Power converter apparatus and related method

A power converter apparatus comprising:

• an inverter main circuit including 1) switching elements responsive to switching control signals, and 2) means for applying phase voltages to a polyphase load via the switching elements;
• command value outputting means for outputting basic voltage command values for phases of the polyphase load respectively;
• command value converting means for converting the basic voltage command values outputted by the command value outputting means into final voltage command values respectively, wherein a time interval for which at least two of the basic voltage command values are approximately equal to each other includes an alternation of first conversion time intervals and second conversion time intervals, wherein during each of the first conversion time intervals, the final voltage command values corresponding to said two of the basic voltage command values are equal to one of a maximum and a minimum, and wherein during each of the second conversion time intervals, only one of the final voltage command values corresponding to said two of the basic voltage command values is equal to one of the maximum and the minimum;
• and
• control signal outputting means for subjecting a carrier wave to pulse-width modulation responsive to the final voltage command values generated by the command value converting means to produce the switching control signals, and for outputting the switching control signals to the switching elements in the inverter main circuit.

A power converter apparatus comprising:

• an inverter main circuit including 1) switching elements responsive to switching control signals, and 2) means for applying phase voltages to a polyphase load via the switching elements;
• command value outputting means for outputting basic voltage command values for phases of the polyphase load respectively;
• command value converting means for comparing the basic voltage command values outputted by the command value outputting means, and for converting the basic voltage command values into final voltage command values respectively in response to results of said comparing, wherein during a specified time interval containing a time point at which at least two of the basic voltage command values are equal, the final voltage command values corresponding to said two of the basic voltage command values are equal to one of a maximum and a minimum;
• and
• control signal outputting means for subjecting a carrier wave to pulse-width modulation responsive to the final voltage command values generated by the command value converting means to produce the switching control signals, and for outputting the switching control signals to the switching elements in the inverter main circuit.

A method of controlling drive of a polyphase load, comprising the steps of:

• applying phase voltages to the polyphase load via switching elements in an inverter main circuit;
• generating basic voltage command values for phases of the polyphase load respectively;
• converting the basic voltage command values into final voltage command values respectively, wherein during a time interval for which at least two of the basic voltage command values are approximately equal to each other, the final voltage command values corresponding to said two of the basic voltage command values are equal to one of a maximum and a minimum;
• subjecting a carrier wave to pulse-width modulation responsive to the final voltage command values to produce switching control signals;
• and
• outputting the switching control signals to the switching elements in the inverter main circuit.

A method of controlling drive of a polyphase load, comprising the steps of:

• applying phase voltages to the polyphase load via switching elements in an inverter main circuit;
• generating basic voltage command values for phases of the polyphase load respectively;
• converting the basic voltage command values into final voltage command values respectively, wherein a time interval for which at least two of the basic voltage command values are approximately equal to each other includes an alternation of first conversion time intervals and second conversion time intervals, wherein during each of the first conversion time intervals, the final voltage command values corresponding to said two of the basic voltage command values are equal to one of a maximum and a minimum, and wherein during each of the second conversion time intervals, only one of the final voltage command values corresponding to said two of the basic voltage command values is equal to one of the maximum and the minimum;
• subjecting a carrier wave to pulse-width modulation responsive to the final voltage command values to produce switching control signals;
• and
• outputting the switching control signals to the switching elements in the inverter main circuit.

A method of controlling drive of a polyphase load, comprising the steps of:

• applying phase voltages to the polyphase load via switching elements in an inverter main circuit;
• generating basic voltage command values for phases of the polyphase load respectively;
• comparing the basic voltage command values;
• converting the basic voltage command values into final voltage command values respectively in response to results of said comparing, wherein during a specified time interval containing a time point at which at least two of the basic voltage command values are equal, the final voltage command values corresponding to said two of the basic voltage command values are equal to one of a maximum and a minimum;
• subjecting a carrier wave to pulse-width modulation responsive to the final voltage command values to produce switching control signals;
• and
• outputting the switching control signals to the switching elements in the inverter main circuit.

A power converter apparatus comprising:

• an inverter main circuit including 1) switching elements responsive to switching control signals, and 2) means for applying phase voltages to a polyphase load via the switching elements;
• command value outputting means for outputting basic voltage command values for phases of the polyphase load respectively;
• command value converting means for converting the basic voltage command values outputted by the command value outputting means into final voltage command values respectively, wherein a specified time interval for which at least two of the basic voltage command values are approximately equal to each other includes an alternation of first conversion time intervals and second conversion time intervals, wherein during each of the first conversion time intervals, the final voltage command values corresponding to said two of the basic voltage command values are equal to one of a maximum and a minimum, and wherein during each of the second conversion time intervals, only one of the final voltage command values corresponding to said two of the basic voltage command values is equal to one of the maximum and the minimum;
• phase changing means for changing a phase of the specified time interval used by the command value converting means;
• and
• control signal outputting means for subjecting a carrier wave to pulse-width modulation responsive to the final voltage command values generated by the command value converting means to produce the switching control signals, and for outputting the switching control signals to the switching elements in the inverter main circuit.

A method of controlling drive of a polyphase load, comprising the steps of:

• applying phase voltages to the polyphase load via switching elements in an inverter main circuit;
• generating basic voltage command values for phases of the polyphase load respectively;
• converting the basic voltage command values into final voltage command values respectively, wherein a time interval for which at least two of the basic voltage command values are approximately equal to each other includes an alternation of first conversion time intervals and second conversion time intervals, wherein during each of the first conversion time intervals, the final voltage command values corresponding to said two of the basic voltage command values are equal to one of a maximum and a minimum, and wherein during each of the second conversion time intervals, only one of the final voltage command values corresponding to said two of the basic voltage command values is equal to one of the maximum and the minimum;
• changing a phase of the specified time interval;
• subjecting a carrier wave to pulse-width modulation responsive to the final voltage command values to produce switching control signals;
• and
• outputting the switching control signals to the switching elements in the inverter main circuit.