A Symmetrical H-Bridge Multilevel converter with Sensor less Voltage Balance

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1. A Symmetrical H - Bridge Multilevel converter with Sensor less Voltage Balance Department of Electrical and Electronics Engineering St. JOHNS COLLEGE OF ENGINEERING & TECHNOLOGY

2. TEAM MEMBERS M S SHIVA KUMAR M.TECH ASSOCIATE PROFESSOR EEE DEPARTMENT UNDER THE GUIEDENCE OF HOD OF EEE DEPARTMENT : Dr.K.CHITAMBARIAH SHETTY. Phd

3. CONTENTS ABSTRACT INTRODUCTION PROPOSED SYSTEM BLOCK DIAGRAM WORKING PRINCIPLE SIMULATION RESULT CONCLUSION FUTURE SCOPE

4. ABSTRACT This project proposes a submodules to minimise the number of active switch semiconductors and conduction losses. H - bridge based multi level converters (e.g.,cascade H - bridge converters) benfit from modulatary and scalability,However they suffer from the complexity and cost The symmetrical half - bridge submodule features a bipolar voltage output, a reduced switch count, and simplicity. This scheme can greatly reduce capacitor voltage ripples, thereby allowing the saving of dc capacitances, particularly in the case of numerous submodules.

5. INTRODUCTION The development of multilevel promises to advance high-voltage dc (HVdc) and ac (HVac) transmissions , medium voltage motor drive (e.g., automotive propulsion and marine drive) Attractive features of multilevel converters include the use of low-voltage semiconductors for high-voltage treatments, high power quality. The possibility of removing passive filters , low electromagnetic interference noises (due to reduced voltage and current changing rates), high reliability and redundancy, and diminished common mode problems.

6. Existing system with Disadvantages : Separate DC sources are required for each of the H-bridges. This will limit its application to products that already have multiple SDCSs readily available. Real power flow is difficult for a single inverter because the intermediate dc levels will tend to overcharge or discharge without precise monitoring and control. The number of clamping diodes required is quadratically related to the number of levels, which can be cumbersome for units with a high number of levels. Switching utilization and efficiency are poor for real power transmission.

7. Proposed system with Advantages The number of possible output voltage levels is more than twice the number of DC sources (m = 2s + 1). The series of H-bridges makes for modularized layout and packaging. This will enable the manufacturing process to be done more quickly and cheaply. Continuos mode of operation The capacitors can be pre charged as a group. Efficiency is high for fundamental frequency switching.

8. Block diagram of proposed multilevel inverter:

9. VARIOUS MULTILEVEL INVERTER Various multilevel inverter configurations were developed. Those configurations include N eutral point clamped (NPC) C ascaded H-bridge (CHB) flying capacitor (FC)

10. Single-phase half-bridge inverter The single-phase voltage source half-bridge inverters, are meant for lower voltage applications and are commonly used in power supplies.Figure 2 shows the circuit schematic of this invert The AC input for an ASD. Single-Phase Half-Bridge Voltage Source Inverter

11. Single-phase full-bridge inverter The full-bridge inverter is similar to the half bridge-inverter, but it has an additional leg to connect the neutral point to the load. Shows the circuit schematic of the single-phase voltage source full-bridge inverter. To avoid shorting out the voltage source, S1+ and S1- cannot be on at the same time, and S2+ and S2- also cannot be on at the same time. Any modulating technique used for the full-bridge configuration should have either the top or the bottom switch of each leg on at any given time. Due to the extra leg, the maximum amplitude of the output waveform is Vi, and is twice as large as the maximum achievable output amplitude for the half-bridge configuration. Single-Phase Voltage Source Full-Bridge Inverter Carrier and Modulating Signals for the Bipolar Pulsewidth Modulation Technique

12. PULSE WIDTH MODULATION Pulse Width Modulation (PWM) is the most effective means to achieve constant voltage battery charging by switching the solar system controller’s power devices. When in PWM regulation, the current from the solar array tapers according to the battery’s condition and recharging needs Consider a waveform such as this: it is a voltage switching between 0v and 12v First you generate a triangle waveform as shown in the diagram below. You compare this with a dc voltage, which you adjust to control the ratio of on to off time that you require. When the triangle is above the 'demand' voltage, the output goes high

13. Cascaded H-Bridges inverter Single-phase structure of a multilevel cascaded H-bridges inverter

14. Output phase voltage waveform of an 11 level cascade inverter with 5 separate dc sources.

15. Proposed simulation diagram: IMBALANCE

16. RESULTS OF VOLTAGE AND CURRENT :- V1u =201v V1l =200v 201 200 X-Axis=time Y-Axis=voltage X-Axis=time Y-Axis=voltage

17. Proposed simulation diagram : BALANCE

18. V2u=201v V0=201v 201 201 X-Axis=time Y-Axis=voltage X-Axis=time Y-Axis=voltage

19. CONCLUSION Finally , the voltage balance scheme is performed, which shows a good agreement with the theoretical analysis.

20. FUTURE SCOPE Advanced Control Algorithms: Integration of AI-based control algorithms for more precise and adaptive voltage balancing, improving efficiency and performance. Wireless Monitoring and Control: Implementation of wireless communication protocols for remote monitoring and control.

21. THANK YOU