OPTIMAL DESIGN OF HARMONIC MONITORING SYSTEM IN DISTRIBUTION NETWORK BASED ON ANT COLONY ALGORITHM

With the widespread of power electronic equipment, harmonic pollution has become increasingly serious in smart distribution networks, and thereby the construction of harmonic monitoring system becomes imperative. Considering the high cost of harmonic monitoring devices, it is uneconomic to monitor the state of all nodes and branches in distribution network. Therefore, this paper proposes an optimal design methodology of harmonic monitoring system based on modified ant colony algorithm, which aims at reducing the cost of harmonic monitoring while estimating all state variables of distribution networks. In the modified algorithm, the number of monitoring devices and the number of state variables that can be estimated jointly by two devices are regarded as the total distance and the heuristic factor of pheromone concentration between two cities, respectively. IEEE-18 bus network is employed as a local distribution network in simulation and the result shows that only six monitoring devices are required to realize the overall system states estimation. Moreover, this paper obtains real values of the system from Simulink/MATLAB for comparison. The highest error between real values and estimated values is lower than 1.0%, which demonstrates the effectiveness of the proposed method.