In this paper, an adaptive nonlinear control strategy for the energy management of a polymer electrolyte membrane fuel cell and supercapacitor-based hybrid electric vehicle is proposed. The purpose of this work was to satisfy: (i) tight DC bus voltage regulation, (ii) good fuel cell reference current tracking, (iii) better supercapacitor reference current tracking (iv) global asymptotic stability of the closed-loop control system, and (v) better vehicle performance by catering to slowly-varying parameters. We have selected the power stage schematic of a hybrid electric vehicle and utilized adaptive backstepping and adaptive Lyapunov redesign-based nonlinear control methods to formally derive adaptive parametric update laws for all slowly-varying parameters. The performance of the proposed system has been tested under varying load conditions using experimental data from the “Extra Urban Driving Cycle.” Mathematical analysis and Matlab/Simulink results show that proposed controllers are globally asymptotically stable and satisfy all the design requirements. The physical effectiveness of proposed system has been verified by comparing simulation results with the real-time controller hardware in the loop experimental results. Results show that proposed system shows satisfactory performance and caters for the time-varying parametric variations and the load requirements.

To enhance the move towards a sustainable society, the solar Photovoltaic (PV) industry and its applications are progressing at a rapid rate. However, the associated issues need to be addressed when connecting PV to the grid. Advanced and efficient controllers are required for the DC link to control the second harmonic ripple and current controllers to inject quality active and reactive power to the grid in the grid-connected PV system. In this paper, DC-link voltage, active power, and reactive power are successfully controlled in stationary reference using Adaptive-PI (A-PI) and Adaptive-Sliding Mode Controller (A-SMC) for a 3 kW single-phase two-stage transformerless grid-connected inverter. A Resonant Harmonic Compensator (RHC)-based Proportional Resonant (PR) controller is employed in the current-controlled loop. The magnitude, phase, and frequency information of the grid voltage are provided by Second-Order General Integral (SOGI)-based PLL that has harmonic immunity, fast-tracking accuracy, and a rapid-dynamic response. MATLAB^®/Simulink^®/Simscape R2017b were used for the test bench implementation. Two scenarios were considered: in the first case, the input PV power feedforward loop was avoided, while in second case, it was included. The feedforward loop of input PV power improved the overall system dynamics. The results show that the designed controller improves both the steady-state and dynamic performance as compared with a proper-regulated PI-controller. The proposed controllers are insensitive to active and reactive power variations, and are robust, stable, faster, and fault tolerant, as compared to controllers from prior studies.

Managed Pressure Drilling (MPD) is a control technique for controlling pressure in the presence of wave disturbance. It works as an insurance against delays due to weather conditions by saving time and increasing the efficiency of offshore drilling operations. During MPD, a circulating drilling fluid is released in well through control choke which helps to dynamically control fluid pressure in the presence of undesirable pressure deviations. Pressure deviations are caused by vertical motion of drill string because of wave disturbance (Heave Motion) which may damage the well. Control system should be able to keep fluid pressure on the desired set value by releasing controlled fluid through control choke. In this paper, backstepping based controller is designed for five volumes model of well pressure dynamics. The controller attenuates pressure fluctuations because of disturbance and keeps pressure near to desired value. Results will be compared with previously used controllers for pressure regulation. Matlab simulation results show that backstepping based controller designed for five volumes model restricts pressure variations within ±1 bar in the presence of heave disturbance of ±10 m. Backstepping based controller is simple to implement on higher order well models. It attenuates heave disturbance of higher amplitudes as compared to previously proposed controllers.

In this paper, a Tri-band antenna for Global Positioning System (GPS) and Digital Video Broadcasting -Handheld (DVB-H) applications is proposed. It cover two bands for GPS L1 (1.557GHz) and L2 (1.21GHz) and one band for DVB-H (1.45GHz) applications. Circular polarization is achieved at both L1 and L2 bands. This paper is an extension of a pervious paper in which antenna was operating at two L1 and L2 bands and circular polarized radiation pattern was achieved at both bands. Proposed antenna can operate at three bands. An additional band is achieved in comparison with the previous design. Impedance bandwidth of 30 MHz & 45 MHz is achieved at L1 and L2 bands respectively and 34.5 MHz at DVB-H band. The antenna is circularly polarized at all the three bands. The gain of antenna is 8.1 dBi, 9.1 dBi and 9.50 dBi at 1.227GHz, 1.557GHz and 1.452 GHz respectively.