An Efficient Scheme of Automation and Control for Conventional Cable Manufacturing Industry

In context of a 132 kV stranded conductor manufacturing plant, a unique automation scheme combining active energy front (AEF) along with variable frequency drives (VFDs) synchronization for achieving virtual electronic shaft aiming for simplified kinematics is implemented. A new design concept of tension control in take-up system and winding pitch control through autotraverse control was developed for unmanned operation. The outcome was optimum line speed and the power consumption linearly varying with increase in line speed, which is the core advantage of using synchronized line speed via VFD. There is no hidden energy loss in the system and the inertia of the whole driven system is also reduced. In case of high-voltage cable, the life expectancy depends upon the uniform pattern of lay length with compactness, and it is a significant achievement in terms of improvement in the product quality. The novelty of this work is the simultaneous implementation of various features in a single working setup. Conventional design of very long shaft attached with huge gearboxes is replaced with a virtual electronic shaft synchronizing seven VFDs attached to a very heavy inertial load. When considering the project size, there should be replacement of the high-maintenance-prone switchgears with AEF and LCL filters coupled with common dc bus; this helps in reducing the overall project cost. Self-controlled clean and quality power [below 3% of total harmonic distortion (THD)] feeding to utility network was achieved. Energy saving with improved power factor and higher efficiency is a significant achievement from this setup. Configurable automation software using the programmable logic control (PLC) and human machine interface (HMI) for flexible production was used as per market requirements (especially for 132-kV conductor sector). The scope of this paper is limited to the overview of implementing the automation scheme, energy savings, harmonics control, and other process control related to plants. The uniqueness of this experimental research project is generation and analysis of basic primary data (from September 2012 to current) and the publication available for this data. All activities from concepts to commissioning were systematically implemented and proved to be techno-economically viable.