US 11,855,572 B2
System and method for increasing braking performance under multi-phase shorting
Nikolaos Adamopoulos, Athens (GR); Dimitrios Papathanasopoulos, Athens (GR); Nikolaos Tsakalakis, Lavrio (GR); Konstantinos Andriotis, Athens (GR); Athanasios Sarigiannidis, Athens (GR); and Nekrarios Karakasis, Pierias (GR)
Assigned to Nidec Motor Corporation, St. Louis, MO (US)
Filed by Nidec Motor Corporation, St. Louis, MO (US)
Filed on Dec. 14, 2021, as Appl. No. 17/550,957.
Claims priority of application No. 20210100781 (GR), filed on Nov. 9, 2021.
Prior Publication US 2023/0144377 A1, May 11, 2023
Int. Cl. H02P 3/22 (2006.01); H02P 3/04 (2006.01)
CPC H02P 3/22 (2013.01) [H02P 3/04 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A multi-phase shorting system for braking an electric motor, the electric motor including a plurality of motor windings, the multi-phase shorting system comprising:
a plurality of braking resistors, including at least one braking resistor for each of the plurality of motor windings;
a plurality of first switches, including at least one first switch for each of the plurality of motor windings, with each first switch being a normally-closed switch connected between a respective motor winding and an electrical ground and in electrical series with the at least one braking resistor, and each first switch being configured to selectively close to connect the respective motor winding to the electrical ground through the at least one braking resistor;
a plurality of second switches, including at least one second switch for each of the plurality of motor windings, with each second switch being a normally-closed switch connected between a respective motor winding and the electrical ground, and the plurality of second switches being configured to selectively close to bypass the plurality of braking resistors and directly connect the plurality of motor windings to the electrical ground and thereby brake the electric motor by diverting power from the plurality of motor windings; and
an electronic controller configured to receive feedback regarding a speed of the electric motor, and based at least in part thereon, to generate and send to the plurality of second switches a pulse width modulated signal which selectively opens and closes the plurality of second power switches and thereby respectively connects and disconnects the plurality of braking resistors to achieve a particular equivalent average stator resistance for the speed of the electric motor which results in a power transfer to the plurality of braking resistors and increases a braking torque through a deceleration speed range as the electric motor slows.