SRPU balance monitoring by wattmeter card

One of key indicators that influence the energy consumption of induction motor of a sucker-rod pumping unit (SRPU) is pumpjack balance which is defined by the counterweight position on the crank - the key parameter of machine mechanical set-up. It addressed the current ways of determining the balance and it identified their weaknesses. It determined that the most affordable and reliable of SRPU diagnostics means is wattmetering. The article considers a SRPU computer model for research patterns and operating modes of unit. The algorithms of the determination of pumpjack balance, counterweight optimum position and “dead centres” are developed. The algorithms do not require mounting any external sensors on the unit and may be operated as a part of the SRPU intelligent control station software providing for a simplicity of control, maintenance and cost cutting.