Photovoltaic generation system and power feeding system

摘要

According to one embodiment, a system includes a battery to charge power and discharge a direct-current power to a converter, the converter supplying the converted power to a power system, detectors detecting a voltage at a point between the converter and power system, a current output from the converter and effective power from the voltage value and a current value detected, units computing an angular frequency of the voltage output from the converter, based on an effective power value and an output target value of effective power and an output voltage target value of the converter, based on a current value, a set voltage value and an angular frequency, and a controller controlling the converter according to the output voltage target value.

主权项

1. A photovoltaic generation system comprising:
a direct-current power supply, which includes a photovoltaic, and a storage battery to charge the power from the photovoltaic, and discharge a direct-current power to an electric power converter; the electric power converter configured to convert a direct-current power output from the direct-current power supply, and supply the converted power to a power system; a voltage detector configured to detect a voltage at a connection point between the electric power converter and power system; a current detector configured to detect a current output from the electric power converter; an effective power detector configured to detect effective power from a voltage value detected by the voltage detector and a current value detected by the current detector; a rotor speed computation circuit configured to compute an angular frequency of a voltage output from the electric power converter, in order to increase the angular frequency when the effective power value is decreased and decrease the angular frequency when the effective power value is increased, based on an effective power value detected by the effective power detector, and an effective power set value to be output from the electric power converter; an electrical characteristics computation circuit configured to compute an output voltage target value of the electric power converter, in order to increase a difference between the phase angle of the output voltage target and the voltage phase angle of the power system in a leading direction when the frequency of the power system is decreased, based on the current value detected by the current detector, a set voltage value which is a reference value as a target of the close voltage of the electric power converter, and the angular frequency; and a power conversion controller configured to control the electric power converter according to the output voltage target value.