Title:
MULTI-PHASE SOFT CHARGING CONTROL METHOD AND SYSTEM FOR MULTI-LEVEL DIRECT-CURRENT SOLID-STATE TRANSFORMER
Document Type and Number:
WIPO Patent Application WO/2021/179707
Kind Code:
A1
Abstract:
A multi-phase soft charging control method and system for a multi-level direct current (DC) solid state transformer, which relate to the technical field of electricity and electronics, and solve the problem of how to reduce current spikes at the alternating current (AC) side and the DC side when a modular multi-level DC solid state transformer starts. The multi-phase soft charging control method comprises: charging a submodule (SM) at the primary side MMC without control; using a peak current to control soft charging of the submodule (SM) at the primary side MMC; and using phase shift modulation to control the soft charging of the submodule (SM) at the secondary side MMC. The control system comprises: an input source (Vdc1), an output source (Vdc2), a primary side MMC, a secondary side MMC, a current limiting resistor (Rd), a current limiting switch (Sd), and a high-frequency transformer (T). The control method achieves rapid and stable charging of a capacitor (C) of a submodule (SM) of a modular multi-level DC solid state transformer, reduces the current spikes at the AC side and the DC side when the transformer starts, protects the power devices (S1, S2) and the high-frequency transformer (T) in the submodules (SM), improves the service life of the capacitor (C), and favors the safe operation of the system.
Inventors:
TANG DEPING (CN)
ZHAO TAO (CN)
MIAO JINGYU (CN)
ZHAO TAO (CN)
MIAO JINGYU (CN)
Application Number:
PCT/CN2020/134878
Publication Date:
September 16, 2021
Filing Date:
December 09, 2020
Export Citation:
Assignee:
HEFEI KEWELL POWER SYSTEM CO LTD (CN)
International Classes:
H02M1/36
Foreign References:
| CN111371302A | 2020-07-03 | |||
| CN108539987A | 2018-09-14 | |||
| CN104993686A | 2015-10-21 | |||
| CN104734484A | 2015-06-24 | |||
| US20160294276A1 | 2016-10-06 |
Attorney, Agent or Firm:
HEFEI CITY, HAO ZHI YUN PATENTAGENCY (CN)
Download PDF: