Abstract: A fiber laser system, includes: N fiber laser units that generates respective laser beams, where N?2; an output combiner that: combines the respective laser beams, and generates output light including, as the respective laser beams, laser beams different from each other in terms of NA power cumulative distribution; and a control unit that sets a power of each of the respective laser beams such that an upper limit NA corresponding to each of not more than (N?1) predetermined power cumulative rate(s) is equal to a specified value for the output light.

Abstract: A laser processing apparatus includes a process laser light source, a first optical system, a pulse laser light source, a second optical system, and an optical detection portion. The process laser light source generates a process laser beam having a continuous energy density during a certain period of time. The first optical system directs the process laser beam to a surface of a workpiece. The pulse laser light source generates a pulse laser beam having an energy density with a peak value that is higher than the energy density of the process laser beam. The second optical system directs the pulse laser beam to a process portion of the workpiece. The optical detection portion detects plasma light produced at the process portion of the workpiece.

Abstract: A fiber laser system, includes: N fiber laser units that generates respective laser beams, where N?2; an output combiner that: combines the respective laser beams, and generates output light including, as the respective laser beams, laser beams different from each other in terms of NA power cumulative distribution; and a control unit that sets a power of each of the respective laser beams such that an upper limit NA corresponding to each of not more than (N?1) predetermined power cumulative rate(s) is equal to a specified value for the output light.

Abstract: A photovoltaic system includes photovoltaic cells, inverters, a reduced electricity output state determiner which determines whether each of the photovoltaic cells is in a reduced electricity output state, a first command value generator which generates a first command value for decreasing a first power factor of a first inverter determined as in the reduced electricity output state, a second command value generator which generates a second command value for increasing a second power factor of at least one of second inverters so as to compensate for output power of the first inverter, and a controller which controls the inverters.

Abstract: A solar power generation system includes an inverter configured to convert DC power inputted from a solar battery to AC power, a MPPT control section configured to perform maximum power point tracking control on the inverter, an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control, an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state, and a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section.

Abstract: A solar power generation system includes an inverter configured to convert DC power inputted from a solar battery to AC power, a MPPT control section configured to perform maximum power point tracking control on the inverter, an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control, an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state, and a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section.

Abstract: A control device 5 of a power converter generates individual current command values Ira to Ird based on a total current command value Ir of inverters 2a to 2d; controls the inverters 2a to 2d respectively based on the generated current command values Ira to Ird; senses at least one current of direct currents Iia to Iid or alternating currents Ioa to Iod for each of the inverters 2a to 2d; and suppresses the current command values Ira to Ird for each of the inverters 2a to 2d when the sensed current exceeds a current limit value, the current limit value being preset, the current limit value being lower than a current causing a protection operation to protect the inverters 2a to 2d.

Abstract: A control device (2) of an inverter converts electrical power generated by a solar cell (3) into alternating current power connecting to an electric power system (7). The control device includes: an alternating current voltage sensor (14) sensing a system voltage (Vr) of the electric power system; an MPPT executer (23) controlling a direct current voltage (Vdc) applied to the inverter (1) to cause the electrical power output from the solar cell (3) to be a maximum when the direct current voltage (Vdc) is higher than a lower limit (VL); a direct current voltage lower limit calculator 22 reducing the lower limit (VL) when the system voltage (Vr) is lower than a predetermined voltage; and an electrical power controller (25) controlling reactive power based on the system voltage (Vr), the reactive power being output from the inverter (1).

Abstract: To provide a fiber laser apparatus capable of detecting a failure of an optical fiber within a wide range of the apparatus with an inexpensive configuration.

Abstract: A photovoltaic system includes photovoltaic cells, inverters, a reduced electricity output state determiner which determines whether each of the photovoltaic cells is in a reduced electricity output state, a first command value generator which generates a first command value for decreasing a first power factor of a first inverter determined as in the reduced electricity output state, a second command value generator which generates a second command value for increasing a second power factor of at least one of second inverters so as to compensate for output power of the first inverter, and a controller which controls the inverters.

Abstract: A control device (2) of an inverter converts electrical power generated by a solar cell (3) into alternating current power connecting to an electric power system (7). The control device includes: an alternating current voltage sensor (14) sensing a system voltage (Vr) of the electric power system; an MPPT executer (23) controlling a direct current voltage (Vdc) applied to the inverter (1) to cause the electrical power output from the solar cell (3) to be a maximum when the direct current voltage (Vdc) is higher than a lower limit (VL); a direct current voltage lower limit calculator 22 reducing the lower limit (VL) when the system voltage (Vr) is lower than a predetermined voltage; and an electrical power controller (25) controlling reactive power based on the system voltage (Vr), the reactive power being output from the inverter (1).

Abstract: An inverter controller is configured to control inverters connected in parallel. The inverter controller is configured to closes switch of a first inverter and turn on a first switching element provided at the first inverter to charge capacitors of the inverters at the time of starting the inverters, and to close the other switches after the capacitors are charged.

Abstract: A power conversion device includes a smoothing capacitor, an input voltage detection unit, a power conversion unit, and a controller. The input voltage detection unit detects a voltage value of the input voltage. The power conversion unit converts a direct-current voltage smoothed by the smoothing capacitor into an alternating-current voltage to output the alternating-current voltage to a power system. The controller has a first operation mode of outputting active power to the power system, has a second operation mode of outputting reactive power to the power system, determines whether or not the voltage value is one of equal to and higher than a determination value, and makes a transition from the first operation mode to the second operation mode within a predetermined time from a time point when it is determined that the voltage value is lower than the determination value.

Abstract: There is provided a control apparatus for a photovoltaic inverter. The control apparatus includes a system voltage detector, a DC voltage detector that detects a DC voltage applied to the inverter, an output voltage deficiency detector that detects an output voltage deficiency of the inverter based on the system voltage and the DC voltage, an output-current detector, an output-current distortion detector that detects distortion of the output current based on a harmonic included in the output current, a MPPT controller, and an output-current distortion controller that performs control to set the DC voltage applied to the inverter to a voltage at a power point less than a maximum power point when the output voltage deficiency is detected and the distortion of the output current is detected.

Abstract: A power apparatus includes a heating element provided in an inside and configured to become hot during operation, a fan configured to produce an airflow from an upper part to a lower part in the inside, a cooling controller configured to control the fan in order to cool the heating element, and a discharge controller configured to control the fan in order to discharge dust in the inside to an outside.

Abstract: To provide a fiber laser apparatus capable of detecting a failure of an optical fiber within a wide range of the apparatus with an inexpensive configuration.

Abstract: An inverter controller is configured to control inverters connected in parallel. The inverter controller is configured to closes switch of a first inverter and turn on a first switching element provided at the first inverter to charge capacitors of the inverters at the time of starting the inverters, and to close the other switches after the capacitors are charged.

Abstract: A power conversion device includes a smoothing capacitor, an input voltage detection unit, a power conversion unit, and a controller. The input voltage detection unit detects a voltage value of the input voltage. The power conversion unit converts a direct-current voltage smoothed by the smoothing capacitor into an alternating-current voltage to output the alternating-current voltage to a power system. The controller has a first operation mode of outputting active power to the power system, has a second operation mode of outputting reactive power to the power system, determines whether or not the voltage value is one of equal to and higher than a determination value, and makes a transition from the first operation mode to the second operation mode within a predetermined time from a time point when it is determined that the voltage value is lower than the determination value.

Abstract: There is provided a control apparatus for a photovoltaic inverter. The control apparatus includes a system voltage detector, a DC voltage detector that detects a DC voltage applied to the inverter, an output voltage deficiency detector that detects an output voltage deficiency of the inverter based on the system voltage and the DC voltage, an output-current detector, an output-current distortion detector that detects distortion of the output current based on a harmonic included in the output current, a MPPT controller, and an output-current distortion controller that performs control to set the DC voltage applied to the inverter to a voltage at a power point less than a maximum power point when the output voltage deficiency is detected and the distortion of the output current is detected.

Abstract: An apparatus for identifying a cylinder to be ignited in an engine. A plurality of teeth are formed on the periphery of the engine crankshaft. A sensor having two spaced detector parts senses the passage of the teeth. The detector parts identify the passage of a leading or a trailing edge of a tooth. An electronic control unit (ECU) determines the rotating direction of the crankshaft by comparing the signals from the two detector parts. Further, the ECU keeps a count indicating the position of the crankshaft and controls the engine in accordance with the count. The apparatus remembers the position of the crankshaft when the engine stops to improve re-ignition.