules. similarly the output modules come in various executions of analog and digital including special functions like pwm, integrated safety etc.
The central processing units (cpu) used in these applications also cover a wide spectrum in terms of the input / output addressing capability, memory, speed and special functions. , redundant systems (also known as soft redundant or r systems, hot standby systems (h systems) , safety integrated systems (sil systems) etc.
Depending on the chosen cpu configuration we can choose the appropriate input/output system as local, remote, redundant etc.
The systems most often used by us include siemens s7-200 , s7-1200, s7-300, s7-400
communication is another significant area where an intelligent choice has to be made depending on the application. Communication is required between the cpu and i/o systems in both local and remote configurations. We also need to communicate between the cpu and human machine interface systems, scada systems, engineering stations, third party controllers, drive systems, heater control units etc. communication can be ‘point to point” , non redundant, redundant and come with a variety of physical and protocol characteristics such as mpi, profibus, canbopen, modbus rtu, modbus tcp/ip, ethernet tcp/ip etc. apart from this the medium can also be electric or fibre glass. an interesting ring topology is sometimes adopted to get a better availability in case of communication cable break. Depending on the distance over which communication is to be established we choose the baud rate and the necessary signal repeaters.
Human machine interfaces ( hmi) are used to enable the plant operators to interact with the control system. They provide a mimic of the plant or machine and allow the setting and viewing of critical parameters. In more advanced hmis we can have multiple communication ports, trending of values, 21cfrii compliance, alarm summary and grouping etc. They also come in a number of versions like simple text displays, graphic displays in mono and colour with varying number of colours and pixel definitions, led,lcd. The sizes are from 2x20 text display, and 3 to 19 inches diagonal. Proper attention has to be paid to the design of the hmi screens as this has to be intuitive as well as useful as possible for the operator.
The most commonly used hmi units are from the siemens and esa make of hmis.
Scada is a substantially more advanced human machine interface system as it is backed by a computer operating systems and interfaces with standard software and databases is possible. Some fo the functions that are available with scada are mimics, trends, alarms,pop up screens, sequence of operation, recipes, reports, interface with databases and erp systems. Significant amount of custom scripting can be done to achieve specific functions, wireless communication with other systems, web connectivity, redundant systems, communication with multiple sources etc can be engineered. vb based front end interfaces are often used. A well designed scada platform decides the effective use of the entire control system.
The common scada platforms that we use are siemens simatic wincc explorer series.
These refer to variable frequency drives that are used in a number of applications that require us to run the motor at different speeds depending on the process requirement. Applications could be simple ones like pumps and fans or conveyers. They may be stand alone drives or may need to run in a coordinated style with other drives such as in a wire drawing line.
The system consists of power electronics that converts the incoming ac to dc and is filtered through capacitors making it practically ripple free. This dc is then converted to variable frequency ac through pwm techniques using igbt switches switching at high frequency ( between 2 to 8khz depending on the rating).
Standard protection includes i2t, overload, over temperature, short circuit, ground fault, phase imbalance, thermistor protection, high bus voltage, stall prevention, under voltage, over voltage etc.
These are normally single quadrant drives with a facility for dynamic braking. For more severe braking external braking units and resistors may have to be added.
Interface with external signals is possible through the i/o ports provided. communicaiton can be incorporated through profibus, modbus etc.
Features include controlled acceleration and deceleration, skip frequencies, speed limits, pre programmed speeds, powerful diagnostics, pid close loop control etc.
Modes of control include field oriented control, sensorless vector control, v/f control.
Special features are provided for crane application, safe torque off options etc are provided as options. range is from a fraction of a kw to 500kw in low tension.
We mostly use siemens and abb drives. ( give web link) we have put in operation more than 750 ac drives for various applications till date.
Most DC drives are meant for shunt wound motors with separate field excitation. Both the armature and the field are controlled. The incoming AC three pahse is converted through a line commutated thyristor bridge circuit to the required dc voltage. Both single quadrant and four quadrant versions are available. Excellent and stable control is possible with DC motors and their range is large. . From a fraction of a kw to more than 2500kw. Independent control of the armature and field allows for very simple control schemes. standard protections include i2t, overload, over temperature, field failure, input unbalance, ground fault, short circuit etc.
Applications are in a number of areas such as wire drawing, rolling mills, strip processing mills, paper mills, extrusion systems, centrifuges etc.
Their use is coming down particularly in the lower ratings as they are being replaced with AC drives that are less expensive and use standard AC motors.
The poor power factor of operation and the harmonics generated is also the reason for the switchover of many to ac drive systems.
Brush maintenance of the motors is required.
However for large ratings they are almost the first choice, especially when four quadrant operation is required.
We have our own version of DC drives both in analog and digital versions.
These rectifier systems that we build is meant for high current low voltage or for high voltage and low current applications.
High current and low voltage applications are for applications such as electrolysis, battery forming, steel strip cleaning, desalination, electrocoat systems in automobile paint shops, vegetable oil industry etc.
We have recently signed a mom with m/s ruttonsha for the joint production of such systems upto 25ka. we have more than 45 high voltage systems in operation generating controlled high voltage of the order of 75 to 150kv and currents in the range of 200 to 1000ma. These are used for applications such as electrostatic precipitator, electron beam welding etc.
We are in the process of setting up a joint venture with m/s nothelfer winding laboratories of usa for the local assembly, testing, erection and maintenance of high frequency systems for electrostatic precipitation that have some unique advantages of low ripple and higher acceleration potential for the dust resulting in much better dust collection efficiencies.
Electrostatic precipitator systems for the environmental control of exhaust gasses. Ratings from 75 to 120kv and 200 to 1500ma. These systems are now available in thyristor phase angle execution and in high frequency switched mode executions. The latter offer low ripple, high power factor and advanced controls that are not possible in 50hz line commutated systems. This is in a joint venture collaboration with m/s nwl of new jersey, usa.
Rapper controllers Rapper controls: operational of the rappers in electrostatic precipitator installations with the programming of the lift and the frequency of operation with significant diagnostics built in. This design is avialable in both embedded and plc versions.
Bag filter controls in both embedded version for small applications and in large systems with plcs. Heater control systems in a variety of options such as analog and digital, single phase and three phase, integral cycle and phase angle control. Range from a a few amps single phase to 1. 5mega watt.
Some clients in environment application
Thermax, clyde bergemann, acc. Over 750 installations
Digital controls with communication and diagnostics
Over 750 installations of controlled and with significant diagnostic feedback to the operator for the correct operation of the tagi rappers used in esp installations.
Over 4000 installations of units to control the power input to heater elements in accordance with the control requirements. Digital designs are offered with very advanced and unique features such as recording, master slave operation, profile setting, communication etc.
previously the plc was used for the electrical infrastructure and the dcs for regulatory control. However nowadays there is a significant convergence between plc and dcs systems. Dcs are used for complex batch and continuous manufacturing facilities and systems that involve plant wide controls. Normally in a dcs architecture, redundancy is often employed for i/o, controllers, networks, and hmi servers to ensure 100% availability. The highest priority of a dcs system is to deliver availability and repeatability.
dcs systems are typically employed when the value of the batch or material being produced is high and downtime expensive or dangerous. Also when there are a very large number of control loops that require deterministic scan execution.
number of systems such as oil refineries, blast furnaces etc need to run non stop. On line configuration changes become necessary. this also helps leverage the operators process knowledge. These are possible in a dcs system.
the plc system has a bottoms up approach to design. In a dcs system there is a top down approach with significant effort in up front design and extensive use of libraries and templates, that minimize rework and promote use of standards. This also makes the working in a group easily possible due to strict adherence to standards.
the most common dcs systems that we use are siemens pcs7. (www. Siemens. Com/simatic-pcs7)