Power conversion device

A power conversion device comprising:

• a converter for converting AC voltage from an AC power supply to DC voltage and supplying the DC voltage to a capacitor;
• an inverter for converting the DC voltage of the capacitor to AC voltage and supplying the AC voltage to the AC load;
• a d-axis current controller for generating a d-axis voltage command value;
• a q-axis current controller for generating a q-axis voltage command value;
• a gate signal generation section for generating a gate signal for driving the inverter, on the basis of the d-axis voltage command value and the q-axis voltage command value;
• a voltage detection section for detecting voltage of the capacitor;
• a filter section for extracting an AC component of the voltage detected by the voltage detection section;
• a multiplier for multiplying output of the filter section by a first gain and outputting a result thereof;
• d-axis voltage compensation section for multiplying output of the multiplier by a second gain and outputting a result thereof as a d-axis voltage correction signal;
• and
• q-axis voltage compensation section for multiplying output of the multiplier by a third gain and outputting a result thereof as a q-axis voltage correction signal,
• the gate signal generation section generates the gate signal on the basis of a signal obtained by adding the d-axis voltage correction signal to the d-axis voltage command value and a signal obtained by adding the q-axis voltage correction signal to the q-axis voltage command value,
• the power conversion device further comprising:
• a d-axis current compensation section for calculating a d-axis current component flowing due to voltage obtained by multiplying output of the multiplier by the second gain, and outputting the d-axis current component as a d-axis current correction signal;
• and
• q-axis current compensation section for calculating a q-axis current component flowing due to voltage obtained by multiplying output of the multiplier by the third gain, and outputting the q-axis current component as a q-axis current correction signal;
• the d-axis current controller generates the d-axis voltage command value so that a deviation between a d-axis current detection value and a value obtained by adding the d-axis current correction signal to a d-axis current command value on a d-q two-axis orthogonal coordinate system becomes zero, and
• the q-axis current controller generates the q-axis voltage command value so that a deviation between a q-axis current detection value and a value obtained by adding the q-axis current correction signal to a q-axis current command value on the d-q two-axis orthogonal coordinate system becomes zero,
• further in the case where sampling of data and calculation thereof are performed with a predetermined control cycle,
• the power conversion device comprising a phase advancing section for advancing each of the d-axis voltage correction signal and the q-axis voltage correction signal by a Phase corresponding to 1.5 multiples of the control cycle in order to compensate for a waste time based on the control cycle,
• the d-axis current compensation section and the q-axis current compensation section are provided with phase delay sections for respectively delaying the d-axis current correction signal and the q-axis current correction signal by a phase corresponding to 0.5 multiples of the control cycle.

A power conversion device comprising:

• a converter for converting AC voltage from an AC power supply to DC voltage and supplying the DC voltage to a capacitor;
• an inverter for converting the DC voltage of the capacitor to AC voltage and supplying the AC voltage to the AC load;
• a d-axis current controller for generating a d-axis voltage command value;
• a q-axis current controller for generating a q-axis voltage command value;
• a gate signal generation section for generating a gate signal for driving the inverter, on the basis of the d-axis voltage command value and the q-axis voltage command value;
• a voltage detection section for detecting voltage of the capacitor;
• a filter section for extracting an AC component of the voltage detected by the voltage detection section;
• a multiplier for multiplying output of the filter section by a first gain and outputting a result thereof;
• a d-axis current compensation section for calculating a d-axis current component flowing due to voltage obtained by multiplying output of the multiplier by a second gain, and outputting the d-axis current component as a d-axis current correction signal;
• and
• q-axis current compensation section for calculating a q-axis current component flowing due to voltage obtained by multiplying output of the multiplier by a third gain, and outputting the q-axis current component as a q-axis current correction signal;
• the d-axis current controller generates the d-axis voltage command value so that a deviation between a d-axis current detection value and a value obtained by adding the d-axis current correction signal to a d-axis current command value on a d-q two-axis orthogonal coordinate system becomes zero, and
• the q-axis current controller generates the q-axis voltage command value so that a deviation between a q-axis current detection value and a value obtained by adding the q-axis current correction signal to a q-axis current command value on the d-q two-axis orthogonal coordinate system becomes zero,
• the gate signal generation section generates the gate signal on the basis of the d-axis voltage command value and the q-axis voltage command value,
• Rather in the case where sampling of data and calculation thereof are performed with a predetermined control cycle,
• in order to compensate for a waste time based on the control cycle, the d-axis current compensation section and the q-axis current compensation section respectively include phase delay sections for delaying the d-axis current correction signal and the q-axis current correction signal by a phase corresponding to twice the control cycle.