Patent ID: 7958730

Claim:
A method for controlling multistage series turbochargers which comprises: a) providing a multistage series turbocharger apparatus which comprises: a low pressure turbocharger comprising a low pressure compressor and a low pressure turbine; a high pressure turbocharger comprising a high pressure compressor and a high pressure turbine; the low pressure turbocharger being connected in series with the high pressure turbocharger such that the low pressure compressor admits ambient air at a parameter x a and discharges the air to the high pressure compressor at a parameter x 12 , which high pressure compressor discharges the air at a parameter x i to an intake manifold of an internal combustion engine; and which high pressure turbine admits exhaust gas from an exhaust manifold of the internal combustion engine at a parameter x e and which high pressure turbine discharges the exhaust gas to the low pressure turbine at a parameter x 21 , which low pressure turbine discharges the exhaust gas to an exhaust; wherein the operation of at least two of the low pressure compressor, high pressure compressor, low pressure turbine and high pressure turbine are variable such that at least two of parameters x i , x 12 , x e and x 21 are variable; sensors for continually measuring at least two of the parameters x i , x 12 , x e and x 21 ; least two independently controlled actuators for continually adjusting at least two of the parameters x i , x 12 , x e and x 21 ; and a multivariable controller having a control algorithm for continually controlling the operation of at least two of the low pressure compressor, high pressure compressor, low pressure turbine and high pressure turbine by continually reading measurement values from the sensors of at least two of the parameters x i , X 12 , X e and x 21 ; continually comparing the measurement values from the sensors of at least two of the parameters x i , x 12 , x e and x 21 to selected values, and then adjusting at least two of the parameters x i , x 12 , x e and x 21 with at least two actuators, such that at least one of parameters x i , x 12 , x e and x 21 is maintained at about a selected value; and b) controlling the operation of at least two of the low pressure compressor, high pressure compressor, low pressure turbine and high pressure turbine, with the controller such that at least one of x i , x 12 , x e and x 21 is maintained about a selected value.