Salp Swarm Optimization Algorithm for Estimating the Parameters of Photovoltaic Panels Based on the Three-Diode Model

Due to the the lack of information about parameters in the datasheets of photovoltaic (PV) panels, it is difficult to study their modeling because PV behavior is based on voltage–current (V-I) data, which present a highly nonlinear relationship. To solve this difficulty, this study presents a mathematical three-diode model of a PV panel that includes multiple unknown parameters: photoinduced current, saturation currents of the three diodes, three ideality factors, serial resistance, and parallel resistance. These parameters should be estimated in the three-diode model of a PV panel to obtain the actual values that represent the voltage–current profile or the voltage–power profile (because of its visual simplicity) of the PV panel under analysis. In order to solve this problem, this paper proposes a new application of the salp swarm algorithm (SSA) to estimate the parameters of a three-diode model of a PV panel. Two test scenarios were implemented with two different PV panels, i.e., Kyocera KC200GT and Solarex MSX60, which generate different power levels and are widely used for commercial purposes. The results of the simulations were obtained using different irradiance levels. The proposed PV model was evaluated based on the experimental results of the PV modules analyzed in this paper. The efficiency of the optimization technique proposed here, i.e., SSA, was measured by a fair comparison between its numerical results and those of other optimization techniques tuned to obtain the best response in terms of the objective function.

Shock Resistance Design of High-Speed Maglev Motor–Stability Considerations and Quantitative Shock Tests

Large external disturbances (such as shock loads) can cause contact between the rotor and touchdown bearings (TDBs). Hence, maintaining the stability of systems with active magnetic bearings (AMBs) is a major challenge for mobile applications such as on-board steam turbines or vehicle turbochargers. In this paper, two key factors (power bandwidth and bi-stable characteristic) that affect the shock stability of AMB-rotor systems are considered in the design of a high-speed maglev motor. Insufficient power bandwidth can induce current saturation leading to destabilization, while a bi-stable characteristic can cause persistent contact between the rotor and TDBs under external disturbances. Theoretical analyzes and criteria are provided, and the influence of these two factors is investigated by base shock experiments of a high-speed maglev motor. These experiments involved mounting a high-speed maglev motor on a shock table then subjecting it to shock loads of different amplitudes. The designed motor continued to operate stably under shock loads up to 20 G, verifying the correctness of the stability considerations.

Evaluation and Optimization of Bypassed Oil in Carbonate Reservoir at Mature Field with Integration of Saturation Log and Cement Bond Quality

AA field is a unitized asset operated by Corporate Oil Company since May 2018. The main producing formation of AA field is a reef build-up carbonate reservoir. The field has been on production since 2004 with OOIP of 297 MMSTB. As of November 2019 the cumulative production was estimated 120.7 MMSTB with RF of 41%. The carbonate reservoir has properties with relatively high heterogeneity –both vertically as well as laterally – which leads to production variation of the wells. The production performance shows an estimated 30% decline and significantly increasing water-cut. The production data shows a much faster water production compared with the cumulative production, which is also the greatest challenge in the AA field.There are several key contributing factors for the water production in AA field:Water channeling behind casing due to poor cement bond. This is supported by Chan Plot analysis.Uneven production of the wells leading to varying water rise and introduces difficulty in water contact determination.Water coning due to production exceeding the critical rate.Several efforts have been performed to optimize production, namely: identification of the potential of remaining hydrocarbon (bypassed oil) in the wells by evaluating current saturation evaluation through downhole surveillance, estimation of current water contact and cement bond improvement.The preparation steps of the production optimization process are summarized below:Screening of Candidate WellsEvaluation of Cement Bond QualityWellsite Execution for Bypassed Oil EvaluationWell PreparationOptimum C/O Log to Evaluate Current Saturation and to Identify Bypassed Oil ZonesBypassed Oil Interval ProductionThis section discusses one of successful cases in the production optimization effort implemented in the AA- field.AA-12 wellThe last production of AA-12 well was 84 BOPD. Chan plot showed possibility of water channeling, which was supported by CBL result. The zone of existing perforation interval was indicated to have “free pipe” behind the casing. Remedial cementing was then performed until sufficient zonal isolation was obtained. After subsequent CBL confirmed good zonal isolation, C/O log was then performed. The C/O log result indicated several reservoir zones with potential bypassed oil. The new production interval was selected based on following consideration: So between 55-60%, height above current OWC of 185 ft (56 m), distance to the adjacent wells of 1306 ft (398 m), porosity 12-17% and Production test of the new perforation resulted in 2186 BOPD with 0% water-cut.