CN116698211A - Online detection device for current junction temperature of power electronic device - Google Patents
Online detection device for current junction temperature of power electronic device Download PDFInfo
- Publication number
- CN116698211A CN116698211A CN202310654386.7A CN202310654386A CN116698211A CN 116698211 A CN116698211 A CN 116698211A CN 202310654386 A CN202310654386 A CN 202310654386A CN 116698211 A CN116698211 A CN 116698211A
- Authority
- CN
- China
- Prior art keywords
- electronic device
- power electronic
- current
- voltage
- junction temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 claims abstract description 38
- 230000000630 rising effect Effects 0.000 claims abstract description 35
- 238000005070 sampling Methods 0.000 claims abstract description 31
- 238000000605 extraction Methods 0.000 claims abstract description 24
- 230000000087 stabilizing effect Effects 0.000 claims description 19
- 230000008569 process Effects 0.000 claims description 13
- 238000002955 isolation Methods 0.000 claims description 12
- 239000003990 capacitor Substances 0.000 claims description 10
- 238000001914 filtration Methods 0.000 claims description 8
- 238000012545 processing Methods 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 10
- 238000004891 communication Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 230000015556 catabolic process Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000010998 test method Methods 0.000 description 4
- 238000009529 body temperature measurement Methods 0.000 description 3
- 238000004422 calculation algorithm Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000013507 mapping Methods 0.000 description 2
- 238000012806 monitoring device Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013528 artificial neural network Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000005382 thermal cycling Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/01—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using semiconducting elements having PN junctions
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K13/00—Thermometers specially adapted for specific purposes
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Power Conversion In General (AREA)
Abstract
The invention discloses a current junction temperature online detection device of a power electronic device, which relates to the technical field of device junction temperature detection, and comprises a high-frequency signal extraction component, a detection module and a detection module, wherein the high-frequency signal extraction component is connected in parallel with a collector-emitter of the power electronic device and is used for acquiring the voltage rise time of the turn-off moment of the power electronic device at the current stage; the current sampling circuit is used for acquiring the collector current of the power electronic device at the current stage; the embedded system is used for determining the junction temperature of the power electronic device at the current stage by adopting a heat-sensitive electrical parameter method according to the voltage rising time of the power electronic device at the current stage at the turn-off moment and the collector current of the power electronic device at the current stage. The invention can acquire the voltage rise time and the collector current value and simultaneously acquire the junction temperature in real time.
Description
Technical Field
The invention relates to the technical field of junction temperature detection of devices, in particular to an on-line detection device for the current junction temperature of a power electronic device.
Background
With the development and progress of power semiconductor technology in recent years, the role of a power electronic system in efficient electric energy conversion systems such as direct current transmission, power supply, motor drive, micro-grid, renewable energy generation, energy storage and the like is increasingly important. Therefore, reliability of the power electronic system is also attracting increasing attention. The mechanism of power electronics failure is quite complex and can be simply divided into two categories, chip failure and package failure, depending on the portion of failure. The chip failure causes mainly include electrical overstress, electrostatic discharge damage, aluminum electrode metal reconstruction, thermal runaway, and the like, and can be categorized into two types, namely electric breakdown and thermal breakdown. The nature of electrical breakdown is also due to excessive temperatures leading to thermal breakdown failure. Package failure can be categorized into bond wire failure and solder layer failure. Wherein bond wire failure is primarily caused by higher junction temperatures and solder layer fatigue is mostly caused by long-term thermal cycling. From the foregoing, it can be seen that power electronics failure has a great relationship with temperature. The power loss generated in the working process of the power electronic device can lead to the rise of the junction temperature of the device, the change of the junction temperature can influence the electrical characteristics of the device, and the aging of the device can be accelerated under the working condition of untimely heat dissipation, so that the device is invalid. Of which 55% of device failures are mainly caused by excessive temperatures. It can be seen that the real-time junction temperature of the monitoring device is critical for reliable operation of the monitoring device and the system. The accurate junction temperature detection can provide important basis for intelligent control, performance evaluation, active heat management, health state evaluation, life optimization and the like of the device.
A great deal of research is being carried out by related professionals at home and abroad. The existing junction temperature detection technology mainly comprises a physical contact test method, an optical non-contact test method, a thermal resistance model prediction method and a thermal-sensitive electrical parameter method. Physical contact testing methods are also divided into thermistor and thermocouple testing methods. The welding material layer, copper layer, ceramic layer and the like exist below the switch tube chip and the diode chip of the high-capacity power module, and certain errors exist in the junction temperature measured by the physical contact test method. The optical non-contact test method is to detect the junction temperature by using the infrared thermal imager, but the highest sampling speed of the existing infrared thermal imager is only 2000 frames, and the working frequency of a power electronic device reaches more than 10k, so that the real-time change of the junction temperature cannot be well reflected. The thermal resistance model prediction method is to build a real-time loss model and a transient thermal impedance network model for the device, and obtain the junction temperature of the internal chip and the variation trend thereof through the modes of simulation or off-line table lookup and the like.
According to the fact that the internal physical parameters of the semiconductor physical device have a certain corresponding relation with the temperature, the temperature can be related by using some electric parameters. For example, the carrier concentration increases with increasing junction temperature, and the carrier mobility decreases with increasing temperature. These temperature-dependent electrical parameters are also called thermally sensitive electrical parameters. Firstly, an off-line calibration model is established, namely corresponding values of electrical parameters at different temperatures are measured. When the power electronic device works, the temperature changes, the electrical parameters also change, and the junction temperature of the chip can be reversely estimated by measuring the electrical parameters. The core idea of the heat-sensitive electrical parameter method is to take the device to be measured as a temperature sensing component and map the chip temperature information of the device to be measured on external electrical variables. The junction temperature measurement by using the heat sensitive electrical parameter method comprises the following steps: firstly, performing an off-line calibration procedure, obtaining a mapping rule of candidate heat-sensitive electrical parameters and known junction temperatures in an off-line mode, and taking the corresponding relation between the measured junction temperatures and the electrical parameters as a reference of a subsequent junction temperature measurement procedure; and secondly, a parameter extraction program is developed, when the device to be tested normally operates, the heat-sensitive electric parameters are measured in real time, the temperature of the chip is reversely pushed by utilizing the mapping relation obtained in the pre-correction program, and the process can be determined by a table look-up method after curve fitting or a neural network prediction method and the like. Is a junction temperature detection method with very good industrial application prospect.
During the power electronic device turn-off process, there is a rising process of the collector-emitter, namely, a voltage rising time. The voltage rising time and the junction temperature have good corresponding relation, and are very suitable thermosensitive electrical parameters. However, the voltage rise time is accomplished during transients, is very short, is very temperature sensitive, and requires accuracy in the ns level. Therefore, in order to realize the thermally sensitive electrical parameter method, a high-precision instrument is required for detection. The junction temperature is detected by adopting a high-precision measuring instrument, so that the device is high in cost and inconvenient to use, and cannot be used in actual working conditions.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides an on-line detection device for the current junction temperature of a power electronic device, and simultaneously, the current rising time and the collector current value are acquired, and the junction temperature is acquired in real time. The device provided by the invention can be used for high-precision temperature measurement and feedback control, and has the characteristics of wide application range, low cost and convenience in use.
In order to achieve the above object, the present invention provides the following solutions:
an on-line detection device for the current junction temperature of a power electronic device, comprising:
the high-frequency signal extraction component is connected in parallel with the emitter of the power electronic device and is used for obtaining the voltage rising time of the turn-off moment of the power electronic device at the current stage;
the current sampling circuit is used for acquiring the collector current of the power electronic device at the current stage;
the embedded system is used for determining the junction temperature of the power electronic device at the current stage by adopting a heat-sensitive electrical parameter method according to the voltage rising time of the power electronic device at the current stage at the turn-off moment and the collector current of the power electronic device at the current stage.
Optionally, the voltage rising time is a time when the collector-emitter voltage rises from the on voltage drop to the bus voltage during the turn-off process of the power electronic device.
Optionally, the turn-off characteristic of the power electronic device is that when the forward current flowing through the power electronic device is constant, the voltage rise time of the collector-emitter of the device and the junction temperature inside the device are in a linear relation in a certain temperature range; alternatively, the turn-off characteristic of the power electronic device is that when the junction temperature inside the device is kept constant, the voltage rise time of the collector-emitter of the device and the positive current flowing through the device are in a nonlinear relation and a negative tertiary fitting relation in a certain current range.
Optionally, the high frequency signal extraction component includes a high frequency signal extraction circuit and a time detection circuit;
the high-frequency signal extraction circuit is connected in parallel to the emitter of the power electronic device and is used for filtering the on-state and off-state voltage signals of the power electronic device at the current stage, extracting the high-frequency voltage signals in the voltage rising process at the current stage and converting the high-frequency voltage signals into square wave pulse signals;
the time detection circuit is used for extracting the time width of the square wave pulse signal by taking the falling edge of the square wave pulse signal as an initial signal and the rising edge of the square wave pulse signal as an end signal, converting the time width into a first digital quantity, and then transmitting the first digital quantity to the embedded system.
Optionally, the high-frequency signal extraction circuit comprises an RLC equivalent circuit, a voltage stabilizing circuit and an isolation circuit; the RLC equivalent circuit is connected in parallel with the collector-emitter of the power electronic device; the voltage stabilizing circuit is connected in parallel with the RL two ends of the RLC equivalent circuit; the isolation circuit is connected with the output end of the voltage stabilizing circuit; the output end of the isolation circuit is connected with the input end of the time detection circuit.
Optionally, the RLC equivalent circuit is a topological network formed by a resistor, a capacitor and an inductor; the voltage stabilizing circuit comprises a voltage stabilizing diode or a comparator; the isolation circuit is a logic output photoelectric coupler.
Optionally, the current sampling circuit comprises a current transformer, a filter circuit and a voltage sampling circuit;
the current transformer is used for obtaining the collector current of the power electronic device at the current stage and converting the collector current into a voltage signal; the filter circuit is used for performing filter processing on the voltage signal output by the current transformer; the voltage sampling circuit is used for converting the voltage signal after the filtering processing into a second digital quantity and sending the second digital quantity to the embedded system.
Optionally, the current transformer is sleeved on a collector terminal lead of the power electronic device; the voltage sampling circuit is an ADC sampling chip.
Optionally, the embedded system at least comprises an MCU chip; the MCU chip is used for determining the junction temperature of the power electronic device at the current stage according to the first digital quantity, the second digital quantity and the relation table; the first digital number represents the voltage rising time of the power electronic device at the turn-off moment of the current stage; the second digital quantity represents collector current of the power electronic device in the current stage, and the relation table is a relation table corresponding to the first digital quantity, the second digital quantity and junction temperature.
Optionally, the embedded system further comprises an external SRAM chip and a FLASH chip;
the FLASH chip is used for storing calibration network data of junction temperature; the calibration network data are data obtained by converting the relation table; the external expansion SRAM chip is used for expanding the memory of the MCU chip; the MCU chip is used for determining the junction temperature of the power electronic device at the current stage according to the first digital quantity, the second digital quantity and the calibration network data.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
(1) The use is simple and convenient; the device provided by the invention can realize junction temperature detection of the power electronic device only by connecting the current sampling circuits in parallel at two ends of the power electronic device and sleeving the current sampling circuits on the collector terminal leads of the power electronic device. Compared with a plurality of detection means, the invention can realize non-invasive measurement without dismantling the power electronic device package.
(2) High speed and high precision; by measuring the junction temperature using an electrical parameter, a fast response speed can be achieved. The principle of the thermosensitive electrical parameter method ensures the measurement precision and can stably and accurately acquire the current junction temperature.
(3) The applicability is wide; the principle of the device provided by the invention is based on the characteristics of power electronic devices, and the device meets the use conditions on power devices such as power MOSFETs, IGBTs and the like which are widely used at present. Can be effectively used in many working scenes such as electric automobiles, frequency converters and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is an equivalent circuit diagram of a power electronic device provided by the present invention;
FIG. 2 is a waveform diagram of a power electronic device turn-off process provided by the present invention;
FIG. 3 is a graph of the relationship between heat sensitive electrical parameters and junction temperature of a power electronic device provided by the invention;
FIG. 4 is a schematic diagram of each module in the on-line detection device for the current junction temperature of the power electronic device provided by the invention;
FIG. 5 is a schematic diagram of a circuit structure of an on-line detection device for the current junction temperature of a power electronic device provided by the invention;
FIG. 6 is a waveform diagram of voltage of each element of the high frequency signal extraction circuit according to the present invention;
fig. 7 is an equivalent circuit diagram of the high-frequency signal extraction circuit provided by the invention;
FIG. 8 is an equivalent circuit diagram of the current sampling circuit provided by the invention;
FIG. 9 is an equivalent circuit diagram of the time detection circuit provided by the invention;
fig. 10 is an equivalent circuit diagram of the embedded system provided by the invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
The invention adopts a heat sensitive electrical parameter method, and utilizes the corresponding relation among the voltage rise time parameter, the current parameter and the junction temperature parameter at the turn-off moment of the power electronic device at the current stage to acquire the real-time junction temperature. Firstly, in an embedded system, an MCU chip can put a calibration grid in a FLASH in an external expansion SRAM so as to accelerate the speed of table lookup. When the power electronic device is in a turn-off moment, the device provided by the invention can convert the voltage waveform of the voltage rising time period of the power electronic device into a low-voltage square wave pulse signal through the high-frequency signal extraction component. The square wave pulse signal is then converted into digital quantity by a time detection circuit and transmitted to the embedded system by SPI communication. Meanwhile, the current transformer continuously converts collector current into a low-voltage signal, and the low-voltage signal is filtered by the filter circuit to remove high-frequency burrs and then is transmitted into the ADC sampling chip. The ADC sampling chip can convert the incoming voltage signal into digital quantity in real time and transmit the digital quantity to the embedded system. After receiving the signals, the embedded system obtains the junction temperature corresponding to the voltage rising time under the current through a table look-up method.
Fig. 1 is an equivalent circuit diagram of a power electronic device representing a power IGBT. As shown in FIG. 1, C gc Is the equivalent capacitance between the gate and collector, and is formed by depletion layer capacitance C dep Gate oxide capacitor C ox Composition is prepared. C (C) ge Is the equivalent capacitance between the gate and emitter, also known as miller capacitance. C (C) ce Is the equivalent capacitance at the collector. R is R g The resistor between the driving signal and the gate electrode is used for absorbing the oscillating current of the capacitor inductor, reducing the oscillation of the driving signal and improving the stability.
In the power electronic device according to the embodiment of the present invention, taking a power IGBT as an example, the voltage and current waveforms of the power IGBT are shown in fig. 2. In the off process, following the driving signal V ge Is turned off, the collector-emitter voltage V of the power electronic device ce The conduction voltage drop (near zero) from the on state increases rapidly. There will be an overshoot during the rise and then oscillate down to the bus voltage V d . At the same time, collector current I through the power electronics of the current stage c Will also quickly drop to zero. The time from zero to bus voltage is the voltage rising time t rv . The time is expressed as follows, and the factor influencing the off-delay time is the Miller capacitance C gc Miller voltage V gp On-state saturation pressure drop V ce,sat 。
Miller capacitance C gc By gate oxide capacitance C ox And a dissipation capacitance C dep A series connection of a gate oxide capacitor C ox Depending on the gate oxide conditions, the dissipation capacitor C is independent of temperature dep Can be represented by the following formula. Wherein A is the effective surface area of the dissipation capacitor, ε is the dielectric constant, q is the unit charge amount, N A And N D Representing acceptor doping concentration and donor doping concentration, respectively. As the temperature increases, the acceptor and donor concentrations increase, and therefore the dissipation capacitance increases, the Miller capacitance C gc Increasing.
Shut off Miller platform voltage V gp Mainly subject to collector current I c Threshold voltage V th And transconductance g m The effect is expressed as follows:
V th (T)＝V th (T a )-9×10 3 (T-T a )。
on saturation pressure drop V ce,sat Increases with increasing temperature, but the on-state saturation pressure drop V ce,sat Far smaller than the bus voltage V dc . Thus V ce,sat Can change with temperatureTo be ignored.
To sum up, as shown in FIG. 3, the working junction temperature T versus the voltage rise time T rv Is positively influenced, collector current I c For the voltage rise time t rv Is negatively affected.
As shown in fig. 4, the device for detecting the current junction temperature of the power electronic device according to the present embodiment includes: the high-frequency signal extraction component is connected in parallel with the emitter of the power electronic device and is used for obtaining the voltage rising time of the turn-off moment of the power electronic device at the current stage; the current sampling circuit is used for acquiring the collector current of the power electronic device at the current stage; the embedded system is used for determining the junction temperature of the power electronic device at the current stage by adopting a heat-sensitive electrical parameter method according to the voltage rising time of the power electronic device at the current stage at the turn-off moment and the collector current of the power electronic device at the current stage.
The voltage rising time is the time when the collector-emitter voltage rises from the conduction voltage drop to the bus voltage in the turn-off process of the power electronic device. The turn-off characteristic of the power electronic device is that when the forward current flowing through the power electronic device is constant, the voltage rise time of the collector-emitter of the device and the junction temperature inside the device are in a linear relation in a certain temperature range; alternatively, the turn-off characteristic of the power electronic device is that when the junction temperature inside the device is kept constant, the voltage rise time of the collector-emitter of the device and the positive current flowing through the device are in a nonlinear relation and a negative tertiary fitting relation in a certain current range.
As a preferred embodiment, the high-frequency signal extraction component of the present embodiment includes a high-frequency signal extraction circuit and a time detection circuit.
The high-frequency signal extraction circuit is connected in parallel to the emitter of the power electronic device and is used for filtering the on-state and off-state voltage signals of the power electronic device at the current stage, extracting the high-frequency voltage signals in the voltage rising process at the current stage and converting the high-frequency voltage signals into square wave pulse signals; the square wave pulse signal is synchronous with the voltage rising time, and can map the voltage rising time.
The time detection circuit is used for extracting the time width of the square wave pulse signal by taking the falling edge of the square wave pulse signal as an initial signal and the rising edge of the square wave pulse signal as an end signal, converting the time width into a first digital quantity, and then transmitting the first digital quantity to the embedded system.
Further, as shown in fig. 5, the high-frequency signal extraction circuit is mainly composed of an RLC equivalent circuit, a voltage stabilizing circuit, and an isolation circuit. The RLC equivalent circuit is a topological network formed by a resistor, a capacitor and an inductor. The resistance, capacitance and inductance in the topological network are all equivalent components; the equivalent resistor is formed by connecting a plurality of resistors in series and parallel; the equivalent capacitor is formed by connecting a plurality of capacitors in series and parallel; the equivalent inductance is an inductance formed by connecting a plurality of inductors in series and parallel.
The voltage stabilizing circuit mainly comprises a voltage stabilizing diode or a comparator; preferably, the zener diode recommended model is BZT52B3V3. The voltage stabilizing diode is connected in parallel with two ends of the resistor inductance to stabilize the voltage higher than the threshold value at the threshold value voltage. The isolation circuit mainly comprises an optocoupler, preferably the optocoupler is a logic output optocoupler, and the optocoupler is used as a system for isolating high voltage from voltage at the rear end. When the voltage at two ends of the voltage stabilizing diode is lower than the threshold voltage, the optocoupler outputs a high level, and when the voltage at two ends of the voltage stabilizing diode is higher than the threshold voltage, the optocoupler outputs a low level.
As shown in fig. 7, the RLC equivalent circuit is connected in parallel to the collector emitter of the power electronic device, and the two ends of the RL of the RLC equivalent circuit output pulse signals. The voltage stabilizing circuit is connected in parallel with the two ends of the RL of the RLC equivalent circuit to stabilize the pulse signal at a low voltage threshold. The isolation circuit is connected with the output end of the voltage stabilizing circuit, isolates the pulse signal from the weak current part and reversely outputs the pulse signal.
As shown in fig. 6, waveforms of respective elements in the high-frequency signal extraction circuit include:
voltage V across collector and emitter of power electronic device CE The conduction voltage drop (near zero) from the on state increases rapidly. There will be an overshoot during the rise and then oscillate down to the bus voltage V d 。
Voltage V across RL RL . The high-frequency signal extraction circuit is connected in parallel with two ends of the power electronic device. The equivalent RLC circuit can filter the on-state and off-state voltage signals of the device, and extract the high-frequency voltage signals in the current stage voltage rising process. The voltage at the two ends of the RL can rise rapidly when the collector-emitter voltage rises rapidly, and can fall rapidly when the collector-emitter voltage falls back. The voltage across RL becomes zero when the collector-emitter voltage stabilizes at a constant value, thus only reflecting the voltage rise time and not other signals.
Voltage V across the voltage stabilizing diode ZD At V RL Will remain at the threshold level when rising to the threshold value until V RL Falling below the threshold value will follow V RL . This low level voltage ensures that the input current exceeding the optocoupler does not exceed a maximum value so as to be damaged.
Voltage V at two ends of optocoupler OPT When the input current is lower than the threshold value, a high level is output, and when the input current is higher than the threshold value, a low level is output. Therefore, only when the zener diode is in the state of the threshold level, the optocoupler will generate an action, namely a section of low level signal. The time width of the voltage signal corresponds to the voltage rise time, and thus can be referred to as the voltage rise synchronization time t w 。
The input end of the time detection circuit is connected with the output end of the isolation circuit, and the output end of the time detection circuit is connected with the embedded system; preferably, the time detection circuit is a time measurement chip, recommended model number MS1005. By setting the falling edge output by the optocoupler as a starting signal and the rising edge as an ending signal, the time width of the square wave pulse signal of the high-frequency signal extraction circuit can be detected, the time width is converted into a first digital quantity, and the first digital quantity is transmitted into the embedded system, so that the voltage rising time is obtained.
Time measurement current connection method as shown in fig. 9, START and STOP pins of the time measurement chip MS1005 are a START signal terminal and an end signal terminal, respectively, for measuring time. The falling edge trigger start signal and the rising edge trigger end signal are set through a program. The time measuring chip is connected with the MCU chip of the embedded system through the SPI communication line and sends the measured pulse time width to the MCU chip.
As a preferred implementation manner, the current sampling circuit in this embodiment mainly includes a current transformer, a filter circuit and a voltage sampling circuit; the current transformer converts the current passing through the coil onto a sampling resistor to form a voltage signal based on electromagnetic induction, namely the current transformer is used for acquiring the collector current of a current-stage power electronic device and converting the collector current into the voltage signal; the filter circuit is used for filtering the voltage signal output by the current transformer, namely filtering high-frequency noise of the voltage signal; the voltage sampling circuit is used for converting the voltage signal after the filtering processing into a second digital quantity and sending the second digital quantity to the embedded system.
The voltage sampling circuit is an ADC sampling chip, and the recommended model is ADC101S101. The embedded system can obtain the value of the current collector current through proportional conversion.
Further, as shown in fig. 8, the current sampling circuit is connected to the collector terminal wire of the power electronic device by using an open type current transformer. The output terminal of the current transformer is connected with the filter circuit, and the high-frequency burrs are filtered and then connected with the ADC sampling chip. The ADC sampling chip will acquire the collector current I at the turn-off instant (when the current is not decreasing) c . The ADC sampling chip is connected with the MCU chip of the embedded system through the SPI communication line, and the collector current value is sent to the MCU chip.
As a preferred implementation manner, the embedded system in this embodiment mainly comprises an MCU chip and related peripheral circuits, and has the main functions of obtaining a voltage rise time and a collector current after the power electronic device is turned off, and obtaining a current junction temperature by a heat-sensitive electrical parameter method, specifically:
the MCU chip is used for determining the junction temperature of the power electronic device at the current stage according to the first digital quantity, the second digital quantity and the relation table; the first digital number represents the voltage rising time of the power electronic device at the turn-off moment of the current stage; the second digital quantity represents collector current of the power electronic device in the current stage, and the relation table is a relation table corresponding to the first digital quantity, the second digital quantity and junction temperature.
Further, the embedded system mainly comprises an MCU chip, an external expansion SRAM chip and a FLASH chip. The MCU chip is mainly used for converting the value and the voltage rising time and obtaining the current junction temperature through a table look-up method. The SRAM chip is used for expanding the memory of the MCU chip to realize the calculation of large-capacity data, and the recommended model is XM8A02M16V33A. The FLASH chip is a memory chip and stores calibration network data of junction temperature, and the recommended model is W25Q64. The calibration network data is data obtained after the relation table is converted. The MCU chip is used for determining the junction temperature of the power electronic device at the current stage according to the first digital quantity, the second digital quantity and the calibration network data.
As shown in FIG. 10, the MCU chip is connected with the FLASH chip through the SPI communication line, and is connected with the SRAM chip through the SPI communication line. The FLASH chip is used for storing junction temperature calibrated data grids, and when the device is operated, the data grids are transmitted to the external expansion SRAM for reading and writing so as to speed up.
Before the device operates, a corresponding relation table of junction temperature, collector current and voltage rise time of the power electronic device needs to be established in advance through a calibration method. And converting the corresponding relation table into a calibration grid through an algorithm, and storing the calibration grid into the embedded system.
The high-frequency signal extraction circuit is used for collecting the rising time of the current, the current sampling circuit is used for collecting the current, the environment temperature of the power electronic device is set, and the calibration data can be obtained by using a double-pulse calibration method. And (3) the calibration data are arranged in an embedded system, and a calibration grid within a range is obtained through an interpolation algorithm. The grid can be used for realizing the online detection of junction temperature. The range of the calibration grid is generally: the current is set to 20A-the maximum allowable passing current of the device, 1A is set to one grid, the temperature is set to 30-the maximum allowable temperature of the device, and 1 ℃ is set to one grid.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.
The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.
Claims (10)
1. An on-line detection device for the current junction temperature of a power electronic device, which is characterized by comprising:
the high-frequency signal extraction component is connected in parallel with the emitter of the power electronic device and is used for obtaining the voltage rising time of the turn-off moment of the power electronic device at the current stage;
the current sampling circuit is used for acquiring the collector current of the power electronic device at the current stage;
the embedded system is used for determining the junction temperature of the power electronic device at the current stage by adopting a heat-sensitive electrical parameter method according to the voltage rising time of the power electronic device at the current stage at the turn-off moment and the collector current of the power electronic device at the current stage.
2. The device for on-line detection of the current junction temperature of a power electronic device according to claim 1, wherein the voltage rising time is a time when the collector-emitter voltage rises from an on-voltage drop to a bus voltage during the turn-off process of the power electronic device.
3. The apparatus according to claim 1 or 2, wherein the turn-off characteristic of the power electronic device is that when the forward current flowing through the power electronic device is constant, the voltage rise time of the collector-emitter of the device is in a linear relationship with the junction temperature inside the device in a certain temperature range; alternatively, the turn-off characteristic of the power electronic device is that when the junction temperature inside the device is kept constant, the voltage rise time of the collector-emitter of the device and the positive current flowing through the device are in a nonlinear relation and a negative tertiary fitting relation in a certain current range.
4. The device for on-line detection of the current junction temperature of a power electronic device according to claim 1, wherein the high-frequency signal extraction component comprises a high-frequency signal extraction circuit and a time detection circuit;
the high-frequency signal extraction circuit is connected in parallel to the emitter of the power electronic device and is used for filtering the on-state and off-state voltage signals of the power electronic device at the current stage, extracting the high-frequency voltage signals in the voltage rising process at the current stage and converting the high-frequency voltage signals into square wave pulse signals;
the time detection circuit is used for extracting the time width of the square wave pulse signal by taking the falling edge of the square wave pulse signal as an initial signal and the rising edge of the square wave pulse signal as an end signal, converting the time width into a first digital quantity, and then transmitting the first digital quantity to the embedded system.
5. The device for on-line detection of the current junction temperature of a power electronic device according to claim 4, wherein the high frequency signal extraction circuit comprises an RLC equivalent circuit, a voltage stabilizing circuit and an isolation circuit; the RLC equivalent circuit is connected in parallel with the collector-emitter of the power electronic device; the voltage stabilizing circuit is connected in parallel with the RL two ends of the RLC equivalent circuit; the isolation circuit is connected with the output end of the voltage stabilizing circuit; the output end of the isolation circuit is connected with the input end of the time detection circuit.
6. The device for on-line detection of the current junction temperature of a power electronic device according to claim 5, wherein the RLC equivalent circuit is a topology network consisting of a resistor, a capacitor and an inductor; the voltage stabilizing circuit comprises a voltage stabilizing diode or a comparator; the isolation circuit is a logic output photoelectric coupler.
7. The device for on-line detection of the present junction temperature of a power electronic device according to claim 1, wherein the current sampling circuit comprises a current transformer, a filter circuit and a voltage sampling circuit;
the current transformer is used for obtaining the collector current of the power electronic device at the current stage and converting the collector current into a voltage signal; the filter circuit is used for performing filter processing on the voltage signal output by the current transformer; the voltage sampling circuit is used for converting the voltage signal after the filtering processing into a second digital quantity and sending the second digital quantity to the embedded system.
8. The device for on-line detection of the current junction temperature of a power electronic device according to claim 7, wherein the current transformer is sleeved on a collector terminal wire of the power electronic device; the voltage sampling circuit is an ADC sampling chip.
9. The device for on-line detection of the current junction temperature of a power electronic device according to claim 1, wherein the embedded system comprises at least an MCU chip; the MCU chip is used for determining the junction temperature of the power electronic device at the current stage according to the first digital quantity, the second digital quantity and the relation table; the first digital number represents the voltage rising time of the power electronic device at the turn-off moment of the current stage; the second digital quantity represents collector current of the power electronic device in the current stage, and the relation table is a relation table corresponding to the first digital quantity, the second digital quantity and junction temperature.
10. The device for on-line detection of the current junction temperature of a power electronic device according to claim 9, wherein the embedded system further comprises an external SRAM chip and a FLASH chip;
the FLASH chip is used for storing calibration network data of junction temperature; the calibration network data are data obtained by converting the relation table; the external expansion SRAM chip is used for expanding the memory of the MCU chip; the MCU chip is used for determining the junction temperature of the power electronic device at the current stage according to the first digital quantity, the second digital quantity and the calibration network data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310654386.7A CN116698211A (en) | 2023-06-05 | 2023-06-05 | Online detection device for current junction temperature of power electronic device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310654386.7A CN116698211A (en) | 2023-06-05 | 2023-06-05 | Online detection device for current junction temperature of power electronic device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116698211A true CN116698211A (en) | 2023-09-05 |
Family
ID=87833294
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310654386.7A Pending CN116698211A (en) | 2023-06-05 | 2023-06-05 | Online detection device for current junction temperature of power electronic device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116698211A (en) |
-
2023
- 2023-06-05 CN CN202310654386.7A patent/CN116698211A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103207362B (en) | For the system and method for the mode of operation of Real-Time Monitoring IGBT device | |
| CN104090224A (en) | On-line detection system and method for work junction temperature of power diode module | |
| CN110658435B (en) | IGBT junction temperature monitoring device and method | |
| CN105572558A (en) | Power diode module working junction temperature on-line detection system and detection method | |
| CN105910730A (en) | High power IGBT module operation junction temperature on-line detection system and detection method thereof | |
| CN104155587A (en) | System and method for on-line detection of operating junction temperature of IGBT module | |
| CN104702253A (en) | Method and apparatus for short circuit protection of power semiconductor switch | |
| CN113466647B (en) | Conduction voltage drop on-line monitoring circuit for junction temperature monitoring | |
| US10955297B2 (en) | Systems and methods for monitoring junction temperature of a semiconductor switch | |
| CN116754915A (en) | Working junction temperature monitoring system and method of semiconductor switching device | |
| CN111142002B (en) | Parallel chip temperature uniformity detection method and device | |
| CN116698211A (en) | Online detection device for current junction temperature of power electronic device | |
| CN113376497A (en) | Online monitoring method suitable for junction and aging information of power semiconductor device | |
| CN110632489B (en) | Leakage current-based IGBT junction temperature monitoring circuit and method | |
| CN117074894A (en) | Transient working condition thermoelectric characteristic characterization system and method based on thermal reflection imaging technology | |
| CN108107333B (en) | IGBT thermosensitive inductive parameter extraction device | |
| Yang et al. | Online monitoring method of PIN diode temperature based on maximum recovery current | |
| CN115951192A (en) | Junction temperature detection device, method and medium of power device | |
| CN115561609A (en) | Temperature sampling method, device and system applied to SiC power device | |
| Zhang et al. | A junction temperature and package aging decoupling evaluating method for SiC MOSFETs based on the turn-on drain-source current overshoot | |
| CN112067967A (en) | Device switching loss-based power electronic online reliability state detection device and method | |
| Lu et al. | Online Junction Temperature Extraction for Cascode GaN Devices Based on Turn-on Delay | |
| CN216718587U (en) | On-line reliability state monitoring device for inverter power device | |
| CN116015261B (en) | Threshold voltage protection circuit and method based on SiC power device | |
| CN218585325U (en) | Circuit model for simulating breakdown voltage of power device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |