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Renewable energy sources (RES) are becoming more attractive due to the global demand for the utilization of clean energy and their easy accessibility. The integration of renewable energy technologies into power systems has been made easy, such that RES can be incorporated into small distribution systems or power grids. This integration of RES has negative impacts on power quality, system reliability, and network security. This could affect the RES performance and causes power quality-related problems such as harmonics, voltage flickers, swell, and sag. This paper presents a generation and transmission expansion planning model with the integration of large-scale RES considering harmonic emissions constraints. This method uses a weighted sum approach to combine the multi-objective optimization problems, thereby minimizing the total costs, active power loss, and harmonic power loss. An analytical technique was developed to estimate and quantify the harmonic emissions from the RES components. The proposed AC mixed-integer non-linear optimization problem was solved using algebraic modeling language. The proposed model is demonstrated on non-distorted Garver's test bus system and 48-bus of Nigeria's power system. The results obtained from the sensitivity analysis can be used as a decision-making tool to determine the best approach to minimize harmonic emissions from RES integration into the grid. [ABSTRACT FROM AUTHOR]

Most industrial loads are inductive in nature and therefore absorb Volts Ampere Reactance (VARs) leading to lagging power factor. Some inductive loads also produce current and voltage signals with frequencies in integer multiples of the 50 or 60 Hz fundamental frequencies called harmonics. Harmonics in power system causes several problems ranging from overheating, premature equipment failure, false tripping of protective relays resulting in unnecessary down time in industrial production. This work compared the use of series and parallel resonant harmonic filters in suppressing harmonics using Simulink model of the power system of NICHEMTEX, a Textile industry in Nigeria as a case study. Mathematical analysis representing current harmonics distributions on industrials loads with and without capacitor banks were presented. From the analysis, series resonant filter mitigated the total harmonic distortion from 30.080% to 3.460%. The installation of capacitor bank along with the series resonant filter in the industrial facility, further reduced the total harmonic distortion to 0.001% and power factor compensated from 0.860 to 0.894.However, the use of parallel resonant filter mitigated the harmonic distortion to 8.107% and a reduction in the power factor from 0.860 to 0.840. With the parallel resonant filter connection with the capacitor bank, harmonic distortion was mitigated to 0.140%, and the power factor reduced to 0.553, the value which is very low. Hence, it is observed that for this sample case, the use of series resonant filter mitigated the harmonics distortion and maintained power factors within the acceptable IEEE standard values. [ABSTRACT FROM AUTHOR]