US 12,237,125 B2
Method for coordinating protective devices in a distribution grid
Shivansh Batra, Offenbach am Main (DE); and Yi Zhu, Kuemmersbruck (DE)
Assigned to Siemens Aktiengesellschaft, Munich (DE)
Appl. No. 17/599,119
Filed by Siemens Aktiengesellschaft, Munich (DE)
PCT Filed Sep. 13, 2019, PCT No. PCT/EP2019/074541
§ 371(c)(1), (2) Date Sep. 28, 2021,
PCT Pub. No. WO2020/200493, PCT Pub. Date Oct. 8, 2020.
Claims priority of application No. PCT/CN2019/080553 (WO), filed on Mar. 29, 2019; application No. PCT/CN2019/080554 (WO), filed on Mar. 29, 2019; and application No. PCT/CN2019/080558 (WO), filed on Mar. 29, 2019.
Prior Publication US 2022/0172914 A1, Jun. 2, 2022
Int. Cl. H01H 33/59 (2006.01); H01H 9/54 (2006.01); H02H 1/00 (2006.01); H02H 3/087 (2006.01); H02H 7/125 (2006.01); H02H 7/22 (2006.01); H02H 7/26 (2006.01); H02H 9/00 (2006.01); H02J 1/10 (2006.01); H02J 1/12 (2006.01)
CPC H01H 33/596 (2013.01) [H01H 9/542 (2013.01); H02H 1/0007 (2013.01); H02H 3/087 (2013.01); H02H 7/1252 (2013.01); H02H 7/1257 (2013.01); H02H 7/222 (2013.01); H02H 7/268 (2013.01); H02H 9/001 (2013.01); H02J 1/10 (2013.01); H02J 1/12 (2013.01); H01H 2009/544 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for coordinating a distribution network of different levels of electromechanical switches and automatically electrically closable apparatuses in a DC circuit, the distribution network being arranged between feed-in devices and loads, and having at least one busbar, wherein each of the apparatuses includes an electrical switch to open or close the DC circuit, a fault current detection device, a tripping unit, and a pre-charging apparatus, wherein if a fault current is detected by the fault current detection device, the electrical switch opens the DC circuit via the tripping unit and the pre-charging apparatus restores a voltage on the at least one busbar before the electrical switch is closed, and wherein each of the apparatuses further includes a control unit to automatically close the electrical switch after successful pre-charging, the method comprising:
in the case of a first apparatus at a feed-in device
setting a counter for the first apparatus to a number of a level in the distribution network;
detecting, using the fault current detection device, whether there is a fault;
if there is a fault, determining whether the fault current exceeds a current threshold;
if the fault current exceeds the current threshold, opening the apparatuses;
determining a direction of the fault current;
in the case of a second apparatus at a load
terminating the method in the case of a positive direction of the fault current; or
in the case of a negative direction of the fault current, checking whether the voltage on the at least one busbar has been restored and, if this is the case, automatically closing the second apparatus; or
in the case of a third apparatus at a feed-in device
terminating the method in the case of a negative direction of the fault current; or
in the case of a positive direction of the fault current, decrementing the counter for the third apparatus by one; and
if the counter for the third apparatus is less than or equal to zero, terminating the method; or
if the counter for the third apparatus is greater than zero, waiting for a switch-off time of the electromechanical switches;
charging, using the pre-charging apparatus, to test whether the fault has been eliminated;
checking whether the charging is possible on a side of the loads using the pre-charging apparatus; and either
if the charging is possible, recharging the distribution network, automatically switching on the third apparatus, and suppressing the switching transient, or
if the charging is not possible, decrementing the counter for the third apparatus by one.