Fuzzy decision-making in stochastic multiobjective short-term hydrothermal scheduling

In the multiobjective framework, fuzzy decision-making methodology is exploited to decide the generation schedule of a short-range fixed-head hydrothermal problem. The multiobjective problem is formulated considering five objectives: (i) cost. (ii) NOx emission. (iii) SO2 emission, (iv) CO2 emission and (v) variance of generation mismatch with the explicit recognition of statistical uncertainties in the thermal generation cost, NOx, SO2 and CO2 emission curves and power demand, which are random variables. The solution set of such formulated problems is non-inferior due to contradictions among the objectives taken. The weighting method is used to simulate the trade-off relation between the conflicting objectives in the non-inferior domain. Once the trade-off has been obtained, fuzzy, set theory helps the system operator to choose the weighting pattern and thus the operating point that maximises the satisfaction of all the objectives. The results are demonstrated on three sample systems.