Improved particle swarm optimization for combined heat and power economic dispatch

This paper presents eight improved particle swarm optimization (ipso) algorithms for solving combined heat and power economic dispatch (chped) problem with valve point loading eects on fuel cost function and transmission losses. the main objective of the problem is to nd the power output and the heat output of available units so that the total fuel cost is minimized while satisfying power and heat demands and power and heat limits. the proposed ipso algorithms are based on some modications on the parameters and the use of cauchy distribution. the effectiveness of the ipso methods has been validated through six different test systems including three systems with quadratic fuel cost function of pure power units neglecting transmission losses, two systems with nonconvex fuel cost function of pure power units considering transmission losses, and one large-scale system with nonconvex fuel cost function of pure units and without transmission losses. the result comparisons between the ipso methods and other methods in the literature have indicated that the proposed methods can obtain higher solution quality with faster computational time than many other methods. therefore, the proposed ipso methods would be very ecient methods for solving the nonconvex chped problem.