Electric power converter and motor driving system

An electric power converter comprising:

• a power module including a plurality of switching devices connected in series and converting DC power to AC power;
• and
• control means for producing a voltage command value in accordance with a control command inputted from the exterior, and producing gate signals to drive the switching devices of said power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation,
• said control means including dead time compensation means for calculating the final voltage command value by applying the dead time compensation to the voltage command value.

An electric power converter comprising:

• a power module including a plurality of switching devices connected in series and converting DC power to AC power;
• and
• control means for producing a voltage command value in accordance with a control command inputted from the exterior, and producing gate signals to drive the switching devices of said power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation,
• said control means including dead time compensation means for calculating a dead time compensation voltage based on a change rate of the voltage command value, a gain, and a polarity of a current, the gain being calculated from a DC voltage value supplied to said electric power converter, a dead time, and a switching frequency.

A motor driving system comprising an electric power converter for converting DC power to AC power, and an AC motor driven with supply of the AC power converted by said electric power converter, said electric power converter comprising:

• a power module including a plurality of switching devices connected in series and converting DC power to AC power;
• and
• control means for producing a voltage command value in accordance with a control command inputted from the exterior, and producing gate signals to drive the switching devices of said power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation,
• said control means including dead time compensation means for producing the final voltage command value which takes a maximum value approximately at a phase π/2 of the voltage command value on both sides thereof and a minimum value approximately at a phase 3π/2 of the voltage command value on both sides thereof.

A motor driving system comprising an electric power converter for converting DC power to AC power, and an AC motor driven with supply of the AC power converted by said electric power converter, said electric power converter comprising:

• a power module including a plurality of switching devices connected in series and converting DC power to AC power;
• and
• control means for producing a voltage command value in accordance with a control command inputted from the exterior, and producing gate signals to drive the switching devices of said power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation,
• said control means including dead time compensation means for calculating the final voltage command value by applying the dead time compensation to the voltage command value.

A motor driving system comprising an electric power converter for converting DC power to AC power, and an AC motor driven with supply of the AC power converted by said electric power converter, said electric power converter comprising:

• a power module including a plurality of switching devices connected in series and converting DC power to AC power;
• and
• control means for producing a voltage command value in accordance with a control command inputted from the exterior, and producing gate signals to drive the switching devices of said power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation,
• said control means including dead time compensation means for calculating a dead time compensation voltage based on a change rate of the voltage command value, a gain, and a polarity of a current, the gain being calculated from a DC voltage value supplied to said electric power converter, a dead time and a switching frequency.