Engine system having multi-stage turbocharging and exhaust gas recirculation

A method of directing exhaust gas of an engine system, the engine system including an engine, an intake system for providing intake air to the engine, and an exhaust system receiving exhaust gas from the engine, the method comprising:

• directing exhaust gas from the engine to a first exhaust turbine arranged downstream from the engine;
• directing exhaust gas from the first exhaust turbine to a second and third exhaust turbines coupled in parallel, the second exhaust turbine being arranged downstream of the first exhaust turbine;
• increasing boost pressure supplied by the intake system to the engine by selectively restricting exhaust gas to one of the second and third exhaust turbines;
• and
• directing at least a portion of exhaust gas from the exhaust system to the intake system.

A method of directing exhaust gas of an engine system, the engine system including an engine, an intake system for providing intake air to the engine, and an exhaust system receiving exhaust gas from the engine, the method comprising:

• directing exhaust gas from the engine to a first exhaust turbine arranged downstream from the engine;
• selectively directing exhaust gas from the first exhaust turbine to one of a second and a third exhaust turbines coupled in parallel by at least partially restricting exhaust gas to one of the second and third exhaust turbines and increasing the exhaust gas to the other, the second exhaust turbine being arranged downstream of the first exhaust turbine;
• and
• directing at least a portion of exhaust gas from the exhaust system to the intake system.