PROBLEM TO BE SOLVED: To provide a power storage type photovoltaic power generation system capable of specifying the power generated by a solar cell and the discharge power of a power storage device, and preventing reverse flow of the discharged power of the power storage device charged with the power from a grid. SOLUTION: A power conditioner of the photovoltaic power generation system in which a solar cell is linked to a grid is provided with: a power converter having both functions of an inverter operation of converting DC power from the solar cell into AC and a converter operation of converting AC power from the grid into DC; a reverse flow relay for detecting that reverse flow is generated in the grid; a single controller for selectively controlling charging/discharging of power for any one of a first power storage device suppressing output variation of the solar cell and a second power storage device charging midnight power; and a changeover switch for interrupting connection between the second power storage device and the controller on the basis of an output of the reverse flow relay when reverse flow of excessive power occurs in the solar cell. In the power conditioner, the controller is connected to a solar cell side of the power converter, and the changeover switch is inserted and connected between the first power storage device, the second power storage device and the power converter. COPYRIGHT: (C)2009,JPO&INPIT

Power storage type photovoltaic power generation system

The invention provides a wind energy and solar energy grid-connected generation system and a control method thereof. The wind energy and solar energy grid-connected generation system comprises a generation unit, an inversion unit, a grid-connecting unit, a main control unit and a detection unit. Each unit is effectively controlled by an integrated control unit which is formed by a digital signal processor (DSP), and operating state parameters of the system are predicted by a neural network, so the defect that the grid-connected system changes due to execution delaying of a control instructionis overcome, and the operating stability of the system is improved. Island detection adopts an active and passive detection mode, so the capacity for anti-island operation of the system is improved. The invention has the advantages that: inverted electric energy is supplied to an electricity grid and can be locally supplied to local alternating current and direct current loads, so the load pressure of the electricity grid is reduced, and the capacity for stable operation of the electricity grid can be improved; and when the output electric energy of the system is smaller than a local load, the electricity grid can supply power to the local load of the system, so the local load is supplied with power doubly by power supplies of the system and the electricity grid, and the time for uninterrupted power supply of the power supplies is prolonged.

Wind energy and solar energy grid-connected generation system and control method thereof

A power storage system and method are disclosed. The system is connected to a load, a power grid, and a power generation system. When the grid is in an abnormal state, a battery is simultaneously charged with power from the power generation system and used to supply power to the load.

Power storage apparatus, method of operating the same, and power storage system

The present invention is an apparatus and method for delivering energy using a renewable resource. The method includes providing a photovoltaic energy source and applying energy storage to the photovoltaic energy source via a battery storage unit. The energy output from the photovoltaic energy source and the battery system is controlled using a battery control system. The battery control system predicts peak load, develops a schedule that includes when to begin discharging power and when to stop discharging power, shifts power to the battery storage unit when excess power is available, and prioritizes the functionality of the battery storage unit and the photovoltaic energy source.

Systems and methods for distributing power using photovoltaic resources and a shifting battery system

Device and method for detecting wind power generation grid-connected system

PROBLEM TO BE SOLVED: To equalize a level of power load and prevent reverse power transmission of the power stored in a storage battery to a power company by promotion of use of midnight electrical power and shift of peak power generated in the day time to midnight. SOLUTION: A home power supply system combined with solar power generation and midnight power storage is provided. The storage battery is charged, as a rule, in the midnight period using the midnight power via an inverter which also operates as an automatic charger, and the commercial power supply is used for household consumption. In the solar power generation period in the day time, when the electrical power generated with the solar system is higher than the preset value, an extra power is sold to the power company via the inverter/ automatic charger. In the intermediate time period between the midnight period and solar power generation period in the day time, the power stored in the storage battery is supplied for household consumption, and storage, if it is generated, is compensated by the commercial electrical power of the power company. In the case where the power stored in the storage battery is supplied for household consumption, a reverse transmission preventing circuit consisting of parallel connection of a forward thyristor and a backward thyristor is provided between the storage battery and the commercial power supply and a control circuit for preventing reverse transmission of power to the power company is also provided. As a result, the reverse transmission of the power stored in the storage battery to the power company is forcibly prevented. COPYRIGHT: (C)2002,JPO

Kuniharu Kojima

Papers

Home power supply system combined with solar power generation and midnight power storage