Regulating device with an electronic control unit for regulating boost pressure in a supercharged internal combustion engine

A regulating device comprising:

• an electronic control unit for regulating boost pressure in a turbocharged internal combustion engine having at least two-stage turbocharging, having a low-pressure stage and a high-pressure stage, wherein the high-pressure stage has a rigid high-pressure turbine and a controllable bypass regulating flap, and wherein the low-pressure stage has a turbine having variably adjustable turbine geometry, and
• a regulating module in the electronic control unit that is configured to perform a one-actuator regulation in which boost pressure regulation is performed solely by way of the adjustable turbine geometry of the low-pressure stage to achieve a specified boost pressure target value, wherein the regulating flap of the high-pressure stage is controlled in the completely closed state, such that:
• the high-pressure stage delivers its maximum possible boost pressure,
• the low-pressure stage delivers a given amount of boost pressure, and
• the given amount of boost pressure corresponds to a difference between the specified boost pressure target value and the maximum possible boost pressure of the high-pressure stage,
• wherein the regulating flap is used for a first defined high load part of the possible operating points as a second actuator for two-actuator regulation, wherein the first defined high load part is smaller than a second defined high load part and the first high load part of the possible operating points is definable by:
• i) exceeding a specified full load speed limiting value, and/or ii) a specified boost pressure limiting value, and/or iii) a specified mass flow limiting value related to component protection.