Advantages And Disadvantages Of A Multilevel Inverter System

A Power system is an connection of generators to load centres. Through H.V. electrical lines & in general is controlled mechanically. It can be divided into 3 subsystems: Generation, X’mission and Distribution-systems. The electric power demand is Growing and building of new generating units & transmission circuits is becoming difficult because of environmental & economic reasons. So, power utilities are forced to depend on utilization of existing generating units and to load existing lines close to their heating limits.

The impact of the proposed sequences has been simulated for 0.4 modulation index with a 0.5 lagging power factor load (power factor angle 60°). The simulation setup consists of the following software: 1) MATLAB/Simulink – used to implement the modulation strategies and switching sequences, and 2) PSIM – used to simulate the T-NPC inverter running with an R-L load and to provide conduction and switching losses of each switch. The inverter switching pulses were generated within Simulink and were fed to PSIM through sim-coupler module which provides a link between PSIM and simulink for the purpose of co-simulation [29].

The innovative inverter technology produces safe, smooth power, protecting your sensitive electronics (computers, smartphones, etc.) from damage.

Figure 1: An example of PWM in AC motor drive. The smoothness of the resultant sinusoidal waveform can be controlled by the width and number of modulated impulses.

Switching power converters offer an easy way to regulate both the frequency and magnitude of the voltage and current applied to a motor shown in fig(1). As a result much higher efficiency and performance can be achieved by these motor drives with less generated noises[3].

Bulk power transfer can be carried out Over long distances by a high voltage direct current (HVDC) connection is cheaper than by a HVAC transmission line. Power transmission to remote load centers and islands has been the major concern for power

The upsides of the synchronous buck converter don't come without cost. To start with, the lower switch normally costs more than the freewheeling diode. Second, the multifaceted nature of the converter is unfathomably expanded because of the requirement for a reciprocal yield switch driver.

Change of converter operating point upon switching: The influence of AC voltage change on firing angles and tap-changer controls.

Simulation of the proposed converter & the results using MATLAB & Simulink can be seen in this

HVDC transmission may also be selected for other technical benefits. HVDC can transfer power between separate AC networks. HVDC powerflow between separate AC systems can be automatically controlled to support either network during transient conditions, but without the risk that a major power system collapse in one network will lead to a collapse in the second. HVDC improves on system controllability, with at least one HVDC link embedded in an AC grid—in the deregulated environment, the controllability feature is particularly useful where control of energy trading is needed.

The flexible AC transmission system (FACTS) concepts, based on applying state-of-the-art power electronic technology to existing AC transmission system, improve stability to achieve power transmission close to its thermal limit [4]. Such devices are installed by utilities and by many private entities in India. In order to achieve this identical goal other way is by converting existing 400kV / 765 kV double circuit HVAC line to HVDC line without any modifications in the existing tower structure, insulators and conductors considering heavy pollution as the worst case.

The growing concern about the impact of CO2 and the anxiety on the effect of using fossil fuels based power generation technology on the environment, in recent years, has made the researchers to focusing on the renewable energy based clean power generation techniques to secure the environment from carbon effect. Among the development of renewable energy based power generation techniques, the solar power generation has a major role in clean power generation. The sunlight is free of cost and everlasting energy sources, but the drawback of this method is that generation of electricity is only possible during the sunshine. In PV system, the DC-DC power converters are used to change the output voltage from one level to another level [25-27]. Typically, the DC-DC converter is connected between the panel and the load, sequentially to extract the available power from the panel using tracking methods. In this work, Boost converters and Super lift boost converters [1] are used to extract the maximum power from the panel and two converters diagram is shown in Figure 1a and Figure 1b respectively.

Power electronic circuits that convert a dc voltage to difference dc voltage level are known as the DC-DC converters. It uses semiconductor devices to perform its operations by controlling or modifying a voltage current. There are different types of conversion method such as electronic, linear, switched-mode, and so on. Whenever we want to change DC electrical power from one level to another level, switched-mode DC-DC converter has been chosen because is much efficient due to the reduced losses in the electronic switch. Switched-mode DC-DC converters is also known as switching power supplies or switchers.

Recently, the technological advancements in power electronics and semiconductor technologies have led to improvements in power electronic systems. The purpose of this project is to design a Boost Converter which is a DC-to-DC power converter with an output voltage exceeding than its input voltage. Boost converter is applied in many applications that require higher DC voltages for superior performance as this helps in reducing the size of the systems because the battery powered systems generally stack cells to attain higher voltage leading to larger size of the system.

Generation of electrical power in low voltage level is very much cost effective. Hence electrical power is generated in low voltage level. Theoretically, this low voltage level power can be transmitted to the receiving end. But if the voltage level of a power is increased, the current of the power is reduced which causes reduction in ohmic or I2R losses in the system, reduction in cross sectional area of the conductor i.e. reduction in capital cost of the system and it also improves the voltage regulation of the system. Because of these, low level power must be stepped up for efficient electrical power transmission. This is done by step up transformer at the sending side of the power system network. As this high voltage power may not be distributed to the consumers directly, this must be stepped down to the desired level at the receiving end with the help of step down transformer. These are the uses of electrical power