INDUSTRIAL APPLICATION OF PLCs IN PAKISTAN:

Following are the main industrial applications of PLCs in Pakistan

WIND TURBINE OPERATIONS:
Alternate energy systems are now very common in Pakistan. PLCs replaces the use of mechanical sensors that were previously used for wind speed measurement and is found to be reliable, affordable and user-friendly. Almost all of the wind turbine power plants uses PLC systems to make the precise measurements and eliminating the inefficiencies. It’s vital that wind turbines have accurate information regarding wind conditions to operate safely, as wind data is useful to record turbulence and to protect the turbine. PLC converts signals from wind speed and directions sensor to better control the wind turbines. Data from the PLCs is transmitted to a control center where engineers perform statistical analysis, program the PLCs and turbine controllers, and analyze data to predict failures before they happen. Information provided by PLC is then transmitted to the control centers where it is analyzed to prevent failures.

CEMENT MANUFACTURING:

Currently there are 26 cement plants operating in Pakistan all of them are using PLC systems to ensure the right quality and quantities of raw materials used for the processes. PLC systems used in cement manufacturing are very comprehensive as there are wide range of analog inputs (temperature, pressure, flow, noise level, height measurement, process values) as well as digital signals that are very useful for equipment safeties and fault diagnostics. This automation has significantly improved plant performance with the reduction in labor cost as all of the information can be gathered in the control center by SCADA which take notice of all the developing problems and take corrective measures.

POWER PLANTS AND GRID STATION:

In Pakistan, power is produced by two vertically coordinated public sector utilities: Water and Power Development Authority (WAPDA) that produces for all of Pakistan (with the exception of Karachi), and the Karachi Electric (K-Electric) for Karachi and its encompassing zones. The independent power producers (IPPs) that also contribute in electricity generation are 42 in total.
There are four major power producers in country: WAPDA, K-Electric, IPPs and Pakistan atomic energy commission (PAEC). 

Power production deals with the generation, transmission and circulation divisions. With respect to this the main aspect is monitoring in all these three territories. The implementation of SCADA in power production increases efficiency of the system that is helpful for optimization and overall supervision of the generation and transmission systems. SCADA enhances the reliability and stability for integrated grid operation.

PLC integrated with SCADA for Power Generating Stations:

With the utilization of PLC integrated with SCADA in power producing stations helps providing flexibility to the system also delivering optimal solution in each and every process.

Automation for Power Distribution System:

Power distribution system includes the transmission of electric power from generating station to the loads with the help of different transmission and distribution substations. Most of the power distribution system depends on manual labor needed for the distribution tasks like interfering the power to loads, monitoring of parameters on hourly basis, fault diagnosis, etc. The implementing SCADA/PLC system to the power distribution not only reduces the cost but also provides automated smooth operations with minimized disruptions.

Programmable logic controllers in substations consistently screen the substation segments and transmits that to centralized PC based SCADA system. In case of any blackouts of power this SCADA permits to distinguish the area of fault in this way without sitting tight for the calls from clients SCADA gives an emergency system to the administrators for recognizing and counteracting it.

Different types of power stations present in Pakistan operating on PLC systems are as follows:

1.      Thermal

2.      Natural Gas

3.      Coal

4.      Hydroelectricity

5.      Nuclear

6.      Renewables

STEEL SECTOR:

In this era of technology demand for electricity has increased with the grown living standards. Most of the power producers are facing difficulties in meeting the increased demands from almost all consumer sectors.

The consumption of industrial sector is about 41% of the total electrical energy generated worldwide.

For iron and steel industries, electricity consumption is about 30% of total production costs.

By taking advantage of incentives in order to encourage users to efficiently use energy so as to minimize load can significantly save electricity cost as well as production costs without negative effects on productivity and quality of production.

Automation is one of the best option available for industries for load management.

Steel has always been the most important engineering material used in the modern era. The steel industry is plays an important role in the economy.

Steel plants processes have complex sequences of operations hence automation plays an essential role. Automation provides information about the plant conditions which helps in maintenance of the plant equipment and make them reliable and available for production.

Automation systems used in the steel industry can be classified as follows.

·         Fixed automation – It is a special purpose dedicated equipment having fixed set of operation. It is used where high production is involved.

·         Programmable automation – Programmable automation system is used where medium to high product volume is involved. In this automation sequence of operation and configuration of the machines is changeable using electronic controls.

·         Flexible automation: This type of automation can be used where variety of products can be manufactured. In this automation system commands in the form of codes are entered in the computer to get optimum output results. It is mostly used where production rates are low and frequent changes are required due to dependency on demands.

·         Integrated automation system: This type of automation performs all operations using information and communication technologies. It makes use of technologies such as flexible machining systems, automated handling machines like robots, automated cranes etc.

There are five levels of automations which are commonly employed in steel industry. These levels are given below.

·         Level 0 – This level usually involves no automation or also called manual control.

·         Level 1 – The level I automation includes DDC (dedicated digital controller) .It is used in production processes. It does not include networking. The level 1 automation systems have capability to handle more complex MIMO (multi input and multi output) systems. They’re operator’s console.

·         Level 2 – This automation level includes supervisory control. It forms a hierarchical control system by combining production process and management information with the process control.

·         Level 3 – Level 3 automation system is an integrated automation system that contains production planning and control functions. Maintenance planning and analysis of data is also included in level 3. Enterprise resource planning (ERP) is a popular software based technology used in level 3 automation.

·         Level 4 – It is similar to level 3 controls but can be easily controlled through satellite from a remote area. Level 4 actually connects customer orders and material and makes capacity allocation to production. 

Fig shows the different level of automation.

Fig Functional hierarchy of a control system at the different level of automation

PHARMACEUTICAL INDUSTRIES:

For the sake of optimized production and enhancements in the supply chain have increased the use of automation technologies across the pharmaceutical industry. Consequently, with the evolution in technology, the process involved in manufacturing of pharmaceuticals have been automated.
The impact of automation systems has transformed the pharmaceutical manufacturing environment.

Continuous Manufacturing and Multi Products:

Earlier manufacturing facilities have to rely on developing the same product every year. To meet the needs of multiple customers flexible facilities are required for which multi-product manufacturing facilities are needed. Hence automation can be employed for such sites that have capability to meet the customer demands accordingly.

Traditional pharmaceutical companies have been slow to find new technologies for continuous production as they have predefined policy of maximum asset utilization on the plant. Therefore, automation helped much in this regard.

 It refers to new tools and procedures that introduces smart decentralized production, intelligent systems that work efficiently and reduces the waste, increasing the production rates with reliability of the equipment.
Automation simply introduces technological advancement that includes some proven solutions and has provided positive and bigger advantage to pharmaceutical manufacturing.

It provides manufacturers full monitoring of operations of the plant and allow them to control, manage and handle the operations of the plant accordingly. This cutting edge technology is making almost everything automated like if a gauge temperature is showing higher than expected reading the system will automatically take the desired action rather than requiring an operator to control the situation.
In addition, this technology uses machine learning algorithms will be able to manage manufacturing lines and production scheduling quickly. Also it can predict due maintenance and the capability to identify and solve issues before they happen.

TEXTILE INDUSTRY:

In most sectors of textile manufacturing process, automation is one of the major key to quality improvement and cost competitiveness. Early modernization and technical developments in textiles concentrated on the automation of textile machines and their processes. Now automation has taken place in all the processes involving textile manufacture i.e. cotton picking, ginning, spinning, weaving, and processing and even to some extent in garment making, resulting in enormous gains in productivity and efficiency. Some of the changes that have come about in textile industry are recapitulated below. 

Automation is one of the key to quality improvement and cost competitiveness in most sectors of textile manufacturing. The technical developments in textiles focused on the automation and processes of textile machinery that results in improved efficiency and high production rates.

Following are the main processing divisions where PLC systems are currently deployed and running successfully.

1). Cotton picking

2). Weaving

3). Ginning

4). Spinning

5). Processing

6). Packing