An apparatus, system, and method are disclosed for preventing turbocharger
overspeed in a combustion engine. The method includes determining a
turbocharger error term as a difference between a nominal turbocharger
maximum speed and a current turbocharger speed. The method further
includes determining a turbocharger speed derivative with respect to
time. The method includes calculating a turbocharger control response
based on the turbocharger error term and the turbocharger speed
derivative with respect to time. The turbocharger control response may be
a modified turbocharger maximum speed calculated by determining a
reference speed multiplier based on the turbocharger error term and the
turbocharger speed derivative with respect to time, and multiplying the
reference speed multiplier by the nominal turbocharger maximum speed. The
method thereby smoothly anticipates turbocharger transient events, and
prevents an overspeed condition of the turbocharger.