Origin Electric Company, Limited

Jinbin Zhao

Masaaki Ohshima

Shuichi Ushiki

Hirokazu Shimizu

A method of controlling a single-phase voltage source AC/DC converting circuit has internal equivalent impedance as seen from an AC terminal, for converting power from a DC voltage source connected to a DC terminal to single-phase AC power or for converting single-phase AC power from a single-phase AC source connected to the AC terminal to DC power in accordance with a pulse width of a gate signal generated based on a PWM command.

Method of controlling single-phase voltage source AC/DC converter and interconnection system

An automatic synchronous parallelization apparatus capable of suppressing an inrush current by automatically adjusting the magnitude, the frequency, and the phase of the voltage when a single-phase voltage-type DC-to-AC converting device performing an autonomous parallel operation is connected in parallel with an external single-phase AC voltage source. The automatic synchronous parallelization apparatus includes a synchronization detecting circuit, a voltage amplitude command value generating circuit, and a frequency command value generating circuit. The voltage amplitude command value generating circuit generates the 1st-axis voltage command value, and the frequency command value generating circuit generates the 2nd-axis voltage command value, based on a value relating to a frequency difference between an external single-phase AC voltage source and a single-phase voltage-type DC-to-AC converting device and an effective value of a voltage of the external single-phase AC voltage source that are detected by synchronization detecting circuit. By using such command values, an output of the single-phase voltage-type DC-to-AC converting device can be adjusted to as to coincide with a voltage waveform of the external single-phase AC voltage source.

Synchronization detecting circuit and automatic synchronous parallelization apparatus

A single-phase voltage source AC/DC converter according to the present invention generates a second axis voltage command from difference between a DC voltage detection value at a DC terminal and a DC voltage command value and controls a DC voltage by increasing and decreasing active power with the second axis voltage command. For example, the voltage at the DC terminal is increased by decreasing active power when the DC voltage detection value at the DC terminal is lower than the DC voltage command, while the DC voltage detection value at the DC terminal is decreased by increasing the active power when the DC voltage detection value at the DC terminal is higher than the DC voltage command.

Single-phase voltage source AC/DC converter and interconnection system

The present invention is a single-phase voltage source DC-AC power converter and a three-phase voltage source DC-AC power converter. Each of the single-phase voltage source DC-AC power converter and the three-phase voltage source DC-AC power converter includes a voltage source DC-AC power converting circuit that converts power from a DC voltage source into AC power to output the AC power from an AC terminal; and target current producing means that includes a filter voltage command device and a voltage controller, the filter voltage command device generating a filter voltage command value that becomes a reference of the AC power output from the AC terminal, the AC output voltage at the AC terminal being input as an input signal to the voltage controller, the voltage controller integrating a difference between the filter voltage command value from the filter voltage command device and the AC output voltage at the AC terminal, the target current producing means outputting a PWM command such that a DC component included in the AC output voltage at the AC terminal becomes zero.

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Tokyo, Japan

Jinbin Zhao