The invention relates to a method and an electrical converter of an elevator. In the method a controller of the electrical converter determines a first reactive power produced by a smoothing filter using pre-determined information on impedance of the smoothing filter. The controller may also receive information on a second reactive power from a remote node over a communication channel, the second reactive power being produced to a grid. The controller adds the first reactive power and the second reactive power to yield a total reactive power. The controller requests the electrical converter to make a plurality of compensative connections in the converter matrix to compensate the first reactive power or the total reactive power.