TransformerWinding transformerWindingAssociation = otherPhaseTapChanger.getTransformerWinding();
du = (config.isInvertVoltageStepIncrementOutOfPhase() ? -1 : 1) * ptc.getVoltageStepIncrementOutOfPhase() / ptc.getTransformerWinding().getRatedU(); } else if (ptc.stepVoltageIncrementIsSet() && ptc.getStepVoltageIncrement() != 0) { du = ptc.getStepVoltageIncrement() / 100f;