Online real-time junction temperature detection method for semiconductor power device

Abstract

The invention belongs to the technical field of power electronics and electricians, and provides an online real-time junction temperature detection method for a semiconductor power device, which is used for detecting junction temperature data of the power device under steady-state and transient-state conditions. The method comprises the following steps: step 1, detecting a main loop current value flowing through a semiconductor power device in a solid-state circuit breaker / solid-state power controller, an input voltage in a power distribution loop, an output voltage in the power distribution loop, a bus voltage and a device surface temperature in real time; 2, in the closing process of the solid-state circuit breaker, discretizing the collected input voltage in the power distribution loop, the output voltage in the power distribution loop and the main loop current value, inputting the discretized input voltage, output voltage and main loop current value to a processor to calculate discretized real-time power consumption, and inputting the real-time power consumption and the device surface temperature to a thermal network model; and finally calculating the junction temperature of the semiconductor device in the closing process. And step 3, in the breaking process of the solid-state circuit breaker, discretizing the current value of the main loop and the bus voltage, inputting the discretized current value and bus voltage into a processor to calculate discretized real-time power consumption, inputting the real-time power consumption and the surface temperature of the device into the thermal network model, and finally calculating the junction temperature of the semiconductor device in the breaking process. The method is suitable for online real-time junction temperature detection of the power device.

Description

Technical Field

[0001] The invention belongs to the field of power electronics technology and electrical engineering technology, and relates to an online real-time junction temperature detection method for a semiconductor power device. Background Art

[0002] With the gradual application of power electronic devices and the application of DC power supply system in distribution network, traditional mechanical circuit breakers are difficult to meet the application requirements in DC environment in terms of mechanical life and reliability. Solid-state circuit breakers use power electronic devices, such as semiconductor power MOSFET, IGBT, etc. for power transmission in the main circuit, which effectively improves the safe distribution and control protection of distribution lines. At the same time, semiconductor power devices also have disadvantages. The questionnaire survey of damaged power electronic components in the industry shows that among all kinds of components, power components have the highest probability of damage, accounting for 34%. The factors of power device failure are divided into two categories, one is package failure and the other is chip failure. The main reason for package failure is that the junction temperature is too high, causing the bonding wire to fall off, or long-term thermal cycle causes solder layer fatigue. Chip failure is mainly divided into thermal breakdown and electrical breakdown, and the essence of electrical breakdown is ultimately caused by thermal breakdown due to excessive temperature. These failure factors are all related to factors such as maximum junction temperature, junction temperature fluctuation and average junction temperature. Therefore, it is necessary to predict the junction temperature of power tubes in real time. Summary of the invention

[0003] The purpose of the present invention is to provide an online real-time junction temperature detection method for a semiconductor power device, which detects the junction temperature data of the power device under steady-state and transient conditions.

[0004] The technical solution of the present invention:

[0005] A method for detecting the junction temperature of a semiconductor power device in real time online, comprising:

[0006] Step 1: Real-time detection of the main circuit current value flowing through the semiconductor power device in the solid-state circuit breaker / solid-state power controller, as well as the input voltage in the distribution circuit, the output voltage in the distribution circuit, the bus voltage and the device surface temperature;

[0007] Step 2: During the closing process of the solid-state circuit breaker, the collected input voltage in the distribution circuit, the output voltage in the distribution circuit, and the main circuit current value are discretized and input into the processor to calculate the discretized real-time power consumption, and then the real-time power consumption and the device surface temperature are input into the thermal network model, and finally the junction temperature of the semiconductor device during the closing process is calculated;

[0008] Step 3: During the disconnection process of the solid-state circuit breaker, the main circuit current value and bus voltage are discretized and input into the processor to calculate the discretized real-time power consumption. The real-time power consumption and device surface temperature are then input into the thermal network model to finally calculate the junction temperature of the semiconductor device during the disconnection process.

[0009] Step 1 includes:

[0010] Step 11, when the solid-state circuit breaker is in a steady state, after the current reaches the minimum current threshold value Imin, at time t0, the processor chip inside the solid-state circuit breaker starts the junction temperature detection function, and the solid-state circuit breaker first collects the shell temperature TC of the semiconductor power device at the current time t0;

[0011] Step 12: At the same time at time t0, the acquisition circuit inside the solid-state circuit breaker product will start to collect three analog values ​​of the input voltage value Vin, the output voltage Vout and the current value IDS of the circuit in the power distribution circuit, and transmit the analog values ​​to the processor interface of the solid-state circuit breaker through the high-speed bus.

[0012] Step 2 includes:

[0013] Step 21, after the processor receives the analog value transmitted by the acquisition circuit, it will calculate the difference between the collected input voltage Vin and the output voltage Vout, and measure the numerical difference between the two. The voltage difference between the two represents the voltage between the drain and source of the semiconductor power device in the on state, that is, VDS;

[0014] Step 22: At the same time, at time t0, the processor module multiplies the voltage value VDS across the drain and source of the power device measured and the current value IDS in the loop collected, and the product is the instantaneous power value PDS0 inside the power device at time t0;

[0015] Step 23, then, the solid-state circuit breaker processor will input the instantaneous power value PDS0 into the thermal network model, which is a digital model between the shell temperature detection point of the semiconductor power device and the internal junction temperature point of the semiconductor power device, and is composed of multi-order thermal resistances Ri and Ci. The instantaneous power value is input into the thermal network model, and after calculation, the temperature rise value △t0 of the semiconductor power device at time t0 is finally calculated;

[0016] Step 24: The internal processing unit of the solid-state circuit breaker adds the temperature rise value Δt0 calculated at time t0 to the shell temperature TC0 collected at time t0, and finally obtains the junction temperature Tj0 of the semiconductor power device at time t0.

[0017] Step 3 includes:

[0018] Step 31, after the solid-state circuit breaker receives the shutdown command, the solid-state circuit breaker completes the breaking operation after us. At the time ta when the breaking operation starts, the solid-state circuit breaker first collects the shell temperature TCa of the power device at time ta;

[0019] Step 32, at the same time, at time ta, the acquisition circuit inside the solid-state circuit breaker will always collect the two analog values ​​of the bus voltage VBus and the current value IDS of the main circuit at the current moment, and regard the collected bus voltage as the voltage between the drain and source of the semiconductor power device. This is because due to the existence of the inductance in the loop, di / dt will have a large value, V=L*di / dt, and the reverse voltage impact caused will be very large. It is difficult to characterize the VDS value of the power device by the difference between the input voltage and the output voltage. Therefore, in order to improve the engineering application capability, the bus voltage / clamping voltage is used to characterize the VDS value of the power device;

[0020] Step 33, the internal processor of the solid-state circuit breaker multiplies the collected bus voltage value VBus and the current value IDS of the main circuit to obtain the instantaneous power value PDS at time ta;

[0021] Step 34, inputting the instantaneous power value PDS at time ta into the thermal network model inside the solid-state circuit breaker processor, and finally calculating the temperature rise value △ta of the semiconductor power device at time ta through the thermal network model;

[0022] Step 35: inside the solid-state circuit breaker processor, the temperature rise value Δta at time ta is added to the accumulated value of the junction temperature at the last moment under the conduction condition and the shell temperature TCa at time ta, and finally the junction temperature Tja of the semiconductor power device at time ta is obtained.

[0023] When performing junction temperature detection, the junction temperature prediction is based on the Foster thermal network model.

[0024] The thermal network model inside the processor refers to the thermal network model between the shell temperature detection point and the PN junction of the power device.

[0025] The detected junction temperature data is compared with the maximum allowable junction temperature value of the power device. When the detected data is greater than or equal to the maximum allowable junction temperature of the device, an alarm signal is issued or a disconnection operation is performed.

[0026] Also includes:

[0027] After the solid-state circuit breaker receives the on / off command, the solid-state circuit breaker performs the closing operation. After a few us, the closing operation is completed. The semiconductor power device always carries the rated current value in the main circuit. When the solid-state circuit breaker is in a steady-state condition, the semiconductor power device is always in a closed state.

[0028] Beneficial effects of the present invention: The present invention can realize the junction temperature detection of power devices in power supply products, ensuring that the power devices will not fail due to excessively high junction temperature during actual operation, thereby ensuring the reliability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of current variation of the solid-state circuit breaker of the present invention in operation / overload / short circuit mode.

[0030] Figure 2 Schematic diagram of the thermal network model of the power device of the present invention.

[0031] Figure 3 The figure is a schematic diagram of the junction temperature detection process of the solid-state circuit breaker of the present invention in different working modes. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] A method for detecting the junction temperature of a semiconductor power device in real time online, comprising:

[0034] Step 1: Real-time detection of the main circuit current value flowing through the semiconductor power device in the solid-state circuit breaker / solid-state power controller, as well as the input voltage in the distribution circuit, the output voltage in the distribution circuit, the bus voltage and the device surface temperature;

[0035] Step 2: During the closing process of the solid-state circuit breaker, the collected input voltage in the distribution circuit, the output voltage in the distribution circuit, and the main circuit current value are discretized and input into the processor to calculate the discretized real-time power consumption, and then the real-time power consumption and the device surface temperature are input into the thermal network model, and finally the junction temperature of the semiconductor device during the closing process is calculated;

[0036] Step 3: During the disconnection process of the solid-state circuit breaker, the main circuit current value and bus voltage are discretized and input into the processor to calculate the discretized real-time power consumption. The real-time power consumption and device surface temperature are then input into the thermal network model to finally calculate the junction temperature of the semiconductor device during the disconnection process.

[0037] Specific as Figure 3 As shown, including:

[0038] (1) The solid-state circuit breaker operates in the whole life cycle, including the conduction condition, overload condition, and short-circuit condition. Any condition includes both steady state and transient conditions. Figure 1 As shown, steady state refers to the conduction process, and transient state refers to the shutdown process.

[0039] (2) After the solid-state circuit breaker receives the on / off command, the solid-state circuit breaker performs the closing operation. After a few us, the closing operation is completed. The semiconductor power device always carries the rated current value in the main circuit. When the solid-state circuit breaker is in a steady-state condition, the semiconductor power device is always in a closed state.

[0040] (3) When the solid-state circuit breaker is in steady state, the current reaches the minimum current threshold I min After that, at time t0, the processor chip inside the solid-state circuit breaker starts the junction temperature detection function. The solid-state circuit breaker first collects the shell temperature T of the semiconductor power device at the current time t0. C (The shell temperature is related to the thermal network model inside the solid-state circuit breaker);

[0041] (4) At the same time, at time t0, the acquisition circuit inside the solid-state circuit breaker product will start to collect the input voltage value V in the power distribution circuit. in , output voltage V out And the current value of the circuit I DS Three analog values, and transmit the analog values ​​to the processor interface of the solid-state circuit breaker through a high-speed bus;

[0042] (5) After the processor receives the analog value transmitted by the acquisition circuit, it will collect the input voltage V in and output voltage V out The difference between the two is calculated by difference calculation. The voltage difference between the two represents the voltage between the drain and source of the semiconductor power device in the on state, that is, V DS；

[0043] (6) At the same time, at time t0, the processor module will calculate the voltage value V across the drain and source of the power device. DS And the current value I in the collected circuit DS Multiply them, and the product is the instantaneous power value P inside the power device at time t0 DS0 ;

[0044] (7) Then, the solid-state circuit breaker processor will convert the instantaneous power value P DS0 The thermal network model is a digital model between the shell temperature detection point of the semiconductor power device and the internal junction temperature point of the semiconductor power device, which consists of a multi-order thermal resistance R i and C i Composition, such as Figure 2 As shown, the instantaneous power value is input into the thermal network model, and after calculation, the temperature rise value △t0 of the semiconductor power device at time t0 is finally calculated;

[0045] (8) The internal processing unit of the solid-state circuit breaker calculates the temperature rise value △t0 at time t0 and the shell temperature T collected at time t0.C0 Add together and finally get the junction temperature T of the semiconductor power device at time t0 j0 ;

[0046] (9) After the solid-state circuit breaker receives the shutdown command, the solid-state circuit breaker completes the disconnection operation after us. At the time ta when the disconnection operation starts, the solid-state circuit breaker first collects the shell temperature T of the power device at time ta. Ca ;

[0047] (10) At the same time, at time ta, the acquisition circuit inside the solid-state circuit breaker will continue to collect the bus voltage V at the current moment Bus And the current value of the main circuit I DS The two analog values ​​are used to take the collected bus voltage as the voltage between the drain and source of the semiconductor power device. This is because due to the existence of inductance in the loop, di / dt will have a large value, V = L*di / dt, and the reverse voltage shock will be very large. It is difficult to characterize the V of the power device by the difference between the input voltage and the output voltage. DS Therefore, in order to improve the engineering application capability, the bus voltage / clamp voltage is used to characterize the V DS value;

[0048] (11) The internal processor of the solid-state circuit breaker collects the bus voltage value V Bus And the current value of the main circuit I DS Multiply the product to get the instantaneous power value P at time ta DS ;

[0049] (12) The instantaneous power value P at the time ta is converted inside the solid-state circuit breaker processor DS The input is then put into the thermal network model, and finally the temperature rise value △ta of the semiconductor power device at time ta is calculated by the thermal network model;

[0050] (13) Inside the solid-state circuit breaker processor, the temperature rise value △ta at time ta is added to the accumulated junction temperature at the last moment under the conduction condition and the shell temperature T at time ta. Ca Add together and finally get the junction temperature T of the semiconductor power device at time ta ja .

[0051] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for detecting the junction temperature of a semiconductor power device in real time online, characterized in that: include: Step 1: Real-time detection of the main circuit current value flowing through the semiconductor power device in the solid-state circuit breaker / solid-state power controller, as well as the input voltage in the distribution circuit, the output voltage in the distribution circuit, the bus voltage and the device surface temperature; Step 2: During the closing process of the solid-state circuit breaker, the collected input voltage in the distribution circuit, the output voltage in the distribution circuit, and the main circuit current value are discretized and input into the processor to calculate the discretized real-time power consumption, and then the real-time power consumption and the device surface temperature are input into the thermal network model, and finally the junction temperature of the semiconductor device during the closing process is calculated; Step 3: During the disconnection process of the solid-state circuit breaker, the main circuit current value and bus voltage are discretized and input into the processor to calculate the discretized real-time power consumption. The real-time power consumption and device surface temperature are then input into the thermal network model to finally calculate the junction temperature of the semiconductor device during the disconnection process.

2. A method for detecting the online real-time junction temperature of a semiconductor power device as claimed in claim 1, characterized in that: Step 1 includes: Step 11: When the current of the solid-state circuit breaker reaches the minimum current threshold I min After that, at time t0, the processor chip inside the solid-state circuit breaker starts the junction temperature detection function. The solid-state circuit breaker first collects the shell temperature T of the semiconductor power device at the current time t0. C ; Step 12: At the same time, at time t0, the acquisition circuit inside the solid-state circuit breaker product will start to collect the input voltage value V in the power distribution circuit. in , output voltage V out And the current value of the circuit I DS The three analog values ​​are transmitted to the processor interface of the solid-state circuit breaker through a high-speed bus.

3. The method for detecting the online real-time junction temperature of a semiconductor power device according to claim 1, characterized in that: Step 2 includes: Step 21: After the processor receives the analog value transmitted by the acquisition circuit, it will collect the input voltage V in and output voltage V out The difference between the two is calculated by difference calculation. The voltage difference between the two represents the voltage between the drain and source of the semiconductor power device in the on state, that is, V DS ; Step 22: At the same time at time t0, the processor module will calculate the voltage value V across the drain and source of the power device. DS And the current value I in the collected circuit DS Multiply them, and the product is the instantaneous power value P inside the power device at time t0 DS0 ; Step 23: Then, the solid-state circuit breaker processor will internally convert the instantaneous power value P DS0 The thermal network model is a digital model between the shell temperature detection point of the semiconductor power device and the internal junction temperature point of the semiconductor power device, which consists of a multi-order thermal resistance R i and C i The instantaneous power value is input into the thermal network model, and after calculation, the temperature rise value △t0 of the semiconductor power device at time t0 is finally calculated; Step 24: The internal processing unit of the solid-state circuit breaker calculates the temperature rise value △t0 at time t0 and the shell temperature T collected at time t0. C0 Add together and finally get the junction temperature T of the semiconductor power device at time t0 j0 .

4. A method for detecting the online real-time junction temperature of a semiconductor power device as claimed in claim 1, characterized in that: Step 3 includes: Step 31: After the solid-state circuit breaker receives the shutdown command, the solid-state circuit breaker completes the disconnection operation after us. At the time ta when the disconnection operation starts, the solid-state circuit breaker first collects the shell temperature T of the power device at time ta. Ca ; Step 32: At the same time, at time ta, the acquisition circuit inside the solid-state circuit breaker will continue to collect the bus voltage V at the current moment. Bus And the current value of the main circuit I DS The two analog values ​​are used to take the collected bus voltage as the voltage between the drain and source of the semiconductor power device. This is because due to the existence of inductance in the loop, di / dt will have a large value, V = L*di / dt, and the reverse voltage shock will be very large. It is difficult to characterize the V of the power device by the difference between the input voltage and the output voltage. DS Therefore, in order to improve the engineering application capability, the bus voltage / clamp voltage is used to characterize the V DS value; Step 33: The internal processor of the solid-state circuit breaker collects the bus voltage value V Bus And the current value of the main circuit I DS Multiply the product to get the instantaneous power value P at time ta DS ; Step 34: The instantaneous power value P at time ta is converted into DS The input is then put into the thermal network model, and finally the temperature rise value △ta of the semiconductor power device at time ta is calculated by the thermal network model; Step 35: In the solid-state circuit breaker processor, the temperature rise value △ta at time ta is added to the accumulated value of the junction temperature at the last moment under the conduction condition and the shell temperature T at time ta. Ca Add together and finally get the junction temperature T of the semiconductor power device at time ta ja .

5. The method for detecting the online real-time junction temperature of a semiconductor power device according to claim 1, characterized in that: When performing junction temperature detection, the junction temperature prediction is based on the Foster thermal network model.

6. A method for detecting the online real-time junction temperature of a semiconductor power device as claimed in claim 1, characterized in that: The thermal network model inside the processor refers to the thermal network model between the shell temperature detection point and the PN junction of the power device.

7. A method for detecting the online real-time junction temperature of a semiconductor power device as claimed in claim 1, characterized in that: The detected junction temperature data is compared with the maximum allowable junction temperature value of the power device. When the detected data is greater than or equal to the maximum allowable junction temperature of the device, an alarm signal is issued or a disconnection operation is performed.

8. The method for detecting the online real-time junction temperature of a semiconductor power device according to claim 1, characterized in that: Also includes: After the solid-state circuit breaker receives the on / off command, the solid-state circuit breaker performs the closing operation. After a few us, the closing operation is completed. The semiconductor power device always carries the rated current value in the main circuit. When the solid-state circuit breaker is in a steady-state condition, the semiconductor power device is always in a closed state.

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