LC device with current detection

Abstract

This invention discloses an LC device with built-in current detection, relating to the control field of a three-level bidirectional DC / DC circuit in a diesel shunting locomotive. Two inductors and one capacitor are mounted on a mounting base plate using bolts. The two inductors are a positive input inductor and a negative output inductor. The positive input inductor is connected to the DC / DC positive input copper busbar at the front and the DC / DC positive output copper busbar at the rear. The negative output inductor is connected to the DC / DC negative output copper busbar at the front and the DC / DC negative input copper busbar at the rear. The DC / DC positive output copper busbar is connected to the DC positive input copper busbar, and the DC / DC negative input copper busbar is connected to the DC negative output copper busbar. One end of the DC positive input and DC positive output copper busbars is stacked and connected to an insulated support terminal with an embedded conductive post, and one end of the DC negative output and DC negative input copper busbars is also stacked and connected to the insulated support terminal with an embedded conductive post. A current sensor is also included in the circuit. This invention features modular components, built-in current sampling redundancy, suitability for high altitudes, and integration of inductors and capacitors, achieving precise control of a three-level DC / DC device.

Description

Technical Field

[0001] This invention relates to the field of control of three-level bidirectional DC / DC circuits in diesel shunting locomotives, specifically to an LC device with built-in current detection. Background Technology

[0002] As the environmental situation becomes increasingly severe and the requirements for environmental protection become increasingly stringent, in order to accelerate the pace of carbon emission reduction, guide green technology innovation, and enhance the global competitiveness of industries and the economy, all sectors in China are continuously promoting industrial and energy structure reforms. While vigorously developing green energy, they are simultaneously making great efforts to reduce the use of existing high-energy-consuming resources and carry out carbon emission reduction work.

[0003] China has a vast territory and its rail transit has developed rapidly. However, due to constraints such as geographical location and power grid construction, diesel shunting locomotives are still widely used in marshalling yards, rolling stock depots, locomotive depots, steel plants, mines, and ports. The characteristics of these operations are mostly light traction tonnage, short distances, long waiting times, low speeds, and frequent starting, acceleration, reversing, and braking. The diesel engine operates at full load for a very low percentage of time and has long idle time, which means that the diesel engine power is not fully utilized, resulting in serious fuel waste and large emissions, which does not meet the requirements of low carbon and environmental protection.

[0004] Therefore, more and more green, environmentally friendly, and efficient shunting locomotives, such as hybrid electric locomotives, hydrogen fuel cell hybrid locomotives, and pure electric locomotives, will be developed, designed, and applied. The power source of these shunting locomotives is the power battery, which inevitably involves charging and discharging. At the same time, in order to meet the locomotive's requirements for high power, high power density, and lightweight design, a three-level bidirectional DC / DC device for charging and discharging the power battery is required. Therefore, a high-frequency, miniaturized, lightweight, integrated, and modular LC device (filter device) is designed to meet the requirements of the three-level bidirectional DC / DC device, thereby satisfying the needs of the entire vehicle.

[0005] In the existing technology, most diesel shunting locomotives currently use unidirectional two-level interleaved control DC / DC devices. Therefore, the switching devices used in the DC / DC devices have high voltage levels and relatively low switching frequencies. The LC devices have a single function, used only for step-down or step-up chopping. The inductors are only used for smoothing, current limiting, or energy storage, and are not used for multiplexing the same LC device for step-down and step-up. Inductors of the same power rating have large capacitance and large size, and are generally cooled by forced air cooling. However, this scheme is not suitable for three-level bidirectional DC / DC circuits. Due to the use of two-level circuits, the DC / DC main circuit switching devices have high voltage levels and low switching frequencies, which is not conducive to achieving high frequency and high density. The inductors and capacitors have large parameters and large size, requiring additional cooling fans or water-cooled inductors, and need to be connected to a water cooling system. Water-cooled reactor technology is a new technology with low safety, large space occupation, and high design cost.

[0006] In the existing technology 2, the LC device uses independent inductors and capacitors, which are installed separately according to the actual layout of the converter cabinet. Electrical connections mostly use copper busbars or cables, resulting in complex and messy wiring that hinders modularization of components. It is particularly unsuitable for shunting locomotive platforms where the entire vehicle lacks an independent converter cabinet and the car body serves as the electrical room. It is also unsuitable as an independent testing device for testing three-level bidirectional DC / DC devices. This scheme is not conducive to modularization of components, is unsuitable for modular shunting locomotive design platforms without independent converter cabinets, cannot be conveniently used as an independent device for testing three-level bidirectional DC / DC devices, and is not conducive to parallel expansion.

[0007] In the existing third technology, a single inductor is typically used in the positive circuit, resulting in poor redundancy. When this single inductor fails, the bidirectional DC / DC device fails, unable to perform smoothing, current limiting, or boost energy storage functions. Furthermore, the main circuit uses only one of the positive and negative circuits for current sampling, connected to the current and voltage sampling unit in the converter cabinet via cables or copper busbars, leading to cumbersome connections and long wiring. The current sampling also lacks redundancy; any current detection anomalies or failures hinder precise DC / DC control, potentially causing control failure and, in severe cases, damage to the DC / DC main circuit. This solution suffers from the following drawbacks: the single inductor lacks redundancy, inductor failure easily leads to functional failure; the lack of redundancy in current sampling hinders precise DC / DC control; the electrical connections are cumbersome, the wiring is unsightly, and the design cost of the electrical connections is high. Summary of the Invention

[0008] In order to solve the problems of poor safety, poor redundancy and complicated wiring of the three-level bidirectional DC / DC devices used for charging and discharging power batteries in the prior art, the present invention provides an LC device with built-in current detection.

[0009] This invention is achieved through the following technical solution: an LC device with built-in current detection, comprising a mounting base plate on which two inductors and one capacitor are mounted. The two inductors are a positive input inductor and a negative output inductor, respectively. The positive input inductor and the negative output inductor are arranged side by side, and the bottom surface has a built-in inductor support frame. The inductor support frame is mounted to the mounting base plate by several bolts. The iron cores at the top of the positive input inductor and the negative output inductor are clamped by metal clamps on both sides and fastened by bolts. A fastening end I is provided in the middle of the metal clamps on both sides. The fastening end I is connected to a corresponding fastening end on the inductor support frame by a long bolt. II. The components are integrated; the positive input inductor is connected to a DC / DC positive input copper busbar at the front and a DC / DC positive output copper busbar at the rear; the negative output inductor is connected to a DC / DC negative output copper busbar at the front and a DC / DC negative input copper busbar at the rear; both the DC / DC positive input copper busbar and the DC / DC negative output copper busbar have pre-drilled double-hole electrical connection ports; the DC / DC positive input copper busbar is secured by a U-shaped insulating plate, and the DC / DC negative output copper busbar is also secured by a U-shaped insulating plate; both insulating plates are fastened to the metal clamp by two bolts passing through the corresponding insulating posts. The positive input inductor's DC / DC positive output copper busbar is connected to the DC positive input copper busbar, and the negative output inductor's DC / DC negative input copper busbar is connected to the DC negative output copper busbar. The other end of the DC positive input copper busbar passes through a DC positive current sensor and is then stacked with one end of the DC positive output copper busbar. The stacked connection end of the DC positive input copper busbar and the DC positive output copper busbar is bolted to the insulating support terminal I with embedded conductive posts on the capacitor, thus achieving electrical connection between the DC positive input copper busbar, the DC positive output copper busbar, and the capacitor. The middle part of the DC positive output copper busbar is bolted to the insulating support terminal II on the capacitor's outer casing. A two-hole electrical connection port is provided at the end of the DC positive output copper busbar. The DC negative output copper busbar... The other end is stacked with one end of the DC negative input copper busbar. The stacked connection end of the DC negative output copper busbar and the DC negative input copper busbar is bolted to the insulating support terminal III with embedded conductive pillars on the capacitor, realizing the electrical connection of the DC negative output copper busbar, the DC negative input copper busbar and the capacitor. The other end of the DC negative input copper busbar passes through the DC negative current sensor, and its middle part is bolted to the insulating support terminal IV on the outer wall of the capacitor. The end of the DC negative input copper busbar has a reserved double-hole electrical connection port. The DC positive current sensor and the DC negative current sensor are both installed and fixed by the current sensor support frame set on the top of the capacitor. The support frame at the bottom of the capacitor is installed on the mounting base plate by multiple bolts. A connecting piece is also fixed to the top of the end of the capacitor that is close to the inductor. The connecting piece is fastened to the fastening end I on both sides of the metal clamp plate of the inductor by a long bolt A. The edge of the metal clamp plate located between the inductor and the capacitor is connected to the support frame at the bottom of the capacitor by a Z-shaped connecting rod, so that the inductor and the capacitor are connected as one unit.

[0010] This invention discloses an LC device with built-in current detection, comprising a mounting base plate on which two inductors and one capacitor are mounted. The two inductors and one capacitor are integrated into a single unit on the base plate via a Z-shaped connecting rod and long bolts A between the fastening ends I on both sides of the metal clamping plates and the connecting pieces of the capacitor. The two inductors are a positive input inductor and a negative output inductor, arranged side-by-side. The positive input inductor is connected to the positive current input terminal of the circuit, and the negative output inductor is connected to the negative current output terminal. Each inductor has a built-in inductor support frame on its bottom surface, which is mounted to the mounting base plate with several bolts. The iron cores at the top of the positive input and negative output inductors are clamped by the metal clamping plates on both sides and secured with bolts. Fastening ends I are located in the middle of the metal clamping plates on both sides, and these fastening ends I are connected to corresponding fastening ends II on the inductor support frames via long bolts, thus tightening and fixing the two inductors as a whole. The positive input inductor has a DC / DC positive input copper busbar connected to its front, used to connect to the positive current input terminal, and a DC / DC positive output copper busbar connected to its rear, used to connect to the capacitor. The negative output inductor has a DC / DC negative output copper busbar connected to its front, used to connect to the negative current output terminal, and a DC / DC negative input copper busbar connected to its rear, used to connect to the capacitor. Both the DC / DC positive input and negative output copper busbars have pre-drilled two-hole electrical connection ports. To prevent the two copper busbars from being unstable and from wobbling, they are secured by pressing them firmly with corresponding U-shaped insulating plates. Two bolts pass through corresponding insulating posts on both sides of each insulating plate and are then fastened to metal clamps. This secures the two copper busbars to the front of the inductor via bolts, insulating plates, and insulating posts, preventing instability during connection and meeting the Class 1B requirements for locomotive vibration and shock. The positive input inductor's DC / DC positive output copper busbar is connected to the DC positive input copper busbar, meaning the DC / DC positive output copper busbar is led out from the positive input inductor and connected to the DC positive input copper busbar. Similarly, the negative output inductor's DC / DC negative input copper busbar is connected to the DC negative output copper busbar, meaning the DC negative output copper busbar again inputs to the negative output inductor through the DC / DC negative input copper busbar. The following is the connection structure on the capacitor: the other end of the DC positive input copper busbar passes through the DC positive current sensor and is stacked with one end of the DC positive output copper busbar, ensuring a reliable connection between the two busbars. The stacked connection end of the DC positive input and DC positive output copper busbars is bolted to the capacitor's built-in insulating support terminal I, achieving electrical connection between the DC positive input copper busbar, DC positive output copper busbar, and capacitor. The middle part of the DC positive output copper busbar is bolted to the capacitor's outer casing insulating support terminal II. The end of the DC positive output copper busbar has a pre-drilled two-hole electrical connection port for connecting the positive current output circuit.The other end of the DC negative output copper busbar is overlapped with one end of the DC negative input copper busbar. The overlapped connection end of the DC negative output copper busbar and the DC negative input copper busbar is bolted to the insulating support terminal III with embedded conductive posts on the capacitor, realizing the electrical connection of the DC negative output copper busbar, the DC negative input copper busbar and the capacitor. The other end of the DC negative input copper busbar passes through the DC negative current sensor, and its middle part is bolted to the insulating support terminal IV on the capacitor shell wall. The end of the DC negative input copper busbar has a reserved two-hole electrical connection port for connecting the negative current input circuit. Both the DC positive current sensor and the DC negative current sensor are mounted and fixed by the current sensor support frame set on the top of the capacitor. The capacitor's built-in support frame is mounted to the mounting base plate with multiple bolts. A connecting piece is also fixed to the top of the end of the capacitor closest to the inductor. This connecting piece is secured to the fastening end I on both sides of the inductor's metal clamp plate by a long bolt A. Long bolt A integrates the connecting piece and the metal clamp plate. The edge of the metal clamp plate located between the inductor and capacitor is connected to the support frame at the bottom of the capacitor via a Z-shaped connecting rod. These methods ensure the inductor and capacitor are connected as a single unit, preventing the device from detaching during system vibration and ensuring stable mounting of the inductor and capacitor to the mounting base plate, meeting the Class 1B requirements for vehicle impact and vibration. The input and output circuits of the LC device in this invention use double-hole, double-bolt electrical connections for the copper busbars. This solves the problems of high current density, terminal rotation, and insecure connections associated with single-hole, single-bolt electrical connections for high current applications. It also prevents overheating, burnout, or even fires caused by excessive contact resistance. The LC device is equipped with a DC positive current sensor and a DC negative current sensor, providing dual redundant current sampling and improving the accuracy and redundancy of the system sampling.

[0011] Preferably, the inductor is a self-cooling heat dissipation method. Since the vehicle system cannot provide cooling for the LC device, and in order to save energy, this heat dissipation method is adopted.

[0012] Preferably, a thermistor is embedded at the location where the inductor is heating up excessively. This excessive heating is defined as exceeding a certain temperature threshold, which is standard practice. The thermistor is connected to the DC / DC control system and, during operation, uploads its resistance value to the DC / DC control system. When the inductor experiences abnormal temperatures, it provides protection and ensures the safe operation of the inductor.

[0013] Preferably, the inductor is mounted on the mounting base plate by four M12 bolts, and the capacitor is mounted on the mounting base plate by two M14 bolts and two M8 bolts.

[0014] Preferably, the material selection and heat dissipation of the inductor and capacitor take into account the application at an altitude of 5100m. This type of LC device can be applied to environments at and below 5100m altitude.

[0015] Furthermore, the positive input copper busbar of the DC / DC converter is connected to the positive current input port of the three-level bidirectional DC / DC circuit, and the negative output copper busbar of the DC / DC converter is connected to the negative current output port of the three-level bidirectional DC / DC circuit.

[0016] Furthermore, the DC positive output copper busbar is connected to the positive current output port of the three-level bidirectional DC / DC circuit, and the DC negative input copper busbar is connected to the negative current input port of the three-level bidirectional DC / DC circuit.

[0017] Based on the function of the entire device, it can be seen that the LC device is suitable for a three-level bidirectional DC / DC main circuit. Its application in the three-level bidirectional DC / DC circuit is as follows: when stepping down, it has the function of smoothing and suppressing current; when stepping up, it has the function of storing energy.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The LC device with built-in current detection provided by the present invention is a modular LC device suitable for three-level bidirectional DC / DC devices, with built-in current sampling redundancy, two-stage inductor, integrated inductor and capacitor, and adaptable to high-altitude environments of 5100m, and has the following technical effects:

[0019] 1) Applicable to bidirectional three-level DC / DC main circuits, using the same LC device to realize buck chopping and boost chopping functions. It can smooth out waves and suppress current during buck chopping, and store energy during boost chopping.

[0020] 2) The positive and negative circuits use two inductors sharing the same iron core, which not only achieves the symmetry of the positive and negative poles of the main circuit, but also improves redundancy. If one of the inductors fails, the DC / DC device can still work normally by adjusting the duty cycle.

[0021] 3) Setting up a current sensor in each of the positive and negative circuits for current sampling facilitates the accuracy and redundancy of current sampling in the DC / DC circuit, enables precise control of the DC / DC device, and improves the reliability of the system.

[0022] 4) The inductors and capacitors are integrated into one unit through the mounting base, realizing modular components, which is more suitable for shunting locomotive platforms with no converter cabinet in the whole vehicle and modular components.

[0023] 5) The bidirectional DC / DC charging device adopts a three-level circuit and interleaved control, with a high switching frequency and small capacity and size of inductors and capacitors, which facilitates the realization of high power density, miniaturization and lightweight DC / DC devices.

[0024] 6) This LC device can be used as an independent test device, and can be easily used with a three-level bidirectional DC / DC power unit to perform boost and buck functions.

[0025] 7) The entire system uses natural cooling, eliminating the need for a dedicated forced air cooling system or water cooling system, thus reducing cooling system space and design costs.

[0026] 8) Support terminals for input and output connection copper busbars are provided on the capacitor casing, which solves the problem of fixing the copper busbars or cables for electrical connection between the capacitor and the converter cabinet or other electrical components of the vehicle, ensuring the reliability of the electrical connection and meeting the Class 1B requirements for locomotive impact and vibration.

[0027] 9) To facilitate external electrical connections, copper busbars are used at the input and output terminals of inductors and capacitors, making wiring and electrical connections convenient. The copper busbars connecting the input and output circuits of the LC device use double-hole, double-bolt electrical connections, solving the problems of high current density and instability associated with single-hole, single-bolt electrical connections for high current applications.

[0028] 10) DC positive current sensor and DC negative current sensor, dual redundant current sampling, improve the accuracy and redundancy of system sampling.

[0029] 11) In addition to being fixed to the mounting base plate, the inductor and capacitor are fastened together with bolts through the fastening connection terminals of the inductor and the connecting piece of the capacitor to ensure that they are integrated and meet the impact and vibration requirements of the shunting locomotive. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the LC device of the present invention.

[0031] Figure 2 This is a schematic diagram of the self-cooled inductor structure of the present invention.

[0032] Figure 3 This is a detailed schematic diagram of the capacitor side structure of the present invention.

[0033] Figure 4 This is a circuit topology diagram of the present invention applied to a three-level bidirectional DC / DC circuit.

[0034] The diagram is labeled as follows: 1-Mounting base plate, 2-Inductor, 3-Capacitor, 4-DC positive input copper busbar, 5-DC positive current sensor, 6-DC positive output copper busbar, 7-DC negative output copper busbar, 8-DC negative current sensor, 9-DC negative input copper busbar, 201-Positive input inductor, 202-Negative output inductor, 203-Inductor support frame, 204-Metal clamp, 205-Fastening end I, 206-Fastening end II, 207-Long bolt, 208-DC / DC positive input copper busbar, 209-DC / DC negative output copper busbar, 210-Rhomboid insulating plate, 211-Insulating post, 212-Iron core, 213-DC / DC positive output copper busbar, 214- DC / DC negative input copper busbar, 301-Insulated support terminal I with embedded conductive post, 302-Insulated support terminal II, 303-Insulated support terminal III with embedded conductive post, 304-Insulated support terminal IV, 10-Connecting piece, 11-Z-shaped connecting rod, 12-Current sensor support frame, 13-Long bolt A. Detailed Implementation

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] This embodiment designs an LC device with built-in current detection for a 200kW three-level bidirectional DC / DC device. The main technical parameters of the three-level bidirectional DC / DC device in this embodiment are as follows:

[0037] Applications: Hybrid shunting locomotives are suitable for use in marshalling yards, locomotive depots, ports, factories, mines, and other similar locations.

[0038] Shaft type: C0-C0, B0-B0;

[0039] Operating modes: internal combustion engine power supply, clean energy fuel cell, power battery power supply, hybrid power supply;

[0040] Altitude: ≤5100m

[0041] Buck chopper mode:

[0042] Charging power: 200kW

[0043] DC input voltage: DC 1000-1900V

[0044] Output voltage: DC700-950V

[0045] Switching frequency: ≤3kHz

[0046] Boost chopper mode:

[0047] Discharge power: 200kW

[0048] Power battery input voltage: DC 650-900V

[0049] Output voltage: DC 1000-1800V

[0050] Switching frequency: ≤3kHz

[0051] Inductance parameters: 2 × 0.65mH / 300A

[0052] Capacitor parameters: 3000μF / 1200V.

[0053] This three-level bidirectional DC / DC converter system includes a three-level rectifier-chopper power module, a self-cooled LC device with built-in dual-channel current detection, a cooling fan for the rectifier-chopper power module, a three-level bidirectional DC / DC control unit, a 0-2000V adjustable DC power supply, a power battery, and a DC load of at least 200 kW. It has completed tests on the 200kW three-level bidirectional DC / DC converter under conditions of voltage reduction, voltage increase, sudden load increase, and sudden load decrease. This system has also been successfully operated on a new energy-saving and environmentally friendly hybrid shunting locomotive, achieving the goals of green, energy-saving, environmental protection, and high efficiency. In this embodiment, the following LC device with built-in current detection is used, such as... Figure 4 As shown. An LC device with built-in current detection, such as... Figures 1-3As shown: The system includes a mounting base plate 1, on which two inductors 2 and one capacitor 3 are mounted. The two inductors 2 are a positive input inductor 201 and a negative output inductor 202, respectively. The positive input inductor 201 and the negative output inductor 202 are arranged side-by-side, and the bottom surface has a built-in inductor support frame 203. The inductor support frame 203 is mounted on the mounting base plate 1 by several bolts. The iron cores at the top of the positive input inductor 201 and the negative output inductor 202 are clamped by metal clamps 204 on both sides and secured with bolts. A fastening end I 205 is provided in the middle of the metal clamps 204 on both sides. The fastening end I 205 is connected to the corresponding fastening end II 206 on the inductor support frame 203 by long bolts 207. The positive input inductor 201... The front of the inductor 201 is connected to a DC / DC positive input copper busbar 208, and the rear is connected to a DC / DC positive output copper busbar 213. The front of the negative output inductor 202 is connected to a DC / DC negative output copper busbar 209, and the rear is connected to a DC / DC negative input copper busbar 214. Both the DC / DC positive input copper busbar 208 and the DC / DC negative output copper busbar 209 have pre-drilled double-hole electrical connection ports. The DC / DC positive input copper busbar 208 is secured by a U-shaped insulating plate 210, and the DC / DC negative output copper busbar 209 is also secured by a U-shaped insulating plate 210. Both insulating plates 210 are fastened to metal clamps 204 by two bolts passing through corresponding insulating posts 211. The positive input inductor 201... The DC / DC positive output copper busbar 213 is connected to the DC positive input copper busbar 4, and the DC / DC negative input copper busbar 214 of the negative output inductor 202 is connected to the DC negative output copper busbar 7. The other end of the DC positive input copper busbar 4 passes through the DC positive current sensor 5 and is stacked with one end of the DC positive output copper busbar 6. The stacked connection end of the DC positive input copper busbar 4 and the DC positive output copper busbar 6 is bolted to the insulating support terminal I 301 with embedded conductive post on the capacitor 3, realizing the electrical connection between the DC positive input copper busbar 4, the DC positive output copper busbar 6 and the capacitor 3. The middle part of the DC positive output copper busbar 6 is bolted to the insulating support terminal II 302 on the outer wall of the capacitor casing, and the end of the DC positive output copper busbar 6 has a reserved double hole for electrical connection. The DC negative output copper busbar 7 is stacked and connected to one end of the DC negative input copper busbar 9. The stacked connection end of the DC negative output copper busbar 7 and the DC negative input copper busbar 9 is installed on the insulating support terminal Ⅲ303 with embedded conductive post of the capacitor 3 by bolts, realizing the electrical connection of the DC negative output copper busbar 7, the DC negative input copper busbar 9 and the capacitor 3. The other end of the DC negative input copper busbar 9 passes through the DC negative current sensor 8, and its middle part is installed on the insulating support terminal Ⅳ304 of the capacitor shell wall by bolts. The end of the DC negative input copper busbar 9 is reserved with a double hole electrical connection port. The DC positive current sensor 5 and the DC negative current sensor 8 are both installed and fixed by the current sensor support frame 12 set on the top of the capacitor 3.The bottom support frame of the capacitor 3 is mounted on the mounting base plate 1 by multiple bolts. A connecting piece 10 is also fixed to the top of the end of the capacitor 3 closest to the inductor 2. The connecting piece 10 is fastened to the fastening ends I205 on both sides of the metal clamp 204 of the inductor 2 by a long bolt A13. The edge of the metal clamp 204 located between the inductor 2 and the capacitor 3 is connected to the bottom support frame of the capacitor 3 by a Z-shaped connecting rod 11, thus connecting the inductor 2 and the capacitor 3 as a single unit.

[0054] This embodiment employs the following preferred solutions: the inductor 2 is self-cooled; a thermistor is embedded in the location of the inductor 2 where heat generation is severe, and the thermistor is connected to the DC / DC control system; the inductor 2 is mounted on the mounting base plate 1 using four M12 bolts; the capacitor 3 is mounted on the mounting base plate 1 using two M14 and two M8 bolts; the DC / DC positive input copper busbar 208 is connected to the positive current input port of the three-level bidirectional DC / DC circuit, and the DC / DC negative output copper busbar 209 is connected to the negative current output port of the three-level bidirectional DC / DC circuit; the DC positive output copper busbar 6 is connected to the positive current output port of the three-level bidirectional DC / DC circuit, and the DC negative input copper busbar 9 is connected to the negative current input port of the three-level bidirectional DC / DC circuit; the material selection and heat dissipation of the inductor 2 and capacitor 3 take into account the application at an altitude of 5100m. Figure 4 As shown, the LC device with built-in current detection of the present invention consists of a self-cooled inductor L1 (L1-1 is the positive input inductor 201, and L1-2 is the negative output inductor 202), a filter support capacitor C3, i.e., capacitor 3, current sensors TA1 and TA2 for current detection in the positive and negative circuits, and corresponding copper busbars. TA1 is a DC positive current sensor 5, and TA2 is a DC negative current sensor 8.

[0055] The specific operation of this embodiment is as follows: the port of the DC / DC positive input copper busbar 208 is connected to the positive current inflow circuit of the three-level bidirectional DC / DC circuit, the port of the DC / DC negative output copper busbar 209 is connected to the negative current outflow circuit, the port of the DC positive output copper busbar 6 is connected to the positive current outflow circuit, and the DC negative input copper busbar 9 is connected to the negative current inflow circuit. Through this LC device, the three-level bidirectional DC / DC circuit can realize the functions of buck chopping and boost chopping. It can smooth the wave and suppress the current in buck chopping, and store energy in boost chopping. The DC positive current sensor 5 and the DC negative current sensor 8 have dual redundant current sampling, which improves the accuracy and redundancy of the system sampling. Moreover, the double hole double bolt electrical connection makes the connection firm and improves safety.

[0056] The scope of protection claimed by this invention is not limited to the specific embodiments described above. Moreover, for those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An LC device with built-in current detection, characterized in that: The system includes a mounting base plate (1), on which two inductors (2) and a capacitor (3) are mounted. The two inductors (2) are a positive input inductor (201) and a negative output inductor (202), respectively. The positive input inductor (201) and the negative output inductor (202) are arranged side by side, and the bottom surface has a built-in inductor support frame (203). The inductor support frame (203) is mounted on the mounting base plate (1) by several bolts. The iron cores at the top of the positive input inductor (201) and the negative output inductor (202) are clamped by metal clamps (204) on both sides and fastened by bolts. The metal clamps (204) on both sides are provided with fastening end I (205) in the middle. The fastening end I (205) is connected to the corresponding fastening end II (206) on the inductor support frame (203) by long bolts (207). The positive input inductor (201) is connected to a DC / DC positive input copper busbar (208) at the front and a DC / DC positive output copper busbar (213) at the rear. The negative output inductor (202) is connected to a DC / DC negative output copper busbar (209) at the front and a DC / DC negative input copper busbar (214) at the rear. Both the DC / DC positive input copper busbar (208) and the DC / DC negative output copper busbar (209) have reserved double-hole electrical connection ports. The DC / DC positive input copper busbar (208) is pressed and secured by a Z-shaped insulating plate (210). The DC / DC negative output copper busbar (209) is also pressed and secured by a Z-shaped insulating plate (210). Both insulating plates (210) are fastened to the metal clamp (204) by two bolts passing through the corresponding insulating posts (211). The DC / DC positive output copper busbar (213) of the positive input inductor (201) is connected to the DC positive input copper busbar (4), and the DC / DC negative input copper busbar (214) of the negative output inductor (202) is connected to the DC negative output copper busbar (7); the other end of the DC positive input copper busbar (4) passes through the DC positive current sensor (5) and is superimposed on one end of the DC positive output copper busbar (6). The superimposed connection end of the DC positive input copper busbar (4) and the DC positive output copper busbar (6) is bolted to the insulating support terminal I (301) with embedded conductive post of the capacitor (3) to realize the electrical connection between the DC positive input copper busbar (4), the DC positive output copper busbar (6) and the capacitor (3); the middle part of the DC positive output copper busbar (6) is bolted to the insulating support terminal II (302) of the capacitor shell wall, and the end of the DC positive output copper busbar (6) is reserved with a double hole electrical connection port; the DC negative output copper busbar (6) is bolted to the insulating support terminal II (302) of the capacitor shell wall. The other end of the output copper busbar (7) is stacked and connected to one end of the DC negative input copper busbar (9). The stacked connection end of the DC negative output copper busbar (7) and the DC negative input copper busbar (9) is installed on the insulating support terminal Ⅲ (303) with embedded conductive pillars of the capacitor (3) by bolts, so as to realize the electrical connection of the DC negative output copper busbar (7), the DC negative input copper busbar (9) and the capacitor (3). The other end of the DC negative input copper busbar (9) passes through the DC negative current sensor (8), and its middle part is installed on the insulating support terminal Ⅳ (304) of the capacitor shell wall by bolts. The end of the DC negative input copper busbar (9) has a reserved double hole electrical connection port. The DC positive current sensor (5) and the DC negative current sensor (8) are both installed and fixed by the current sensor support frame (12) set on the top of the capacitor (3). The support frame at the bottom of the capacitor (3) is installed on the mounting base plate (1) by multiple bolts. A connecting piece (10) is also fixed to the top of the end of the capacitor (3) that is close to the inductor (2). The connecting piece (10) is fastened to the fastening end I (205) on both sides of the metal clamp (204) of the inductor (2) by a long bolt A (13). The edge of the metal clamp (204) located between the inductor (2) and the capacitor (3) is connected to the support frame at the bottom of the capacitor (3) by a Z-shaped connecting rod (11), so that the inductor (2) and the capacitor (3) are connected as one unit.

2. The LC device with built-in current detection according to claim 1, characterized in that: The inductor (2) is a self-cooling heat dissipation method.

3. The LC device with built-in current detection according to claim 1, characterized in that: A thermistor is embedded in the location where the inductor (2) generates severe heat, and the thermistor is connected to the DC / DC control system.

4. The LC device with built-in current detection according to claim 1, characterized in that: The inductor (2) is mounted on the mounting base plate (1) by four M12 bolts; the capacitor (3) is mounted on the mounting base plate (1) by two M14 bolts and two M8 bolts.

5. An LC device with built-in current detection according to claim 1, characterized in that: The DC / DC positive input copper busbar (208) is connected to the positive current input port of the three-level bidirectional DC / DC circuit, and the DC / DC negative output copper busbar (209) is connected to the negative current output port of the three-level bidirectional DC / DC circuit.

6. An LC device with built-in current detection according to claim 5, characterized in that: The DC positive output copper busbar (6) is connected to the positive current output port of the three-level bidirectional DC / DC circuit, and the DC negative input copper busbar (9) is connected to the negative current input port of the three-level bidirectional DC / DC circuit.

7. An LC device with built-in current detection according to claim 1, characterized in that: The material selection and heat dissipation of the inductor (2) and capacitor (3) are considered for applications at an altitude of 5100m.

8. The application of the LC device with built-in current detection according to claim 1, characterized in that: The LC device is used in a three-level bidirectional DC / DC circuit as follows: it functions as a smoothing and current suppression device during step-down and as an energy storage device during step-up.

9. The application of the LC device with built-in current detection according to claim 7, characterized in that: It is suitable for environments below 5100m altitude.

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