Current sharing control in a parallel inverter system
First Claim
1. An inverter system including a plurality of inverters connected in parallel,each of said plurality of inverters comprising:
- current detection means for detecting an output current of a corresponding inverter;
voltage control means for generating a voltage control signal corresponding to a difference between a voltage reference and an actual voltage of said corresponding inverter;
frequency control means adapted for generating a frequency control signal corresponding to a difference between a frequency reference and an actual frequency of said corresponding inverter;
current difference formation means for forming a current difference signal relating to said corresponding inverter on the basis of a detected result of said current detection means;
d-q axis orthogonal coordinate transform means for transforming a current difference signal formed by said current difference detection means to a signal on the d-q axis orthogonal coordinate system, thus to form a first correction signal relating to the frequency of an output voltage of said corresponding inverter and a second correction signal relating to the amplitude of said output voltage thereof;
first correction means for correcting said frequency control signal by said first correction signal;
second correction means for correcting said voltage control signal by said second correction signal; and
means for controlling said corresponding inverter in accordance with outputs from said first correction means and said second correction means.
1 Assignment
0 Petitions
Accused Products
Abstract
This inverter system is directed to an inverter system in which a plurality of inverters adapted for generating output voltages corresponding to a voltage reference and a frequency reference respectively given through voltage controllers and frequency controllers are operated in parallel. In this inverter system, a difference between an output current of a corresponding inverter and output currents of other inverters is detected. By implementing the d-q axis orthogonal coordinate transform processing to that current difference, a first correction signal relating to the frequency of an output voltage of that inverter and a second correction signal relating to the amplitude of the output voltage thereof are provided.
270 Citations
13 Claims
-
1. An inverter system including a plurality of inverters connected in parallel,
each of said plurality of inverters comprising: -
current detection means for detecting an output current of a corresponding inverter; voltage control means for generating a voltage control signal corresponding to a difference between a voltage reference and an actual voltage of said corresponding inverter; frequency control means adapted for generating a frequency control signal corresponding to a difference between a frequency reference and an actual frequency of said corresponding inverter; current difference formation means for forming a current difference signal relating to said corresponding inverter on the basis of a detected result of said current detection means; d-q axis orthogonal coordinate transform means for transforming a current difference signal formed by said current difference detection means to a signal on the d-q axis orthogonal coordinate system, thus to form a first correction signal relating to the frequency of an output voltage of said corresponding inverter and a second correction signal relating to the amplitude of said output voltage thereof; first correction means for correcting said frequency control signal by said first correction signal; second correction means for correcting said voltage control signal by said second correction signal; and means for controlling said corresponding inverter in accordance with outputs from said first correction means and said second correction means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification