Abstract: A distributed power supply system is configured to execute a process for determining whether or not to permit a diagnostic process in such a manner that it is determined whether or not a difference between a set upper limit value and an actual measurement current value is not less than a load current value, the set upper limit value being a predetermined upper limit value set with respect to a detected current of a current sensor, the measurement current value being detected by the current sensor in a state where the diagnostic process is not executed, and the load current value being a value of a current flowing from a commercial power utility to a power load during execution of the diagnostic process; and if it is determined that the difference is not less than the load current value, the controller permits the diagnostic process.

Abstract: A distributed power generation system includes: an inverter connected to the first connection point; a first power generation device, a current sensor provided on the electric wire in a position between the utility power supply and the first connection point; and a controller wherein in a case where a current flowing in a direction from the first connection point to the power supply utility is a positive current, the controller determines that there is an abnormality in an installation state of the current sensor, or performs notification of the abnormality in the installation state of the current sensor, when an electric power difference obtained by subtracting electric power consumed in the power load from the electric power output from the inverter is greater than a first threshold which is greater than 0.

Abstract: The distributed power generation system includes: an inverter connected to the first connection point; a first power generator; a current sensor provided on the power line between the commercial power supply and the first connection point; and a controller. In a case where a current flowing in a direction from the first connection point to the commercial power supply is a positive current, in a state where the inverter is disconnected, the controller determines that there is an abnormality in an installation state of the current sensor, or gives a notification of the abnormality in the installation state of the current sensor, if differential power that is obtained by subtracting power consumed by the electrical load from output power of the inverter is greater than a first threshold greater than 0.

Abstract: A distributed power supply system of the present invention comprises a distributed power supply apparatus (4) for supplying electric power to a customer load (2) interactively with a commercial electric power utility (1); an internal load (7) supplied with electric power from the commercial electric power utility; a current sensor (5a, 5b) for detecting a magnitude of a current and a direction of the current, the current being in a location closer to the commercial electric power utility than the internal load and the customer load; and a controller (8); wherein in a state where the distributed power supply apparatus 84) is not generating the electric power, the controller causes the internal load (7) to actuate, performs determination control as to an installation state of the current sensor (5a, 5b) plural times based on a value detected by the current sensor, and performs the determination control in such a manner that at least one of plural intervals at which the determination control is performed is set

Abstract: A power converter of the present invention is configured to convert DC power generated by a power generator (1) into AC power. The power converter includes: a boost converter circuit (3) configured to boost an output voltage of the power generator (1); an inverter circuit (5) configured to convert an output voltage of the boost converter circuit (3) into AC power and to interconnect the AC power with a power system (2); a buck converter circuit (8) configured to perform power conversion of output power of the boost converter circuit (3) and to supply resultant power to an internal load (60); and a controller (9). The controller (9) is configured to control the output voltage of the boost converter circuit (3) to be lower than or equal to a second voltage value which is less than the maximum value of AC voltage of the power system (2), in a case of supplying output power of the power generator (1) to the internal load (60) via the boost converter circuit (3) and the buck converter circuit (8).

Abstract: A power converter of the present invention is configured to convert DC power generated by a power generator (1) into AC power. The power converter includes: a boost converter circuit (3) configured to boost an output voltage of the power generator (1); an inverter circuit (5) configured to convert an output voltage of the boost converter circuit (3) into AC power and to interconnect the AC power with a power system (2); a buck converter circuit (8) configured to perform power conversion of output power of the boost converter circuit (3) and to supply resultant power to an internal load (60); and a controller (9). The controller (9) is configured to control the output voltage of the boost converter circuit (3) to be lower than or equal to a second voltage value which is less than the maximum value of AC voltage of the power system (2), in a case of supplying output power of the power generator (1) to the internal load (60) via the boost converter circuit (3) and the buck converter circuit (8).

Abstract: A distributed power generation system of the present invention is a distributed power generation system connected to a three-wire electric power system including first to third electric wires, the third electric wire being a neutral wire, and includes: an electric power generator (105); a connection mechanism (110) configured to connect any two electric wires among the first to third electric wires (101a to 101c) to an internal electric power load (111); a first current sensor (109a) set so as to detect a current value of the first electric wire (101a); a second current sensor (109b) set so as to detect a current value of the second electric wire (101b); and an operation controller (112) configured to determine the electric wire on which each of the first current sensor (109a) and the second current sensor (109b) is provided and an installing direction of each of the first current sensor (109a) and the second current sensor (109b) by determining whether or not the amount of change in the current value detecte

Abstract: A distributed power supply system is configured to execute a process for determining whether or not to permit a diagnostic process in such a manner that it is determined whether or not a difference between a set upper limit value and an actual measurement current value is not less than a load current value, the set upper limit value being a predetermined upper limit value set with respect to a detected current of a current sensor, the measurement current value being detected by the current sensor in a state where the diagnostic process is not executed, and the load current value being a value of a current flowing from a commercial power utility to a power load during execution of the diagnostic process; and if it is determined that the difference is not less than the load current value, the controller permits the diagnostic process.

Abstract: A distributed power supply system of the present invention comprises a distributed power supply apparatus (4) for supplying electric power to a customer load (2) interactively with a commercial electric power utility (1); an internal load (7) supplied with electric power from the commercial electric power utility; a current sensor (5a, 5b) for detecting a magnitude of a current and a direction of the current, the current being in a location closer to the commercial electric power utility than the internal load and the customer load; and a controller (8); wherein in a state where the distributed power supply apparatus 84) is not generating the electric power, the controller causes the internal load (7) to actuate, performs determination control as to an installation state of the current sensor (5a, 5b) plural times based on a value detected by the current sensor, and performs the determination control in such a manner that at least one of plural intervals at which the determination control is performed is set

Abstract: It has been expected that more economical power generation could be performed using a fuel cell. The present invention provides a fuel cell power generation apparatus including a fuel cell 1 for generating power and heat to be supplied to a consumption point, storing means 11 of storing data on past patterns of time variations of power and/or heat consumption at the consumption point, power controlling means 12 of performing control for regulating power generation carried out based on the stored data and flow rate controlling means 4.

Abstract: An automatic offset adjusting apparatus for current detectors in a digital controller for a servo motor is constructed so that, when errors occur in offset correction values due to a temperature change and the like while the servo motor is in operation, an electrical angle detecting unit detects a ripple of the torque of the servo motor, on the basis of a ripple of a torque command value, and detects a first electrical angle, where the torque command value becomes maximum, and a second electrical angle, where the torque command value becomes minimum, based on an electrical angle signal of the servo motor, a judgement unit judges whether or not offset correction errors have occurred on the basis of a difference between the first and second electrical angles, and, if the judgement unit judges that the offset correction errors have occurred, a correction unit adds adjustment values for the offset correction values corresponding to the first electrical angle to the respective offset correction values to update th

Abstract: In a DC motor control system, switching element driving circuits are connected to respective base circuits of four switching elements arranged to form a bridge circuit which has a DC motor connected thereto as an electric load thereon, and an output signal interlocking circuit is provided in each paired driving circuits associated with the corresponding paired switching elements which are connected in series across a DC power source, respectively, thereby preventing simultaneous conduction of each paired switching elements. By virtue of the provision of the output signal interlocking circuits, it is possible to realize a PWM control system for DC motors with a simplified circuit construction and yet to thereby prevent power source short-circuiting trouble with elevated safety and reliability.