A power system comprising: an engine ; an exhaust conduit ; a particulate filter ; a backpressure valve disposed in the exhaust conduit , wherein the backpressure valve is configured to regenerate the particulate filter ; and a controller configured to: operate the power system in a first operation mode , wherein the operation of the power system in the first operation mode comprises opening the backpressure valve ; operate the power system in a second operation mode to regenerate the particulate filter , wherein the operation of the power system in the second operation mode comprises closing the backpressure valve ; characterised in that the controller is further configured to: transition the power system from the second operation mode to the first operation mode, wherein the transition comprises opening the backpressure valve; wherein the backpressure valve is opened at a first rate when an amount of soot in the particulate filter falls below a threshold; and wherein the backpressure valve is opened at a second rate when a load on the engine increases; further wherein the second rate is faster than the first rate. an engine ; an exhaust conduit ; a particulate filter ; a backpressure valve disposed in the exhaust conduit , wherein the backpressure valve is configured to regenerate the particulate filter ; and a controller configured to: operate the power system in a first operation mode , wherein the operation of the power system in the first operation mode comprises opening the backpressure valve ; operate the power system in a second operation mode to regenerate the particulate filter , wherein the operation of the power system in the second operation mode comprises closing the backpressure valve ; characterised in that the controller is further configured to: transition the power system from the second operation mode to the first operation mode, wherein the transition comprises opening the backpressure valve; wherein the backpressure valve is opened at a first rate when an amount of soot in the particulate filter falls below a threshold; and wherein the backpressure valve is opened at a second rate when a load on the engine increases; further wherein the second rate is faster than the first rate. operate the power system in a first operation mode , wherein the operation of the power system in the first operation mode comprises opening the backpressure valve ; operate the power system in a second operation mode to regenerate the particulate filter , wherein the operation of the power system in the second operation mode comprises closing the backpressure valve ; characterised in that the controller is further configured to: transition the power system from the second operation mode to the first operation mode, wherein the transition comprises opening the backpressure valve; wherein the backpressure valve is opened at a first rate when an amount of soot in the particulate filter falls below a threshold; and wherein the backpressure valve is opened at a second rate when a load on the engine increases; further wherein the second rate is faster than the first rate. characterised in that the controller is further configured to: transition the power system from the second operation mode to the first operation mode, wherein the transition comprises opening the backpressure valve; wherein the backpressure valve is opened at a first rate when an amount of soot in the particulate filter falls below a threshold; and wherein the backpressure valve is opened at a second rate when a load on the engine increases; further wherein the second rate is faster than the first rate. <EOS>