Ravi Nath Tripathi

A MATLAB-simulink-based solar photovoltaic array (SPVA) module with MPPT

The performance of a solar photovoltaic array (SPVA) is dependent upon the temperature and irradiance level and it is necessary to study the characteristics of photovoltaic (PV) array. To utilize PV power or extract maximum power from PV array, the maximum power point tracking (MPPT) technique is essential to study and implement. In this paper, an equivalent electrical circuit of PV system has been modelled and its characteristics are studied. Response of the PV array with different irradiance level is also obtained. Incremental conductance algorithm of MPPT is modelled and developed to extract maximum power from PV array. The design of dc-dc boost converter has been carried out. It is observed that maximum power from PV array is achieved at input and output side of the dc-dc converter. The simulation work is done in MATLAB/SIMULINK environment.

SRF theory based grid interconnected Solar Photovoltaic (SPV) system with improved power quality

This paper presents the concept of interconnection of Solar Photovoltaic (SPV) power generating system using Synchronous Reference Frame (SRF) theory based control in indirect current control mode of operation. This proposed theory improves the power factor and voltage at point of common coupling (PCC). Voltage at PCC is maintained through reactive power compensation. The whole power generating system consists of SPV system, dc-dc boost converter, maximum power point tracking (MPPT), voltage source converter (VSC), ripple filter, different types of loads, interfacing inductor and three phase grid. This system eliminates harmonic currents and load balancing is also possible using it. The grid-interconnected SPV system is tested for two modes i.e. unity power factor mode of operation and voltage regulation mode, with load balancing problems of linear loads.

FRIT based optimized PI tuning for DC link voltage control of grid connected solar PV system

The grid connected photovoltaic (PV) system have been modeled and simulated using control algorithm with dedicated PI control for dc link voltage regulation. Generally, the PI controller used for the system is tuned using trial and error method but this method is having manual limitation for the tuning of controller so as to obtain the desired response like as regulating dc link voltage to reference value. Fictitious reference iterative tuning (FRIT) method using particle swarm optimization (PSO) helps to generate optimized gains for PI controller which can results in the improved response in terms of response time and overshoot. In this paper, PSO-FRIT based optimized tuning of controller is proposed for the application in LCL filter interfaced grid connected PV system. The current controlled dc-ac power converter has been used for grid connected PV system. Active power reference current for pulse width modulated (PWM) converter is been generated using power balance theory (PBT). The idea of the FRIT based optimized tuning of PI controller is implemented by using the input data and output data from the system obtained using the trial and error method based controller gains. The power quality of the system configuration have been maintained as according to the IEEE-519 standards.

Improvement in power quality using Fryze conductance algorithm controlled grid connected solar PV system

In this paper the grid connected PV system is modelled and simulated by using the Fryze conductance based current minimization algorithm. The control algorithm for grid connected PV system is based upon the generation of average active component of current by the calculation of instantaneous average conductance for the load. The dedicated PI controller is used to maintain the dc link voltage. In this paper the control algorithm is implemented to force the source current and supply the average active component of load with the loss compensation current generated by PI controller to maintain the dc link voltage. The power quality improvements have been shown using the simulation results for non-linear load and linear load. The concept behind the current minimization is to supply the average active power of the loads from the source with minimum r.m.s. value of current.

2-DOF based novel controller design for DC voltage regulation of LCL interfaced three phase grid connected solar PV system

The dedicated PI controller for dc voltage regulation and control has been implemented with control technique for operation of grid-connected PV system. Generally, dedicated PI controller have been used for the dc link voltage control due to ease of implementation. The PI controller is having constraint regarding response time and overshoot with only proportional and one integral gain. The conventional PI controller is having one degree of freedom (DOF). In this paper the 2-DOF PI controller in PI-P configuration is been proposed for the dc link voltage control. It is based upon the concept to increase the DOF in the system. The system with PI-P controller with 2 DOF having two proportional gains and one integral gain. The performance of the PI-P controller is compared with the PI controller while PV system connected to grid (considering grid current response) and under disturbance in reference dc voltage. The system transient during interconnection have been improved and showing better response for dc voltage control.

Multiband HCC for cascaded H-bridge multilevel inverter based DSTATCOM

In this paper, cascaded H-bridge multilevel inverter (CHBMLI) based distribution static compensator (DSTATCOM) has been proposed. Synchronous reference frame theory (SRFT) based indirect current control is employed to extract the reference current. The instantaneous error in between the reference current and output current is processed through multiband hysteresis current controller (MHCC) for inner current control loop of DSTATCOM. MHCC algorithm requires switching pattern which leads to the generation of multilevel output for the inverter. DSTATCOM executes task like compensation of reactive power, harmonic compensation and load balancing. LCL filter is designed and employed to interface the multilevel inverter and grid, due to its advantage of low cost, smaller size, superior attenuation capability. The performance of CHBMLI based DSTATCOM model simulated in MATLAB-Simulink has been investigated and analyzed under different load condition.

Cascaded H-bridge multilevel inverter for renewable energy generation

In this paper cascaded H-bridge multilevel inverter (CHBMLI) has been investigated for the application of renewable energy generation. Energy sources like solar, wind, hydro, biomass or combination of these can be manipulated to obtain alternative sources for renewable energy generation. These renewable energy sources have different electrical characteristics like DC or AC level so it is challenging to use generated power by connecting to grid or load directly. The renewable energy source require specific power electronics converter as an interface for conditioning generated power .The multilevel inverter can be utilized for renewable energy sources in two different modes, the power generation mode (stand-alone mode), and compensator mode (statcom). The performance of the multilevel inverter has been compared with two level inverter. In power generation mode CHBMLI supplies the active and reactive power required by the different loads. For operation in compensator mode the indirect current control based on synchronous reference frame theory (SRFT) ensures the grid operating in unity power factor and compensate harmonics and reactive power.