A method for controlling an electrical transmission link between first and second AC voltage buses (11, 21) connected respectively to first and second AC voltage areas of an electrical transmission grid, the transmission link comprising a high-voltage DC line, a first AC/DC converter connected firstly to the first bus and secondly to the high-voltage DC line, and a second AC/DC converter connected firstly to the second bus and secondly to the high-voltage DC line, the method comprising: - retrieving a setpoint active power value applied to the first or to the second converter (321, 322); - retrieving the instantaneous values V1 and V2 of the voltages on the first and second buses, respectively; - wherein the setpoint active power of the first or of the second converter is modified by a value including a term ΔPdc, so as to impose new dynamics on the grid including the first and second areas, where: Δ Pdc = Δ Pdc s + Δ Pdc a Where ΔPdc s is a synchronization term: Δ Pdc s = λδ ∗ δref − δ where δ = δ 1 - δ 2 is the phase offset between the voltages of the first and second buses for the retrieved instantaneous values, δ 1 is the angle of the voltage on the first bus, δ 2 is the angle of the voltage on the second bus, δref is an initial phase offset value between the voltages of the first and second buses, λδ is an amplification gain; where ΔPdc a is a damping term: Δ Pdc a = λω ∗ ω 1 − ω 2 where ω1 is the electrical angular frequency of the area 1, ω2 is the electrical angular frequency of the area 2, λω is an amplification gain. - retrieving a setpoint active power value applied to the first or to the second converter (321, 322); - retrieving the instantaneous values V1 and V2 of the voltages on the first and second buses, respectively; - wherein the setpoint active power of the first or of the second converter is modified by a value including a term ΔPdc, so as to impose new dynamics on the grid including the first and second areas, where: Δ Pdc = Δ Pdc s + Δ Pdc a Where ΔPdc s is a synchronization term: Δ Pdc s = λδ ∗ δref − δ where δ = δ 1 - δ 2 is the phase offset between the voltages of the first and second buses for the retrieved instantaneous values, δ 1 is the angle of the voltage on the first bus, δ 2 is the angle of the voltage on the second bus, δref is an initial phase offset value between the voltages of the first and second buses, λδ is an amplification gain; where ΔPdc a is a damping term: Δ Pdc a = λω ∗ ω 1 − ω 2 where ω1 is the electrical angular frequency of the area 1, ω2 is the electrical angular frequency of the area 2, λω is an amplification gain. Where ΔPdc s is a synchronization term: Δ Pdc s = λδ ∗ δref − δ where δ = δ 1 - δ 2 is the phase offset between the voltages of the first and second buses for the retrieved instantaneous values, δ 1 is the angle of the voltage on the first bus, δ 2 is the angle of the voltage on the second bus, δref is an initial phase offset value between the voltages of the first and second buses, λδ is an amplification gain; where ΔPdc a is a damping term: Δ Pdc a = λω ∗ ω 1 − ω 2 where ω1 is the electrical angular frequency of the area 1, ω2 is the electrical angular frequency of the area 2, λω is an amplification gain.