High-voltage and high-power stabilized DC power supply using modified sine wave output 3-phase inverter

• US 5,652,699 A
• Filed: 08/11/1995
• Issued: 07/29/1997
• Est. Priority Date: 05/09/1995
• Status: Expired due to Fees

• Current Assignee: Korea Electric Power Corporation (Government of South Korea), Korea Atomic Energy Research Institute (Government of The Republic of Korea)
• Original Assignee: Korea Electric Power Corporation (Government of South Korea), Korea Atomic Energy Research Institute (Government of The Republic of Korea)
• Inventors: Jung, Euo-Chang, Kim, Jung-Moog, Pak, Seung-Kyu, Lee, Jong-Min, Kim, Cheol-Jung
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US08/514,505
• Time in Patent Office: 718 Days
• Field of Search: 363/8, 363/9, 363/21, 363/23, 363/25, 363/37
• US Class Current: 363/8
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

A stable DC power system of high-voltage and good-output performance is provided by adding a 3-phase inverter, whereby modified waveform for an output control is produced and a filter to a conventional DC power system and by bridge-rectifying. The modified sinusoidal wave such as a varied wave whose upper portion ranging from 30° to 150° is flat of a 1/2 cycle of the sinusoidal wave, a modified wave whose portions ranging from 30° to 90° and from 90° to 150° are linear in a 1/2 cycle of the sinusoidal wave and a modified wave whose portions ranging from 30° to 90° and from 210° to 270° are recessed so as to be symmetrical with respect to a line in the whole cycle of the sinusoidal wave are used for reducing ripples of the output voltage after the 3-phase rectification.

Claims

1. A DC power system, comprising:

a 3-phase inverter for modulating a 3-phase power input into a form of a pulse train and outputting the modulated input;

a filter, operably connected to said 3-phase inverter, for receiving said modulated input and for filtering said modulated input of said 3-phase inverter to make the filtered signal into a form of a sinusoidal wave;

a 3-phase transformer, operably connected to said filter, for receiving said sinusoidal wave and for increasing or decreasing the voltage of said sinusoidal wave into a desired voltage level; and

a 3-phase bridge rectifier, operably coupled to said 3-phase transformer, for receiving and rectifying the output voltage of said 3-phase transformer and outputting direct current having no ripples theoretically to thereby attain stable current of high-voltage, high-power and good output performance.

2. A DC power system as claimed in claim 1 further comprising an output controller for controlling said 3-phase inverter in response to the DC signal output from three-phase bridge rectifier.

3. A DC power system as claimed in claim 1 wherein said modulated sinusoidal wave is a modified wave whose upper portion ranging from 30°

to 150°

is flat in a half cycle of the sinusoidal wave.

4. A DC power system as claimed in claim 1 wherein said modulated sinusoidal wave is a modified wave whose portions ranging from 30°

to 90° and

from 90°

to 150°

are linear in the whole cycle of the sinusoidal wave.

5. A DC power system as claimed in claim 1 wherein said modulated sinusoidal wave is a modified wave whose portions ranging from 30°

to 90° and

from 210°

to 270°

are recessed so as to be symmetrical with respect to a line in a 1/2 cycle of the sinusoidal wave.