以并联泵站群日提水耗电费用最少为目标, 构建包含各时段泵站运行数、站内水泵开机数、水泵叶片安放角及 机组转速4 个决策变量的并联泵站群变角变速组合日优化运行数学模型, 提出基于二级子系统试验选优的大系统 二级分解2动态规划聚合法。通过将原模型进行二次分解, 获得以单机组日提水耗电费用最小为目标, 各时段水泵 叶片安放角及机组转速为决策变量的单机组变角变速组合日优化运行数学模型, 采用大系统试验选优法求解。进 而通过一系列二级子系统不同提水要求下的优化计算, 获得单机组日提水量与提水费用的一一对应关系, 原模型即 可转化为以并联泵站群日提水费用最少为目标、各机组日提水量为决策变量的聚合模型, 并采用动态规划方法求 解。该方法可进一步完善组合工况调节方式下并联泵站群优化运行理论, 较由站内单工况优化运行下获得的并联 泵站群优化运行效益更为显著。以典型并联泵站群为计算实例, 优化结果表明: 各日均扬程下满负荷、80% 负荷、 60%负荷优化运行单位费用较定角恒速运行分别平均节约8. 41%、23. 07%、32. 79%。

Taking t he minimal daily elect ric cost of par allel pumping statio ns as t he objectiv e function, t he mathematical model of daily optimal o per atio n fo r parallel pumping st ations with adjustable blades and var iable speeds w as co nstr ucted w ith four deci2 sio n variables, including the operation number of pumping st ations, o per ation number of units in a sing le pumping statio n, blade ang le, and unit speed. T he tw o2stag e decomposit ion2dynamic prog ramming ag gr eg atio n met ho d based o n t he ex per imental o pt i2 mization for the seco nd stag e sub2mo del w as pro po sed to so lve the mathematical model. Thro ug h the t wo2stag e decomposition of the o riginal mo del, the mathemat ical model o f daily optima l operation fo r the sing le pump unit wit h adjustable blades and var ia2 ble speeds wer e obtained. The second2stag e sub2model too k the minima l da ily electric cost o f the sing le pump unit as the objec2 tive function, the blade angle and unit speed in each time per iod as the decision v ariables, and w as so lved by the ex per imental op2 timization. After a series of optimization o f t he sub2model under different water pumping quantities, the r elationship betw een each w ater pum ping quant ity and the cor responding w ater pumping cost was obtained. Then the o riginal mo del w as tr ansfo rmed into the ag g regat ion model of daily o ptimal o per ation fo r the parallel pumping statio ns w ith adjustable blades and v ariable speeds, and was solv ed by t he one2dimensional dynamic pr og ramming method. The pr oposed method can further impro ve the op2 timal o per atio n theor y of parallel pumping st at ions w ith var ious operatio n mo des, and the operatio n benefit w as mo re sig nificant compar ed with that o bt ained from the o ptimal operatio n w ith a single o perat ion mo de. A study case using the optimization meth2 o d show ed that the unit co st of o ptima l operat ion under 100% , 80%, and 60% loads w ithin the aver age daily heads can be re2 duced by 8. 41%, 23. 07%, and 32. 79% compar ed w ith the operation with t he fixed blade ang le and constant speed.

江苏省自然科学基金–青年基金项目( BK20130446) ; 2014 年度扬州大学科技创新培育基金( 2014C XJ026)