In control system design it is difficult to ascertain the appropriate value of controller gain. Generally a high gain value causes an excessively oscillatory response with the possibility of instability, while a low gain value produces a slow system response. The desired optimal response is a value of gain that produces a quick system response with minimal steady state error and oscillation; this paper investigates various steps to get this system response. The main objective of this proceeding is to achieve unit step response curve of the designed system which exhibits a maximum overshoot of no more than 15%. To check the system response for reducing maximum overshoot, the system has been controlled via a PID Controller with Variable Plant Transfer Function. The proposed controller is mathematically designed and modeled with MATLAB, and the results are presented to confirm the PID controller effectiveness. Furthermore, the proposed approach is fairly simple for implementation in real time.

For healthy environment and sustainable economic growth we need clean and efficient electric power generation systems. The natural sources of renewable energy available to human are: the solar, tidal, wind, bio-gas and biomass etc. This paper introduces a new renewable source of energy; energy from cow urine that can produce electricity by electrolytic conductions. The alkaline nature of fresh cow urine acts as a good electrolyte liquid. The system works like a conventional battery system. However, a discharged battery needs to recharge by electricity in order to reactivate it. On the other hand, cow urine based system needs only to replace old urine by fresh urine to activate the system again. As no electricity is required for charging the system, the daily available fresh urine from a dairy farm could be a possible source of renewable energy. In order to understand the feasibility of the source, we built a car battery size prototype that can hold approximate five liter of fresh urine as electrolyte. We used similar and equal number of electrode that a typical car battery does. We measured the performance of the source with loads and observed its outputs. The details of the system and its performances have been described in this paper.