Electric-power conversion apparatus

An electric-power conversion apparatus comprising:

• an electric-power conversion circuit which is provided with a positive-side switching element connected to a positive electrode of a DC power source, a negative-side switching element connected to a negative electrode of the DC power source, and an external connection point at which the positive-side switching element and the negative-side switching element are connected in series to each other and from which an AC output is taken out;
• a voltage detector that detects a voltage between a positive side and a negative side of the electric-power conversion circuit;
• a phase current detector that detects a phase current flowing between the external connection point of the electric-power conversion circuit and an output destination of the AC output;
• and
• a control device having:
• a controller that outputs a control signal to control the above switching elements, on a basis of an external command value, and that outputs a speed instruction signal to specify a switching speed of the switching elements;
• an overvoltage protector that outputs an overvoltage interruption signal when the voltage detected by the voltage detector is larger than a predetermined overvoltage determination threshold value;
• an overcurrent protector that outputs an overcurrent interruption signal when the phase current detected by the phase current detector is larger than a predetermined overcurrent determination threshold value;
• and a gate driver that turns on/off the switching elements on a basis of the control signal outputted by the controller, that changes a turn on/off speed of the switching elements on a basis of the speed instruction signal, and that stops turning on/off the switching elements on a basis of the overvoltage interruption signal outputted by the overvoltage protector and/or the overcurrent interruption signal outputted by the overcurrent protector;
• wherein, when the control device changes the speed instruction signal, it simultaneously changes at least one of the overvoltage determination threshold value and the overcurrent determination threshold value.