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Power converter apparatus
| Details |
Inventors: Shima, Seiya; Kuroha, Hiroaki; Ando, Takeki; Kurosawa, Toshiaki; Inaba, Hiromi; Sakai, Yoshio;
Assignee: Hitachi, Ltd. (Tokyo, JP)
Primary Examiner: Shoop; William M.
Assistant Examiner:
Attorney, Agent or Firm: Craig and Antonelli
A power converter for power conversion between an a.c. system and a d.c. system includes a full-wave bridge circuit having GTO connected in at least one arm of the full-wave bridge circuit on the positive polarity side. During a conduction-enabled period of GTO which is determined by a firing phase angle, the GTO is so controlled as to perform current chopping operation by a pulse signal of a predetermined pulse width. |
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DETAILED DESCRIPTION What is claimed is: 1.
A power converter apparatus for effecting power conversion between an a.
c.
system and a d.
c.
system by using a full-wave bridge circuit in which at least one arm is provided with controllable switch means capable of performing a current breaking function, comprising: phase angle control means for controlling phase angle of said switch means; pulse width control means for controlling width of pulse which causes said switch means to perform current chopping operation; and gate signal generating means for turning on and off said switch means with said chopping pulse of the controlled pulse width during a conduction-enabled period determined at least by said phase angle.
2.
A power converter apparatus according to claim 1, wherein said gate signal generating means is arranged to generate a gate signal which is effective to turn on and off said switch means plural times with said pulse of the controlled pulse width during said conduction-enabled period.
3.
A power converter apparatus according to claim 1, wherein said phase angle control means and said pulse width control means are so arranged as to vary said phase angle and said pulse width in dependence with a desired voltage appearing between d.
c.
terminals of said full-wave bridge circuit.
4.
A power converter apparatus according to claim 3, wherein said pulse angle is made variable when said desired voltage is not higher than a predetermined value, while said pulse width is made variable when said desired voltage goes beyond said predetermined value.
5.
A power converter apparatus according to claim 4, wherein said phase angle control means is adapted to vary said phase angle in accordance with said desired voltage when said desired voltage is not higher than said predetermined value, and maintain said phase angle to be smallest when said desired voltage goes beyond said predetermined value.
6.
A power converter apparatus according to claim 4, wherein said pulse width control means is adapted to maintain said pulse width to be smallest when said desired voltage is not higher than said predetermined value and make said pulse width variable in accordance with said desired voltage when said desired voltage goes beyond said predetermined value
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