Abstract: A plurality of capacitors are interposed between ones of a plurality of input lines. The clamp capacitor is connected between two DC power supply lines. A current-source converter includes a plurality of switch devices, where x represents r, s and t. The switch device selects conduction/non-conduction through a first diode between corresponding one of the input lines and the first DC power supply line and conduction/non-conduction through a second diode between said corresponding one of input lines and the second DC power supply line based on external signals and brings corresponding one of the input lines with the first and second DC power supply lines in a state of not receiving the signals.

Abstract: A converter performs full-wave rectification on a single-phase voltage, thus outputting a rectified voltage across DC power supply lines. An inverter receives the rectified voltage and then supplies a three-phase AC current to an inductive load. Between the DC power supply lines is connected a charge and discharge circuit. The charge and discharge circuit includes a buffer circuit and a boost circuit. The buffer circuit includes a series connection between a capacitor and a switch. The boost circuit, which may be configured by a boost chopper, includes a switch, a reactor and a diode. The charge and discharge circuit provides and receives part of pulsations of the power input to the converter between the DC power supply lines.

Abstract: In a first period when a cosine value is positive that is a cosine value of a value twice a phase angle determined while an AC waveform output from a single-phase AC power source is regarded as a sine value of the phase angle, a discharge duty for making a first switch conducting is set to be higher than a first value determined by dividing the product of an amplitude of an AC voltage of the single-phase AC power source and the cosine value by the product of an across voltage of a capacitor and ?2. In addition to or alternatively to this, in a second period when the cosine value is negative, a rectifying duty for making a diode rectifier conducting is set to be higher than a second value that is the reciprocal of the product of the absolute value of the sine value and ?2.

Abstract: A converter full-wave rectifies a single-phase voltage, and outputs the rectified voltage across DC power supply lines. An inverter receives the rectified voltage, and supplies a three-phase AC current to an inductive load. A power buffer circuit is connected between the DC power supply lines. The power buffer circuit includes a discharge circuit and a charge circuit. The discharge circuit includes a capacitor and a switch connected in series to each other. The discharge circuit is configured, for example, by a boost chopper, and includes a switch, a reactor, and a diode. The power buffer circuit provides and receives part of pulsations of a power input into the converter to and from the DC power supply lines.

Abstract: A first capacitor is provided between a first power supply line and a second power supply line. A charge/discharge circuit includes a second capacitor provided between the first power supply line and the second power supply line and a first switch connected in series to the second capacitor on the side of the first power supply line. A booster circuit boosts the rectified voltage from a diode rectifier to charge the second capacitor. A current blocking part is provided on the first power supply line or the second power supply line between the first capacitor and the second capacitor and blocks flowing of the current from the second capacitor to the first capacitor.

Abstract: A current-source converter includes high-arm side switching elements and low-arm side switching elements. A voltage between the DC power supply lines is detected as a line voltage of an input line, based on a conduction pattern of the high-arm side switching elements and the low-arm side switching elements.

Abstract: A converter performs full-wave rectification on a single-phase voltage, thus outputting a rectified voltage across DC power supply lines. An inverter receives the rectified voltage and then supplies a three-phase AC current to an inductive load. Between the DC power supply lines is connected a charge and discharge circuit. The charge and discharge circuit includes a buffer circuit and a boost circuit. The buffer circuit includes a series connection between a capacitor and a switch. The boost circuit, which may be configured by a boost chopper, includes a switch, a reactor and a diode. The charge and discharge circuit provides and receives part of pulsations of the power input to the converter between the DC power supply lines.

Abstract: A converter performs full-wave rectification on a single-phase voltage, thus outputting a rectified voltage across DC power supply lines. An inverter receives the rectified voltage and then supplies a three-phase AC current to an inductive load. Between the DC power supply lines is connected a charge and discharge circuit. The charge and discharge circuit includes a buffer circuit and a boost circuit. The buffer circuit includes a series connection between a capacitor and a switch. The boost circuit, which may be configured by a boost chopper, includes a switch, a reactor and a diode. The charge and discharge circuit provides and receives part of pulsations of the power input to the converter between the DC power supply lines.

Abstract: Disclosed herein is a device that includes a first semiconductor chip. The first semiconductor chip includes a first data storage area storing data, a first refresh circuit repeating a first refresh operation on the first data storage area to make the first data storage area retain the data, a first terminal supplied with a first control signal from outside of the first semiconductor chip, and a first control circuit coupled between the first terminal and the first refresh circuit to control a repetition cycle of the first refresh operation in response to the first control signal.

Abstract: A converter includes switching devices connected between each of a plurality of input ends and a DC power supply line, and switching devices connected between each of the plurality of input ends and a DC power supply line. A capacitor, a resistor and a diode are connected in series with each other between the DC power supply lines.

Abstract: A power converter includes a rectifier section, an inverter section, a capacitance element connected between inverter section input ends, an inductance element forming part of an LC filter with the capacitance element, a voltage detector detecting an inductance element voltage, and a controller controlling the inverter section based on the detected voltage. The LC filter has a resonance frequency set such that ripple current components contained in DC current outputted from the rectifier section passes through, and current components of a frequency equal to a carrier frequency of the inverter section are dampened. The controller controls the inverter section so that a transfer characteristic of input voltage of the inverter section versus the DC voltage from the rectifier section becomes a damping characteristic given by a phase lead element and a second-order lag element connected in series, and a damping coefficient of the transfer characteristic is set larger than 1.

Abstract: A period composed of a total of three periods, namely a period when an actual voltage vector is employed and periods before and after it can be regarded as an isolation period when an actual voltage vector is isolated in a vicinity where switching for commutation in a current-source converter is generated. When the switching in the current-source converter occurs at the isolation period, zero-current switching is realized. When presence of dead time is thus taken into consideration, a width of the timing when the zero-current switching is realized is made to be broader than a case where the presence of the dead time is not taken into consideration by the dead time.

Abstract: A first capacitor is provided between a first power supply line and a second power supply line. A charge/discharge circuit includes a second capacitor provided between the first power supply line and the second power supply line and a first switch connected in series to the second capacitor on the side of the first power supply line. A booster circuit boosts the rectified voltage from a diode rectifier to charge the second capacitor. A current blocking part is provided on the first power supply line or the second power supply line between the first capacitor and the second capacitor and blocks flowing of the current from the second capacitor to the first capacitor.

Abstract: In a first period when a cosine value is positive that is a cosine value of a value twice a phase angle determined while an AC waveform output from a single-phase AC power source is regarded as a sine value of the phase angle, a discharge duty for making a first switch conducting is set to be higher than a first value determined by dividing the product of an amplitude of an AC voltage of the single-phase AC power source and the cosine value by the product of an across voltage of a capacitor and ?2. In addition to or alternatively to this, in a second period when the cosine value is negative, a rectifying duty for making a diode rectifier conducting is set to be higher than a second value that is the reciprocal of the product of the absolute value of the sine value and ?2.

Abstract: A cycle is divided into a first period and a second period. The first period is longer than the second period. Two sections in which a unit voltage vector is adopted in the first period are adopted as a first section and a second section. A first measured value of a link voltage is measured at a midpoint of the first section and a second measured value of the link voltage is measured at a midpoint of the second section. Then, a representative value of the link voltage in a cycle including the first period is obtained by interpolation of the first measured value and the second measured value. A maximum value of the link voltage is obtained by dividing the representative value by cos ?.

Abstract: Capacitors are connected in series between a first DC link section and a second DC link section when the capacitors are charged by a regenerative current derived from an inverter section. During discharge, as first, second switching circuits turn on, the capacitors are discharged with those capacitors connected in parallel between a first DC link section and a second DC link section.

Abstract: Disclosed heroin is a device that includes a plurality of memory circuits and a refresh control circuit configured to generate a plurality of refresh initiation signals such that one of the refresh initiation signals takes an active level. Each of the memory circuits comprises a memory cell array including a plurality of memory cells, at least one data terminal, a data read/write circuit performing a data read operation to read out read-data from a selected one of the memory cells and supply the read-data to the data terminal and a data write operation to receive write-data from the data terminal and write the write-data into a selected one of the memory cells, and a refresh circuit performing a data refresh operation on selected one or ones of the memory cells of the memory cell array in response to an associated one of the refresh initiation signals taking the active level.

Abstract: Disclosed herein is a device that includes a first semiconductor chip. The first semiconductor chip includes a first data storage area storing data, a first refresh circuit repeating a first refresh operation on the first data storage area to make the first data storage area retain the data, a first terminal supplied with a first control signal from outside of the first semiconductor chip, and a first control circuit coupled between the first terminal and the first refresh circuit to control a repetition cycle of the first refresh operation in response to the first control signal.

Abstract: A voltage control rate of an inverter has a DC component and an AC component. This AC component has a frequency which is six times a fundamental frequency of an AC voltage outputted by the inverter. Even when there are not only a fifth-order harmonic component but also a seventh-order harmonic component of a load current, a ratio between the magnitude of the AC component and the DC component can be appropriately set.

Abstract: Disclosed herein is a device that includes a plurality of memory circuits and a refresh control circuit configured to generate a plurality of refresh initiation signals such that one of the refresh initiation signals takes an active level. Each of the memory circuits comprises a memory cell array including a plurality of memory cells, at least one data terminal, a data read/write circuit performing a data read operation to read out read-data from a selected one of the memory cells and supply the read-data to the data terminal and a data write operation to receive write-data from the data terminal and write the write-data into a selected one of the memory cells, and a refresh circuit performing a data refresh operation on selected one or ones of the memory cells of the memory cell array in response to an associated one of the refresh initiation signals taking the active level.