Method of controlling component concentration of plating solution in continuous electroplating

A method of controlling a component concentration of a plating solution in a method of continuously electroplating a metallic strip by using a series of devices comprising a plating cell for plating by using an insoluble anode;

• a circulating tank for supplying the plating solution to the plating cell;
• a dissolution tank connected to the circulating tank, for supplying the plating solution in which plating ions are adjusted;
• a metal feeding device and an acid feeding device for feeding at least one metal and an acid, respectively, to the dissolution tank;
• and an evaporator unit for evaporating water;
• the control method comprising:
• when a total amount of the plating solution flowing in the series of devices varies from a preselected target value of the total amount of the plating solution, controlling a feedback control target value of a metal ion concentration by changing it to a corrected target value of the metal ion concentration computed on the basis of the preselected target value of the metal ion concentration and said variation in the total amount of the plating solution flowing in the series of devices, and feeding to the plating solution amounts of the at least one metal or the acid determined on the basis of the corrected target value of the metal ion concentration, so that an acid concentration of the plating solution is kept constant.