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: A technology for suppressing a performance degradation of a solar battery caused by PID is provided. A conversion device includes a DC/DC converter and a control part. A solar battery is connected to an input end of the DC/DC converter. When direct-current power generated by the solar battery is converted and output, the DC/DC converter makes a potential of a negative electrode of the solar battery to be higher than a potential in a negative electrode of the output when the power input from the solar battery exceeds a prescribed value. The control part changes a voltage of the power output from the solar battery to detect a peak value of the power, and stops the operation of the DC/DC converter when the peak value is smaller than the prescribed value.

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: A power supply system for recovering degraded performance of a solar cell due to PID is provided. The power supply system includes a solar cell, a non-isolated type DC/DC converter that boosts a DC voltage from the solar cell input from an input end with a predetermined boosting ratio and outputs a DC voltage from an output end, and an inverter that converts a DC voltage output from the output end of the DC/DC converter into an AC voltage, the power supply system being connected to an external power system for system interconnection, wherein the power supply system includes a potential adjustment device for applying a voltage of an external power system to the solar cell via the inverter to set a ground potential of a negative electrode of the solar cell to positive when an output of the solar cell is smaller than a predetermined value.

Abstract: A technology for suppressing a performance degradation of a solar battery caused by PID is provided. A conversion device includes a DC/DC converter and a control part. A solar battery is connected to an input end of the DC/DC converter. When direct-current power generated by the solar battery is converted and output, the DC/DC converter makes a potential of a negative electrode of the solar battery to be higher than a potential in a negative electrode of the output when the power input from the solar battery exceeds a prescribed value. The control part changes a voltage of the power output from the solar battery to detect a peak value of the power, and stops the operation of the DC/DC converter when the peak value is smaller than the prescribed value.

Abstract: A voltage transform part transforms the direct-current power input to an input part. A first input and output part outputs the transformed direct-current power to a battery unit and to which direct-current power is input from the battery unit. A conversion part converts the direct-current power input to the input part into alternating-current power. A second input and output part outputs the alternating-current power to a power system or a load and to which an alternating-current power is input from the power system. The conversion part converts the alternating-current power input to the second input and output part into direct-current power. The second voltage transform part transforms the direct-current power converted by the conversion part and transforms the direct-current power input to the first input and output part. The conversion part converts the direct-current power transformed by the second voltage transform part into alternating-current power.

Abstract: A voltage transform part transforms the direct-current power input to an input part. A first input and output part outputs the transformed direct-current power to a battery unit and to which direct-current power is input from the battery unit. A conversion part converts the direct-current power input to the input part into alternating-current power. A second input and output part outputs the alternating-current power to a power system or a load and to which an alternating-current power is input from the power system. The conversion part converts the alternating-current power input to the second input and output part into direct-current power. The second voltage transform part transforms the direct-current power converted by the conversion part and transforms the direct-current power input to the first input and output part. The conversion part converts the direct-current power transformed by the second voltage transform part into alternating-current power.

Abstract: The disclosure provides a technique for appropriately recovering an output reduction due to PID. A solar power generation system which has a solar cell, converts an output of the solar cell to predetermined AC power and outputs the converted AC power includes a voltage application part configured to apply an DC voltage to the solar cell and to perform an output recovery operation, and a stop control part configured to stop applying of the DC voltage when a stop condition is satisfied after the DC voltage is applied. Further, when an output correspondence information acquisition part that acquires output correspondence information indicating a value corresponding to an output value of the solar cell is provided, stop control part determines that the stop control part satisfies the stop condition and stops the applying of the DC voltage when the output value corresponding to the output correspondence information exceeds a threshold value.

Abstract: A distributed power supply that enables a user to easily determine whether or not a ground fault that has occurred is a received ground fault when a ground fault occurs is provided. A distributed power supply connected to a single-phase three-wire distribution line includes a power generation device, an alternating current generation circuit that generates an alternating current to be supplied between a W-phase wire and a U-phase wire of the single-phase three-wire distribution line on the basis of an output of the power generation device, a ground voltage detection circuit that detects a ground voltage of a non-grounded portion in the alternating current generation circuit, and an output part that outputs detection result information indicating a detection result of the ground voltage of the ground voltage detection circuit.

Abstract: A power supply system for recovering degraded performance of a solar cell due to PID is provided. The power supply system includes a solar cell, a non-isolated type DC/DC converter that boosts a DC voltage from the solar cell input from an input end with a predetermined boosting ratio and outputs a DC voltage from an output end, and an inverter that converts a DC voltage output from the output end of the DC/DC converter into an AC voltage, the power supply system being connected to an external power system for system interconnection, wherein the power supply system includes a potential adjustment device for applying a voltage of an external power system to the solar cell via the inverter to set a ground potential of a negative electrode of the solar cell to positive when an output of the solar cell is smaller than a predetermined value.

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: A vibrating body includes a substrate, a piezoelectric element comprising a piezoelectric layer and electrode layers and joined to the substrate, and a ceramic layer between the substrate and the piezoelectric element. The ceramic layer comprises a first region and a second region which is adjacent to the first region in a direction perpendicular to a thickness direction of the ceramic layer. The first region has a square shape, each side of the first region having a length equal to a thickness of the ceramic layer, the second region has a square shape, each side of the second region having the length equal to the thickness of the ceramic layer, and a difference between a porosity of the first region and a porosity of the second region is not greater than 15%.

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: A vibrating body comprising a substrate a piezoelectric element comprising a piezoelectric layer and electrode layers and joined to the substrate and a ceramic layer between the substrate and the piezoelectric element, wherein the ceramic layer comprises a first region and a second region which is adjacent to the first region in a direction perpendicular to a thickness direction of the ceramic layer, wherein the first region has a quadrangular prism shape, each side of the first region having a length equal to a thickness of the ceramic layer, wherein the second region has a quadrangular prism shape, each side of the second region having the length equal to the thickness of the ceramic layer, and wherein a difference between a porosity of the first region and a porosity of the second region is not greater than 15%.

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.