配水ポンプ施設のエネルギー特性のモデル化と水運用計画立案での活用

摘要

消費エネルギーを低減する水運用計画の立案には、ポンプの消費エネルギーを精緻に評価するとともに、実時間での計画立案に適した消費エネルギー推定モデルが必要となる。本論文では配水ポンプ施設を対象に、配水流量から消費電力を求めるモデルの凸区分線形関数での近似を試みた。赤池情報量基準を用いて実運転データにフィットするモデルを構築し精度を評価した。配水系でのシミュレーシヨンにて、本モデルを活用した計画立案手法は、消費電力をラフに考慮する従来法に比べて消費エネルギーを1〜3％低減した。また短時間（約1秒）で計画立案できることを確認した。合わせてポンプ特性と制御則に基づく高精度なモデルも提案し比較を行った。%Scheduling of water distribution by optimization methods is effective in saving energy consumption of pumps. It requires models of pump stations which can accurately estimate nonlinear power characteristics. In addition, it should be considered that the optimization problem based on the power models can be solved by an efficient algorithm in order to apply the scheduling process into daily operations. This paper proposes two approaches. In the first approach, the more accurate nonlinear model is constructed from the hydraulic and efficiency curves of pumps and the control logic of the pump station. In the second approach, the convex piecewise linear model is constructed by fitting directly to the measurements, and its number of parameters is determined using the Akaike information criteria. Both approaches were applied to the actual data of a distribution pump station. The mean absolute errors of the constructed models were less than 4%, and the both models were suited for use in water distribution scheduling. In a simulation study, the optimal scheduling methods using the constructed models reduced pump energy consumption by 1-3% compared with a conventional method without explicit power characteristics model. Especially, the scheduling method with the convex piecewise linear model, which was modeled as a linear programming program, computed optimal scheduling in about a second, and so it is expected to be applied to larger scale distribution systems in a reasonable computation time. In conclusion, it is suggested that the proposed models are effectively applied to water distribution scheduling.