Meidensha Corporation

Shota Urushibata

Takeshi Kondo

Isamu Hasegawa

Takashi Kodama

Yugo Tadano

Masakazu Muneshima

Shizunori Hamada

Kenji Kobori

Keiichi Kodachi

Hiromi Sako

Hui Zhang

A multilevel power conversion device includes: N (N&#x2265;1) direct current voltage sources; a first flying capacitor; a second flying capacitor; and a phase module of a M phase (M&#x2265;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.

Multilevel power conversion device with flying capacitor

Basic circuit of U phase includes first to fourth semiconductor elements (SUto SU) connected between positive and negative ends of DC voltage source (DCC), fifth semiconductor element (SU) connected to a common connection point of the first and second semiconductor elements (SU, SU), and sixth semiconductor element (SU) connected to a common connection point of the third and fourth semiconductor elements (SU, SU). Flying capacitor (FC) is inserted between the fifth semiconductor element (SU) and the sixth semiconductor element (SU). Voltage selection circuits have the common connection points of the second and third semiconductor elements (SU, SU) of the respective basic circuits as input terminals, and includes semiconductor elements (SUto SU) between the input terminals and output terminals (U, V, W). Consequently, it is possible to output arbitrary voltage in all phases in multilevel power convertor, and to simplify control for outputting arbitrary voltage level in all phases.

Multilevel power convertor

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 deviceof the present invention has a polarity judgment sectionthat judges a polarity of a neutral-point bias voltage Vcalculated by a neutral-point potential fluctuation suppression control sectionof a voltage command value control circuit, then on the basis of this polarity of the neutral-point bias voltage V, selects a polarity of an on-pulse bias voltage Vby an on-pulse control section. With this control, it is possible to prevent for the polarities of the neutral-point bias voltage Vand the on-pulse bias voltage Vfrom being different then prevent for the both bias voltages from interfering with each other.

Neutral-point-clamped multilevel power conversion device

[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 (SWthrough SW) of a matrix converter () 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.

Matrix converter space vector modulation method

Growing community of inventors

Odawara, Japan

Shota Urushibata