A Study on Adaptive Interpolated PI Gain Scheduling for SEPIC Voltage Regulation in Solar Application

The Single-Ended Primary Inductor Converter (SEPIC) Using Adaptive Interpolation PI Gain Scheduling.

The research aimed at maintaining the output voltage level (Vout) using DC/DC buck-boost of SEPIC type and designing the control algorithm in overcoming the input voltage fluctuation.

This was the quantitative research design. The research showed the modeling, design, and Simulation result of SEPIC circuit controlled using the adaptive interpolated PI control. The Simulation process was conducted using PSPICE software. Data were collected from the exploration result of Kp and Ki values for the value of the Average Absolute Verror (AAVe), Maximum Overshoot (Mp) and Settling Time (Ts) on each of Vin 20V, 40V, 60V, and 80V, and the Simulation time used was 100ms. From the data of exploration result determined the best value of Kp and Ki with some certain method that is (Mp) criteria for transient and (AAVe) for steady (method 1), average with certain weight (method 2), average with the same weight (method 3) And summation of three criteria with certain constants (method 4). Then modeled of the Kp and Ki polynomial Interpolation equations which are adaptive to Vin changes.

The results show that the four Adaptive PI control methods are capable to maintaining (Vout) according to (Vreff) even though Vin has fluctuating values. The four methods of generating (AAVe) values are below 100mV. The average of (Mp) value is less than 1V or 2% of 50V. The average of (Ts) time less than 7ms, representing the time that can still be tolerated. Based on the combined effect of voltage Overshoot, resistance to Vin change and algorithm complexity, method 1 is the best method.