Patent ID: 7644586

Claim:
A method of controlling an engine system comprising an internal combustion engine having an exhaust valve, a supercharging system having at least one supercharger to boost intake air to said internal combustion engine, a turbine, and a motor, wherein said turbine receives an exhaust gas flow from an exhaust system of said internal combustion engine and drives said at least one supercharger, and wherein said motor drives either said at least one supercharger or a second supercharger of said supercharger system, and a controller which controls said exhaust valve and said motor, the method comprising: operating said exhaust valve in a first exhaust state where said exhaust valve opens at a first exhaust open timing during a cylinder cycle and operating said motor in a first motor state when a speed of said internal combustion engine is below a first engine speed; operating said exhaust valve in said first exhaust state and operating said motor in a second motor state where power to drive said motor is reduced from that in said first motor state when the speed of said internal combustion engine is between said first engine speed and a second engine speed, said second engine speed being greater than said first engine speed; and operating said exhaust valve in a second exhaust state where said exhaust valve opens at a second exhaust open timing which is earlier than said first exhaust open timing during a cylinder cycle whereby energy transmitted from said internal combustion engine to said turbine is reduced from that in said first exhaust state and operating said motor in said second motor state when the speed of said internal combustion engine is above said second engine speed.