Direct current (DC) servomotor-based parabolic antenna is automatically positioned using control technique to track satellite by maintaining the desired line of sight for quality transmission and reception of electromagnetic wave signals in telecommunication and broadcast applications. With several techniques proposed in the literature for parabolic antenna position control, there is still a need to improve the tracking error and robustness of the control system in the presence of disturbance. This paper has presented positioning control of DC servomotor-based antenna using proportional-integral-derivative (PID) tuned compensator (TC). The compensator was designed using the control and estimation tool manager (CETM) of MATLAB based on the PID tuning design method using robust response time tuning technique with interactive (adjustable performance and robustness) design mode at a bandwidth of 40.3 rad/s. The compensator was added to the position control loop of the DC servomotor–based satellite antenna system. Simulations were carried out in a MATLAB environment for four separate cases by applying unit forced input to examine the various step responses. In the first and second cases, simulations were conducted without the compensator (PID TC) in the control loop assuming zero input disturbance and unit input disturbance. The results obtained in terms of time-domain response parameters showed that with the introduction of unit disturbance, the rise time improved by 36 % (0.525–0.336 s) while the peak time, peak percentage overshoot, and settling time deteriorate by 16.3 % (1.29–1.50 s), 43.5 % (34.7–49.8 %), and 7.6 % (4.35–4.68 s), respectively. With the introduction of the PIDTC for the third case, there was an improvement in the system’s overall transient response performance parameters. Thus to provide further information on the improved performance offered by the compensator, the analysis was done in percentage improvement. Considering the compensated system assuming zero disturbance, the time-domain response performance parameters of the system improved by 94.1, 94.7, 73.1, and 97.1 % in terms of rising time (525–30.8 ms), peak time (1,290–67.9 ms), peak percentage overshoot (34.7–9.35 %), and settling time (4.35–0.124 s), respectively. In the fourth case, the compensator’s ability to provide robust performance in the presence of disturbance was examined by comparing the step response performance parameters of the uncompensated system with unit input disturbance to the step response performance parameters of the compensated system tagged: with PID TC + unit disturbance. The result shows that PID TC provided improved time-domain transient response performance of the disturbance handling of the system by 91.0, 95.4, 80.0, and 93.1 % in terms of rising time (336–30.5 ms), peak time (1500–69.1 ms), peak percentage overshoot (34.7–10.0), and settling time (4.68–0.325 s), respectively. The designed compensator provided improved robust and tracking performance while meeting the specified time-domain performance parameters in the presence of disturbance.

Gas turbine as a fast response unit, suitable for improving transient response of the power system at any time when there is problem usually from 15-20 seconds in some cases has been lost to some unforeseen issues due to energy demand, lack of control measures, improper attention , relatively high constraints in increasing and decreasing the power output during the nominal operation. Refinery which is one of the outfit of Nigeria National Petroleum Corporation (NNPC) is one of the most important sources of revenue to the federal government of Nigeria . Hence efficient energy and stability of energy is very paramount. This paper has presented a control system for improving the response time of speed/load-frequency of a typical gas turbine in a refinery in Nigeria. The objective of the study is to reduce the response time of the Gas turbine when there is abnormal increase in load or transient in the system, to enhance stability. . In order to realize the objective, the dynamic equations of a single shaft heavy duty gas turbine (HDGT) were obtained for loadfrequency control operation. The dynamic equations were transformed into their equivalent simulink model in Matlab/Simulink environment. A lead phase compensator was initially developed for the control loop and maintaining the optimized performance specification, a proportional, integral and derivative (PID) controller was developed in Matlab/Simulink environment. The governor speed droop of 4% was used for the simulation. An analogue controller was designed. The essence of the analogue controller is only to demonstrate the fact that the control loop developed in this context used a permanent droop of 4% which gave the speed governor gain of 25 (per unit MW/per unit speed). Hence the optimized compensator performance specifications were then maintain and used to develop a PID structure with the same performance but with improved tracking. The designed PID controller was improved by adding a low pass filter to the derivative component. This greatly improved the transient response time. The simulations results showed that the introduction of the nonlinear PID controller significantly improved the transient response time of the system from 20s to 10.5s. This was achieved by introducing a nonlinear PID controller as part of the control loop, and consequently improved the performance thereby reducing the response time greatly.