Hi, could anyone explain to me how odd harmonics in the power system are reduced or removed? I've read that in transformers the harmonics produced by the load circulate if the secondary side is wired as delta configuration, yet star is usually used on secondary side i believe? I've looked around a little and I saw that zigzag transformer could help reduce the harmonics, how? I could not find any good explanation about this, also I do not fully understand how a zig zag transformer work. Are there any other common techniques used to reduce the influence of harmonics in the power system? Best regards.