Load estimation in industrial power systems for expansion planning

To increase the competition in the future global shipbuilding markets, CSBC Corp., Taiwan (CSBC) has started to do an expansion plan to install more efficient facilities for valuing productivity and improving the overall efficiency of plant operations. The shipyard, however, has no power SCADA system due to old building ages and cost considerations and consequently real-time measurements for most load buses in the system are not available. For future expansion purposes, CSBC tries to develop a methodology for expansion planning of the shipyard power system. This paper presents the methodology and expansion planning results. A two-stage load estimation model that combines typical load characteristics and state estimation (SE) theory is developed to provide the daily load curves for all buses in the industrial distribution network at a sound accuracy with relatively few real-time measurements. It makes use of network information to check the validation of their estimates and even to eliminate errors in estimated load data so that the resulted estimates can match the available measurements and comply with power system operation relationships and constraints. The load estimation results that could reflect true system operation are then used as a base-case for expansion planning to determine proper system reinforcements to accommodate an increase in the site's electrical demand. The analysis model developed in this paper can be used for expansion planning, or possible performance measure of similar industrial power systems.