Since 2004, INERGY is working on the development of SCR (Selective Catalytic Reduction) system Components and controls to enable the reduction of NOx (Nitrogen Oxides) in the exhaust gas using an aqueous urea solution. This paper is focused on the pump control strategy.
In this paper, we modelled an INERGY SCR pump system (gear pump, DC motor, line and injector) used. Then we considered PID (Proportional-Integral-Derivative) controllers since they are common in the automotive industry.
We developed 4 controllers to achieve the necessary system function which include: line filling, pressure build-up, pressure hold-up, and purge. Windup introduced by saturation of the motor command and transition between the controllers were taken into account during development.
We tested different anti-windup approaches on this model. We derived lessons regarding the overshoot, the rise time and the performance of the different anti-windup techniques. Then we showed the results of anti-windup methods applied on INERGY 1st and 2nd generation SCR systems