Research And Development Of Electric Power Monitoring Technology Of Pumping Unit Driven By Variable Frequency

The oil well indicator diagram is the important basis of reference for working condition,its application has become very common.With the implement of the national energy conservation and environmental protection policy,more and more oilfield enterprises use pumping unit driven by variable frequency which can improve the condition of pumping unit working at low load and low efficiency.The electrical diagrams can react to the working condition of pumping unit in some degree and it is easier to detect electrical signals than polished rod load and displacement.However,the motor voltage is PWM waveform and the current is distortion,which brings a lot of challenge to the electrical diagrams monitoring and algorithm implementation.This paper developed a system and technology of monitoring electrical diagrams of pumping unit driven by variable frequency,the topic of this paper has important practical significance.In view of the current electricity monitoring indicator diagrams are mostly limited to driving under 50 Hz,more and more pumping unit is driven by variable frequency,this paper developed a pumping unit motor monitoring system which is suitable for PWM voltage and no sinusoidal current.This paper designed a set of high-speed synchronous sampling hardware system,including the hall sensor module,signal conditioning module,A/D sampling module and DSP with its peripheral circuit.This paper elaborated the design and working principle of each module,and gave the specific circuit structure.Through DSP software design,this paper completed the main program module,signal sampling module and data processing module writing.This paper use add window FFT algorithm to complete the electrical diagrams of pumping unit driven by variable frequency quasi real-time monitoring.Through simulation and experimental results,verify the feasibility of system solutions.