Abstract: A multilevel power conversion device includes: N (N?1) direct current voltage sources; a first flying capacitor; a second flying capacitor; and a phase module of a M phase (M?2) being configured to output, from the output terminal, a potential of one of the input terminals, or a potential obtained by adding or subtracting the voltage of the capacitor to or from the potential of the one of the input terminals, by selectively controlling the respective switching elements in an ON/OFF manner.

Abstract: Basic circuit of U phase includes first to fourth semiconductor elements (SU1.1 to SU1.4) connected between positive and negative ends of DC voltage source (DCC1), fifth semiconductor element (SU1.5) connected to a common connection point of the first and second semiconductor elements (SU1.1, SU1.2), and sixth semiconductor element (SU1.6) connected to a common connection point of the third and fourth semiconductor elements (SU1.3, SU1.4). Flying capacitor (FC1) is inserted between the fifth semiconductor element (SU1.5) and the sixth semiconductor element (SU1.6). Voltage selection circuits have the common connection points of the second and third semiconductor elements (SU1.2, SU1.3) of the respective basic circuits as input terminals, and includes semiconductor elements (SU1 to SU4) between the input terminals and output terminals (U, V, W).

Abstract: The present invention provides a power conversion device in which an on-pulse bias voltage and a neutral-point bias voltage do not interfere with each other. A power conversion device 1 of the present invention has a polarity judgment section 8 that judges a polarity of a neutral-point bias voltage VNPC calculated by a neutral-point potential fluctuation suppression control section 4 of a voltage command value control circuit 3, then on the basis of this polarity of the neutral-point bias voltage VNPC, selects a polarity of an on-pulse bias voltage VMPC by an on-pulse control section 5. With this control, it is possible to prevent for the polarities of the neutral-point bias voltage VNPC and the on-pulse bias voltage VMPC from being different then prevent for the both bias voltages from interfering with each other.

Abstract: A multilevel power conversion device includes: N (N?1) direct current voltage sources; a first flying capacitor; a second flying capacitor; and a phase module of a M phase (M?2) being configured to output, from the output terminal, a potential of one of the input terminals, or a potential obtained by adding or subtracting the voltage of the capacitor to or from the potential of the one of the input terminals, by selectively controlling the respective switching elements in an ON/OFF manner.

Abstract: Basic circuit of U phase includes first to fourth semiconductor elements (SU1.1 to SU1.4) connected between positive and negative ends of DC voltage source (DCC1), fifth semiconductor element (SU1.5) connected to a common connection point of the first and second semiconductor elements (SU1.1, SU1.2), and sixth semiconductor element (SU1.6) connected to a common connection point of the third and fourth semiconductor elements (SU1.3, SU1.4). Flying capacitor (FC1) is inserted between the fifth semiconductor element (SU1.5) and the sixth semiconductor element (SU1.6). Voltage selection circuits have the common connection points of the second and third semiconductor elements (SU1.2, SU1.3) of the respective basic circuits as input terminals, and includes semiconductor elements (SU1 to SU4) between the input terminals and output terminals (U, V, W).

Abstract: The present invention provides a power conversion device in which an on-pulse bias voltage and a neutral-point bias voltage do not interfere with each other. A power conversion device 1 of the present invention has a polarity judgment section 8 that judges a polarity of a neutral-point bias voltage VNPC calculated by a neutral-point potential fluctuation suppression control section 4 of a voltage command value control circuit 3, then on the basis of this polarity of the neutral-point bias voltage VNPC, selects a polarity of an on-pulse bias voltage VMPC by an on-pulse control section 5. With this control, it is possible to prevent for the polarities of the neutral-point bias voltage VNPC and the on-pulse bias voltage VMPC from being different then prevent for the both bias voltages from interfering with each other.

Abstract: [Problem] To provide a space vector modulation method for a matrix converter which uses only one carrier for three phases when a carrier comparison is made. [Means for solving problem] Provided is a matrix converter space vector modulation method in which bidirectional switches (SW1 through SW9) of a matrix converter (3) are PWM controlled in a space vector modulation from a multi-phase AC power source. Switching patterns for which virtual indirect space vectors are used are converted into switching patterns for which direct conversion space vectors constituted by five vectors are used. Any one of the converted switching patterns satisfying predetermined conditions is selected and duties of the five vectors of the selected switching pattern are calculated using duty relationship equations between the virtual indirect conversion space vectors and the direct conversion space vectors. Then, the matrix converter is PWM-controlled on a basis of the calculated duties.

Abstract: [Problem] To provide a space vector modulation method for a matrix converter which uses only one carrier for three phases when a carrier comparison is made. [Means for solving problem] Provided is a matrix converter space vector modulation method in which bidirectional switches (SW1 through SW9) of a matrix converter (3) are PWM controlled in a space vector modulation from a multi-phase AC power source. Switching patterns for which virtual indirect space vectors are used are converted into switching patterns for which direct conversion space vectors constituted by five vectors are used. Any one of the converted switching patterns satisfying predetermined conditions is selected and duties of the five vectors of the selected switching pattern are calculated using duty relationship equations between the virtual indirect conversion space vectors and the direct conversion space vectors. Then, the matrix converter is PWM-controlled on a basis of the calculated duties.