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.