Online Junction Temperature Estimation Research Articles

A Gate Degradation Independent Online Junction Temperature Estimation Method for SiC MOSFETs Based on Residual Resistance

A Gate Degradation Independent Online Junction Temperature Estimation Method for SiC MOSFETs Based on Residual Resistance

An Online Junction Temperature Estimation Method of IGBTs based on the improved on-state voltage measuring circuit

An Online Junction Temperature Estimation Method of IGBTs based on the improved on-state voltage measuring circuit

Coordinated Online Junction Temperature Estimation of MOSFETs and Antiparallel Diodes in Three-Phase SiC Inverters

Coordinated Online Junction Temperature Estimation of MOSFETs and Antiparallel Diodes in Three-Phase SiC Inverters

An On-Line Calibration Method for TSEP-Based Junction Temperature Estimation

Temperature sensitive electrical parameters (TSEP) provide an indirect and noninvasive method for on-line junction temperature estimation of power semiconductor devices. It is known that the fundamental of TSEP-based methods is to calibrate the relationship between TSEP and junction temperature in advance. However, the calibration methods in the literature need to open the module, require pretesting, or record the operating data of a converter in the entire power rating range, which are inconvenient in field applications. This article proposes an on-line and noninvasive calibration method by measuring the data at three operating states that are already existed in the regular converter operation. It is achieved by measuring the accessible heatsink/case temperature and TSEP during converter regular operation. The concept, implementation, and error analysis of the proposed method are presented in this article. Experimental verification is given to prove the effectiveness, accuracy, and convenience of the proposed method.

Accurate Online Junction Temperature Estimation of IGBT Using Inflection Point Based Updated I–V Characteristics

The junction temperature (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> ) estimation of the insulated gate bipolar transistor (IGBT) is important for reliable operation of the power converters in various applications. For T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> estimation, on-state collector-emitter voltage (v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> ) at higher collector currents (i <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> ) is widely used temperature sensitive electrical parameter (TSEP). For real-time T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> estimation, this TSEP is calibrated using the I-V characteristics of the new IGBT. Due to bond-wire degradation, the original I-V characteristics of IGBT changes resulting in inaccurate T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> estimation. In this article, a technique is proposed to update the I-V characteristics of the degraded IGBT, without affecting the normal operation of the power converter. It is achieved by estimating the increment in bond-wire resistance (\triangle R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">con</sub> ) by using real-time samples of v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> and inductor current. The mathematical analysis is also presented to find an error in estimated \triangle R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">con</sub> . The major contributions of this article are as follows: a) it enables the accurate T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> estimation of the IGBT throughout its lifetime; and b) it also provides the parameter \triangle R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">con</sub> , which could be utilized in condition monitoring of the IGBT. Further no additional circuitry is required. The proposed technique is validated on experimental setup, which is developed in the laboratory. The error in T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> estimation is observed within $1$ °C the degraded IGBT, which shows the effectiveness of the proposed scheme.

Online junction temperature estimation using integrated NTC thermistor in IGBT modules for PMSM drives

Drastic junction temperature fluctuations of power modules in electric vehicles (EV) have a significant impact on system reliability. This paper aims to estimate the junction temperature of IGBT modules with direct coolant for permanent magnet synchronous motors (PMSM) under complex boundary conditions. The advantage of the thermal network proposed in this article is that it does not require any temperature sensor except the built-in negative thermal coefficient (NTC) thermistor. Finally, the good accuracy of this model is demonstrated by a series of experiments considering complicated boundary conditions and multiple working conditions.

Online Estimation of the Junction Temperature Based on the Gate Pre-Threshold Voltage in High-Power IGBT Modules

A model for the online estimation of junction temperature based on the gate pre-threshold voltage in high-power insulated-gate bipolar transistors (IGBTs) was proposed. First, the turn-on behavior and temperature dependence of the gate-emitter voltage during the turn-on delay period were studied. It was revealed that the turn-on waveform of the gate-emitter voltage exhibits a point of inflection after which the voltage between the gate and emitter increases significantly; at this point, the relationship between the voltage and the temperature changes from a positive correlation to a negative correlation. Meanwhile, analyses on the basis of semiconductor physics revealed that the negative correlation between gate-emitter voltage and temperature is caused by the temperature dependence of the flatband voltage. Finally, a model for estimating the junction temperature was established based on a combination of the turn-on delay time and the gate prethreshold voltage which is negatively correlated with the temperature, to eliminate the effect of the bus voltage.

A Fast Electro-Thermal Model of Traction Inverters for Electrified Vehicles

In this paper, a fast electro-thermal model of traction inverters for electrified vehicles is proposed. First, a thermal model considering the thermal coupling is presented and experimentally verified. The impact of the thermal spreading effect, heat convection, and temperature-dependent material thermal properties on the accuracy of the linear assumption is investigated by ANSYS-Fluent simulation. In order to reduce the influence of the temperature-dependent thermal conductivity on the accuracy of the thermal model, the average temperature is applied to determine the thermal conductivity of the power module package. Second, an accurate temperature-dependent switching power loss model is represented as the lookup table through experimental measurements. In order to simplify the lookup table, the switching power loss is considered proportional to the dc-link voltage and, therefore, the inputs of the lookup table are current and temperature. Finally, a scheme to speed up the online junction temperature estimation is proposed by considering both the thermal network properties and the required accuracy. With the proposed calculation rate determination method, the total computational time for the junction temperature estimation is reduced significantly.

An Online Frequency-Domain Junction Temperature Estimation Method for IGBT Modules

This letter proposes a new frequency-domain thermal model for online junction temperature estimation of insulated-gate bipolar transistor (IGBT) modules. The proposed model characterizes the thermal behavior of an IGBT module by a linear time-invariant (LTI) system, whose frequency response is obtained by applying the fast Fourier transform (FFT) to the time derivative of the transient thermal impedance from junction to a reference position of the IGBT module. The junction temperature of the IGBT is then estimated using the frequency responses of the LTI system and the heat sources of the IGBT module. Simulation results show that the proposed method is computationally efficient for an accurate online junction temperature estimation of IGBT modules in both steady-state and transient loading conditions.

Active thermal control of power electronic modules

Active thermal control techniques make it feasible to regulate the steady state and transient thermal-mechanical stress in power electronic modules for applications such as motor drives. Online junction temperature estimation and manipulation of the switching frequency and current limit to regulate the losses are used to prevent overtemperature and power cycling failures in insulated gate bipolar transistor (IGBT) power modules. The techniques developed in this work are used to actively control the junction temperature of the power module. This control strategy improves power module reliability and increases utilization of the silicon thermal capacity by providing sustained operation at maximum attainable performance limits.