Wire electric discharge machine, and control method for wire electric discharge machine

A method of controlling a wire electrical discharge machine configured to carry out machining of a workpiece by generating an electric discharge in an inter-electrode gap between a wire electrode and the workpiece, the method of controlling the wire electrical discharge machine comprising:

• a discharge state value acquisition step of acquiring, as a discharge state value, any one of an average inter-electrode voltage, which is a time average of a voltage applied to the inter-electrode gap, a reciprocal of a number of discharge pulses in the inter-electrode gap per unit time, or a discharge delay time period, which is a time period from when the voltage is applied to the inter-electrode gap until when the electric discharge is generated in the inter-electrode gap;
• a discharge state value compensation step of compensating the discharge state value to obtain a compensated value in accordance with a machining speed, which is a relative speed of the wire electrode with respect to the workpiece;
• a driving step of causing the wire electrode to move relatively with respect to the workpiece by a driving unit;
• and
• a control step of controlling the driving unit based on the compensated value, and thereby keeping a size of the inter-electrode gap constant during machining;
• wherein, in the discharge state value compensation step, the compensated value is determined based on an equation in which the discharge state value defines a numerator, and a value obtained by exponentiation with a coefficient as a base and the machining speed as an exponent defines a denominator.