Design Based On Three Level ESP Inverter Of Space Vector Control

Harmonic problem is much discussed in academic circles at home and abroad in recent years,international has repeatedly held special meetings on harmonic problems.Power system harmonics generate a lot of energy losses,reduce the working efficiency of the electrical equipment,and make influence on the performance of the equipment workings,so that the service life of them will decline.Our company's ESP units also be affected by harmonic problems in the process of application.In some remote oilfield,due to the bad environment,harmonic and interference are especially obvious.They often cause the output voltage of generator fluctuates with the additional temperature rise and frequency fluctuations.With the result of that,the pumps have to derating use.Based on these field application situation,in order to ensure the normal operation of the units underground,I will analyze the generating mechanism of harmonic deeply,and put forward solutions.This paper analyzed the damage to the ESP units of the harmonic firstly,then did the quantitative analysis on the impact of motor bearing,insulation,pump parts through mathematical calculation.Secondly I made simple explanation on the working principle of ESP,and then further analyzed the working status of ESP units and the pump efficiency of the operation under different frequency,and put forward the matters needing attention in the process of converter designing.Then the modulation algorithm of three level inverter based on space vector control were introduced,and the adjustment of the charge was achieved by changing the effect time of redundancy small vector through detailed analysis and calculation.In the face of failure,I analyzed decomposition characteristics of the reference vector carefully in different locations,so as to put forward the correction method of the algorithm.This paper adopted the DSP control chip to do hardware design and software design on frequency conversion control system in order to realize the control of ESP.Finally based on selected harmonic scheme,I made on-site validation and tracked improvement,so as to achieve the purpose of management on harmonic interference at the scene of the submersible electric pump frequency conversion control cabinet,and extend the life of the units.