势能负载条件下感应电机变频–调压分段节能控制策略研究

Research on Sectionalized Energy-Saving Control Strategy Based on Frequency and Voltage Regulator Technique for Induction Motor With Potential Loads

目前投入油田应用的节能设备大多基于单一节能技术,且通用性较差。该文结合抽油机负载特点及四连杆运动规律,提出一种基于变频器的变频?调压分段协调运行的通用节能新技术。该技术通过在不同曲柄运行位置区间选择性地改变感应电机供电模式,使其运行状态发生改变,主要特征:1)采用变频手段控制悬点加速度大小,间接削弱悬点载荷中的惯性力矩成分,从而减小上冲程阶段电机消耗的电功率;2)实时监测电机实际负荷状况,采取跟踪调压技术确保电机运行效率最优。以一台Y2-280S、37k W感应电机及其驱动的CYJ10型游梁式抽油机为算例,对多种复杂工况下的节电效果进行综合仿真对比。结果表明:该方法能够有效改善上冲程前半周期平衡块对负载的平衡作用,降低了最大载荷值;不同动液面、平衡配重下系统节电率大于12%,具有较强通用性;从而为油田节能开辟了新思路,具有重要理论意义和实用价值。

The current energy-saving devices used in oil field are mostly based on single energy-saving technology and with the poor universality. Combining with load characteristics of beam pump unit （BPU） and mechanical features of four-bar linkage, this paper presented a sectionalized control strategy of frequency and voltage regulator based on the converter. This technique makes induction motor operate in preset range selectively by changing the power supply mode in different crank position sectors, whose main features are as follows： 1） Controlling horse-head acceleration through frequency conversion and indirectly weakening the inertia component of polished rod load, thereby dropping the power consumption during the up-stroke; 2） According to real-time monitoring load conditions of motor, adopting the tracking regulator technique to optimize running efficiency. Taking a CYJ10 BPU driven by an Y2-280S, 37kW induction machine as an example, the comparative analysis of energy-saving effect of various BPU conditions was carried out. Results show that this control strategy can effectively improves the load balance effect acted by counterbalance during the first half of the up-stroke and reduces the maximum load value. In addition, the system energy-saving rate is above 12% under different fluid level and counter weight; the universality is also verified. The achievement breaks a new path for oil field energy-saving work, which has important theoretical significance and practical value.