Investigations on Control Strategies of Multilevel Inverters to Reudced CMV and THD for Improved Power Quality

Volume 7 Issue 10 (October 201

RANCANG BANGUN INVERTER 1 FASA DENGAN TEKNIK MODULASI THIRD HARMONIC INJECTION PULSE WIDTH MODULATION UNTUK PANEL SURYA 1 KWP

Indonesia is a tropical country, means that Indonesia gets more sun exposure than other countries. Therefore, Indonesia has the potential to develop Renewable Energy, especially solar panels. Solar panels can be used in homes for small scale, as well as on large scale such as power plants. However, electricity generated from solar panels cannot be directly used for some household appliances, because electricity produced is direct current (DC) electricity. So we need a device that can convert DC electricity into AC electricity (Alternating Current) called an inverter. A good inverter is one that has a THD (Third Harmonic Distortion) rating of no more than 5%. High THD can damage electronic equipment. Therefore, this study uses the THIPWM modulation method that is able to reduce THD

Multi Level Inverter Under Unbalanced Voltage Conditions

A Multilevel Inverter(MLI) is a power electronic device built to synthesize a desired A.C voltage from several levels of DC voltages. Generally unbalanced voltages will occur at supply side these can be eliminated by using Multi level Inverter. In this paper a closed loop Control system is designed using PI controller in order to maintain load voltage constant for under voltage and Over voltage conditions and MATLAB simulations have been carried out

Performance investigation of an innovative H-bridge derived multilevel inverter topology for marine applications

441-449An innovative single-phase and three-phase H-bridge derived multilevel inverter topology is being proposed in this manuscript. The proposed topology makes use of relatively fewer switching devices compared to conventional Cascaded H-Bridge (CHB) multilevel inverter. In other words, the proposed inverter topology is capable of producing more number of levels in the voltage waveform with same number of switching devices. It is also established in this paper, that this proposed topology is superior in terms of requirement of lesser number of gate driving circuits and reduction in the harmonic content in the output voltage waveform. The proposed inverter topologies are driven by SPWM modulation technique. These converter topologies are not only beneficial for the power conditioning systems in the power system network but also for the other novel applications like in marine ships. In this manuscript, the performance comparisons of the proposed inverter topologies with that of conventional topology based on simulation results with MATLAB/SIMULINK have been presented

Investigation of TTMC-SVPWM Strategies for Diode Clamped and Cascaded H-bridge Multi-level Inverter Fed Induction Motor Drive

This paper presents a concept of two types multilevel inverters such as diode clamped and cascaded H-bridge for harmonic reduction on high power applications. Normally, multilevel inverters can be used to reduce the harmonic problems in electrical distribution systems. This paer focused on the performance and analysis of a three phase seven level inverter including diode clamped and cascaded H-bridge based on new tripizodal triangular space vector PWM technique approaches. TTMC based modified Space vector Pulse width modulation technique so called tripizodal triangular Space vector Pulse width modulation (TTMC-SVPWM) technique. In this paper the reference sine wave generated as in case of conventional off set injected SVPWM technique. It is observed that the TTMC-Space vector pulse width modulation ensures excellent, close to optimized pulse distribution results and THD is compared to seven level, diode clamped and cascaded multi level inverters. Theoretical investigations were confirmed by the digital simulations using MATLAB/SIMULINK software

One dimensional feed-forward modulation of a cascaded H-bridge multi-level converter including capacitor balancing with reduced switching frequency

Multi-level converters are well suited to medium and high power applications where the priority is for high quality a.c. currents with low harmonic content and for low switching losses. Suitable modulation schemes must find a good compromise between these two conflicting aims. This paper relates one-dimensional feed-forward modulation (1DFFM) to carrier based modulation. 1DFFM can produce high quality currents despite d.c. capacitor voltage ripple by accounting for measured capacitor voltages in the modulation process and can balance capacitor voltages by eliminating states that cause the capacitor voltages to diverge. It is shown in this paper that this method increases the device switching frequency compared to carrier-based modulation with the same sampling rate. An alternative modulation method is presented which balances the capacitor voltages by assigning commutations to bridges during each sampling period. This approach is less likely to cause two bridges to commutate at the same time so produces a lower device switching frequency than 1DFFM. It is shown experimentally that the two methods produce similar a.c. current distortion and both effectively balance the capacitor voltages

A comparative study of Total Harmonic Distortion in Multi level inverter topologies

This paper presents a detailed harmonic analysis in terms of Total Harmonic Distortion (THD) for different power circuit topologies of multi level inverter fed induction motor drives. The most common multilevel inverter topologies are the neutral-point-clamped inverter (NPC), flying capacitor inverter (FC), and cascaded H-bridge inverter (CHB). This work is to analyze the performance of all the power circuit topologies of multilevel inverter with various multi carrier PWM control techniques. Simulation and results shows that the superiority of these inverters over two-level pulse width modulation based inverter fed drives. Keywords: Medium-voltage drives, Multi Carrier PWM, Multi level inverter, Induction motor drives