A system for controlling exhaust gas recirculation flow rates and power augmentation of a turbocharged internal combustion engine operating on diesel fuel or other fuels. Exhaust gas from the engine's exhaust manifold is used to drive the turbocharger. Exhaust gas exiting from the turbocharger is directed through a filter trap. A first portion of the exhaust gas exiting the filter trap flows through an exhaust gas recirculation cooler to provide a first input to an electronically controlled diverter valve. Filtered intake air is supplied as a second input to the electronically controlled diverter valve. A mixed output of intake air and recirculated exhaust gas is directed from the diverter valve to an electrically driven compressor and then to the intake manifold of the diesel engine. The combination of the electronically controlled diverter valve and the electrically driven compressor controls both the exhaust gas recirculation flow rates and smoke limited power output at speeds below the peak torque speed of the associated engine. Above peak torque speeds, the turbocharger generally supplies all required intake air to the engine and the electrically driven compressor supplies only recirculated exhaust gas to control NO.sub.x emissions from the engine.
Magdi K. Khair