Differential protection device comprising: - a differential current (Id) measurement sensor (1, 6, 8), and - a differential fault processing unit connected to said measurement sensor so as to receive a differential current measurement signal (Id) and so as to deliver a trip signal to an actuator, said processing unit comprising: - a differential fault detection module receiving a signal representative of a differential current (Id) and delivering a signal representative of a differential fault threshold being exceeded, - a trip delay module controlled by said differential fault detection module so as to activate said trip delay when said differential fault threshold is exceeded, and - a high-energy signal detection module, characterized in that said trip delay module is connected to said high-energy signal detection module and comprises trip delay management for controlling the trip delay period depending on the detection of the presence of high-energy signals, said trip delay module comprising: - a long or slow delay which is ordered when the high-energy signal detection module detects a first high-energy wave, and - a short or fast delay by default for as long as a first wave is not detected or when a series of high-energy waves is detected, and said high-energy signal detection module comprising at least one high-energy signal detection threshold (SP, SPA, SPB) which is higher than a differential protection threshold, with a view to ordering a change to a slow or long delay, said high-energy waves and/or signals being detected when said at least one high-energy signal detection threshold (SP, SPA, SPB) is exceeded. - a differential current (Id) measurement sensor (1, 6, 8), and - a differential fault processing unit connected to said measurement sensor so as to receive a differential current measurement signal (Id) and so as to deliver a trip signal to an actuator, said processing unit comprising: - a differential fault detection module receiving a signal representative of a differential current (Id) and delivering a signal representative of a differential fault threshold being exceeded, - a trip delay module controlled by said differential fault detection module so as to activate said trip delay when said differential fault threshold is exceeded, and - a high-energy signal detection module, characterized in that said trip delay module is connected to said high-energy signal detection module and comprises trip delay management for controlling the trip delay period depending on the detection of the presence of high-energy signals, said trip delay module comprising: - a long or slow delay which is ordered when the high-energy signal detection module detects a first high-energy wave, and - a short or fast delay by default for as long as a first wave is not detected or when a series of high-energy waves is detected, and - a long or slow delay which is ordered when the high-energy signal detection module detects a first high-energy wave, and - a short or fast delay by default for as long as a first wave is not detected or when a series of high-energy waves is detected, and said high-energy signal detection module comprising at least one high-energy signal detection threshold (SP, SPA, SPB) which is higher than a differential protection threshold, with a view to ordering a change to a slow or long delay, said high-energy waves and/or signals being detected when said at least one high-energy signal detection threshold (SP, SPA, SPB) is exceeded.