US 11,993,479 B2
Method for reducing thermal stress of a power semiconductor switch, an electrical converter unit and an elevator
Mikko Paakkinen, Helsinki (FI); Lauri Stolt, Helsinki (FI); and Tuukka Kauppinen, Helsinki (FI)
Assigned to KONE Corporation, Helsinki (FI)
Filed by KONE Corporation, Helsinki (FI)
Filed on Feb. 15, 2022, as Appl. No. 17/672,150.
Application 17/672,150 is a continuation of application No. PCT/EP2019/074213, filed on Sep. 11, 2019.
Prior Publication US 2022/0169479 A1, Jun. 2, 2022
Int. Cl. H02K 11/00 (2016.01); B66B 1/28 (2006.01); B66B 1/30 (2006.01); H02H 3/04 (2006.01); H02H 7/08 (2006.01); H02P 6/08 (2016.01)
CPC B66B 1/308 (2013.01) [B66B 1/285 (2013.01); H02P 6/085 (2013.01)] 28 Claims
OG exemplary drawing
 
1. A method for reducing thermal stress of a power semiconductor switch, such as an IGBT, of an electrical converter unit, the electrical converter unit comprising at least a gate control circuit wherein the electrical converter unit controls an electrical motor, wherein the method comprises:
determining load,
estimating required motor current based on the determined load and/or a predetermined speed profile,
wherein the electrical converter unit has at least a first operating state and a second operating state,
wherein the second operating state is used if predetermined criteria is fulfilled, the predetermined criteria relating to at least one of the following: estimated required current, measured motor speed, temperature of the power semiconductor switch and/or electrical converter unit, temperature model of the power semiconductor switch and/or electrical converter unit,
wherein in the second operating state a lower switching frequency of the power semiconductor switch is used than in the first operating state, and
in the second operating state a higher switching speed of the power semiconductor switch is used than in the first operating state.