System and method of operating an internal combustion engine

A system comprising:

• an internal combustion engine comprising a plurality of cylinders of the engine for combusting a mixture of fresh air and fuel;
• a fuel injection system for injecting fuel into the plurality of cylinders of the engine;
• a turbocharger unit including a turbine coupled via a turbocharger shaft to a compressor, wherein the compressor is configured to receive the fresh air and discharge a compressed air stream to an intake manifold of the internal combustion engine;
• a first flow path for allowing a first portion of exhaust gases from an exhaust manifold into the turbine for expanding the first portion of the exhaust gases;
• a second flow path for allowing a second portion of exhaust gases from the exhaust manifold via an exhaust channel bypassing a first-stage turbine;
• a third flow path for recirculating a third portion of exhaust gases from the exhaust manifold into the intake manifold after mixing with the fresh air;
• and
• a controller comprising a plurality of sensors for sensing a plurality of operating parameters, wherein the controller is configured to reduce nitrogen oxide (NOx) and particulate matter (PM) emission levels by a) reducing the engine speed at a given engine power while maintaining the given engine power constant by increasing a fuel injection duration per cycle for increasing torque, b) increasing a flow rate of the exhaust gas recirculation, c) increasing injection pressure, and d) advancing a fuel injection timing.