Proportional integral controller gain tuning using real time digital simulation models and multi-objective optimization based co-simulation

Proportional integral (PI) controller is a widely used controller strategy. It has two gain constants: proportional(kp) and integral(ki) gain constant. The dynamics of the PI controller depends on the values of the gain constant used. If gains of these control terms are not selected properly, instability will occur. Gain tuning methodologies are available to tune these controllers to avoid instability. But, these gain tuning strategies and algorithms utilize simplified mathematical model of the plant in order to obtain gain values. This approach might not provide optimal gain values for models used in real time digital simulator. In the proposed approach, the algorithm utilizes the step response of the system to obtain optimal gain constants. The plant is modeled using the real time digital simulator (RTDS). A multi-objective optimization formulation is used to find the optimal gain constants. Results are presented here to support the effectiveness of proposed multi-objective gain tuning strategy.