IGBT rectifiers possess higher efficiency, greater power factor, higher resolution, faster response time and constant ripple. Ripple matters in a plating application with an SCR rectifier and on precious metals plating.
Using a rectifier at the lower end of its rated capacity affects the ripple factor. In some applications, there will be a negative influence on the current distribution and throwing power of the deposit. A few deposits are tolerant than others. Precious and other transition elements differ in this attribute. Much of them are because of price. At a sub-optimal capacity combined with a poor specification, a rectifier can yield a deposit with defective morphology compromising adhesion and the physical characteristics.
Note: Ripple is not the only cause a compromise can occur on the morphology of a deposit. Among many other variables, Helmholtz electrical double layer effect has a substantial effect on the morphology with the continuity of the deposit.
Other than a ripple, there are cost impacts. A client of Haney, about 3 years back, purchased a 25,000 amperes rectifier. On most loads, they had applied ~ 10,000 amps and seldom they applied 15,000 amperes. And the applicator does not foresee applying 20, 000 amperes within the next few years. The tank volume and the rack capability do not support the calculation. In hindsight, the applicator could have saved by considering a lower ampere rectifier
On high ampere applications, power consumption is an important factor. When the distance between shunt and electrode terminals is higher, power consumption (resistivity) and the cost is high.