05-07-2013, 02:33 PM
SCADA Implementation of Industrial Temperature Automation
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Abstract
This paper concentrates upon the development of an automated setup for the measurement of temperature of any industrial environment, for example boilers, refrigerators and heaters etc. The hardware requirements are significantly curtailed using the microcontroller’s modern embedded features like A/D conversion, display interface, hardware and software interrupts, and communication protocols for interfacing cellular phones and GSM modules. This truncation in hardware requirement has lead to a smarter industrial temperature automation design.
Introduction
There are several industrial processes including those of manufacturing, power generation, fabrication and refining that require an immediate and accurate temperature control and monitoring infrastructure. This paper concentrates upon the development of one such infrastructure, with fewer hardware details. The hardware requirement is minimized by using simpler firing angle generation hardware and data acquisition particulars.
This design incorporates a temperature sensor installed in any industrial environment, a motherboard card for deciphering the temperature senor’s FEEDBACK information and based on SETPOINT definition, issuing a timed firing pulse for actuating a TRIAC controlling the magnitude of HVAC provided to the particular industrial equipment. The SETPOINT is communicated to the motherboard via wireless channel, from the HMI. Once the coincidence between SETPOINT and FEEDBACK temperatures occur the equipment is made to operate in equilibrium. Both the SETPOINT and FEEDBACK temperatures are displayed on an LCD panel, for the convenience of operation and maintenance of the particular equipment.
Software Description
The algorithmic representation of this project is outlined below in figure 2. The algorithm was embedded into a PIC18F452 microcontroller using the compiler called MikroC Pro for PIC v4.6 [4].
The entire algorithm is divided into following major steps,
1. Acquiring the SETPOINT temperature via HMI
2. Continuously monitoring the FEEDBACK temperature from the temperature sensor
3. Comparing the FEEDBACK with SETPOINT, and accordingly ramping up or down the HVAC output from the actuator.
So first of all the SETPOINT temperature is acquired from the HMI. The operator is required to send a temperature array (in the following format
) from the HMI via text message. This text message is deciphered by the microcontroller using the standard AT Commands. This way a 3-digit SETPOINT temperature number is extracted from it. In the flowchart below, this number is represented as SETPOINT TEMP.
Results
The software simulation of this project was carried out in Proteus Professional ISIS 7.7. However, Proteus ISIS has a simulation shortcoming that it cannot perform necessary mathematical modeling of the clipping waveforms. So in order to perform the mathematical modeling, the aid of LabVIEW was employed.
In this section of the research paper, we wish to explore the error between the paper calculated values for output voltage from the HVAC actuator, and the values obtained from the mathematical model of LabVIEW. Figure 3 below shows the simulation environment of Proteus ISIS and Figure 4 shows the front panel of the LabVIEW VI.
Conclusions
In this research paper, our prime concern was the development of demonstrating how industrial temperature automation can be made possible using little hardware and more refined software details. The prime concern was to generate firing pulse for an HVAC controlling actuator while displacing them at the same time to vary the magnitude of the ac voltage output. The direction of displacement of the pulse was described by the SETPOINT definition from an HMI using AT commands, and FEEDBACK from the temperature sensor installed in the industrial environment. The mathematical modeling was done in LabVIEW for investigating the impact of varying firing angle on the magnitude of the ac voltage. This controlled variation of output ac voltage can be subjected to controlling temperature of the particular industrial environment.