e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science ( Peer-Reviewed, Open Access, Fully Refereed International Journal ) Volume:05/Issue:11/November-2023 Impact Factor- 7.868 www.irjmets.com www.irjmets.com @International Research Journal of Modernization in Engineering, Technology and Science [846] ANALYSIS AND IMPROVEMENT OF CONTROL OF OVER-VOLTAGES IN THREE PHASE GRID TIED INVERTER SYSTEMS Inyama, Kelechi *1 , Uchegbu, Eberechi Chinenye *2 , Okoronkwo, Oluchi Gift *3 *1,2,3 Department Of Electrical And Electronic, Abia State University, Uturu, Abia State, Nigeria. DOI : https://www.doi.org/10.56726/IRJMETS46141 ABSTRACT This work studied transient analysis in transmission systems and their effects on over voltages in electronic/electrical systems. It causes enormous damage to equipment by generating harmonics, over- currents, and over-voltages. The objective is to identify the reasons for and effects of transitory. For the study, secondary sources were used. The project considers 4 transmission stations (TS) in Nigeria connected to the Afam Generation Station, these transmission stations includes Onitsha TS, Alaoji TS, Eket TS and Ikot Ekpene TS and the effect of transient over voltages on their transmission lines. Consequently the application of the relay logic to the protection of transient over voltage on transmission lines has been studied here with the case taken for 4 TS. Transmission and power station faults arte the main causes of over voltages on transmission lines. The protection circuits functions by enveloping the voltage spikes using switching carriers constituting of switching reactors, Matlab/simulink has been used for the design and simulation of a the transmission link among Afam TS and the other 4 Distribution Station (DS) and the over voltage circuit has also been implemented here using the relay logics. The results presented shows the over voltage signal as simulated and also the protected voltage signal, the study also shows that at high transformer ratings, the line over voltages tend to be more as seen from the transformer rating of the studied DS. The table 4.1 presented in chapter 4 shows the values of the voltage before and after protection of the line voltages for each of the TS. I. INTRODUCTION In our everyday life we often hear of how over voltages has caused harm to human life, properties and equipments in the industry. Voltage surge or voltage transients popularly known as over voltage are the increase in voltage for a short time period. External and internal factors cause over voltage in power system. Three-phase grid-tied inverter systems often face challenges related to over voltages, which occur when the voltage levels exceed acceptable limits. Over voltages can lead to equipment damage, efficiency losses, and instability in the grid. Therefore, it is essential to analyze and improve the control mechanisms of these systems to effectively manage and mitigate over voltage issues. By addressing these challenges, we can enhance the stability, reliability, and overall performance of grid-tied inverter systems, thus promoting the widespread adoption of renewable energy technologies. In electrical engineering, overvoltage is defined as the raising of voltage beyond the he designed limit of a circuit. In other words it’s a situation which the voltage flowing in a circuit exceeds the designed limit of that circuit or system Next is an inverter system, which is simply defined as a system or a power electronic device that converts direct currents (DC) to alternating currents (AC) AC is what is needed for own home electrical devices operate.AC power cannot be stored; it must be converted to DC power before storing in the battery. Therefore inverters are used to provide back-up power during power outages and supply AC appliances Therefore knowing what over voltages are, we can agree it is not a good thing in an electronic device, because it causes hazards to the system and can as well damage the system entirely, in the cause of this research and analysis, we hope to ascertain proper measures that the overvoltage can be improved and controlled Over voltage in a system is a situation where the voltage rises beyond the designed voltage limit of the circuit, this condition can be hazardous to a system. In three-phase grid-tied inverter systems voltage may exceed the rated value, which can cause damage to the equipment and pose a safety hazard.