Solar PV fed cascaded H-bridge multilevel inverter and SIMO-SEPIC based MPPT controller for 3-phase grid connected system with power quality improvement
01 Dec 2017-
TL;DR: This paper proposes a new two stage Solar Energy Conversion System (SECS) for grid power support and power quality improvement where extendable symmetric cascaded H-bridge multilevel inverter for grid synchronization and the SIMO-SEPIC for maximum Power point tracking (MPPT) is used.
Abstract: This paper proposes a new two stage Solar Energy Conversion System (SECS) for grid power support and power quality improvement where extendable symmetric cascaded H-bridge multilevel inverter for grid synchronization and the Single Input Multiple Output Single Ended Primary Inductance Converter (SIMO-SEPIC) for maximum Power point tracking (MPPT) is used. The inverter reference signals are obtained through Synchronous Reference Frame (SRF) control and the gate signal is generated by Phase Disposition Pulse Width Modulation (PD-PWM). The control of SIMO-SEPIC is achieved by Perturb & Observe (P&O) based MPPT algorithm. The SECS is designed for 250kVA, 415V system and the proposed model is tested for 7 level output voltage (line-line). The intensive simulation studies under various load conditions and irradiation variations are carried out using MATLAB with its SIMULINK platform. The steady state and dynamic performance results validate the theoretical findings.
Citations
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TL;DR: A binary hybrid multilevel inverter (BHMLI) based grid-connected solar energy conversion system (SECS), controlled by damped second-order generalized integral (DSOGI), designed to inject active power to the grid, and also mitigates the harmonic and reactive power demands of the load.
Abstract: This paper presents a binary hybrid multilevel inverter (BHMLI) based grid-connected solar energy conversion system (SECS), controlled by damped second-order generalized integral (DSOGI). The BHMLI architect has a cascaded half-bridge array, which modifies the DC-link of the H-bridge of the voltage source inverter, and results in approximate reference waveform. It reduces the dV/dt of the H-bridge switches and improves output waveform quality. The DSOGI control damps the oscillations and overshoots and provides longer service period of low power switches at transient conditions. It is implemented in the multilevel inverter application for the first time in literature. The SECS is designed to inject active power to the grid, and also mitigates the harmonic and reactive power demands of the load. The cascading of n' half-bridges and one H-bridge generate (2
(nC1)
- 1) output voltage levels. The maximum power extraction from solar photovoltaic (PV) array is achieved through incremental conductance (IC) algorithm based maximum point tracking (MPPT) operation of the DC-DC converter. An isolated single-input multiple-output single-ended primary inductance converter (SIMO-SEPIC) realizes it. SECS with 15-level BHMLI is analyzed with extensive simulation as well as with a hardware prototype. Moreover, the shunt active filter functionality of the system at various load conditions are verified and maintained the grid power quality within the IEEE-519 standard throughout the operation. The laboratory developed setup is tested for 5 kW, 400 V, three-phase system, and the experimental analysis at steady-state and dynamic variations of load-side and insolation variations validate the theoretical claims.
28 citations
Cites background or methods from "Solar PV fed cascaded H-bridge mult..."
...The inductance value of La is derived as [8],...
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...It is well used for PV applications and reported in [8], and it is in conjunction with a SEPIC converter....
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...The output voltage across the nth secondary winding of SIMO-SEPIC Vn is derived as [8],...
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TL;DR: In every mode of operation, the SPCS mitigates the total load demanding NFAP and thereby keeping the grid currents as sinusoidal and in-phase with the fundamental grid phase voltages and maintaining the IEEE-519 grid power quality standard.
Abstract: This article presents a new control for the multi-functional operation of a grid-connected solar power conversion system (SPCS). It is a combination of several generalized integrals for grid synchronization as well as fundamental load current component extraction. This multiple generalized integral (MGI) control is designed to overcome the demerits of conventional integral controllers with inadequate operation at adverse grid conditions such as grid frequency variation, phase jumps, DC offsets, noise, harmonics and other waveform distortions. The control is designed to separate the load power accurately into two-parts, i.e. active fundamental part (AFP) and non-active fundamental part (NAFP). This control extracts the AFP of the load current even during the disturbed grid and unbalanced load conditions. According to the comparison with the load current AFP and the photovoltaic (PV) available power ( $P_{pv}$ ), three operating modes are used such as bright mode, dim mode and dark mode. During the bright mode, the total load power is being supported by the system and the remaining power is injected to the grid, the load power is shared by the system and the grid during the dim mode, and the load current AFP is supported by the grid during the dark mode. In every mode of operation, the SPCS mitigates the total load demanding NFAP and thereby keeping the grid currents as sinusoidal and in-phase with the fundamental grid phase voltages and maintaining the IEEE-519 grid power quality standard. This system is modelled and the performance is simulated in MATLAB/Simulink platform, and simulated results are presented. A prototype of the system, is developed in the laboratory and test results at various operating conditions are reported for validation of the system.
13 citations
Cites methods from "Solar PV fed cascaded H-bridge mult..."
...The d− q components of the grid voltages are evaluated from the positive sequence voltage component by Park’s transformation [14] and the grid frequency, ωg is derived from the quadrature component,...
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...An SPCS with synchronous reference frame (SRF) theory based controller is reported in [14]....
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01 Dec 2018
TL;DR: A two stage Solar Energy Grid Connected System with Zeta converter for DC-DC and Cascaded H-bridge Multilevel Inverter (CHB-MLI) for DCAC conversions are proposed and results produced to validate the theory are produced.
Abstract: In this paper a two stage Solar Energy Grid Connected System (SEGCS) with Zeta converter for DC-DC and Cascaded H-bridge Multilevel Inverter (CHB-MLI) for DCAC conversions are proposed. The shunt connected SEGCS is demonstrated with a non linear unbalance reactive local load. The active power generated in the Photo Voltaic (PV) system with respect to the irradiations is shared to the load and the grid. The reactive and distortion power demand of load is continuously delivered by the SEGCS and therefore keeping the grid voltage and current sinusoidal and in phase by implementing Synchronous Reference Frame Theory-Phase Disposition PWM (SRFT-PDPWM) based control. The power sharing by the cascaded H-bridges improves the power rating. The increased number of levels and reduced switching frequency results reduction in harmonics and filter dimensions compared to two level inverters. The performance of CHB-MLI is compared with other topologies in this paper. The wide range operation of Zeta converter utilized for Maximum Power Point Tracking (MPPT) in addition with the firefly algorithm based duty ratio calculation. The Simulation analysis of the proposed work carried out with a 100 kVA capacity in MATLAB/SIMULINK model and a hardware prototype is developed. The steady state and dynamic performance of the SEGCS under various PV side and load side disturbances is carried out and results produced in this paper to validate the theory.
8 citations
01 Feb 2019
TL;DR: This paper proposes a grid tied Solid Oxide Fuel Cell (SOFC) system that has been further connected to a boost converter and an inverter to create a grid connected power generation system.
Abstract: Solid Oxide Fuel Cell (SOFC) based Transportation system have been reported as the future of human society. The SOFC based systems are pollution free and it converts fuel to electrical energy at high efficiency. The use of these fuel cell electric vehicle as stationary power production unit has added to the future prospects of such systems. This will help in creating a network of decentralized small scale power production units in the grid. Such power production units can be used effectively to meet the peak power demands in the grid.This paper proposes a grid tied Solid Oxide Fuel Cell (SOFC) system. The mathematical modelling of fuel cell given literature has been analysed and a Solid Oxide Fuel Cell (SOFC) model has been simulated. The SOFC has been further connected to a boost converter and an inverter to create a grid connected power generation system. Synchronous reference frame (SRF) theory has been used to syncronise the output of the proposed system to the grid. The proposed system has also been simulated using MATLAB with its Simpower system Blockset. The performance of the proposed system is found to be satisfactory.
7 citations
Cites methods from "Solar PV fed cascaded H-bridge mult..."
...The reference signal (Ig*) for the inverter is obtained by using a control strategy based on Syncronous Reference frame (SRF) theory and further Phase disposition – Pulse width modulation (PD-PWM) is used to get the gating signals [20]....
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16 Dec 2020
TL;DR: In this paper, a grid-connected photovoltaic-fuel cell hybrid system with a fixed power dispatch to the grid using a modified least mean square control has been proposed to control the power flow from the sources and the load.
Abstract: Hybrid systems comprising renewable energy sources based distributed energy generation connected to the grid with energy storage systems increase the cost and control complexity. But, to provide reliable power to the grid, storage systems are essential. Here, a grid-connected Photovoltaic-Fuel cell hybrid system with a fixed power dispatch to the grid using a modified least mean square control has been proposed. This has been realized to control the power flow from the sources and the load. Any variation in the photovoltaic power is balanced by power from the fuel cell by introducing a power management scheme. The change in power flow to the load arising at the transient stage due to the slow response of the fuel cell is met by power support from the grid. Moreover, the hybrid system mitigates power quality issues at the point of interconnection in the grid. The performances of the system during steady-state and transient conditions are verified by extensive simulation analysis with MATLAB with its simpower system block set.
4 citations
References
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TL;DR: In this article, the authors focus on inverter technologies for connecting photovoltaic (PV) modules to a single-phase grid and categorize the inverters into four classifications: 1) the number of power processing stages in cascade; 2) the type of power decoupling between the PV module(s) and the single phase grid; 3) whether they utilizes a transformer (either line or high frequency) or not; and 4) the kind of grid-connected power stage.
Abstract: This review focuses on inverter technologies for connecting photovoltaic (PV) modules to a single-phase grid. The inverters are categorized into four classifications: 1) the number of power processing stages in cascade; 2) the type of power decoupling between the PV module(s) and the single-phase grid; 3) whether they utilizes a transformer (either line or high frequency) or not; and 4) the type of grid-connected power stage. Various inverter topologies are presented, compared, and evaluated against demands, lifetime, component ratings, and cost. Finally, some of the topologies are pointed out as the best candidates for either single PV module or multiple PV module applications.
3,530 citations
TL;DR: In this article, some of the recently proposed multilevel inverter topologies with reduced power switch count are reviewed and analyzed, both in terms of the qualitative and quantitative parameters.
Abstract: Multilevel inverters have created a new wave of interest in industry and research. While the classical topologies have proved to be a viable alternative in a wide range of high-power medium-voltage applications, there has been an active interest in the evolution of newer topologies. Reduction in overall part count as compared to the classical topologies has been an important objective in the recently introduced topologies. In this paper, some of the recently proposed multilevel inverter topologies with reduced power switch count are reviewed and analyzed. The paper will serve as an introduction and an update to these topologies, both in terms of the qualitative and quantitative parameters. Also, it takes into account the challenges which arise when an attempt is made to reduce the device count. Based on a detailed comparison of these topologies as presented in this paper, appropriate multilevel solution can be arrived at for a given application.
890 citations
"Solar PV fed cascaded H-bridge mult..." refers background in this paper
...The transformer less multilevel inverters in the area of grid connected PV system of high power, medium voltage is finding more applications [11]-[13] and are advantageous due to ability to generate lower harmonic output, less number of components and high power handling capacity [14]-[15]....
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TL;DR: In this paper, an extensive literature review is conducted on emerging power quality challenges due to renewable energy integration, which are caused by non-controllable variability of renewable energy resources.
Abstract: Renewable energy becomes a key contributor to our modern society, but their integration to power grid poses significant technical challenges. Power quality is an important aspect of renewable energy integration. The major power quality concerns are: 1) Voltage and frequency fluctuations, which are caused by noncontrollable variability of renewable energy resources. The intermittent nature of renewable energy resources due to ever-changing weather conditions leads to voltage and frequency fluctuations at the interconnected power grid. 2) Harmonics, which are introduced by power electronic devices utilized in renewable energy generation. When penetration level of renewable energy is high, the influence of harmonics could be significant. In this paper, an extensive literature review is conducted on emerging power quality challenges due to renewable energy integration. This paper consists of two sections: 1) Power quality problem definition. Wind turbines and solar photovoltaic systems and their power quality issues are summarized. 2) Existing approaches to improve power quality. Various methods are reviewed, and the control-technology-based power quality improvement is the major focus of this paper. The future research directions for emerging power quality challenges for renewable energy integration are recommended.
518 citations
TL;DR: An improved maximum power point tracking with better performance based on voltage-oriented control (VOC) is proposed to solve a fast-changing irradiation problem andSimulations and experimental results demonstrate that the proposed method provides effective, fast, and perfect tracking.
Abstract: In this paper, an improved maximum power point (MPP) tracking (MPPT) with better performance based on voltage-oriented control (VOC) is proposed to solve a fast-changing irradiation problem. In VOC, a cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous orthogonal d,q frame using a decoupled feedback control. The reference current of proportional-integral (PI) d-axis controller is extracted from the dc-side voltage regulator by applying the energy-balancing control. Furthermore, in order to achieve a unity power factor, the q-axis reference is set to zero. The MPPT controller is applied to the reference of the outer loop control dc voltage photovoltaic (PV). Without PV array power measurement, the proposed MPPT identifies the correct direction of the MPP by processing the d-axis current reflecting the power grid side and the signal error of the PI outer loop designed to only represent the change in power due to the changing atmospheric conditions. The robust tracking capability under rapidly increasing and decreasing irradiance is verified experimentally with a PV array emulator. Simulations and experimental results demonstrate that the proposed method provides effective, fast, and perfect tracking.
500 citations
"Solar PV fed cascaded H-bridge mult..." refers background in this paper
...The single stage finds the applications in medium power transfer because the converter stage is responsible for Maximum Power Point Tracking (MPPT) [5],[6] and grid synchronization which lead over burden to the device....
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07 Jul 1998
TL;DR: In this paper, the suitability of multilevel voltage source inverters for single-phase grid connected photovoltaic systems is investigated regarding issues such as component count and stress, system power rating, and the influence of the PV array earth capacitance.
Abstract: Multilevel voltage source inverters offer several advantages compared to their conventional counterparts. By synthesising the AC output terminal voltage from several levels of voltages, staircase waveforms can be produced, which approach the sinusoidal waveform with low harmonic distortion, thus reducing filter requirements. The need of several sources on the DC side of the converter makes multilevel technology attractive for photovoltaic applications. This paper provides an overview an different multilevel topologies and investigates their suitability for single-phase grid connected photovoltaic systems. Several transformerless photovoltaic systems incorporating multilevel converters are compared regarding issues such as component count and stress, system power rating and the influence of the photovoltaic array earth capacitance.
453 citations
"Solar PV fed cascaded H-bridge mult..." refers background in this paper
...The transformer less multilevel inverters in the area of grid connected PV system of high power, medium voltage is finding more applications [11]-[13] and are advantageous due to ability to generate lower harmonic output, less number of components and high power handling capacity [14]-[15]....
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