A negative pressure wound therapy system comprising - an electrical pump for generating negative pressure, - optionally a tachometer for determining a pump speed associated with the electrical pump, - a pressure sensor for determining negative pressure values, - a controller for controlling activity of the electrical pump, - an input means for adjusting settings on the negative pressure wound therapy system, said input means being operable by the user of the negative pressure wound therapy system, - a first fluid path (6, 14, 15) fluidly connectable to a wound site and to the electrical pump such that the wound site can be subjected to a negative pressure, wherein the pressure sensor is located in the first fluid path (6, 14, 15) between the wound site and the electrical pump, characterised in that the controller of the negative pressure wound therapy system is adapted to execute a method of generating a negative pressure at the wound site during a negative pressure wound therapy, comprising the steps of i. setting a target negative pressure on the negative pressure wound therapy system, said negative pressure wound therapy system being used for the negative pressure wound therapy, ii. determining a negative pressure value by means of the pressure sensor, iii. calculating a difference between the determined negative pressure value and the target negative pressure setting to obtain a negative pressure error, iv. determining a target negative pressure gradient by means of a first function, wherein the first function maps the negative pressure error to the target negative pressure gradient, v. determining an actual negative pressure gradient, vi. calculating a difference between the actual negative pressure gradient and the target negative pressure gradient to obtain a negative pressure gradient error, vii. determining an integrator input by means of a second function, wherein the second function maps the negative pressure gradient error to the integrator input, viii. determining a control signal for the electrical pump comprising the use of an integrator, said integrator processes the integrator input and said control signal controls the speed of the electrical pump. - an electrical pump for generating negative pressure, - optionally a tachometer for determining a pump speed associated with the electrical pump, - a pressure sensor for determining negative pressure values, - a controller for controlling activity of the electrical pump, - an input means for adjusting settings on the negative pressure wound therapy system, said input means being operable by the user of the negative pressure wound therapy system, - a first fluid path (6, 14, 15) fluidly connectable to a wound site and to the electrical pump such that the wound site can be subjected to a negative pressure, wherein the pressure sensor is located in the first fluid path (6, 14, 15) between the wound site and the electrical pump, i. setting a target negative pressure on the negative pressure wound therapy system, said negative pressure wound therapy system being used for the negative pressure wound therapy, ii. determining a negative pressure value by means of the pressure sensor, iii. calculating a difference between the determined negative pressure value and the target negative pressure setting to obtain a negative pressure error, iv. determining a target negative pressure gradient by means of a first function, wherein the first function maps the negative pressure error to the target negative pressure gradient, v. determining an actual negative pressure gradient, vi. calculating a difference between the actual negative pressure gradient and the target negative pressure gradient to obtain a negative pressure gradient error, vii. determining an integrator input by means of a second function, wherein the second function maps the negative pressure gradient error to the integrator input, viii. determining a control signal for the electrical pump comprising the use of an integrator, said integrator processes the integrator input and said control signal controls the speed of the electrical pump.