Abstract: In order to extract maximum power from a solar cell, maximum power point tracking (MPPT) control is performed under ordinary circumstances. If the output current of the solar cell becomes too small, the operating point of the solar cell is caused to fluctuate over a range wider than that of MPPT control at a period longer than that of MPPT control and the output voltage and current of the solar cell is sampled. In a case where it is indicated by power values obtained from the sample voltage values and current values that a plurality of maximal points of power value exist, a voltage value corresponding to a power value indicative of the largest value is set as the operating point of the solar cell.

Abstract: A solar cell module in which the reduction in conversion efficiency is small, and a passive solar heating system using the solar cell module. The solar cell module has a solar cell covered with a filler. A back reinforcement member, the filler and a back insulating member larger than the solar cell are superposed on the non-light-receiving side of the solar cell. The back insulating member has openings corresponding to pierced portions of the solar cell module at which the solar cell module is affixed to a roof. A greater amount of clean energy is obtained with the system. The solar cell is used without any additional base to limit the reduction in the conversion efficiency of the solar cell.

Abstract: Power supplied from a battery power supply to a load through a power conversion unit is maximized with a relatively simple arrangement and a small processing load. In addition, an output command value for controlling the power conversion unit is detected, a set voltage for which the output command value is maximized is calculated with reference to a past or present set voltage, as needed, and set as the next set voltage such that the maximum output is supplied to the load without any erroneous operation in the case of variation in solar radiation. In this case, a plurality of voltages are sequentially set for a relatively short period. Output command values for the respective set voltages are fetched while setting the same voltage at the start and end of the operation. A variation in output command value caused by the fetching difference for the same set voltage is detected. The output command value for calculating the next set voltage is corrected in accordance with this variation.

Abstract: A solar cell module comprising at least one solar cell element and at least a front surface covering material disposed to cover the light receiving face of said at least one solar cell element, said surface side covering material comprising a light transmissive resin and a light transmissive surface protective film situated on the outermost surface in contact with said light transmissive resin, characterized in that said front surface side covering material includes means for forming a desired display pattern on the light receiving face of said at least one solar cell element, said means comprising (a) a patterned surface region forming said desired display pattern and (b) another patterned surface region having a surface pattern which is different from that of said patterned surface region (a), and said patterned surface region (a) and said patterned surface region (b) being situated next to each other.

Abstract: In a charge/discharge control system for a charging the output of a storage battery from a solar cell, the output voltage of the storage battery connected to a node between the solar cell output and a load is detected. If the detected voltage is less than a first setting value, discharge from the storage battery to the load is inhibited. The discharge inhibition is released in response to a discharge inhibition release command after the storage battery voltage increases to a second setting value.

Abstract: A power source apparatus includes a power generation device, a battery and an overcharge protection circuit. The overcharge protection circuit includes a shunt circuit, including a switching device for short-circuiting the power generation device when an input signal is at an `L` level. A reverse current protection circuit prevents an electric current from reversely flowing to the power generation device and/or the shunt circuit. A voltage detection section detects the voltage of the load or between the poles of the battery. An overcharge judgement section outputs an `L` level to the switching device when the voltage value detected by the voltage detection section surpasses a preset voltage value. When the voltage across the battery surpasses a predetermined value, the power source apparatus is short-circuited by the overcharge protection circuit, and therefore it is possible to prevent overvoltage from being applied to the load.

Abstract: An object of the present invention is to provide an insulation state measurement method and a judgement apparatus for a power conversion system, which can monitor the insulation state of an electric path with one end to which a power scarce is connected, or the power source itself in a non-use state of the power source, and can prevent an unexpected failure.A solar cell array connected to one end of an electric path is set in a non-grounded state upon operation of a change-over switch, and a measurement switch which receives an operation command from an operating circuit temporarily applies a high voltage to the electric path. A current detector detects a weak current flowing through connection lines, and supplies detection data to an insulation judgement unit. The insulation judgement unit calculates the insulator resistance on the basis of the magnitude of the applied voltage, and the magnitude of the weak current detected by the current detector.

Abstract: It is an object of the invention to accurately detect a defective photoelectric conversion element regardless of the installation place and indicate the corresponding information. The above object can be achieved by a power generating system having a solar cell array constituted by a plurality of parallel-connected solar cell strings each consisting of a plurality of series-connected solar cell modules. The system includes electrical parameter detection units for measuring electrical parameters in solar cell strings, a comparing unit for mutually comparing the detected electrical parameters, and a unit for warning of an abnormality on the basis of the comparison result.

Abstract: A solar cell module is provided which is excellent in foldability and durability. The filler thickness in the downwardly facing parts, engagement parts, and upwardly facing folded parts of the solar cell module are made thinner than the filler that is placed at the other non-folded parts.

Abstract: In a charging control method and apparatus which can improve the operating efficiency of a power generation system and prolong the service life of an accumulation unit, a short-circuit switch is closed, and a current generated in a solar cell is charged in the accumulation unit in a charging state. With this charging, the terminal voltage of the accumulation unit rises. This voltage is detected by a detection unit and is loaded into a control unit. When the detected voltage rises to a predetermined voltage, the short-circuit switch is closed by a short-circuit control signal. The output current from the solar cell is then discharged to the ground, and charging is stopped. In this state, the control unit determines the connected state of a load from an output signal from the detection unit.

Abstract: A solar cell module in which the reduction in conversion efficiency is small, and a passive solar heating system using the solar cell module. The solar cell module has a solar cell covered with a filler. A back reinforcement member, the filler and a back insulating member larger than the solar cell are superposed on the non-light-receiving side of the solar cell. The back insulating member has openings corresponding to pierced portions of the solar cell module at which the solar cell module is affixed to a roof. A greater amount of clean energy is obtained with the system. The solar cell is used without any additional base to limit the reduction in the conversion efficiency of the solar cell.

Abstract: An improved solar cell module is provided comprising a plurality of solar cell elements, each comprising a semiconductor layer and an upper electrode disposed in this order on the conductive surface of a substrate. This plurality of solar cell elements are spacedly disposed on a common, electrically insulative base member, with each solar cell element electrically connected in series with its adjacent element. An insulating material is disposed in the space between the solar cell elements in each pair of adjacent solar cell elements and a conductor formed of a conductive paste is disposed on the insulating material, such that one end of the conductor is electrically connected to the conductive substrate surface of one solar cell element, and the other end of the conductor is electrically connected to the upper electrode of the adjacent solar cell element. A process for producing the above solar cell module is also provided.