Exhaust system for internal combustion engines with particle filter

An exhaust system for an internal combustion engine, comprising:

• an exhaust tract which is connectable to an outlet side of the internal combustion engine;
• at least one catalytic converter arranged in the exhaust tract downstream of the engine;
• a particulate filter downstream of the at least one catalytic converter;
• a secondary-air inlet port provided in the exhaust tract upstream of the particulate filter for introducing secondary air compressed by a turbocharger compressor into the exhaust tract via at least one flutter valve, wherein the compressed secondary air is introduced into the exhaust tract downstream of the at least one catalytic converter and upstream of the particulate filter;
• and
• a controller having non-transitory instructions executable to:
• adjust an opening of a compressor bypass valve based on the compressed secondary air introduced into the exhaust tract as controlled by the flutter valve,
• wherein the flutter valve is controlled by a controller to be blocked closed when a soot load of the particulate filter is below a threshold.