Title:
ELECTRICAL PROTECTIVE DEVICE FOR LOW-VOLTAGE DIRECT CURRENT (LVDC) NETWORK
Document Type and Number:
WIPO Patent Application WO/2021/253317
Kind Code:
A1
Abstract:
An Electrical Protective Device for Low-Voltage DC networks (EPDL) has a controller that on start-up first closes a mechanical relay (20) in a ground line, waits a first delay, then closes a bipolar transistor (24) to allow current to flow through a positive supply line, then turns on a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) (22) connected in parallel with the bipolar transistor (24) once an output voltage reaches a minimum target. The controller reverses the start-up order to open the MOSFET (22), bipolar transistor (24), and finally the mechanical relay (20) when an over-voltage, input-power, or integrated-current fault is detected. The output current is integrated over time and compared to a threshold, allowing for capacitor charging or other temporary over-loads. When the output voltage dips below the minimum target, the MOSFET (22) is turned off until the voltage recovers. If the voltage does not recover within a time period, the bipolar transistor (24) and then the mechanical relay (20) are turned off.
Inventors:
LI XIN (CN)
WONG KIN LAP (CN)
LI TIN HO (CN)
WONG KIN LAP (CN)
LI TIN HO (CN)
Application Number:
PCT/CN2020/096774
Publication Date:
December 23, 2021
Filing Date:
June 18, 2020
Export Citation:
Assignee:
HONG KONG APPLIED SCIENCE & TECH RESEARCH INST CO LTD (CN)
International Classes:
H01H33/59; H01H9/54; H01H83/20; H02H3/087
Domestic Patent References:
| WO2014177874A2 | 2014-11-06 |
Foreign References:
| CN109314004A | 2019-02-05 | |||
| CN105609344A | 2016-05-25 | |||
| CN106099841A | 2016-11-09 | |||
| CN104137211A | 2014-11-05 | |||
| CN104756339A | 2015-07-01 | |||
| CN102687221A | 2012-09-19 | |||
| EP0945983A2 | 1999-09-29 |
Attorney, Agent or Firm:
BEIJING PAT SF INTELLECTUAL PROPERTY AGENCY CO., LTD (CN)
Download PDF: