A Novel Computational Approach for Harmonic Mitigation in PV Systems with Single-Phase Five-Level CHBMI

Abstract

In this paper, a novel approach to low order harmonic mitigation in fundamental switching frequency modulation is proposed for high power photovoltaic (PV) applications, without trying to solve the cumbersome non-linear transcendental equations. The proposed method allows for mitigation of the first-five harmonics (third, fifth, seventh, ninth, and eleventh harmonics), to reduce the complexity of the required procedure and to allocate few computational resource in the Field Programmable Gate Array (FPGA) based control board. Therefore, the voltage waveform taken into account is different respect traditional voltage waveform. The same concept, known as "voltage cancelation", used for single-phase cascaded H-bridge inverters, has been applied at a single-phase five-level cascaded H-bridge multilevel inverter (CHBMI). Through a very basic methodology, the polynomial equations that drive the control angles were detected for a single-phase five-level CHBMI. The acquired polynomial equations were implemented in a digital system to real-time operation. The paper presents the preliminary analysis in simulation environment and its experimental validation.It is well known that the fundamental multilevel topologies include the diode-clamped [4-6], flying capacitor [7], and cascaded H-bridge (CHB) structures [8]. Diode-clamped technology employs diodes to separate direct current (DC) voltage levels from one DC source at its midpoint. The flying capacitor technique substitutes diodes with capacitors. The cascaded H-bridge technique employs different DC sources to create different DC voltage levels.An interesting review can be found in the literature [9], which also takes into account the inverter's cost, by taking the factors numbers sources, switches, and variety. In the works of [10][11][12], good reviews are also performed.Inverters can also be classified according to their applications [10]: renewable energy applications [11][12][13][14][15][16][17][18][19][20][21], automotive [22][23][24][25][26][27], heavy traction [28,29], power quality [30,31], and industrial drives [32,33]. In the literature [13], the performance in terms of harmonics distortion rates were faced in order to extract maximum power from the PV modules. Again, that authors of [14,15] face the harmonics distortion by implementing a fast switching modulation, but without considering power losses. The authors of [16] recommend a single phase multilevel inverter configuration with three series connected full bridge inverter and a single half bridge inverter. In this case, a reduction of harmonics in terms of total harmonic distortion rate (THD) is evaluated around 9.85%. In another paper [17], a spice model considers not only the THD, but also the storage element. Again, in the literature [18], a simulation of the performance of multilevel inverter is made taking into account the partial shaded condition of PV panels. In the work of [19], a multilevel invert is used to reduce the THD. The simulation generates a 15-level output voltage with 8.12% of total har...

Hardware in the Loop Real-time Simulation for the Associated Discrete Circuit Modeling Optimization Method of Power Converters

“…After calculating the statistical parameters of e ges , we can obtain the SNR using Equation (20). In order to apply the SNR calculation to power electronic modeling, SNR calculation needs to be generalized to matrix operation.…”

“…One possibility is to consider a priori the switch admittance parameter, and then find the corresponding optimum value by comparing the offline simulation results with the benchmark results to minimize the relative errors; however, such a trial-and-error method has a low efficiency [19]. Within this context, the paper proposes a novel approach to choose the optimal switch admittance parameter, Gs, by minimizing the switching loss to reduce the computations required and increase the simulation precision.The high parallelism offered by FPGAs and their potential to conduct a real-time simulation in the nanosecond range make these devices an emerging processor for real-time simulation of a complex power electronic system [20][21][22][23][24]. However, due to the limited FPGA hardware resources, it is especially important to balance FPGA resource consumption and simulation accuracy.…”

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A Harmonic Compensation Strategy in a Grid-Connected Photovoltaic System Using Zero-Sequence Control

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