scholarly journals A Study on Real Time IGBT Junction Temperature Estimation Using the NTC and Calculation of Power Losses in the Automotive Inverter System

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2454
Author(s):  
Heesun Lim ◽  
Jaeyeob Hwang ◽  
Soonho Kwon ◽  
Hyunjun Baek ◽  
Juneik Uhm ◽  
...  
Keyword(s):  
Real Time ◽  
Measurement Data ◽  
Time Estimation ◽  
Estimation Algorithm ◽  
Junction Temperature ◽  
Measured Temperature ◽  
Thermal Impedance ◽  
Power Losses ◽  
Temperature Estimation ◽  
Impedance Model

This paper proposes a junction temperature estimation algorithm for the insulated gate bipolar transistor (IGBT) based on a power loss calculation and a thermal impedance model for inverter systems. The Simulink model was designed to calculate the power losses of power semiconductor devices and to estimate the junction temperature with a simplified thermal impedance model. This model can estimate the junction temperature up to the transient state, including the steady state. The parameters used to calculate the power losses, the thermal resistance, and the thermal capacitance were optimized for a given inverter to be tested for improving the accuracy. The simulation results and experimental measurement data were compared to verify the proposed junction temperature estimation algorithm. Finally, the algorithm was installed on the inverter controller, and the performance was verified by comparing the real time estimation result with the measured temperature.

scholarly journals Least Squares Method for Identification of IGBT Thermal Impedance Networks Using Direct Temperature Measurements

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3749
Author(s):  
Humphrey Mokom Njawah Achiri ◽  
Vaclav Smidl ◽  
Zdenek Peroutka ◽  
Lubos Streit
Keyword(s):  
Least Squares ◽  
Least Squares Method ◽  
Voltage Drop ◽  
State Of The Art ◽  
Junction Temperature ◽  
Measured Temperature ◽  
Thermal Impedance ◽  
Heating And Cooling ◽  
Igbt Module ◽  
Art Methods

State-of-the-art methods for determining thermal impedance networks for IGBT (Insulated Gate Bipolar Transistor) modules usually involves the establishment of the relationship between the measured transistor or diode voltage and temperature under homogenous temperature distribution across the IGBT module. The junction temperature is recomputed from the established voltage–temperature relationship and used in determining the thermal impedance network. This method requires accurate measurement of voltage drop across the transistors and diodes under specific designed heating and cooling profiles. Validation of the junction temperature is usually done using infrared camera or sensors placed close to the transistors or diodes (in some cases and open IGBT module) so that the measured temperature is as close to the junction as possible. In this paper, we propose an alternative method for determining the IGBT thermal impedance network using the principles of least squares. This method uses measured temperatures for defined heating and cooling cycles under different cooling conditions to determine the thermal impedance network. The results from the proposed method are compared with those obtained using state-of-the-art methods.

scholarly journals Real-Time Estimation of Glenohumeral Joint Rotation Center With Cable-Driven Arm Exoskeleton (CAREX)—A Cable-Based Arm Exoskeleton

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Ying Mao ◽  
Xin Jin ◽  
Sunil K. Agrawal
Keyword(s):  
Real Time ◽  
Glenohumeral Joint ◽  
Kinematic Model ◽  
Estimation Method ◽  
Time Estimation ◽  
Estimation Algorithm ◽  
Joint Rotation ◽  
Rotation Center ◽  
Arm Rehabilitation ◽  
Novel Approach

In the past few years, the authors have proposed several prototypes of a Cable-driven upper ARm EXoskeleton (CAREX) for arm rehabilitation. One of the assumptions of CAREX was that the glenohumeral joint rotation center (GH-c) remains stationary in the inertial frame during motion, which leads to inaccuracy in the kinematic model and may hamper training performance. In this paper, we propose a novel approach to estimate GH-c using measurements of shoulder joint angles and cable lengths. This helps in locating the GH-c center appropriately within the kinematic model. As a result, more accurate kinematic model can be used to improve the training of human users. An estimation algorithm is presented to compute the GH-c in real-time. The algorithm was implemented on the latest prototype of CAREX. Simulations and preliminary experimental results are presented to validate the proposed GH-c estimation method.

Real-Time Estimation of Glenohumeral Joint Rotation Center With CAREX: A Cable-Based Arm Exoskeleton

2012 ◽  
Author(s):  
Ying Mao ◽  
Xin Jin ◽  
Sunil K. Agrawal
Keyword(s):  
Real Time ◽  
Healthy Subjects ◽  
Degrees Of Freedom ◽  
Glenohumeral Joint ◽  
Kinematic Model ◽  
Time Estimation ◽  
Estimation Algorithm ◽  
Experimental Results ◽  
Joint Rotation ◽  
Rotation Center

In the past few years, the authors have proposed several prototypes of a Cable-driven upper ARm EXoskeleton (CAREX) for arm rehabilitation. The key advantages of CAREX over conventional exoskeletons are: (i) It is nearly an order of magnitude lighter. (ii) It does not have conventional links and joints, hence does not require joint axes alignment and segment lengths adjustment. (iii) It does not limit the natural degrees-of-freedom of the upper limb. (iv) The structure of the exoskeleton is novel as the cables are routed from the proximal to the distal segments of the arm. Preliminary experimental results with CAREX on a robotic arm and on healthy subjects have demonstrated the effectiveness of the exoskeleton within “assist-as-needed” training paradigm. In this paper, we propose a novel approach to estimate the glenohumeral joint rotation center (GH-c) using measurements of shoulder joint angles and cable lengths. This helps in locating the glenohumeral joint rotation center appropriately within the kinematic model. As a result, more accurate kinematic model can be used to improve the training of human users. An estimation algorithm is presented to compute the GH-c in real-time. The algorithm was implemented on the latest prototype of CAREX which controls four degrees-of-freedom of the shoulder and elbow. Preliminary experiments were performed on two healthy subjects under two different scenarios: (i) GH-c was assumed to be a fixed point and (ii) GH-c was estimated using the proposed algorithm. Experimental results are presented to compare the two scenarios.

Modelling, Identification and Control of Thermal Deformation of Machine Tool Structures, Part 3: Real-Time Estimation of Heat Sources

1999 ◽  
Vol 121 (3) ◽  
pp. 501-508 ◽  
Author(s):  
S. Fraser ◽  
M. H. Attia ◽  
M. O. M. Osman
Keyword(s):  
Real Time ◽  
Time Domain ◽  
Measurement Errors ◽  
Thermal Deformation ◽  
Heat Conduction Problem ◽  
Time Estimation ◽  
Inverse Heat Conduction Problem ◽  
Dimensional Structure ◽  
Measured Temperature ◽  
Real Time Estimation

Compensation of thermal deformation of machine tools requires real-time estimation of the heat input to the structure in order to fully describe its thermoelastic response. Available solutions of the inverse heat conduction problem IHCP are not suitable for real-time feedback control applications, since they are too slow and/or rely on future data to stabilize the solution. A new real-time IHCP solver is derived in the form of a convolution integral of the inverse thermal transfer function G−1(s) and the measured temperature difference at two points near the heat source. An expression for G−1(s) is derived for multi-dimensional structural components. To transform G−1(s) to the time domain, a special consideration is given to the treatment of its complex singularity functions. Analytical approach was followed to identify these functions and to determine their time-domain representation. Computer-simulation test cases were conducted using a finite element model of a three-dimensional structure. The random temperature measurement errors, which can lead to non-uniqueness and instability problems, have also been simulated. The test results showed that the computation time can significantly be improved to achieve a control cycle of less than one second, without compromising the accuracy and stability requirements.

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