© MAY 2022 | IRE Journals | Volume 5 Issue 11 | ISSN: 2456-8880 IRE 1703467 ICONIC RESEARCH AND ENGINEERING JOURNALS 231 Maximum Loadability Assessment of the Nigerian 330kv Transmission Network Using P-V Curve Method CHRISTOPHER O. AHIAKWO 1 , DIKIO C. IDONIBOYEOBU 2 , SEPIRIBO L. BRAIDE 3 , CHUKWUKA L. ONITA 4 1, 2, 3, 4 Electrical Engineering Department, Rivers State University Abstract- System operating limits are usually based upon certain operating criteria though they are not limited to the following: Facility ratings, Voltage stability ratings, Transient stability ratings and System voltage limits. All components in the Nigerian 330KV transmission network operate between predefined limits in normal condition and the technical operational thresholds for power systems involve physical and system theoretical. Newton-Rapson load flow method was used to determine optimal location for static var placement. 5 buses were identified and compensated using NEPLAN Software for the system modeling. P-V curve plot showcased the maximum loading of the system {operating margin). P-V curve comparison for pre-upgrade, post-upgrade and artificial neural network respectively in respect to the 5 buses was plotted. For Gombe bus, the red curve indicates the maximum loadability of the pre-upgrade network at 700MW. The green curve indicates the effect of static var compensation with maximum loadability at 1100MW. Therefore, the improvement achieved is 400MW. Finally, the artificial neural network technique is represented by the blue curve and it validated the improvement achieved as the voltage and real power remain fairly constant with static compensators. For Jalingo bus, the red curve maximum loadability is at 550MW. The green curve maximum loadability is at 1150MW. Finally, the blue curve validated the improvement achieved. For Yola bus, the maximum loadability is at 620MW. The green curve maximum loadability is at 1100MW. Finally, the blue curve validated the improvement achieved. For Maiduguri bus, the red curve maximum loadability is at 600MW. The green curve maximum loadability is at 1120MW. Finally, the blue curve validated the improvement achieved. For Damaturu bus, the red curve maximum loadability is at 450MW while the green curve maximum loadability is at 1150MW meaning about 650MW improvement was achieved. I. INTRODUCTION The Nigerian 330KV transmission network is the highest bulk power transfer in Nigeria grid system managed by Nigerian Transmission Company. The Nigeria national grid system is an interconnection of 9,454km length of 330KV transmission line made of 22 generating stations through a network of fifty-nine (59) buses and sixty-seven (67) transmission lines of either dual or single circuit lines with 48 load buses and four control centers (one national control center at Oshogbo and three supplementary control centers at Benin, Shiroro and Egbin). The Nigeria 330KV transmission network covers a total length of 9,454km with total installed transformer capacity of 7688MVA and average available capacity of 7364MVA. (Ezekiel, et al., 2019) A system operating limit is defined as the value (such as MW, MVar, Amperes, Frequency or Volts) that satisfies the most limiting of the prescribed operating criteria for a specified system configuration to ensure operation within acceptable reliability criteria. System operating limits are usually based upon certain operating criteria though they are not limited to the following: Facility ratings (applicable pre- and post- contingency equipment or facility rating), Voltage stability ratings (applicable pre- and/or post- contingency voltage stability) and Transient stability ratings (applicable pre- and/or post- contingency stability limits) and System voltage limits (applicable pre- and post- contingency voltage limits). All components operate between predefined limits in normal condition and the technical operational thresholds for power systems involve physical and system theoretical (Ademola, et al., 2016). For the power system operational safety and stable power transfer across Nigerian 330kv transmission system without violating any operating limit, it’s imperative for operating limit monitoring by efficient tools for the voltage stability assessment and the eventually correction of the system state for the safe systems operation near their technical limit thereby supporting the Nigerian 330kv transmission system