Engineering topics

Sadhukhan, Debashis

Publications and source records attributed to Sadhukhan, Debashis.

4 records

NASA NTRS2013

The Integration of DCS I/O to an Existing PLC

At the NASA Glenn Research Center (GRC), Existing Programmable Logic Controller (PLC) I/O was replaced with Distributed Control System (DCS) I/O, while keeping the existing PLC sequence Logic. The reason for integration of the PLC logic and DCS I/O, along with the evaluation of the resulting system is the subject of this paper. The pros and cons of the old system and new upgrade are described, including operator workstation screen update times. Detail of the physical layout and the communication between the PLC, the DCS I/O and the operator workstations are illustrated. The complex characteristics of a central process control system and the plan to remove the PLC processors in future upgrades is also discussed.

Sadhukhan, Debashis↗

NASA NTRS2003

The Integration of Fieldbus Devices to an Existing DCS

Existing analog strain gauge transducers and signal conditioners were replaced with new Foundation Fieldbus Transmitters in the Distributed Control System, DCS, at the NASA Glenn Research Center (GRC). The reasons for implementing this upgrade and an evaluation of the results of the project are the subjects of this paper. Problems and advantages with the original transducers and the newly installed transmitters are described and compared. Detail of the physical network layer between the Foundation Fieldbus Transmitters, Programmable Logic Controllers (PLCs), Multipurpose Micro-Processor (MMPs) and the operator workstations are illustrated. The complex nature of the facility and methods of future control of the associated processes are also discussed.

Sadhukhan, Debashis↗

NASA NTRS2003

Static Frequency Converter System Installed and Tested

A new Static Frequency Converter (SFC) system has been installed and tested at the NASA Glenn Research Center s Central Air Equipment Building to provide consistent, reduced motor start times and improved reliability for the building s 14 large exhausters and compressors. The operational start times have been consistent around 2 min, 20 s per machine. This is at least a 3-min improvement (per machine) over the old variable-frequency motor generator sets. The SFC was designed and built by Asea Brown Boveri (ABB) and installed by Encompass Design Group (EDG) as part of a Construction of Facilities project managed by Glenn (Robert Scheidegger, project manager). The authors designed the Central Process Distributed Control Systems interface and control between the programmable logic controller, solid-state exciter, and switchgear, which was constructed by Gilcrest Electric.

Brown, Donald P.↗

NASA NTRS1998

The Application of Dedicated Controllers to Parallel/Serial Exhauster Trains

Twenty new dedicated controllers were interfaced to the Distributed Control System (DCS) at NASA Lewis Research Center. Better surge avoidance, improved energy savings, interface intricacies, and plant complexities are the subjects of this paper. Problems with the existing Programmable Logic Controller (PLC) control logic are described as well as the solutions implemented with the new controllers. The complexity of the new communication network between the dedicated controllers, Multipurpose Micro-Processor (MMPs), and the operator workstations are illustrated. The complicated nature of the plant and methods of controlling the associated processes are also discussed.

Sadhukhan, Debashis↗