The present invention provides a method, computer program product, and apparatus and control system and method for providing substantially uninterrupted power to a load. The apparatus includes a control system coupled with an electrical power storage subsystem and a electrical power generator. The control system is configured to provide a plurality of modes of operation including at least a static compensator (STATCOM) mode, an uninterruptible power supply (UPS) mode and a generator mode (gen set), and to control transitions between each of the plurality of modes. In one embodiment, the control system is an integrated closed loop control system that includes a current control system and a voltage control system. The apparatus is capable of operating at least two of the plurality of modes simultaneously, including ramping the gen set mode up and simultaneously ramping the UPS mode down as the gen set mode is ramped down.

Integrated closed loop control method and apparatus for combined uninterruptible power supply and generator system

A power conversion device includes a power switching circuit that supplies AC voltages generated between switching elements operating as upper arms and switching elements operating as lower arms, and a control circuit that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements by a PWM method in a first operational region in which frequency of an AC power to be outputted is low, and that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements at timings based upon the phase of the AC power to be outputted in an operational region in which the frequency of the AC power to be outputted is higher than in the first operational region.

Power Conversion Device

An operation assisting system enhances the operator's willingness to participate in energy-saving efforts. The operation assisting system stores information about the actual operation of operated equipment carried out by the operator, evaluates the stored operation information, and displays the results of evaluation. The evaluation results relate to the cost concerning the operated equipment, the cost of supplying energy to the operation target facility, the cost concerning the operated equipment, the amount of emission of carbon dioxide, nitride oxide, and global warming substances, the amount of primary energy consumption, the crude oil-converted amount of energy consumption, the amount of excess or shortage of supply of energy, or electric power quality.

Operation-assisting system and operation-assisting computer program

Embodiments of the invention relate to devices and methods and systems for controlling a reactive power contribution to reactive power flowing in an electricity distribution network, so as to optimise this reactive power flow. Conventional methods of controlling reactive power flow focus on minimising a reactive power contribution by power provision and power consumption devices connected to the electricity distribution network, in accordance with, for example, regulations governing a maximum allowed power factor and/or under the control of a central controlling entity. However, such methods are slow to react to changing network conditions, and do not take account of local variations in reactive power. In an embodiment of the present invention, there is provided a reactive power control device for use with a power consumption and/or provision device. The reactive power control device comprises detecting means for detecting, at the power device, a reactive power characteristic of electrical power flowing in the electric power distribution network, the reactive power characteristic relating to a reactive power component of electricity flowing in the network. The reactive power control device further comprises control means for controlling, on the basis of the detected reactive power characteristic, a reactive power contribution to the electricity distribution network so as to adjust a value of the detected reactive power characteristic. This enables individual power consumption and/or provision devices to react autonomously to local variations in the electricity distribution network,and to provide a reactive power contribution, to drive the detected reactive power characteristic towards a desired value.

Reactive power management

PROBLEM TO BE SOLVED: To suppress fluctuation in an interconnection point voltage which is caused by an effective power output from a distributed power supply, in the case where the distributed power supply is interconnected with an existing power distribution system to supply power to a load. SOLUTION: The distributed power supply that is interconnected with an existing power distribution system to supply power to a load, comprises a power generating means which generates an effective power and a reactive power and outputs them to an interconnection point, and a control means which controls the power generating means so that an optimum value is output according to the effective power by acquiring an optimum value of the reactive power which suppresses fluctuation in the interconnection point voltage caused by the effective power. When the control means judges that the effective power is in a rising state based on the effective power acquired in the previous detecting opportunity and current detecting opportunity, the control means detects an interconnection point voltage by successively changing the reactive power output to the interconnection point, and searches for the reactive power which the detected interconnection point voltage becomes equal to the interconnection point voltage acquired in the previous detecting opportunity as the optimum value. COPYRIGHT: (C)2011,JPO&INPIT

Distributed power supply, power distribution facility, and power supply method

PROBLEM TO BE SOLVED: To provide a reactive power controller which is capable of reducing capital investment and maintenance cost by omitting the reactive power controllers installed at the premises of consumers or power systems. SOLUTION: A reactive power controller, which controls the reactive power of a power system 1 interconnected with a power unit 20 is provided with a DC-AC converter having a reactive power control function, is provided with a voltage measuring means 50 which detects the system voltage or reactive voltage of the private power system of a consumer or a power system 1 for commercial power supply provided with the DC-AC inverter 23, an appropriate reactive power flow value calculating means 41, which receives the signal of the detecting means 50 and calculates the appropriate value of a reactive power flow, a reactive electric energy commanding means 43 which calculates and instructs an appropriate reactive power command value to the converter 23 upon receiving the calculated results of the calculating means 41, and an operation mode discriminating means 42 which discriminates the operation mode of the converter 23 and controls the reactive power of the converter 23 based on the command from the reactive electrical energy commanding means 43. COPYRIGHT: (C)1999,JPO

Apparatus and method for controlling reactive power

PROBLEM TO BE SOLVED: To realize a price calculation of service for energy saving. SOLUTION: The service of support system for energy saving comprises a receiving means receiving amount data of energy demand and status data of services of energy supply facilities at established time intervals from a dada collecting device for each customer, a data base for energy information of customers storing received data at each customer, a calculating means calculating the real energy cost and the energy cost at the state before getting this service at each calculating intervals for service price with referring of the data base, and calculating the service price of energy saving for each customer on the basis of the calculating result and the predetermined rule. Furthermore, a determining means determining an optimum operating method for the energy supplying facilities of each customer and a transmitting means transmitting information of the optimum operating method to terminals of each customer are added to the system with referring of the data base, so that an service reducing additionally real energy cost becomes available.

Sysytem of service support for energy saving and method of service price calculation for the same

PURPOSE:To trip a DC breaker and prevent counter discharge, by stopping an inverter circuit through an abnormality detecting signal generated from each abnormality detection circuit for an abnormality in voltage-difference, voltage, and frequency. CONSTITUTION:An output voltage from an inverter 2 and an output voltage (a voltage at a linkage point) from a dispersed power supply unit (A) are entered in a voltage-difference abnormality detecting circuit 8. A voltage abnormality detecting circuit 9 detects that the output voltage from the dispersed power- supply unit (A) becomes out of a permissible range. A frequency abnormality detecting circuit 10 detects that the output frequency from the dispersed power- supply unit (A) becomes out of a permissible range. A trip circuit 11 trips a DC breaker (S) provided at a linked point through an abnormality signal from these abnormality detecting circuits 8, 9 and 10. At the same time, an inverter 2 is stopped by an inverter stopping circuit 12 through the abnormality signal from the abnormality detecting circuits 8, 9 and 10, and counter discharge can be prevented.

哲久熊野

Papers

Apparatus and method for controlling reactive power

Sysytem of service support for energy saving and method of service price calculation for the same

Dispersed power supply and counter-charge preventive method by dispersed power-supply for linked commercial frequency power line

哲久 熊野

Papers

Apparatus and method for controlling reactive power

Sysytem of service support for energy saving and method of service price calculation for the same

Dispersed power supply and counter-charge preventive method by dispersed power-supply for linked commercial frequency power line

哲久熊野