Description:Field of Invention
The present invention relates to design a multilevel inverter with reduced number of semiconductor switches, a 5-Level Cascaded H-bridge multilevel inverter is achieved by using only 6 MOSFET switches instead of 8 switches.
Objectives of the invention
The goal of the innovation is to employ a 5-level inverter instead of a typical 5-level inverter, which requires eight switches, to reduce switching costs, complexity, and losses. The model may be used for high voltage or power applications as well as driving applications in industries.
Background of the invention
A large number of conditions for grid- connected solar inverters, similar as high effectiveness, affair current or voltage low harmonious content, low EMI concern, trust ability added to the price competition, have driven the inverter development toward more advanced druthers.

The need for renewable energy sources has grown as a result of the rising demand for electrical energy and the environmental issues connected to the usage of fossil fuels. Power electronics converters that are suitable for a wide range of applications are needed for many renewable energy sources, including solar, wind, ocean heat, waves, and fuel cells. In both residential and commercial power systems, DC-AC converter inverters are essential parts. Conventional five-level inverters are not appropriate for high voltage and power applications due to their flaws, such as the high voltage ratings of power semiconductor devices (switches and/or power diodes), and high levels of Total Harmonic Distortion (THD).Traditional five-level inverters require large inductor and capacitor assemblies to filter output harmonics for some high-fidelity applications, which raises the inverter's price.

A multilayer inverter is a power converter that generates a stepped output voltage using a succession of power semiconductor components with connections to DC voltage sources or capacitors, such as switches or power diodes. A multi-level inverter (MLI) may create waveforms with greater output voltages using switches that are rated at considerably lower voltages. The output voltage waveform becomes more sinusoidal and the overall harmonic distortion is enhanced with a greater level count. Inverters lessen the need for filters as a consequence. Multi-level inverters also provide advantages including improved efficiency, less dv/dt stress, decreased electromagnetic interference, and lower voltage stress across switches.

Hybrid multilevel inverter designed to operate one of the FCs and a number of switches to provide N-level output voltages. According to one embodiment, the hybrid multilevel inverter uses Neutral Point Clamped (NPC) Flying Capacitor (FC) technology. A stacked multi-cell NPC multilevel inverter is the multilevel inverter in one embodiment.

It is proposed that a sub-module of a multilevel converter be expanded to include a short-circuit circuit, so that the charge on the capacitor of the sub-module can be reduced in a controlled manner, in particular in stages via a number of series circuits made up of short-circuiting and damping elements. It is advantageous here that the further operation of the converter can be ensured via the short-circuit circuit in the event of a voltage dip or over-voltage at the at least one electronic switch arranged in parallel with the short-circuit circuit. The invention can be used for HVDC converters.

According to one implementation of the invention, a multi-level inverter features a voltage link unit that splits an input voltage into at least two voltages and a voltage link unit output that sends both of the voltage link unit's ends and the voltage link unit's input voltage to another device. It has several switching elements that are each connected to an intermediate node that divides the, and it outputs a multi-level voltage in accordance with how the switching elements are driven and how the first group and the second group, which are connected to both ends of the switching unit, are switched. and an inverter device that periodically switches the polarity of the multi-level voltage and outputs it when the first group of switching elements or the second group of switching elements are operating complimentary to one another.

Description of Prior Art
Neutral Point Clamp (NPC), Flying Capacitor (FC), and Cascaded H-Bridge (CHB) inverters are examples of traditional multilevel inverter topologies. Flying capacitors need several capacitors, whereas neutral point clamp topologies theoretically allow for any number of levels at the price of switches and clamp diodes. Higher voltage levels, like cascaded H-bridges, depend on the quantity of separated DC voltage sources. Many studies have been conducted to discover innovative multilayer inverter topologies that use fewer switches and DC voltage sources to attain greater output voltage levels in order to address these drawbacks. For each aspect, a number of symmetrical and asymmetrical topologies have been developed. All DC sources are the same size in the former; they differ in the later.In comparison to symmetrical designs, asymmetrical topologies generate more levels with the same number of DC sources and switches.
The hybrid type of multilevel inverters is another category. Typically, a multi-level hybrid inverter has two components. Level generation, the first stage, creates a stepped voltage with unidirectional polarity. It is done by switching the DC sources in particular combinations to achieve different levels. The polarity-changing component, which generates both positive and negative voltages on the load, is the second component. Very often, H-bridge inverters are employed. timid. Hinago and Koizumi's single-phase hybrid multilevel inverter.

Hybrid multilevel inverter designed to operate one of the FCs and a number of switches to provide N-level output voltages. According to one embodiment, the hybrid multilevel inverter uses Neutral Point Clamped (NPC) Flying Capacitor (FC) technology. A stacked multi-cell NPC multilevel inverter is the multilevel inverter in one embodiment. (US20170194877A1)

It is proposed that a sub-module of a multilevel converter be expanded to include a short-circuit circuit, so that the charge on the capacitor of the sub-module can be reduced in a controlled manner, in particular in stages via a number of series circuits made up of short-circuiting and damping elements. It is advantageous here that the further operation of the converter can be ensured via the short-circuit circuit in the event of a voltage dip or over-voltage at the at least one electronic switch arranged in parallel with the short-circuit circuit. The invention can be used for HVDC converters. (DE102013217672B3)

The present invention relates to a multi-level inverter and a method of driving the inverter, and a multi-level inverter according to an embodiment of the present invention has a voltage link unit that divides an input voltage into at least two voltages, and a voltage link unit output both ends of the voltage link unit and the voltage It has several switching elements that are each connected to an intermediate node that divides the, and it outputs a multi-level voltage in accordance with how the switching elements are driven and how the first group and the second group, which are connected to both ends of the switching unit, are switched.the inverter unit that periodically changes the polarity of the multi-level voltage and outputs it during the complementary operation of the first group of switching elements or the second group of switching elements.(KR101312589B1)

The inverter unit in the multilevel inverter includes a first switch unit between the first node and a first output terminal, a second switch unit between the second node and the first output terminal, and a third switch unit between the third node and the first output terminal. The multilevel inverter also includes a rectifier, a smoothing unit, and a third node between the first and second nodes. (US9419541B2)

A multi-level inverter with one or more banks that each have a number of low voltage MA OSFET transistors. a CPU with the ability to flip each bank's many low voltage MOSFET transistors several times every cycle. (EP2930839A2)
Summary of the invention
In the present innovative invention, the five-level cascaded multilevel inverter is designed to be used for high level power consumption in the industries and to reduce filter usages, switching costs and complexity of circuit. The basic function of an inverter is to change a dc input voltage into ac output voltage with the required magnitude and frequency. A staircase waveform at the output, which resembles a sinusoidal waveform, is created by the multilevel inverter output voltage. and multilevel inverter converts input dc voltage to ac output voltage, and control of gating signal systems produce the pulses that regulates the H-bridge MOSFET switches switching patterns.
Inverter circuit configuration research has focused mostly on lowering switches at higher voltage levels. By minimizing switches and raising voltage levels, filter costs and harmonic content can be reduced.CHB MLI topology with five layers is required. Eight switches and two independent dc sources are needed,but in order to reduce switching loss and cost, just six switches are needed to produce the same MLI output voltage.
Detailed description of the invention
Global warming and depletion of energy resources have received widespread attention in recent decades. Understanding the need to mitigate and adapt to current world change has created a global imperative for the development and deployment of sustainable alternative fuels. There is a rise in the power consumption around the world and a quality power is needed to be delivered, the multilevel inverter is one of the solutions for many problems. The electrical energy usage is growing day by day and the fossil fuels and other natural resources are depleting, the usage of these resources need to be done carefully with minimal wastage and with maximum efficiency.
The working hardware model of 5-level inverter is designed with, a power transformer which is a device that converts power from one circuit to another circuit is used, two step down transformer with 14V as input voltage are connected to a printed circuit board (PCB) and to a driver circuit. The voltage from the step down transformer is be measured using a multi-meter. The PCB consists of two bridge rectifiers which is used to convert the AC current from the step down transformer to DC current which can be used as input voltage for the inverter, since the inverters are used to convert DC to AC currents, these two bridge rectifiers are soldered on the board. Also the PCB consists of six MOSFET semiconductor switches, these MOSFET switches are used instead of any other semiconductor switches because MOSFET switches can reduce unbalanced voltages. For the protection of circuit from sudden current two capacitors are soldered in along with a rectifier. The load is attached to the end of the PCB board at the multilevel inverter's output side, and the two DSO probes may be used to monitor the output by attaching them to the load's end terminals.
The output waveform of the multilevel inverter mainly depends on the input voltage and the triggering of the semiconductor switches. The driver circuit which is IRF 840 MOSFET driver board is given input from the step down transformer and from the UNO Arduino, the driver board can withstand only up to 17V. The step-down transformer gives 14V, and UNO Arduino gives 3V to the driver board which measures to 17V as required. By connecting the MOSFET driver board to the terminals of the MOSFET semiconductor switches the triggering is possible. The code written in the UNO Arduino is responsible for the triggering of the switches and for producing the output wave form on the Digital Oscilloscope.
The obtained output waveform is a multilevel waveform having five steps or levels, which is produced by using only six MOSFET semiconductor switches. The output voltage is about 24V which is almost double to the input given to the multilevel inverter. The output waveform can be varied by changing the values of the voltage levels.Also instead of using a step down transformer as the input to the PCB, solar energy an also be used as the input. The solar energy can be used by placing solar panel in the sun and by connecting a battery to it so that the solar energy received by the solar panel can be connected to the PCB as the input. In and way if the input given to and five-level inverter is 10V then the output voltage obtained will be up-to 20V which is twice the input voltage. In and way the multilevel inverter can be used very efficiently without using any filters and also by reducing switching losses, and costs; there by also reducing the complexity of circuit.
To combat rising energy demands and dwindling fossil fuels, researchers have turned to multilevel inverters as a sustainable and efficient solution. This innovative 5-level inverter boasts an impressive design, requiring just six MOSFET switches compared to the eight in traditional H-bridge models. This translates to cost savings, higher efficiency due to reduced switching losses, and a compact footprint ideal for applications like electric vehicles. Despite the minimal switch count, it maintains the key benefits of multilevel technology, delivering cleaner power with reduced harmonic distortion and lower EMI. This groundbreaking design holds immense potential to revolutionize power conversion across diverse fields, paving the way for a greener and more efficient future in solar energy, electric vehicles, and beyond.

Global warming and the depletion of fossil fuels are pressing issues that demand immediate attention. As the world's energy consumption continues to rise, finding efficient and sustainable ways to generate and deliver power is crucial. Multilevel inverters offer a promising solution to these challenges.
A multilevel inverter is a power electronic device that converts DC (direct current) to AC (alternating current) by generating multiple voltage levels at the output. This is in contrast to traditional two-level inverters, which only switch between two voltage levels (high and low). By generating more voltage levels, multilevel inverters offer several advantages, including:
Reduced harmonic distortion: The stepped waveform produced by a multilevel inverter has lower harmonic content than a two-level waveform. This results in cleaner power and improved compatibility with sensitive electronic equipment.
Higher efficiency: Multilevel inverters can achieve higher efficiency than two-level inverters due to lower switching losses. This is because there are fewer abrupt transitions between voltage levels.
Smaller size and weight: Multilevel inverters can be more compact and lighter than two-level inverters for the same output power rating. This is because they require fewer components and can operate at higher switching frequencies.
Hardware Design of a 5-Level Multilevel Inverter
The 5-level multilevel inverter you described consists of several key components:
Power Transformer: This component steps down the input AC voltage to a lower level suitable for the inverter circuit.
Printed Circuit Board (PCB): The PCB houses the electronic components of the inverter, including:
Bridge rectifiers: These convert the AC voltage from the transformer to DC voltage.
MOSFET switches: These semiconductor switches control the output voltage levels of the inverter.
Capacitors and rectifier: These components protect the circuit from sudden current surges.
DSO probes: These probes are used to monitor the output voltage waveform of the inverter.
Driver Circuit: This circuit controls the timing and sequence of the MOSFET switches to generate the desired output waveform.
Control Unit: This unit, often implemented using a micro controller like the Arduino, provides the driver circuit with the necessary control signals.
Operation of the 5-Level Multilevel Inverter
The output waveform of the 5-level multilevel inverter is generated by turning the MOSFET switches on and off in a specific sequence. The driver circuit receives control signals from the control unit and drives the MOSFET switches accordingly. By varying the timing and sequence of the switching signals, the control unit can generate different output voltage levels.
Advantages of Using Solar Energy as Input
The 5-level multilevel inverter can be powered by solar energy instead of the power transformer. This makes it a more sustainable and environmentally friendly solution. Solar panels convert sunlight into DC electricity, which can be directly fed into the inverter. This eliminates the need for the transformer and its associated losses.
Overall, the 5-level multilevel inverter is a promising technology with several advantages over traditional two-level inverters. Its ability to generate high-quality power, achieve high efficiency, and operate with a compact size makes it suitable for a wide range of applications, including renewable energy systems, electric vehicles, and industrial motor control.
Brief description of Drawing
Figure 1 Block Diagram of the Overall Structure of the present Invention.
Figure 2 Hardware Implementation.
Detailed description of the drawing
From the figure 1, The power transformer gives input power to the multilevel inverter, since the power transformer gives ac power, bridge rectifiers are used to convert the ac power to dc power which is suitable for the input of the multilevel inverter. Arduino is also given power supply and it is used to provide triggering to the MOSFET switches, the triggering to the switches is provided by a driver circuit whose input is given by Arduino and a driver transformer. At the output side of the multilevel inverter a load is connected so the output waveform is observed in digital oscilloscope by connecting the probes to the load.
From the figure 2, it shows the hardware model of the present invention. It consists of a two step down transformers which are used to give input to PCB and MOSFET driver board. Six MOSFET semiconductor switches are used, the triggering to the switches is given by driver board and the output wave form is seen in the digital oscilloscope by connecting the probes with the terminals of load. , Claims:The scope of the invention is defined by the following claims:

Claim:
1. The5-level cascaded multilevel inverter, comprising:

a) A set of Six MOSFET semiconductor switches producing a five-level voltage output and by reduce the switching losses and costs;
b) The MOSFET semiconductor switches, only six switches are used which there by reduces the complexity and the cost.

2. The 5-level cascaded multilevel inverter according to claim 1, includes a MOSFET driver board for generating triggering pulses to the MOSFET semiconductor switches.

3. The 5-level cascaded multilevel inverter according to claim 1, uses a Arduino for generating the output waveform on the digital oscilloscope.