Academic and Professional Background[edit | edit source]
Samiksha Koirala from Nepal is an Electrical Engineer with an interest in renewable energy. She completed he Bachelor of Engineering degree from Kathmandu University in 2021.
During her studies, she was involved in several academic projects, which includes, the design and fabrication of a personal occupancy indicator, a pollution trapper, a three-phase sequence detector and voltage protection circuit, and a PLC-based elevator. She completed a semester in the Masters program in Entrepreneurship and Innovation at the University of Oslo in Oslo, Norway. However, She could not complete the degree for personal reasons.
During the final year of her undergraduate studies, she interned at the Pokhara Grid Branch, Nepal Electricity Authority (Government of Nepal). Here, she gained valuable insights into power distribution systems and understood how the grid works and is maintained. Additionally, her work as an intern and full-time employee at Comtronics Pvt. Ltd., a renewable/solar energy company, provided her with hands-on experience in field surveys, system design and development, installation and commissioning of photovoltaic systems. Comtronics Pvt. Ltd. mostly deals with solar roof-top systems, electric fencing, pumping and others. She is currently working here.
Till now, She has been involved in 2 on-site projects.
- 15kWp Roof-top Solar PV system at Star Hospital Limited in Sanepa, Lalitpur, Nepal.
- 81.45kWp Roof-top Solar PV system at Aarus Lifestyle Hospital in Pulchowk, Lalitpur Nepal.
Thesis Research Topic[edit | edit source]
Bachelors Degree in Electrical and Electronics Engineering
PLC Based Elevator Control System_ Jan 2021[edit | edit source]
Samiksha Koirala Pushparaj Kandel Lamin Lama
Supervisor: Dr. Diwakar Bista, Assistant Professor, Kathmandu University [./Https://www.researchgate.net/profile/Diwakar-Bista
Introduction
Traditional elevator control systems are relay logic-controlled systems. These relay-controlled systems have several limitations: high fault ratio, highly complex circuits, and difficulty replacing the defective parts of the automated system. It is difficult to provide fault tolerance using the relay logic. PLC(Programmable Logic Controller) is the replacement to relay logic controller; one can make better use of PLC in the designing of the elevator control system. A Programmable Logic Controller (PLC) is an industrial computer control system that continuously monitors the state of input devices, then makes decisions based upon a custom program in order to control the state of output devices.
Objective
The aim of the thesis was to get familiar with the workings of PLC, execute the PLC (Programmable Logic Controller) based elevator control system using EcoStruxure Machine Expert, and visualize the system in VTSCADA.
Methodology
At the starting phase of the project, a literature review was done. So, different books, internet resources, and the research paper related to Programmable Logic Controller (PLC). From this, the primary and secondary data were collected. Different systems available in the market were also considered to understand how the system works. Then, the team started designing the elevator system. First of all, the no. of elevator floors to be installed was decided. Then the calculation for the elevator cabin including the no. of passengers was determined. Based on the passenger’s maximum weight, the size and weight of the cabin, as well as a counterweight, was selected. Then the calculation of the motor’s power and torque was done. Different sensors including load cell, IR sensor, temperature, and rotary encoders are used for sensing the individual presence, pressure applied as well as the rotation speed of the motor. All these outputs from sensors are provided as input to the controller. PLC programming was used to control the overall system. PLC ladder programming was done in EcoStruxure Machine Expert and the model of the elevator was implemented in VTSCADA.
Result
The program-controlled elevator operations such as car calls, floor calls, open, and close buttons as well as safety sensors. An HMI screen was also added to the project for visualisation and better monitoring of the program. The ladder logic was used to implement the logic for PLC interfacing with the SCADA. All the parameters associated with the system were calculated and every connection diagram required for the system was developed. These calculations and diagrams can be used for prototype development.
Conclusion and Discussion
The objectives of the thesis were fulfilled in the end. This elevator system can be expanded by using additional inputs and outputs of PLC to control elevators for high-rise buildings and more features can be offered in this system.
Leadership and Volunteering Activities[edit | edit source]
In addition to her professional work, she is also actively involved in leadership and volunteer activities. She is a former National Board Member of Amnesty Nepal, and she has also served as an executive member of several other organizations, including NESCO, the Kathmandu University Robotics Club, and the president of Student Welfare Council of Diamond Model School. She coordinated the biggest annual event of the Department of Electrical and Electronics Engineering, Kathmandu University. She was also the hostel prefect of Kathmandu University Girls Hostel.