scholarly journals New Optimized Control of Cascaded Multilevel Converters for Grid Tied Photovoltaic Power Generation

2021 ◽  
Vol 54 (5) ◽  
pp. 769-776
Author(s):  
Karima Benamrane ◽  
Thameur Abdelkrim ◽  
Benlahbib Benlahbib ◽  
Noureddine Bouarroudj ◽  
Abdelhalim Borni ◽  
...  
Keyword(s):  
Duty Cycle ◽  
Fuzzy Logic Controller ◽  
Pulse Width Modulation ◽  
Multilevel Converters ◽  
Pi Regulator ◽  
Duty Cycles ◽  
Dc Bus ◽  
Bus Voltage ◽  
Two Stages

This paper proposes a new optimized control of photovoltaic two stages conversion cascade composed by Three Levels Boost (TLB) and Three Levels Neutral Point Clamped (TLNPC) inverter. In order to extract the maximum power from photovoltaic generator and get a balanced DC bus voltage, the duty cycles of the two TLB switches are determinate from a Fuzzy Logic Controller (FLC) for the first switch and by adding to the first duty cycle an additional duty cycle obtained by integration of the error between the two capacitors voltages of DC bus. Balancing the bus voltages by the TLB using a single regulator avoid us to use a complex balancing algorithm by the redundant vectors of TLNPC inverter. For the control of the inverter, we used a Proportional Integral (PI) regulator optimized by PSO. This command allows us to have on one side a constant DC bus voltage and a current injection in phase with the grid voltage. To have an efficient follow-up of the TLNPC inverter reference voltages, the Space Vector Pulse Width Modulation (SVPWM) is applied. The simulation is carried out in MATLAB/SIMULINK platform. The results obtained from the application of the FLC command associated with PI PSO are better compared to the simulation without optimization in terms of sum of the absolute values of the errors at the inputs of the three PI regulators.

Photovoltaic System with SEPIC Converter Controlled by the Fuzzy Logic

2016 ◽  
Vol 7 (4) ◽  
pp. 1283 ◽  
Author(s):  
Meryem Oudda ◽  
Abdeldjebar Hazzab
Keyword(s):  
Fuzzy Logic ◽  
Duty Cycle ◽  
Output Voltage ◽  
Fuzzy Logic Controller ◽  
Photovoltaic System ◽  
Utilization Efficiency ◽  
Solar Pv ◽  
Solar Panels ◽  
Dc Bus ◽  
Bus Voltage

<span lang="EN-US">In this work, a fuzzy logic controller is used to control the output voltage of a photovoltaic system with a DC-DC converter; type Single Ended Primary Inductor Converter (SEPIC). The system is designed for 210 W solar PV (SCHOTT 210) panel and to feed an average demand of 78 W. This system includes solar panels, SEPIC converter and fuzzy logic controller. The SEPIC converter provides a constant DC bus voltage and its duty cycle controlled by the fuzzy logic controller which is needed to improve PV panel’s utilization efficiency. A fuzzy logic controller (FLC) is also used to generate the PWM signal for the SEPIC converter. </span>

scholarly journals Novel approach for SVPWM of two-level inverter fed induction motor drive

2020 ◽  
Vol 11 (4) ◽  
pp. 1750
Author(s):  
Olwi A. Elkholi ◽  
Mohamed A. Enany ◽  
Ahmed F. Abdo ◽  
Mahmoud Eid
Keyword(s):  
Induction Motor ◽  
Pulse Width Modulation ◽  
Frequency Converter ◽  
Harmonic Distortion ◽  
Motor Drives ◽  
New Approaches ◽  
Novel Approach ◽  
Three Phase ◽  
Dc Bus ◽  
Bus Voltage

<p class="Abstract">Due to their better DC bus utilization and easier digital realization, Space Vector Pulse Width Modulation (SVPWM) scheme is the most widely used PWM scheme. Also two level inverter is the traditional frequency converter because it has fewer components and is lower complex to control, but on the other hand it generates higher harmonic distortion. This paper presents the realization of novel SVPWM approaches applied to the three phase induction motor drives. Specifically various schemes are based on using more combinations of step operation in each cycle to approximate the reference vector, such as 24 and 48 step operations in each cycle. The basic principle of conventional SVPWM with different modulation index M is presented. The switching sequences of new approaches are described. The modulation signals waveforms, DC bus voltage utilization, De-rated motor torque, standard error of average torque, voltage and current harmonic of new approaches are analyzed by the MATLAB/SIMULINK software. The results confirms that 48 step SVPWM approach is the best compared to other approaches.</p>

scholarly journals Fast compensation of DC bus voltage drops using modular multilevel converters

2019 ◽  
Vol 2019 (17) ◽  
pp. 3906-3911 ◽  
Author(s):  
Christoph Stark ◽  
Dierk Danowski ◽  
Jose-Luis Marqués ◽  
Claus Hillermeier
Keyword(s):  
Multilevel Converters ◽  
Voltage Drops ◽  
Modular Multilevel Converters ◽  
Dc Bus ◽  
Bus Voltage

scholarly journals A simplified SVPWM method for cascaded multilevel inverters

2021 ◽  
Vol 2062 (1) ◽  
pp. 012032
Author(s):  
Nishant Matale ◽  
Mohan Thakre ◽  
Rakesh Shriwastava
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Strategies ◽  
Harmonic Distortion ◽  
Superior Performance ◽  
The Novel ◽  
Multilevel Converters ◽  
Medium Voltage ◽  
Multilevel Inverters ◽  
Bus Voltage

Abstract A highly popular alternative in medium voltage and high-power applications is multilevel converters because of their superior performance over conventional two-level converters. The most commonly used control methods in the case of multilevel inverters are sine pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) methods. Among these two control strategies, SVPWM has superior performance over SPWM in terms of DC bus voltage utilization along with a reduction in total harmonic distortion (THD) of line voltages. The classical SVPWM method has various drawbacks such as computational complexity for identifying the location of reference voltage vector, sector identification, region identification, memory requirement to store lookup tables for switching vectors. The novel simplified SVPWM technique is presented for cascaded H-Bridge multilevel inverter (CHBMLI) in this paper. This simplified SVPWM method has overcome the drawbacks of the classical SVPWM method. This new technique has been implemented into a five-level CHBMLI to evaluate performance and also to compare with the SPWM method. The simulation has been performed in MATLAB software.

MPPT of Wind Generation for DC Microgrid

2013 ◽  
Vol 448-453 ◽  
pp. 1802-1805 ◽  
Author(s):  
Yuan Sheng Xiong ◽  
Su Xiang Qian ◽  
Qing Song Liu ◽  
Yan Zhan
Keyword(s):  
Duty Cycle ◽  
Output Voltage ◽  
Maximum Output Power ◽  
Boost Converter ◽  
Wind Generation ◽  
Maximum Output ◽  
Output Current ◽  
Dc Microgrid ◽  
Dc Bus ◽  
Bus Voltage

In order to maintain the maximum output power of the WGS (Wind generation system) for all wind speed conditions, a boost converter is used as the power interface between the WGS and DC microgrid. Traditional method is to directly measure the real-time output voltage and current of WGS by sensors. Considering the DC bus voltage is actually stable, the output voltage can be computed by the duty cycle of boost converter and the stable DC bus voltage. A MPPT method is proposed, which only measures the output current of WGS. The output scale power can be obtained by the output current and the duty cycle, and then the perturbation and observation method is executed. A number of voltage sensors and associated circuitry are cancelled. It reduces the interference and system cost and improves the system reliability. Simulation results with PSIM prove the validity of the proposed method.

scholarly journals Performances of Photovoltaic System Using Grid Tied Transformerless Inverter

2021 ◽  
pp. 287-292
Author(s):  
Ashish Raut ◽  
Sneha Tibude
Keyword(s):  
Leakage Current ◽  
Pulse Width Modulation ◽  
Neutral Line ◽  
Photovoltaic System ◽  
Pv Systems ◽  
Double Frequency ◽  
Power Switches ◽  
Dc Bus ◽  
Bus Voltage ◽  
Inverter Topology

In order to eliminate the common-mode (CM) leakage current in the transformer less photovoltaic (PV) systems, the concept of the virtual dc bus is proposed in this paper. By connecting the grid neutral line directly to the negative pole of the dc bus, the stray capacitance between the PV panels and the ground is bypassed. As a result, the CM ground leakage current can be suppressed completely. Meanwhile, the virtual dc bus is created to provide the negative voltage level for the negative ac grid current generation. Consequently, the required dc bus voltage is still the same as that of the full-bridge inverter. Based on this concept, a novel transformer less inverter topology is derived, in which the virtual dc bus is realized with the switched capacitor technology. It consists of only five power switches, two capacitors, and a single filter inductor. Therefore, the power electronics cost can be curtailed. This advanced topology can be modulated with the unipolar sinusoidal pulse width modulation (SPWM) and the double frequency SPWM to reduce the output current ripple. As a result, a smaller filter inductor can be used to reduce the size and magnetic losses.

scholarly journals An Evolutionary Algorithm-Based PWM Strategy for a Hybrid Power Converter

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1247
Author(s):  
Alma Rodríguez ◽  
Avelina Alejo-Reyes ◽  
Erik Cuevas ◽  
Francisco Beltran-Carbajal ◽  
Julio C. Rosas-Caro
Keyword(s):  
Direct Current ◽  
Duty Cycle ◽  
Pulse Width Modulation ◽  
Differential Evolution Algorithm ◽  
Power Converter ◽  
Power Sharing ◽  
Input Current ◽  
Cuk Converter ◽  
Duty Cycles ◽  
Current Ripple

In the past years, the interest in direct current to direct current converters has increased because of their application in renewable energy systems. Consequently, the research community is working on improving its efficiency in providing the required voltage to electronic devices with the lowest input current ripple. Recently, a hybrid converter which combines the boost and the Cuk converter in an interleaved manner has been introduced. The converter has the advantage of providing a relatively low input current ripple by a former strategy. However, it has been proposed to operate with dependent duty cycles, limiting its capacity to further decrease the input current ripple. Independent duty cycles can significantly reduce the input current ripple if the same voltage gain is achieved by an appropriate duty cycle combination. Nevertheless, finding the optimal duty cycle combination is not an easy task. Therefore, this article proposes a new pulse-width-modulation strategy for the hybrid interleaved boost-Cuk converter. The strategy includes the development of a novel mathematical model to describe the relationship between independent duty cycles and the input current ripple. The model is introduced to minimize the input current ripple by finding the optimal duty cycle combination using the differential evolution algorithm. It is shown that the proposed method further reduces the input current ripple for an operating range. Compared to the former strategy, the proposed method provides a more balanced power-sharing among converters.

scholarly journals Parallel Resonant DC Link Inverter for Thermoacoustic Power Generation

2014 ◽  
Vol 8 (1) ◽  
pp. 379-389
Author(s):  
Ma Li Li ◽  
Xia Jia Kuan
Keyword(s):  
Pulse Width Modulation ◽  
Short Circuit ◽  
Parameter Design ◽  
Generation System ◽  
Circuit Structure ◽  
Working Principle ◽  
Mathematical Equations ◽  
Dc Bus ◽  
Bus Voltage ◽  
Zero Voltage

A new parallel resonant soft-switching DC link inverter which can deal with the output power from thermoacoustic energy generation system is proposed. Auxiliary resonant unit is added to DC link to make DC bus voltage decreased to zero periodically, which realized all switches with zero voltage operation of in the inverter. The time of the duration for the DC bus zero voltage has nothing to do with the load current. The same bridge arm in the inverter is not made instantaneous short circuit and controlled reliably. Random duration of zero voltage was obtained through the on-off instant control of the auxiliary switch. Various flexible pulse width modulation strategies can be applied in the softswitching inverter. The topology structure is put forward and the circuit working principle is analyzed in this paper. The equivalent different working modes are analyzed and the mathematical equations are given. The principle of parameter design is put forward according to the circuit structure. The experiment is carried out and through it the validity and correctness of the theoretical analysis is proved.

scholarly journals Implementation of Intelligent Controlling Mechanism to Improve Conversion Efficiency of Solar PV Module

2020 ◽  
Vol 6 (5) ◽  
pp. 168-172
Author(s):  
Kakarla Deepti
Keyword(s):  
Conversion Efficiency ◽  
Duty Cycle ◽  
Fuzzy Logic Controller ◽  
Control Method ◽  
Learning Automata ◽  
Photovoltaic Module ◽  
Solar Pv ◽  
Pv Module ◽  
Power Point ◽  
Two Stages

The research article aims at an intelligent control method to improve conversion efficiency of solar photovoltaic module by tracking maximum operating point irrespective of variations in temperature and irradiance. A novel hybrid maximum power point based on learning automata is proposed. The algorithm works in two stages, first the learning automata detects the temperature and irradiation of light incidenting on PV module, second it identifies the zone of operation and adjusts the duty cycle of DC-DC converter. This implementation is done by designing the learning automata using artificial neural network and the adjustment of duty cycle is implemented with fuzzy logic controller. The design is verified using matlab/simulink environment.

Sign in / Sign up

Export Citation Format

Share Document