Alivarani Mohapatra, Byamakesh Nayak and Kanungo Barada Mohanty
This paper aims to propose a simple, derivative-free novel method named as Nelder–Mead optimization algorithm to estimate the unknown parameters of the photovoltaic (PV) module…
Abstract
Purpose
This paper aims to propose a simple, derivative-free novel method named as Nelder–Mead optimization algorithm to estimate the unknown parameters of the photovoltaic (PV) module considering the environmental conditions.
Design/methodology/approach
At a particular temperature and irradiation, experimental current-voltage (I-V) and power-voltage (P-V) characteristics are drawn and considered as a reference model. The PV system model with unknown model parameters is considered as the adaptive model whose unknown model parameters are to be adapted so that the simulated characteristics closely matches with the experimental characteristics. A single diode (Rsh) model with five unknown model parameters is considered here for the parameter estimation.
Findings
The key advantages of this method are that parameters are estimated considering environmental conditions. Experimental characteristics are considered for parameter estimation which gives accurate results. Parameters are estimated considering both I-V and P-V curves as most of the applications demand extraction of the actual power from the PV module.
Originality/value
The proposed model is compared with other three well-known models available in the literature considering various statistical errors. The results show the superiority of the proposed model with a minimum error for both I-V and P-V characteristics.
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Kanungo Barada Mohanty, Kishor Thakre, Aditi Chatterjee, Ashwini Kumar Nayak and Vinaya Sagar Kommukuri
This study aims to propose a modified topology for an asymmetric multilevel inverter as a basic module that generates 13-level output voltage waveform. The basic module consists…
Abstract
Purpose
This study aims to propose a modified topology for an asymmetric multilevel inverter as a basic module that generates 13-level output voltage waveform. The basic module consists of eight switches (unidirectional and bidirectional switch) and four DC voltage sources with unequal magnitudes. The proposed topology reduces the number of switches, isolated DC sources, cost and size of the circuit significantly as compared to other topologies. In addition, the proposed circuit provides a modular structure for a multilevel inverter.
Design/methodology/approach
The proposed configuration is implemented through simulation and hardware development of a single-phase 13-level inverter prototype. A multicarrier-based pulse width modulation scheme is adopted for generating switching signals by using dSPACE real-time controller.
Findings
To demonstrate the advantages of the proposed configuration, a comparative analysis is carried out with other multilevel topologies in terms of number of switches, gate driver circuits, on-state switches and blocking voltage on the switches. The comparison results confirmed that the proposed configuration requires less number of components for the same number of voltage levels. Moreover, the peak inverse voltage on switches and losses is lower in the proposed configuration.
Originality/value
In the available literature, numerous topologies are presented with main emphasis on the reduced components count. In this study, the authors proposed a new topology for an asymmetrical source configuration. The performance of the proposed topology under steady-state and dynamic conditions is evaluated using simulation and experimental implementation.
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Swagat Pati, Kanungo Barada Mohanty and Sanjeeb Kumar Kar
This paper aims to demonstrate the efficacy of fuzzy logic controller (FLC) over proportional integral (PI) and sliding mode controller (SMC) for maintaining flat voltage profile…
Abstract
Purpose
This paper aims to demonstrate the efficacy of fuzzy logic controller (FLC) over proportional integral (PI) and sliding mode controller (SMC) for maintaining flat voltage profile at the load bus of a single-generator-based micro-grid system using STATCOM.
Design/methodology/approach
A STATCOM is used to improve the voltage profile of the load bus. The performance of the STATCOM is evaluated by using three different controllers: PI controllers, FLCs and SMCs. The performance comparison of the controllers is done with different dc bus voltages, different load bus voltage references, various loads such as R-L loads and dynamic loads.
Findings
A comparative analysis is done between the performances of the three different controllers. The comparative study culminates that FLC is found to be superior than the other proposed controllers. SMC is a close competitor of fuzzy controller.
Originality/value
Design of fuzzy logic and SMCs for a STATCOM implemented in a single-generator-based micro-grid system is applied.
Details
Keywords
Ashwini Kumar Nayak, Kanungo Barada Mohanty, Vinaya Sagar Kommukuri and Kishor Thakre
The purpose of this paper is to show the effect of randomness of wind speed on the capacity value estimation of wind power. Three methods that incorporate hourly wind speed have…
Abstract
Purpose
The purpose of this paper is to show the effect of randomness of wind speed on the capacity value estimation of wind power. Three methods that incorporate hourly wind speed have been evaluated.
Design/methodology/approach
Wind speed is simulated using autoregressive moving average method and is included in the calculation of reliability index as a negative load on an hourly basis. The reliability index is calculated before and after the addition of wind capacity. Increment of load or alteration of conventional capacity will lead to capacity estimation.
Findings
Among the aforementioned three methods, the former two exclude the availability rate and give the exact value for wind capacity addition. The third method is based on the availability rate and provides a little higher capacity value, indicating a clear correlation between availability and capacity value.
Originality/value
The methods that exclude the availability rate show consistent results. By including the availability rate, the third method predicts the inverse relation between the availability rate and the capacity value.
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Kanungo Barada Mohanty and Pavankumar Daramukkala
The purpose of this study is to provide the enhancement of power quality of a high power-rated voltage source inverter driven induction motor with a three-phase, three-level…
Abstract
Purpose
The purpose of this study is to provide the enhancement of power quality of a high power-rated voltage source inverter driven induction motor with a three-phase, three-level neutral point clamped converter placed at the front end, while a passive power filter is connected in shunt with it. The improvement in power quality can be achieved by reducing the total harmonic distortion in source current. The controllers were designed for the linearization of the high-power induction motor drive. A control method is presented for the regulation of the common DC-link voltage.
Design/methodology/approach
The induction motor is modeled using its dynamic equations, and a decoupling controller is designed to linearize the nonlinear dynamics of the drive through feedback. The common DC-link voltage of the proposed front-end connected converter is monitored and controlled through a control method which feeds the pulse width modulated inverter that drives the induction motor. A passive power filter is designed to meet the reactive power requirement of the system in addition to improve the power quality.
Findings
Simulations were carried out for the proposed topology of the drive mechanism, and the outcomes were analyzed by a comparative analysis of the drive system both in the presence of the passive filter as well as in the absence of the filter. The total harmonic distortion is found to be reduced enough to meet the standards with the designed filter, and the reactive power is also compensated considerably. The input power factor at the supply side is maintained almost to unity, and the DC-link voltage of the proposed circuit topology is maintained at the desired level. The overall performance of the drive system was found to be useful and economical.
Originality/value
A new topology of a front-end connected three-level neutral point clamped converter to a high power-rated induction motor drive is proposed. The drive is fed by a pulse width modulated inverter with a common DC-link with the front end connected converter. A passive filter is designed with respect to the reactive power requirement of the system and connected in shunt to the converter at the supply side. Control schemes are designed and used for the drive system and also for the regulation of the common DC-link voltage of the proposed front end connected converter.
Details
Keywords
Swagat Pati, Kanungo Barada Mohanty and Sanjeeb Kumar Kar
The purpose of this paper is to evaluate the suitability and robustness of sliding mode controller (SMC) for maintaining flat voltage profile at the load bus of two different…
Abstract
Purpose
The purpose of this paper is to evaluate the suitability and robustness of sliding mode controller (SMC) for maintaining flat voltage profile at the load bus of two different micro-grid systems using STATCOM.
Design/methodology/approach
Two micro-grid systems are dynamically modelled and simulated using MATLAB/Simulink. The first micro-grid has a single diesel engine-driven synchronous generator. The second micro-grid has one diesel engine-driven synchronous generator and a doubly fed induction generator-based wind energy conversion system. The STATCOM is connected to the load bus in both the micro-grids. SMC is used for the control of STATCOM for voltage profile improvement of micro-grid. The performance of SMC-based STATCOM is analysed and compared with the performance of conventional PI controller-based STATCOM.
Findings
The SMCs are more suited for STATCOM control as these are more immune to load disturbances even with the presence of wind energy generators. The voltage deviations and the steady state errors in voltage are less with SMC. Although SMC introduces a bit of steady state error in the dc link voltage of the STATCOM, it is much less than the settling limit of 2 per cent, which is quite acceptable. SMC proves to be better than conventional PI controllers in both the proposed models of micro-grid.
Originality/value
Design of a robust first-order SMC for a STATCOM is used for voltage profile improvement in two different micro-grid systems.