Optimal Placement of Reclosers to Minimize Power Losses during Non-Load Bearing Disturbances in a Power Distribution Using Firefly Algorithm

The research reported in this paper focuses on non-technical power loss reduction for power distribution systems. Such reduction of costs of energy not served (ENS.COST), is intelligently evaluated and optimized using a firefly algorithm, from where savings of 43.3% on energy not served are achieved.

Distribution of contact loads in crushed zone between tunnel boring machine disc cutter and rock

The construction efficiency and quality of tunnel boring machines(TBMs)is largely determined by the service life of cutting tools,which is the result of contact loads in the crushed zone between cutter ring and rock.In this paper,a series of rock breaking tests were conducted with a 216 mm diameter disc cutter and concrete samples.Based on the superposition principle,the distribution of contact loads between disc cutter and rock were obtained by using the truncated singular value decomposition(TSVD).The results show that both the peak value and the whole numerical distribution of the radial strains on the cutter ring increase with the increase of the penetration.The distribution curves of the contact loads show an approximate parabola going downwards,which indicates contact loads are more concentrated.The front non-loading area with a ratio from 1.8%to 5.4%shows an increasing trend with the increase of penetration.However,the change of rear non-loading area is not obvious.It is believed that the conclusions have guidance for the study of rock breaking mechanism and manufacturing process of the disc cutter.

An investigation into the feasibility of a hybrid generator-photovoltaic-wind farm with variable load profile:case of headland south-west of Morocco

A hybrid system proposed by three different specifications for the equipment of a tourist lodge in the headland of south-west Morocco was sized by analysing the limits of load profile constraints,such as hour-to-hour variability(HHR),day-to-day variability(DDR)and the operating reserve rate(ROR).Based on the three-factor Doehlert matrix recommendations,the simulations employed an energy-sizing tool for hybrid renewable-energy systems.Testing was conducted with DDR at 5-30%,HHR at 10-30%and ROR at 0-20%.Under these conditions,a second-order polynomial relationship with a correlation rate of~90%was found between the net present cost(NPC)of the system,the levelized cost of electricity and the various constraint factors.The first specification,SPC(1),composed of generators and batteries,was introduced to control and validate the simulation independently of renewable energy,which showed a positive manifestation with the imposed constraints.The analysis expanded by introducing solar and wind energy resources.The SPC(2)configuration added PV modules to the SPC(1)and the SPC(3)configuration added wind turbines to SPC(2).The effect of DDR,HHR and ROR in the trials was significant by linear regression.At the same time,only DDR had a significant quadratic regression.The others,with their pairwise interactions,were insignificant.The desirability procedure made it possible to calculate the maximum limits of load profile constraint variables leading to targets of LCOE=0.41 US$/kWh and NPC=US$320080.1 of the load profile constraints:the DDR=15.47%and the HHR=26.55%at an ROR rate of 17.77%.