Optimal Allocation of Active Power Filter On real distribution network for improvement of power quality by use of BBO: A case study

ABSTRACT:  According to development of power electronics device, harmonic distortion spread on the network. Thus harmonic is a threat for instrument, network, decreasing of line capacity and etc. Active power filter (APF) can be employed for harmonic compensation in power systems. In this paper a distorted distribution feeder is considered and analyzed from power quality viewpoint using power analyzer device and simulated in MATLAB-Mfile. Then the size and place of active power filters are determined by use of Biogeography Based Optimization (BBO). The goal of this optimization is minimizing of losses and total harmonic distortion (THD) in feeder by considering economical cost.  The performance of the approaches are assessed and appreciated by a case study on the Ghaemshahr-Iran Distribution network. Measurement is done on the city network by power analyzer CA8310. All data was collected on Computer. Then researcher algorithm BBO, it is selected the best place and size for Active power filter. The results show a good performance

CASCADE TOPOLOGIES FOR THE ASYMMETRIC MULTILEVEL INVERTER BY NEW MODULE TO ACHIEVE MAXIMUM NUMBER OF LEVELS

ABSTRACT:  Multilevel inverters have been introduced as useful devices to connect between DC-AC systems. They are high quality output and cost benefit systems with a wide range of applications. Asymmetric multilevel inverters are a type of multilevel inverters with unequal DC link to create more voltage levels through fewer components. This paper presents new topologies of cascade multilevel inverter by a new module with a reduced component. Base module produces 13 levels by two types of unequal DC sources and 10 switches. Modular can be used to produce more and higher voltages levels. The designing of proposed multilevel inverter makes some preferable index with better quality than similar modular multilevel inverters, such as less semiconductors and DC sources, low switching frequency, creating of negative levels without any additional circuit, and module in cascade connections. Also, two cascade topologies are presented in the modular connections of the proposed module to achieve high and significant number of levels. Nearest level control (NLC) method as a switching technique is used in step changing levels for topologies to get more quality and lower harmonics. The presented module and cascade topologies are simulated by MATLAB/Simulink and are implemented by the experimental prototype in laboratory to validate the performance of proposed topologies in which simulated and experimental results show a good performance with the high quality output

The P-Type Module with Virtual DC Links to Increase Levels in Multilevel Inverters

There has been an active interest in the evolution of newer multilevel inverter topologies in which the highest operation of DC sources become an important subject. In the paper, a new structure module presented a seventeen levels asymmetrical multilevel inverter by using two unequal DC sources (with the ratio 3:1). The configuration was focused on creating virtual DC links by two chargeable capacitors. The module had a simple inherent charging for capacitors without any additional circuit. The proposed multilevel inverter could produce higher voltage levels by a lower number of components; therefore, it is suitable for a wide range of applications. Also, the cascade connection of the module led to a modular topology with more voltage levels at higher voltages. The capability of the inherent negative voltage was involved. The simulation results obtained in MATLAB/Simulink, as well as the experimental results, verified the proposed topology.Peer reviewe

Single dc source multilevel inverter with changeable gains and levels for low-power loads

Different types of multilevel converters have been used to convert DC voltage to AC voltage for different applications. It is, however, desirable for flexible AC output voltage to be created from a single DC source at lower cost. This paper presents a new type of single DC source multilevel inverter which has the ability to create a different number of levels with low rate components. This device is also able boost the magnitude of the output voltage by means of a variable gain with one DC source. The advantages of the multilevel inverter are rapid stepping among levels, and its ability to produce different ranges of levels (seven, nine and eleven) and gains (two, four and eight). The proposed multilevel inverter includes six semiconductor switches, eight diodes, two capacitors and two inductors, making it suitable for low-power applications. A simulation in MATLAB and experimental tests on a prototype setup showed good performance for different modulations, with THD% down to 2.29%, which are meets the IEEE standard (IEEE 519).Peer reviewe

Single-Phase Active Power Harmonics Filter by Op-Amp Circuits and Power Electronics Devices

This paper introduces a new structure for single-phase Active Power Harmonics Filter (APHF) with the simple and low-cost controller to eliminate harmonics and its side effects on low voltage grid. The proposed APHF includes an accurate harmonic detector circuit, amplifier circuit to trap tiny harmonics, switching driver circuit for precise synchronization, and inverter to create injection current waveform, which is extracted from reference signal. The control circuits are based on electrostatic devices consist of Op-Amp circuits. Fast dynamic, simplicity, low cost, and small size are the main features of Op-Amp circuits that are used in the proposed topology. The aim is removing the all grid harmonic orders in which the proposed APF injects an appropriate current into the grid in parallel way. The proposed control system is smart enough to compensate all range of current harmonics. A prototype is implemented in the power electronics laboratory and it is installed as parallel on a distorted grid by the non-linear load (15 APeak-Peak) to verify the compensating of harmonics. The harmonics are compensated from THD% = 24.48 to THD% = 2.86 and the non-sinusoidal waveform is renovated to sinusoidal waveform by the proposed APHF. The experimental results show a good accurate and high-quality performance.Peer reviewe

An innovative dual-boost nine-level inverter with low-voltage rating switches

This article presents an innovative switched-capacitor based nine-level inverter employing single DC input for renewable and sustainable energy applications. The proposed configuration generates a step-up bipolar output voltage without end-side H-bridge, and the employed capacitors are charged in a self-balancing form. Applying low-voltage rated switches is another merit of the proposed inverter, which leads to extensive reduction in total standing voltage. Thereby, switching losses as well as inverter cost are reduced proportionally. Furthermore, the comparative analysis against other state-of-the-art inverters depicts that the number of required power electronic devices and implementation cost is reduced in the proposed structure. The working principle of the proposed circuit along with its efficiency calculations and thermal modeling are elaborated in detail. In the end, simulations and experimental tests are conducted to validate the flawless performance of the proposed nine-level topology in power systems.Peer reviewe