抽油机电动机断续供电节能技术断电时刻判定方法

摘要

游梁式抽油机电动机在一个运行周期内会存在重载、轻载、电动及发电工况交替出现的现象,针对此类型负荷,采用“断续供电”控制技术能够获得明显的节能效果,但受传动环节振动、井下液面等影响,电机负荷始终处于无规则波动状态,导致难以准确判定断电时刻.为了解决这一问题,提出一种基于模糊控制的断电时刻判定方法及相应控制策略.对负荷曲线变化特点、电动及发电工况持续时间等参数进行辨识;根据辨识结果选择最优“断续供电”控制方案,设计了以断电后转速变化值为输入变量、功率累加值为输出变量的模糊控制器,实现断电时刻准确判定.该控制器还可以实现动态负荷自动跟踪.基于所提策略研制了节能控制器并投入油田现场应用,获得了良好的节能效果.%Beam pumping motors undergo heavy and light loads,as well as motor and generation modes alternatively during a running cycle.The "intermittent power supply" control technology can achieve obvious energy saving effects in this case.However,the motor load randomly fluctuates due to the vibration of the transmission link and the dynamic liquid level in the oil well.Therefore,it is difficult to determine the power-off times.To solve this problem,a power-off time determining method based on fuzzy control strategy and corresponding control strategy is presented.The operation parameters,such as the load rates and the duration of motor and generation modes,are identified,the optimal "intermittent power supply" control scheme is selected according to the identification results,and the fuzzy controller with the speed change after the power-off as the input variable and the accumulated power value as the output variable,is established to accurately determine the power-off time.In addition,the controller can automatically track dynamic load.The energy-saving controller is developed based on the presented strategies and applied to oil fields,achieving good energy saving effect.