Method of controlling a turbocharger
Systems and methods are described for operating a turbocharger. A current exhaust manifold pressure is determined based on an engine operating condition. A current operating condition of the turbocharger is determined. A surge correction factor is determined based on the current operating condition of the turbocharger. The current exhaust manifold pressure is adjusted based on the surge correction factor.
1. A method for operating a turbocharger the method comprising:
determining, via a control unit comprising processing circuitry, a current exhaust manifold pressure of an exhaust system based on an engine operating condition of an engine;
determining, via the processing circuitry, a current operating condition of the turbocharger;
determining, via the processing circuitry, a surge correction factor based on the current operating condition of the turbocharger; and
adjusting, via an actuator of the exhaust system, the current exhaust manifold pressure based on the surge correction factor.
2. The method of claim 1 , wherein the engine operating condition comprises at least one of: an aftertreatment condition; an aftertreatment condition at idle; an engine speed; an engine loading condition; an engine temperature; an air flow rate; an engine operating condition at high altitudes; and a combustion mode.
3. The method of claim 1 , wherein the current operating condition of the turbocharger comprises at least one of a current boost pressure, a compressor mass flow rate and a compressor inlet pressure.
4. The method of claim 1 , wherein determining the surge correction factor comprises determining, via the processing circuitry, a maximum operating boost pressure of the turbocharger corresponding to a surge limit of the turbocharger.
5. The method of claim 4 , further comprising determining by the processing circuitry, a surge ratio, the surge ratio being a ratio of the maximum operating boost pressure to the current boost pressure.
6. The method of claim 5 , further comprising integrating, by the processing circuitry, the surge ratio to determine the surge correction factor.
7. The method of claim 6 , further comprising limiting, by the processing circuitry, the surge correction factor to an upper limit equal to 1 and a lower limit.
8. The method of claim 7 , further comprising at least one of: reducing the surge correction factor towards the lower limit when the current boost pressure is determined, by the processing circuitry, to be exceeding the surge limit; increasing the surge correction factor when the current boost pressure is determined to be below the surge limit; and fixing the surge correction factor when the current boost pressure is determined to be at the surge limit.
9. The method of claim 1 , further comprising outputting, by the processing circuitry, the adjusted exhaust manifold pressure to control the turbocharger.
10. The method of claim 1 , further comprising alternating, via the processing circuitry, between a primary objective of adjusting the current exhaust manifold pressure and a primary objective of adjusting the current boost pressure.
11. A system for operating a turbocharger, the system comprising:
an engine;
an exhaust system comprising an actuator configured to control the flow of exhaust gases through the exhaust system; and
a control unit communicatively coupled to the engine, the exhaust system, and the actuator, wherein the control unit comprises processing circuitry configured to:
determine a current exhaust manifold pressure based on an engine operating condition;
determine a current operating condition of the turbocharger;
determine a surge correction factor based on the current operating condition of the turbocharger; and
adjust the current exhaust manifold pressure, via the actuator, based on the surge correction factor.
12. The system of claim 11 , wherein the engine operating condition comprises at least one of: an engine speed; an engine loading condition; an engine temperature; an air flow rate; an engine operating condition at high altitudes; and a combustion mode.
13. The system of claim 11 , wherein the current operating condition of the turbocharger comprises at least one of a current boost pressure, a compressor mass flow rate and a compressor inlet pressure.
14. The system of claim 11 , wherein the processing circuitry is further configured, when determining the surge correction factor, to determine a maximum operating boost pressure of the turbocharger corresponding to a surge limit of the turbocharger.
15. The system of claim 14 , wherein the processing circuitry is further configured to determine a surge ratio, the surge ratio being a ratio of the maximum operating boost pressure to the current boost pressure.
16. The system of claim 15 , wherein the control circuitry is further configured to integrate the surge ratio to determine the surge correction factor.
17. The system of claim 16 , wherein the control circuitry is further configured to limit the surge correction factor to an upper limit equal to 1 and a lower limit.
18. The system of claim 17 , wherein the control circuitry is further configured to:
reduce the surge correction factor towards the lower limit when the current boost pressure is determined, by the control circuitry, to be exceeding the surge limit;
increase the surge correction factor when the current boost pressure is determined to be below the surge limit; and
fix the surge correction factor when the current boost pressure is determined to be at the surge limit.