This project is based on cascaded H bridge inverter and various topologies. This fifteen level inverter is reduced the components and also reduce the cost of the inverter. So reduce the power switches.
Multilevel inverter provides a suitable solution for medium and high power systems to synthesize an output voltage which allows a reduction of harmonic content in voltage and current waveforms. The solar photovoltaic (PV) modules directly converts the light energy into the electrical energy, but energy obtained from the PV module acts as low voltage DC source and has relatively low conversion efficiency. In order to improve the efficiency and convert low voltage DC source into usable AC source, the power electronics converters are used to transform DC into AC.
In this project, a digital logic control circuit is proposed for a solar fed CMLI to achieve higher levels with reduced number of switches without the requirement of bidirectional switches, filter components, detailed look-up tables and output transformers. The techniques include ‘binary’, ‘trinary’ and modified multilevel connections’ (MMCs) to achieve 15 level and 27 level, respectively So that total harmonic distraction (THD) is high.
In this project proposed new multilevel inverter with reduced number of switches and the switching losses is also get reduced with reduced total harmonics distortion(THD).
Block Diagram Explanation
- Pulse generator: - Here we have used PIC microcontroller (PIC 16F877A) to make a switching signal.
- Driver circuit: -It can be used to amplify the pulses and provided isolations for using opto coupler. It has two functions
- Bridge Rectifier: It is converted into AC to DC Supply.
- Inverter: It is converted into DC to AC Supply.
Pic Controller Board
The pic controller is used to generate the pwm pulses for converter and inverter circuit. The pic controller pulses are given to the driver circuit as input. Driver board is mainly used to isolate and amplify the input signalsfrom the controller. The amplifieddriver output will be connected to the main power circuit devices. And the devices are turned on by using the pwm pulses. The power transformer is directly connected to the bridge rectifier. The bridge rectifier is converts the ac voltage into dc voltage. Dc voltage is converted into ac voltage by using multilevel inverter circuit. The multilevel inverter output waveform is shown in below.
Circuit Diagram For Dc To Ac 15level Inverter
- Reduce the switching loss.
- High efficiency.
- Reduced THD.
- Reduced number of switches.
- Industrial machines
- Automobiles medical equipment
- Household appliances
- High Power Applications
In this project it reduces the uneven degradation of power switches, switching losses when compared to the conventional PWM technique and harmonics are reduced and the output waveform level is increased. And also increase the efficiency.
Multilevel Inverter Output