A switching control device, usable with a load drive system equipped with a direct current voltage converter and an electric power converter, the switching control device being capable of controlling a switching timing of switching elements in switching element pairs of the direct current voltage converter and the electric power converter,
- wherein the direct current voltage converter has a reactor and at least a switching element connected to the reactor, the reactor is capable of charging and discharging electric energy, an input voltage to be supplied to the reactor from a direct current power source is converted to an output voltage by turning on and off the switching elements, and the electric power converter has a plurality of switching element pairs, each switching element pair comprises a switching element at a high voltage side and a switching element at a low voltage side, the switching elements are alternately turned on and off to convert the direct current power output from the direct current voltage converter to an alternating current power, and the alternating current power is supplied to a load, wherein
- the switching control device comprises:
- a direct current voltage converter control circuit capable of calculating a control value of the direct current voltage converter on the basis of an instruction voltage for the output voltage of the direct current voltage converter;
- a direct current voltage converter drive circuit capable of driving the switching elements of the direct current voltage converter on the basis of the control value of the direct current voltage converter calculated by the direct current voltage converter control circuit;
- an electric power converter control circuit capable of calculating a control value of the electric power converter on the basis of a requested output of the load;
- an electric power converter drive circuit capable of driving the switching element pairs of the electric power converter on the basis of the control value of the electric power converter calculated by the electric power converter control circuit;
- a direct current voltage converter switching inhibition period calculation means capable of performing a direct current voltage converter switching inhibition period calculation process which calculates a direct current converter switching inhibition period Pp, the direct current converter switching inhibition period Pp indicating a period of inhibiting the switching of the switching elements of the direct current voltage converter during a predetermined period which is in synchronization with an electric power converter switching timing prior to this electric power converter switching timing as a switching timing of at least a pair of the switching elements forming the electric power converter, and the electric power converter switching timing indicating a switching timing on a time axis, and further indicating a switching electrical angle on an electrical angle axis when an electric rotary machine is the load;
- and
- a direct current voltage converter switching correction means capable of performing a switching timing correction process of correcting the switching timing of a correction target to a timing prior to a start timing of the direct current voltage converter switching inhibition period, wherein a direct current voltage converter switching timing is a switching timing of the correction target when it is predicted for the direct current voltage converter switching timing as the switching timing of at least the switching element in the direct current voltage converter to be within the direct current voltage converter switching inhibition period.