Electric actuator current control responsive to temperature

Abstract

Various methods for controlling current supply to a wastegate actuator based on temperature are thus provided. In one example, a method for operating a wastegate comprises limiting a boost amount in response to a current limit based on a temperature of a wastegate actuator. The temperature may be an ambient temperature proximate the wastegate actuator.

Description

technical field [0001] The field of the present disclosure relates to wastegate control in turbochargers. Background technique [0002] Some internal combustion engines utilize compression devices such as turbochargers to increase engine torque / power output density. In one example, a turbocharger may include a compressor and a turbine coupled by a driveshaft, where the turbine is coupled to the exhaust manifold side of the engine and the compressor is coupled to the intake manifold side of the engine. In this way, the exhaust-driven turbine energizes the compressor to increase pressure in the intake manifold (eg, boost or boost pressure) and increase airflow into the engine. Boost may be controlled by adjusting the amount of gas to the turbine, eg, using a wastegate. The actuator may be operably coupled to the wastegate valve via a linkage mechanism and actuated to position the wastegate valve at any position between a fully open position and a fully closed position (eg, a...

AI Technical Summary

Problems solved by technology

First, estimating the temperature of an electric motor based on the voltage supplied to the motor and its operating current can be inaccurate and, in some cases, can lead to an underestimation of the temperature, which can lead to degraded motor operation and thus boost control

The accuracy of estimating motor temperature by such methods is further degraded by not taking into account other influences on motor temperature, such as ambient temperature due in part to proximity to the exhaust flow

Second, the measures taken to prevent motor degradation may be more than necessary to ensure normal motor operation, such as reducing the current supplied to the motor by an excessive amount, or stopping the current supply completely, which will reduce the boost voltage significantly to Lower than desired boost level and adversely impacting the vehicle operator experience

Alternatively, reducing the current supplied to the motor may not be sufficient to avoid degraded motor operation

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