An intelligent semiconductor device for a 24-pulse rectifier cabinet for subway power supply

Abstract

An intelligent semiconductor device for a subway power supply 24-pulse rectifier cabinet includes a tube shell seat and a tube shell cover. A tube core and a silver sheet are arranged on the tube shell seat in sequence. Positioning rings are arranged at both ends of the tube core. The tube shell cover is located on the tube shell seat. The two are sealed and connected to form a closed cavity. The closed cavity is filled with inert protective gas. A mounting hole with a diameter of 5 to 8 mm is opened on the tube shell cover. A temperature sensor is embedded in the mounting hole. The temperature sensor is located at the axial center position of the outer side of the tube shell cover, and its top is not more than 2 mm away from the inner surface of the tube shell cover. The present invention selects a new structure through simulation analysis and calculation. Under the condition that the electrical structure of the existing semiconductor device and the internal mechanical structure and sealing structure of the device are not affected, the device junction temperature measurement function is added to realize the measurement of the junction temperature of the semiconductor device, achieve real-time state recognition, and realize the digitization of the reliability of the semiconductor device.

Description

Technical Field

[0001] The invention belongs to the field of subway power supply, and in particular relates to an intelligent semiconductor device for a subway power supply 24-pulse rectifier cabinet. Background Art

[0002] The subway power supply system is a key system in the subway field. After years of high-speed construction, the scale and volume of subway operating lines and subway power supply equipment are huge, the service life has increased, and the failure rate has increased accordingly, which is very likely to cause safety hazards such as vehicle suspension in tunnels and excessive passenger flow in stations. In this case, it has become an urgent problem to establish a large-scale networked power supply intelligent operation and maintenance system that integrates four core functions, including real-time perception and early warning of the status of key equipment in the power supply system, full life management, intelligent driving of business processes, and expert system diagnosis and analysis, to ensure the safety, reliability and economy of the power supply system operation.

[0003] In the subway power supply system, the rectifier transformer and the rectifier form a rectifier unit. The rectifier transformer steps down the input 10KV power supply and shifts the phase to divide it into two groups of 3AC1180V power output, which is then converted to DC1500V by the rectifier for output. A single rectifier unit constitutes a 12-pulse rectifier power supply, and two rectifier units are connected in parallel to form a 24-pulse rectifier power supply. Therefore, the rectifier in the subway power supply system is also called a 24-pulse rectifier. The 24-pulse rectifier unit is equipped with a high-voltage side input protective switch and a DC side DC protective switch to form a subway power supply system.

[0004] The traditional subway power supply system 24-pulse rectifier uses ordinary high-power semiconductor diode devices to realize the conversion from AC power to DC power. The core structure of this rectifier diode is PN junction (after the P-type semiconductor and N-type semiconductor are connected, a very thin space charge area is formed at the connection between the two, which is the PN junction). When the PN junction is applied with a forward voltage, it presents a low resistance and has a large forward conduction current, which is called the forward conduction state. When the PN junction is applied with a reverse voltage, it presents a high resistance and has a very small reverse drift current, which is called the reverse blocking state. Temperature, especially the PN junction temperature, is a key state parameter of the high-power semiconductor rectifier diode, which directly reflects the electrical performance of the power semiconductor device and also reflects the reliability of the device after being in the rectifier installation environment. This type of high-power semiconductor rectifier diode generally chooses a press-fit structure. In this structure, the rectifier diode is a surface-contact type diode with a large junction area, which can accept a large forward current and a high reverse voltage. At the same time, it is convenient to arrange heat sinks on both sides of the device to ensure reliable heat dissipation under working conditions. After the device structure and heat dissipation structure design of the 24-pulse rectifier semiconductor diode are confirmed, the junction temperature of the semiconductor diode becomes an important factor in characterizing the reliability of the device. The device design and the heat dissipation analysis and calculation of the device in the rectifier design process are relied on, and the semiconductor diode performance is guaranteed to be stable after a special characteristic test. The real-time process status of the semiconductor diode junction temperature cannot be monitored.

[0005] This type of semiconductor diode device only has the ability to conduct and cut off current, but does not have a state perception function. It is unable to accurately detect its process status and manage its entire life cycle. It is also unable to be accurately identified and judged during daily manual inspections, posing a hidden danger to the safe operation of the subway power supply system.

[0006] The present invention mainly proposes a new intelligent solution for the traditional semiconductor rectifier diode device used in the key 24-pulse rectifier in the subway power supply system. Summary of the invention

[0007] The purpose of the present invention is to provide an intelligent semiconductor device for a 24-pulse rectifier cabinet for a subway power supply. A new structure is selected through simulation analysis and calculation. Under the condition that the electrical structure of the existing semiconductor device and the internal mechanical structure of the device are not affected, and the sealing structure of the device is not affected to ensure the electrical performance and heat dissipation performance of the device, the device junction temperature measurement function is added to realize the measurement of the junction temperature of the semiconductor device. With the help of data analysis of the junction temperature, the purpose of real-time status recognition of the reliability of the semiconductor device is achieved, and the reliability of the semiconductor device is digitized.

[0008] The technical solution adopted by the present invention is:

[0009] An intelligent semiconductor device for a 24-pulse rectifier cabinet for a subway power supply comprises a tube shell seat and a tube shell cover. A tube core and a silver sheet are arranged on the tube shell seat in sequence, and positioning rings are arranged at both ends of the tube core. The tube shell cover is located on the tube shell seat, and the two are sealed and connected to form a closed cavity, which is filled with inert protective gas; a mounting hole is opened on the tube shell cover, and a temperature sensor is embedded in the mounting hole.

[0010] Furthermore, the temperature sensor is located at the axial center position of the outer side of the tube shell cover or within a range of no more than 30 mm from the center position. The distance mentioned here refers to the horizontal direction and needs to be determined after thermal analysis calculation.

[0011] Furthermore, the diameter of the mounting hole is 5 to 8 mm.

[0012] Furthermore, the top of the temperature sensor is no more than 2 mm away from the inner surface of the tube shell cover. The distance here refers to the vertical direction (with the Figure 1 shown as an example).

[0013] Furthermore, the temperature sensor is an intelligent temperature sensor or an analog temperature sensor.

[0014] Furthermore, the temperature sensor has a temperature measurement range of -50°C to 150°C and an accuracy of ±0.4°C.

[0015] Furthermore, the temperature sensor is an analog temperature measurement chip LMT84, the package form is TO-92, and a three-lead structure is adopted, and the lead wires include a power line and a signal output line.

[0016] Furthermore, the temperature sensor is embedded in the countersunk hole on the outer surface of the tube shell cover and then subjected to curing and packaging treatment, and the sensor lead wire is insulated before the packaging is cured.

[0017] Beneficial effects of the present invention:

[0018] The present invention selects a method of drilling a hole near the PN junction lead-out electrode and sinking a temperature sensor. On the basis of not affecting the sealing performance of the press-fit semiconductor device and not affecting the electrical performance and thermal resistance performance of the press-fit semiconductor rectifier diode, it integrates the semiconductor junction temperature measurement function to realize the state recognition and digitization of the semiconductor diode device during the working process, and constitutes an intelligent semiconductor device.

[0019] The linear analog output voltage of the LMT84 chip selected by the present invention is inversely proportional to the temperature and is suitable for measuring the junction temperature of a semiconductor diode.

[0020] After the rectifier of the subway power supply system adopts the intelligent semiconductor diode device of the present invention, it can:

[0021] (1) Realize the real-time measurement and state identification of the junction temperature of semiconductor rectifier diodes, and then use the junction temperature as the characteristic quantity to realize the real-time state identification and reliability quantitative analysis of semiconductor diode devices; the absolute value of the junction temperature and the gradient of the junction temperature change per unit time during the use of the device in the whole life cycle constitute the reliability index of the device in the whole life cycle, forming the basis for the repair and maintenance of the device;

[0022] (2) Based on real-time junction temperature status data recording, big data and network management of semiconductor rectifier diodes can be realized;

[0023] (3) Based on the big data analysis of semiconductor rectifier diodes, the reliability management of devices throughout their life cycle can be achieved;

[0024] (4) Based on the real-time status and reliability data of the junction temperature of the semiconductor rectifier diode, the real-time status and reliability of the rectifier are analyzed to realize intelligent monitoring of the rectifier of the power supply system, replacing manual scheduled inspection operations and realizing intelligent operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of a semiconductor diode device of the present invention;

[0026] Figure 2 It is a temperature distribution diagram obtained after simulating and analyzing the heat dissipation characteristics of the original device under the working conditions of the device;

[0027] Figure 3 This is a temperature distribution diagram of the device after the hole is opened and the sensor is placed, which is obtained through simulation analysis of the heat dissipation characteristics after the hole is opened.

[0028] In the figure, 1. tube shell seat, 2. tube core (PN junction), 3. silver sheet, 4. positioning ring, 5. tube shell cover, 6. inert protective gas, 7. temperature sensor. DETAILED DESCRIPTION

[0029] like Figure 1As shown, an intelligent semiconductor device for a 24-pulse rectifier cabinet for a subway power supply includes a tube shell seat 1 and a tube shell cover 5. A tube core 2 and a silver sheet 3 are arranged on the tube shell seat 1 in sequence. Positioning rings 4 are arranged at both ends of the tube core 2 (the positioning rings are used to position the tube core and the silver sheet to ensure that the tube shell seat, the tube core and the silver sheet are concentric). The tube shell cover 5 is located on the tube shell seat 1, and the two are sealed and connected to form a closed cavity, which is filled with an inert protective gas 6. A mounting hole with a diameter of 5 mm is opened on the tube shell cover 5, and a temperature sensor 7 is embedded in the mounting hole. The temperature measurement range is -50℃-150℃, and the accuracy is ±0.4℃. The temperature sensor 7 is an analog temperature measurement chip LMT84, the package form is TO-92, and a three-lead structure is adopted. The lead wires include a power line and a signal output line (to output the measurement signal safely to achieve the measurement and identification of the temperature state of the semiconductor diode junction). LMT84 is a precision CMOS temperature sensor, which is a wide voltage working chip with a voltage range of 1.5V-5.5V. The temperature sensor 7 is embedded in the countersunk hole on the outer surface of the tube shell cover 5 and then cured and packaged. The sensor lead wires are insulated before the package is cured.

[0030] The temperature sensor 7 is located at the axial center of the outer side of the tube shell cover 5 (sunk into the tube shell cover through the mounting hole, close to the PN junction, and measures the junction temperature of the tube core (PN junction) in real time). The top of the temperature sensor 7 (towards the tube shell seat) is 2mm away from the inner surface of the tube shell cover 5 (the end surface close to the tube shell seat). The hole diameter and hole position are determined by simulation analysis and calculation, and the specific results are shown below.

[0031] The high-power semiconductor crimping diode device used in the subway power supply rectifier has a multi-physical coupling field of electromagnetic field, temperature field and structural field. The PN junction temperature inside the device is affected by the bidirectional coupling of the temperature field and the structural field inside the device. The present invention improves the semiconductor rectifier diode device to obtain an intelligent device. The semiconductor device model ZP2600-44 is used as an example for upgrading.

[0032] Analysis of the size and position selection of the sensor hole: Simulation and analysis of the heat dissipation characteristics of the original device to obtain the temperature release under the working conditions of the device, such as Figure 2 As shown in the figure, the heat dissipation characteristics after the hole is opened are simulated and analyzed, and the temperature distribution of the device after the hole is opened and the sensor is placed, as shown in the figure. Figure 3 The temperature analysis results of different apertures and different positions are shown in Table 1. According to the simulation results, the aperture is selected to be 5 mm, and the position can meet the requirements within a range of no more than 30 mm from the center. The temperature compensation data of different sizes are selected according to the calculation results.

[0033] Table 1 Temperature analysis results of different apertures and positions

[0034]

[0035] Definition of smart device reliability: The maximum junction temperature of the device ZP2600-44 is theoretically 125°C, and the maximum junction temperature that may occur during normal operation is 85°C. Therefore, its reliability is defined as 1.00 when the junction temperature is lower than 85°C. The device reliability is defined as 1.00-0 according to a linear relationship between the junction temperature of 85°C and 125°C. For example, the reliability is 0.875 when the junction temperature is 90°C.

[0036] When the device reliability is 1, the device is normal;

[0037] When the device reliability is lower than 1 and higher than 0.8, pay attention to monitoring;

[0038] When the device reliability is lower than 0.8 and higher than 0.6, it is recommended to arrange maintenance;

[0039] If the device reliability is lower than 0.60, stop using it immediately.

Claims

1. An intelligent semiconductor device for a 24-pulse rectifier cabinet for subway power supply, characterized in that: The invention comprises a tube shell seat (1) and a tube shell cover (5), wherein a tube core (2) and a silver sheet (3) are arranged on the tube shell seat (1) in sequence, and positioning rings (4) are arranged at both ends of the tube core (2); the tube shell cover (5) is located on the tube shell seat (1), and the two are sealed and connected to form a closed cavity, and the closed cavity is filled with an inert protective gas (6); a mounting hole is opened on the tube shell cover (5), and a temperature sensor (7) is embedded in the mounting hole; The temperature sensor (7) is located at the axial center position of the outer side of the tube shell cover (5) or within a range of no more than 30 mm from the center position; the diameter of the mounting hole is 5 to 8 mm; the top of the temperature sensor (7) is no more than 2 mm away from the inner surface of the tube shell cover (5); and the semiconductor device is a press-fit rectifier diode.

2. The intelligent semiconductor device for a subway power supply 24-pulse rectifier cabinet as claimed in claim 1, characterized in that: The temperature sensor (7) is an intelligent temperature sensor or an analog temperature sensor.

3. The intelligent semiconductor device for a subway power supply 24-pulse rectifier cabinet as claimed in claim 1, characterized in that: The temperature sensor (7) has a temperature measurement range of -50°C to 150°C and an accuracy of ±0.4°C.

4. The intelligent semiconductor device for a subway power supply 24-pulse rectifier cabinet as claimed in claim 1, characterized in that: The temperature sensor (7) is an analog temperature measurement chip, the package form is TO-92, and adopts a three-lead structure, the lead wires include a power line and a signal output line.

5. The intelligent semiconductor device for a subway power supply 24-pulse rectifier cabinet as claimed in claim 1, characterized in that: The temperature sensor (7) is embedded in the countersunk hole on the outer surface of the tube shell cover (5) and then subjected to a curing and packaging process. Before the packaging and curing process, the sensor lead wire is insulated.

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