| The petroleum and petrochemical industry is a pillar industry in the development of the national economy,while creating huge profits,it also brings huge energy consumption.The problems of high energy consumption and low production efficiency of oilfield injection and production systems are particularly prominent,controlling the energy consumption of crude oil extraction has become a challenging subject in the field of oil extraction technology,equipment research and development and manufacturing.The oil well energy mutual feedback energy-saving control system designed by the research team in the early stage adopts an AC transformer connected to the rectification device,and uses a common DC bus to connect multiple inverters with pumping units in parallel to enable the oil well pumping motors can realize energy mutual feedback and energy saving to achieve the purpose of reducing consumption.However,the rectifier side of the pumping unit control system uses ordinary power diode rectification,when the operation scheduling is poor,the inverted energy by the oil well pumping unit will cause the common DC bus voltage to pump up,and the AC side current waveform will be severely distorted,and there will be a lot of harmonics,the power factor is low,which seriously affects the power quality of the power grid.Therefore,it is of great significance to research and develop a controllable rectifier device suitable for oil well production demand,high power factor operation and bidirectional energy flow.In this paper comprehensively considers the design implementation complexity and hardware cost of the control strategy,and chooses the topology of the three-phase voltagetype PWM half-bridge rectifier circuit as the main circuit structure of the rectification device.In order to facilitate the controller design,the working principle and commutation process are systematically analyzed,the mathematical model of three-phase rectifier circuit in different coordinate system is established,and the double-closed-loop direct current control strategy of outer voltage loop and inner current loop is adopted.In order to improve and realize the ability of rapid current tracking on the AC side and large load fluctuation resistance on the DC side,the current inner loop adopts traditional PI control,the voltage outer loop adopts fuzzy adaptive PI control,and the space voltage vector modulation(SVPWM)technology to generate three-phase PWM control waveform,and the MATLAB/Simulink platform is used to simulate the operational states of oil well energy feedback and load fluctuation,and the feasibility of the design idea of the threephase PWM rectification device is simulated and verified.Based on this,the main electronic components and parameters of the main circuit and control circuit module are selected,and the three-phase voltage-type PWM halfbridge rectifier circuit main circuit is built,with TMS320F28335 as the core of the controller,designed the data acquisition and processing,DSP control system and signal drive,other peripheral hardware circuits and PCB boards to complete the hardware design and debugging.Based on the DSP,the control algorithm and the underlying driver proposed front of paper are developed,an experimental platform for the rectification device is set up,and the experimental test and performance analysis of the well conditions are simulated.The results show that the performance of the developed controllable rectification device is compared with the traditional diode rectifiers used in oil fields,that has obvious advantages,the AC side current waveform is sinusoidal and the power factor tends to 1,the DC voltage is stable when the load mutation,and energy can be feedback to the grid during reverse power generation,and can flexibly set control parameters according to the characteristics of different well working condition,which is targeted and open,laying a technical foundation for the implementation of further energy-saving production in the oil field. |
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