The impact of losses in cable selection for distribution circuit in Malaysia

Abstract

This paper describes the impact of losses in cable selection for distribution circuit in Malaysia. A minimum lifecycle cost methodology is utilized as a basic for circuit design. Minimum life-cycle cost methodology is a method that balances the capital cost against the cost of circuit losses. The result obtained shows the optimal utilisation of 11kV distribution cable in Malaysia is quite low, in the range of 32% to 41%. Parametric analyses on discount rate, load factor and electricity price were carried out to validate the robustness of the results. List of symbols:A = effective cross-sectional area of conductor, mm 2 a = coefficient for capital cost/current carrying capacity correlation for a given circuit typology, RM/km/A 2b b = exponent for capital cost/current carrying capacity correlation for a given circuit typology, p.u CC = annuitised capital cost, RM/year CL = total annual cost of losses, RM/year I cap = current carrying capacity, A = optimal current carrying capacity, A I max = maximum value of annual current of circuit, A I(t) = current in circuit in time period t, A K = annuitized incremental investment cost, RM/(A,km,year) L = length of circuit, km nl = total number of circuits R = circuitresistance, Ω t = time unit T = circuit technical useful lifespan, years TC = annuitized total cost, RM/year = optimal utilisation of circuit, % = coefficient for current-carrying capacity/cross-sectional area correlation for a given circuit typology, / · β = exponent for current-carrying capacity/cross-sectional area correlation for a given circuit typology, p.u. (t) = estimated specific cost of losses (RM/kWh) at hour t = resistivity of the aluminum conductor, Ω · / Abbreviations CC annuitized capital cost CL annual cost of losses LF load factor TC annuitized total cost