US 12,222,738 B2 · Method and system for controlling electric drive system according to predicted temperature of DC-link capacitor to prevent overheating

Abstract

An electric drive system includes a power electronics module (PEM) having a DC-link capacitor and an inverter. A controller reduces power output of the inverter while a sensed temperature of an inverter power switch, a sensed current of the PEM, such as a sensed ripple current of the DC-link capacitor, and parameter values of the DC-link capacitor are indicative of a predicted temperature of the capacitor being greater than a threshold to maintain capacitor temperature lower than the threshold. The parameter values are obtainable from a thermal model of the DC-link capacitor. The thermal model may be derived from testing a test version of the PEM under different drive cycles in which for each drive cycle a set of information is recorded including a sensed temperature of the inverter power switch test version, a current of the PEM test version, and a sensed temperature of the DC-link capacitor test version.

Claims16

Dependent claims

An electric drive system, comprising:

a power electronics module having a DC-link capacitor and an inverter;
and
a controller configured to reduce power output of the inverter while a temperature of the DC-link capacitor, predicted from a thermal equation given a sensed temperature of a power switch of the inverter, a sensed current of the power electronics module, and values of parameters of the thermal equation obtained from a thermal model of the DC-link capacitor, is greater than a threshold to thereby maintain DC-link capacitor temperature lower than the threshold.

An electric vehicle comprising:

an electric drive system including a traction battery, a power electronics module having a DC-link capacitor and an inverter, and a motor, the inverter configured to convert an input electrical power from the traction battery via the DC-link capacitor into an output electrical power and provide the output electrical power to the motor for propelling the electric vehicle;
a controller configured to predict a temperature of the DC-link capacitor using a sensed temperature of a power switch of the inverter, a sensed current of the power electronics module, and parameter values obtained from a thermal model of the DC-link capacitor, wherein the thermal model of the DC-link capacitor is derived from a test version of the power electronics module being tested under a plurality of drive cycles in which for each drive cycle a set of information is recorded including a sensed temperature of the power switch of the inverter of the test version of the power electronics module, a sensed current of the test version of the power electronics module, and a sensed temperature of the DC-link capacitor of the test version of the power electronics module;
and
the controller is further configured to de-rate the electric drive system while the predicted temperature of the DC-link capacitor is greater than a temperature threshold to prevent overheating.

1 more element

A method for an electric drive system including a power electronics module having an inverter and a DC-link capacitor, the method comprising:

sensing a temperature of a power switch of the inverter;
sensing a current of the power electronics module;
obtaining parameter values of the DC-link capacitor from a thermal model of the DC-link capacitor, wherein the thermal model of the DC-link capacitor is derived from a test version of the power electronics module being tested under a plurality of drive cycles in which for each drive cycle a set of information is recorded including a sensed temperature of the power switch of the inverter of the test version of the power electronics module, a sensed current of the test version of the power electronics module, and a sensed temperature of the DC-link capacitor of the test version of the power electronics module;
and
reducing power output of the inverter while the sensed temperature of the power switch, the sensed current of the power electronics module, and the parameter values of the DC-link capacitor are indicative of a predicted temperature of the DC-link capacitor being greater than a threshold to maintain DC-link capacitor temperature lower than the threshold.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

17/590,237Filed 1 Feb 2022

Published

US 2023/0244257 A13 Aug 2023

Granted

11 Feb 2025

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

B60L 3/003
Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train: relating to inverters
G05D 23/2033
With sensing elements having variation of electric or magnetic properties with change of temperature: details of the sensing element
B60L 3/12
Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy…:…
B60L 15/007
Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles: physical arrangements or structures of…

Method and system for controlling electric drive system according to predicted temperature of DC-link capacitor to prevent overheating

Life of this patent

Method and system for controlling electric drive system according to predicted temperature of DC-link capacitor to prevent overheating

Life of this patent

Abstract

Claims16