考虑负荷及煤气量不确定性的企业微电网自发电调度模型

A Self-power Generation Scheduling Model Under Load Demand and Uncertainty of a By-product of Gas Production in Enterprises Microgrid

合理地制定企业微电网自备电厂机组出力及煤气消耗计划,对降低企业发用电成本,减少环境污染有着非常重要的意义。以企业微电网发用电成本最小化为目标,采用情景树来描述用电负荷及煤气量的不确定性,建立企业微电网自发电调度随机优化模型。该模型中存在安全约束,采用盒式不确定集合描述该安全约束;为避免盒式集合安全约束过于保守的特性,利用椭圆集合替代盒式集合,通过调节风险系数,改变决策的保守特性;给出煤气柜位状态转移图,将安全约束等价转化为线性约束进行求解。应用某大型钢铁企业实际数据进行测试,结果表明:在电网负荷谷时段,企业以电网购电为主;在用电高峰时段,企业以自发电为主;用椭圆集合替代盒式集合,通过调节风险系数能有效避免决策的保守性。

Scheduling of the self-generation plants is very helpful to the energy saving and emission reduction for enterprises microgrid. In this paper, the objective function was to minimize the overall cost of the electricity. The scenario tree was used to analyze the uncertainties of electricity load and gas supplication. The self-generation stochastic model was built. In this model, rectangle set was used to describe the safety constraint. In order to avoid that rectangle set is too conservative, we used ellipsoid set instead of rectangle set by adjusting risk parameter. State transition diagram of gas holder level was given to transform safety constraint into linear constraint. Results show that during off-peak periods, most of the enterprises load is afforded by the grid; and that during peak periods, most of load is afforded by the self-generation plants. In addition, using ellipsoid set instead of rectangle set reduces decision conservatism by adjusting the risk coefficient.