A control power supply device for an inverter, the control power supply device being configured to supply stable power to the inverter, the control power supply device comprising: a main switched-mode power supply, SMPS, configured to supply rated voltages to a controller of the inverter and to an auxiliary circuit of the inverter, wherein the controller of the inverter is configured to control an operation of an inverter unit of the inverter, and wherein the auxiliary circuit of the inverter is configured to operate an I/O circuit, a communications circuit, a gate drive circuit and a fan drive circuit of the inverter; an auxiliary SMPS configured to be operated when the main SMPS is interrupted, characterized in that: the auxiliary SMPS is configured to be operated in a first mode, a second mode or a third mode; and the control power supply device further comprises: an SMPS controller configured to: receive a DC-link voltage from a DC-link of the inverter, compare the DC-link voltage with a set voltage at the time of turning ON or OFF the inverter, and when the DC-link voltage of the inverter is greater than the set voltage at the time of turning ON or OFF the inverter, sense an output voltage from the main SMPS, determine whether the sensed output voltage from the main SMPS is within a normal range, and, if the sensed output voltage from the main SMPS is not within the normal range: - interrupt the main SMPS, - operate the auxiliary SMPS in the first mode, for supplying power only to the controller of the inverter, or in the second or third modes, for supplying power to the controller of the inverter and to the auxiliary circuit of the inverter, and - transmit trip information to the controller of the inverter. a main switched-mode power supply, SMPS, configured to supply rated voltages to a controller of the inverter and to an auxiliary circuit of the inverter, wherein the controller of the inverter is configured to control an operation of an inverter unit of the inverter, and wherein the auxiliary circuit of the inverter is configured to operate an I/O circuit, a communications circuit, a gate drive circuit and a fan drive circuit of the inverter; an auxiliary SMPS configured to be operated when the main SMPS is interrupted, characterized in that: the auxiliary SMPS is configured to be operated in a first mode, a second mode or a third mode; and the control power supply device further comprises: an SMPS controller configured to: receive a DC-link voltage from a DC-link of the inverter, compare the DC-link voltage with a set voltage at the time of turning ON or OFF the inverter, and when the DC-link voltage of the inverter is greater than the set voltage at the time of turning ON or OFF the inverter, sense an output voltage from the main SMPS, determine whether the sensed output voltage from the main SMPS is within a normal range, and, if the sensed output voltage from the main SMPS is not within the normal range: - interrupt the main SMPS, - operate the auxiliary SMPS in the first mode, for supplying power only to the controller of the inverter, or in the second or third modes, for supplying power to the controller of the inverter and to the auxiliary circuit of the inverter, and - transmit trip information to the controller of the inverter. the auxiliary SMPS is configured to be operated in a first mode, a second mode or a third mode; and the control power supply device further comprises: an SMPS controller configured to: receive a DC-link voltage from a DC-link of the inverter, compare the DC-link voltage with a set voltage at the time of turning ON or OFF the inverter, and when the DC-link voltage of the inverter is greater than the set voltage at the time of turning ON or OFF the inverter, sense an output voltage from the main SMPS, determine whether the sensed output voltage from the main SMPS is within a normal range, and, if the sensed output voltage from the main SMPS is not within the normal range: - interrupt the main SMPS, - operate the auxiliary SMPS in the first mode, for supplying power only to the controller of the inverter, or in the second or third modes, for supplying power to the controller of the inverter and to the auxiliary circuit of the inverter, and - transmit trip information to the controller of the inverter. receive a DC-link voltage from a DC-link of the inverter, compare the DC-link voltage with a set voltage at the time of turning ON or OFF the inverter, and when the DC-link voltage of the inverter is greater than the set voltage at the time of turning ON or OFF the inverter, sense an output voltage from the main SMPS, determine whether the sensed output voltage from the main SMPS is within a normal range, and, if the sensed output voltage from the main SMPS is not within the normal range: - interrupt the main SMPS, - operate the auxiliary SMPS in the first mode, for supplying power only to the controller of the inverter, or in the second or third modes, for supplying power to the controller of the inverter and to the auxiliary circuit of the inverter, and - transmit trip information to the controller of the inverter. - interrupt the main SMPS, - operate the auxiliary SMPS in the first mode, for supplying power only to the controller of the inverter, or in the second or third modes, for supplying power to the controller of the inverter and to the auxiliary circuit of the inverter, and - transmit trip information to the controller of the inverter.