Solar photovoltaic (PV) is one of the most emerged and widely used alternative source of energy that can support existing conventional sources of energy used in electrical power generation to a larger extent. At present, grid connected solar PV systems are used extensively, but standalone solar PV system plays a very important role in providing electric power to the places where power grid is not available (e.g., some villages located at remote places and remote islands). It can also be used in standalone mode for applications such as toys, calculator, electric vehicle, space crafts, and satellites. This paper presents high gain DC-DC converters which enables the use of low voltage solar PV system for high-voltage applications which can be used as a DC link voltage of modular multilevel converter (MMC). It minimizes the effect of changing weather conditions which continuously changes solar irradiance by varying duty cycle. Simulation of the converter is carried out by using MATLAB/Simulink software under constant load condition and by varying the load at the output.

High Gain DC-DC Converter for Modular Multilevel Converter Applications

The increasing consumption of conventional energy in the world with increasing costs of fossil fuel is justifiable reason for using fuel cell technology with high performance. However, the output voltage of fuel cell stack is very low and it is not sufficient to drive the electric vehicle. This paper put forward the three level hybrid boost dc-dc converter, which can be step-up the fuel cell output voltage with high voltage gain. The working principle of present converter is based on the traditional neutral clamped multi level inverter. Here, IGBT based three level converter is designed and steady state of filtering capacitors are observed with MATLAB software. Fuel cell stack is designed in the place of normal dc battery. Hybrid boost dc-dc converter is connected to Multi level inverter for AC output to drive EV. Finally, the simulation results are discussed.

Design and simulation of front end converter for fuel cell based electric vehicle applications

This article, presents a hybrid converter for micro-grid application is proposed. It consists of a Solar PV as a DC source, and a storage battery to power a local DC load. The proposed converter is a simple circuit that integrated a bidirectional half-bridge DC-DC converter and a boost converter to perform charging, discharging of storage battery, and MPPT control respectively. The MPPT control for solar PV is achieved using Perturb and Observe method. A closed-loop control system is developed using PI control to charge and Discharge the battery. This DC micro-grid is integrated with the grid system and the performance of the converter is evaluated using MATLAB/Simulink software. In comparison to existing converters, the proposed converter has a lower number of power components and achieved an efficiency of 95.7%.

Hybrid DC-DC Converter for DC Microgrid Applications

This article, presents a hybrid converter for micro-grid application is proposed. It consists of a Solar PV as a DC source, and a storage battery to power a local DC load. The proposed converter is a simple circuit that integrated a bidirectional half-bridge DC-DC converter and a boost converter to perform charging, discharging of storage battery, and MPPT control respectively. The MPPT control for solar PV is achieved using Perturb and Observe method. A closed-loop control system is developed using PI control to charge and Discharge the battery. This DC micro-grid is integrated with the grid system and the performance of the converter is evaluated using MATLAB/Simulink software. In comparison to existing converters, the proposed converter has a lower number of power components and achieved an efficiency of 95.7%. 

The output voltage from renewable energy sources like photovoltaic cell or array will be at low level. This must be stepped up by an order of around 20 for practical applications or grid connection. Series connection of arrays is not a viable solution. The proposed DC-DC converter topology consists of a novel single switch high gain DC-DC converter which will be a combination of coupled inductor and voltage multiplier cells (VMCs). The approach is to achieve high step up gain by using appropriate duty cycle and the turns ratio of the coupled inductor. This is done by charging the two capacitors in parallel and discharging them in series via a coupled inductor. The voltage multiplier cell operates as regenerative circuit reducing the problems with layout. These characteristics allow the operation with high efficiency and high static gain.

High gain hybrid DC-DC converter

This article presents a dynamic model of a pneumatic braided muscle (PBM) actuator which is inspired from skeletal muscle model. The behavior of the PBM actuator can be simulated as Hill muscle model and thus, it is modeled as an equivalent nonlinear spring dashpot system. Instead of empirical relations, the force-stretch relation of the actuator derived in our earlier work based on finite deformation theory is utilized. The nonlinear equation of motion is solved for both free and forced vibration cases numerically. The frequency analysis of the forced vibration is performed using the multiple scales method. Furthermore, the effect of various parameters like damping, material stiffness, and geometry on the nonlinear response of the actuator has been examined using time response, phase portrait, and frequency response at simple resonance condition. This study will assist researchers to determine safe system parameter range for diverse applications. 

Dynamic modeling of pneumatic braided muscle actuator based on Hill muscle model

Abstract In booster synchrotron, fast-ramped power converters (FRPCs) are used for ramping up the magnetic field of electromagnets connected in series, at a fast rate, typically 1,000s of ampere per second. In large accelerators, the number of electromagnets is large. Therefore, during ramping, the peak value of driving voltage becomes prohibitively large considering the insulation requirement of the magnets and cables. The power converter is therefore developed by connecting a suitable number of smaller voltage rated modules in series. The series-connected modules are operated in phase-staggered mode to reduce the output voltage ripple or to reduce the filtering requirement to meet the prescribed ripple voltage. Since the filter component values predominantly decide the dynamic response, the achievable small-signal bandwidth of the control loop and hence the achievable tracking accuracy of the ramping output current are essentially governed by the filter components. To optimise the filter design, quantification of overall ripple voltage is crucial, that too under the most practical conditions considering non-ideal conditions. In this paper, estimation of overall ripple voltage is performed for series-connected two-quadrant power converters (TQPCs) operating in phase-staggering mode for ideal and non-ideal conditions. Simulation and experimental verification results are shown to be in good agreement with the analytical results.

Abhishek Srivastava

Papers

High gain hybrid DC-DC converter

Dynamic modeling of pneumatic braided muscle actuator based on Hill muscle model

Estimation of Output Voltage Ripple in Phase-Staggered Series-Connected Two-Quadrant Power Converters for Electromagnets in Particle Accelerators