Abstract: A converter is configured for connecting between a solar cell and an inverter configured to convert direct-current power output from the solar cell into alternating current power, and the converter is configured to increase the potential-to-ground at the negative terminal of the solar cell to greater than the potential-to-ground at the negative terminal of the inverter when outputting the direct-current power generated by the solar cell to the inverter side.

Abstract: The power conditioner includes: a reactor; a capacitor; a first switching circuit that alternately switches, at a first frequency, between a first state where the DC current supplied from the DC power source is supplied to the reactor and supply of the DC current to the capacitor is shut off and a second state where an electric current is supplied to the capacitor from the reactor in which energy is accumulated by the supply of the DC current and the electric current from the DC power source to the reactor is shut off; and a second switching circuit that alternately switches, at a second frequency, between a first direction in which an electric current supplied from the capacitor flows toward a second output terminal through a first output terminal and a second direction in which the electric current flows toward the first output terminal through the second output terminal.

Abstract: An output voltage is suppressed from changing and high efficiency is realized in a power conversion apparatus capable of performing a step-up/step-down operation. In a power conversion apparatus including a DAB DC/DC converter, when energy transmitted from a primary side and energy accumulated in a reactor at a secondary side are output from the secondary side, of a control signal of a first switching element and a control signal of a fourth switching element which are both in ON states, the first and fourth switching elements being diagonal to each other in a full bridge at the primary side, a period Toff2 in which the control signal of the first switching element is turned off before the control signal of the fourth switching element is turned off is controlled, and thereby a step-up/step-down ratio is continuously changed.

Abstract: A DC-DC converter includes: a positive-side capacitor connected to a positive-electrode-side output terminal; a negative-side capacitor with one end thereof connected to the positive-side capacitor and the other end thereof connected to a negative-electrode-side output terminal; an inductor with one end thereof connected to the positive-electrode-side output terminal and an input-side end thereof opposite thereto connected to the negative-electrode-side output terminal, the inductor including a center tap between the end near the positive-electrode-side output terminal thereof and the input-side end; and a switching element with one end thereof connected to the input-side end of the inductor and the other end thereof connected to a positive electrode of a solar cell; a negative electrode of the solar cell connected to a region between the positive-side capacitor and the negative-side capacitor and to the center tap of the inductor.

Abstract: The power conditioner includes: a reactor; a capacitor; a first switching circuit that alternately switches, at a first frequency, between a first state where the DC current supplied from the DC power source is supplied to the reactor and supply of the DC current to the capacitor is shut off and a second state where an electric current is supplied to the capacitor from the reactor in which energy is accumulated by the supply of the DC current and the electric current from the DC power source to the reactor is shut off; and a second switching circuit that alternately switches, at a second frequency, between a first direction in which an electric current supplied from the capacitor flows toward a second output terminal through a first output terminal and a second direction in which the electric current flows toward the first output terminal through the second output terminal.

Abstract: A converter is configured for connecting between a solar cell and an inverter configured to convert direct-current power output from the solar cell into alternating current power, and the converter is configured to increase the potential-to-ground at the negative terminal of the solar cell to greater than the potential-to-ground at the negative terminal of the inverter when outputting the direct-current power generated by the solar cell to the inverter side.

Abstract: An output voltage is suppressed from changing and high efficiency is realized in a power conversion apparatus capable of performing a step-up/step-down operation. In a power conversion apparatus including a DAB DC/DC converter, when energy transmitted from a primary side and energy accumulated in a reactor at a secondary side are output from the secondary side, of a control signal of a first switching element and a control signal of a fourth switching element which are both in ON states, the first and fourth switching elements being diagonal to each other in a full bridge at the primary side, a period Toff2 in which the control signal of the first switching element is turned off before the control signal of the fourth switching element is turned off is controlled, and thereby a step-up/step-down ratio is continuously changed.

Abstract: A DC-DC converter includes: a positive-side capacitor connected to a positive-electrode-side output terminal; a negative-side capacitor with one end thereof connected to the positive-side capacitor and the other end thereof connected to a negative-electrode-side output terminal; an inductor with one end thereof connected to the positive-electrode-side output terminal and an input-side end thereof opposite thereto connected to the negative-electrode-side output terminal, the inductor including a center tap between the end near the positive-electrode-side output terminal thereof and the input-side end; and a switching element with one end thereof connected to the input-side end of the inductor and the other end thereof connected to a positive electrode of a solar cell; a negative electrode of the solar cell connected to a region between the positive-side capacitor and the negative-side capacitor and to the center tap of the inductor.

Abstract: A power conversion apparatus includes an inverter for drive controlling a plurality of switching elements, drive circuits, a control circuit, a current detection part, an overcurrent detection circuit, and a protection circuit. The protection circuit, which receives a detection signal that the overcurrent detection circuit outputs to indicate detection of overcurrent, outputs a signal to the drive circuits for turning off a switching element that has been turned on by a control signal from the control circuit for a predetermined time.

Abstract: A power conversion apparatus includes an inverter for drive controlling a plurality of switching elements, drive circuits, a control circuit, a current detection part, an overcurrent detection circuit, and a protection circuit. The protection circuit, which receives a detection signal that the overcurrent detection circuit outputs to indicate detection of overcurrent, outputs a signal to the drive circuits for turning off a switching element that has been turned on by a control signal from the control circuit for a predetermined time.

Abstract: A step up/down inverter circuit (10) is provided with: a plus line (13p) and a minus line (13m) connected to the plus terminal and minus terminal of a DC power supply, respectively; a voltage dividing circuit (14), a first leg (15), and a second leg (16) which are disposed between the plus line (13p) and the minus line (13m); a first reactor L1, having one end connected to a first intra-leg wiring connecting the switching elements SW1, 2 of the first leg (15); a second reactor L2, having one end connected to second intra-leg wiring connecting the switching elements SW3, 4 of the second leg (16) and having the other end connected to the other end of the first reactor (L1); a bidirectional switching element SW5 disposed between the first intra-leg wiring and a w-terminal (12w); another bidirectional switching element SW6 disposed between the second intra-leg wiring and a u-terminal (12u); and a smoothing circuit (17) for smoothing the voltages output from the bidirectional switching elements SW5, 6.

Abstract: A step up/down inverter circuit (10) is provided with: a plus line (13p) and a minus line (13m) connected to the plus terminal and minus terminal of a DC power supply, respectively; a voltage dividing circuit (14), a first leg (15), and a second leg (16) which are disposed between the plus line (13p) and the minus line (13m); a first reactor L1, having one end connected to a first intra-leg wiring connecting the switching elements SW1, 2 of the first leg (15); a second reactor L2, having one end connected to second intra-leg wiring connecting the switching elements SW3, 4 of the second leg (16) and having the other end connected to the other end of the first reactor (L1); a bidirectional switching element SW5 disposed between the first intra-leg wiring and a w-terminal (12w); another bidirectional switching element SW6 disposed between the second intra-leg wiring and a u-terminal (12u); and a smoothing circuit (17) for smoothing the voltages output from the bidirectional switching elements SW5, 6.

Abstract: A distributed power system that is connected to a utility grid during both daytime and nighttime includes a plurality of power supplies including a solar array, a non-isolated DC-DC converter that has an input terminal and an output terminal and raises, at a predetermined step-up ratio, a DC voltage input from the power supplies via the input terminal and outputs the DC voltage via the output terminal, an inverter that converts the DC voltage output from the DC-DC converter via the output terminal into an alternating current, and a potential adjustment section that adjusts a potential at a negative electrode of the solar array to a potential higher than a potential at a negative electrode of the inverter at least during nighttime.

Abstract: A distributed power system that is connected to a utility grid during both daytime and nighttime includes a plurality of power supplies including a solar array, a non-isolated DC-DC converter that has an input terminal and an output terminal and raises, at a predetermined step-up ratio, a DC voltage input from the power supplies via the input terminal and outputs the DC voltage via the output terminal, an inverter that converts the DC voltage output from the DC-DC converter via the output terminal into an alternating current, and a potential adjustment section that adjusts a potential at a negative electrode of the solar array to a potential higher than a potential at a negative electrode of the inverter at least during nighttime.

Abstract: An inverter apparatus comprising a first switch group that is connected to a DC power source and includes a first switch and a second switch connected in series; a capacitor that has one end thereof connected to a first connection point between the first switch and the second switch; a second switch group that is connected in parallel with the capacitor and includes a third switch and a fourth switch that are connected in series; a switch control section that controls an ON/OFF state of the first switch, the second switch, the third switch, and the fourth switch to convert DC voltage from the DC power source into AC voltage and output the AC voltage from a second connection point between the third switch and the fourth switch; and a smoothing circuit that is connected to the second connection point and normalizes a pulse waveform of the AC voltage.

Abstract: A power conditioner that suppresses distortion in a waveform of a sinusoidal generated voltage includes a first and second group including two switches each connected in inverse parallel and in series. The power conditioner alternately turns on and off both switches in the first group at a prescribed chopping frequency and alternately turns on and off both switches in the second group at a PWM frequency higher than the chopping frequency. If control is performed with a dead-time provided in the on/off timing for both switches in each group, the power conditioner adjusts and controls the on/off duty for the second group switches to correspond to the effective on drive in one switch by each diode during the dead-time for each switch in the first group.

Abstract: An inverter apparatus comprising a first switch group that is connected to a DC power source and includes a first switch and a second switch connected in series; a capacitor that has one end thereof connected to a first connection point between the first switch and the second switch; a second switch group that is connected in parallel with the capacitor and includes a third switch and a fourth switch that are connected in series; a switch control section that controls an ON/OFF state of the first switch, the second switch, the third switch, and the fourth switch to convert DC voltage from the DC power source into AC voltage and output the AC voltage from a second connection point between the third switch and the fourth switch; and a smoothing circuit that is connected to the second connection point and normalizes a pulse waveform of the AC voltage.

Abstract: A power conditioner that suppresses generation of voltage spikes in a part of a generated sinusoidal voltage waveform. An offset between the timing of chopping, which depends on whether the voltage difference between the voltage of a third pulse voltage series and a sinusoidal voltage is positive or negative, and the timing of the switching between on/off duty cycles of a seventh and eighth switch is calculated, and the on/off duty cycles of the seventh and eighth switches are controlled on the basis of the timing offset.

Abstract: A first circuit generates a first sequence of square wave voltages having a voltage level that changes to a positive side relative to a first reference potential, which is a potential on a negative-electrode side of a direct current power source, from a direct current voltage. A second circuit generates a second sequence of square wave voltages having a voltage level lower than the voltage level of the first sequence of square wave voltages on the positive side that changes to a negative side relative to a second reference potential. The second chopper circuit further generates a third sequence of square wave voltages having a voltage level that changes to the positive and negative side in turns in the manner of sinusoidal wave relative to the first reference potential by summing the first sequence of square wave voltages and the second sequence of square wave voltages. A third circuit outputs the third sequence of square wave voltages as a charge/discharge output.

Abstract: A first chopper circuit generates a first sequence of square wave voltages having a voltage level that changes to a positive side by chopping a direct current voltage at a system frequency. A second chopper circuit generates a second sequence of square wave voltages having a voltage level that changes to a negative side by chopping a direct current voltage at a frequency twice as high as the system frequency. The second chopper circuit further generates a third sequence of square wave voltages having a voltage level that changes to the positive and negative side in turns in the manner of sinusoidal wave by summing the first sequence of square wave voltages and the second sequence of square wave voltages.