A frequency converter

Abstract

The utility model discloses a frequency converter, include: box and install rectification module, inverter module, heat abstractor in the box inside, rectification module with inverter module is connected, heat abstractor installs rectification module and inverter module's back side, inverter module includes: a plurality of groups IGBT, and the IGBT at least one end side by side is provided with a plurality of terminals, and the buckle is installed between the terminal, the card pin in the buckle is located the end of body part, and the body part is higher than the portion of the upper side of card pin forms the blocking surface, when the buckle inserts between the terminal, the card pin is connected between the terminal, and the blocking surface is with the outer surface of IGBT abuts, and carries out the location, the utility model discloses through assembling the buckle between the conductive part of IGBT different potential, to increase its electrical distance and the creepage distance, prevents the insulation breakdown and the risk of electric leakage under high voltage.

Description

Technical Field

[0001] This utility model relates to the field of industrial automation control technology, specifically to a frequency converter. Background Technology

[0002] A frequency converter (VFD) is a power control device that uses frequency conversion technology and microelectronics to control an AC motor by changing the frequency of the power supply. It mainly consists of a rectifier module (AC to DC), an inverter module (DC to AC), and heat dissipation components. The VFD adjusts the voltage and frequency of the output power supply by switching its internal insulated-gate bipolar transistors (IGBTs), providing the required power voltage according to the actual needs of the motor, thereby achieving energy saving and speed regulation. In addition, the VFD has many protection functions, such as overcurrent, overvoltage, and overload protection. With the continuous improvement of industrial automation, VFDs have been widely used.

[0003] In fields such as industrial drives, renewable energy, and power electronics systems, modularly packaged IGBTs are commonly used, especially the industrial-grade IGBT module standard package form Economual (e.g., from Infineon). Figure 1 As shown in the figure, its core features are an optimized balance between cost and performance, high power density and heat dissipation, and standardization and easy integration. However, after prolonged use, dust and other contaminants can easily accumulate on the insulating surfaces between conductive components at different potentials in Economial-packaged IGBTs. This leads to a shortening of the electrical and creepage distances between conductive parts, affecting the stability of the IGBT and potentially causing insulation breakdown and leakage risks under high voltage. Utility Model Content

[0004] The purpose of this invention is to provide a frequency converter that increases the electrical and creepage distances by assembling clips between conductive parts of the IGBT at different potentials, thereby preventing insulation breakdown and leakage risks under high voltage. To achieve the above objective, this invention adopts the following technical solution: This utility model discloses a frequency converter, including: a housing and a rectifier module, an inverter module, and a heat dissipation component installed inside the housing.

[0005] The rectifier module is connected to the inverter module, and the heat dissipation component is installed on the rear side of the rectifier module and the inverter module.

[0006] The inverter module includes: several groups of IGBTs, each IGBT having several terminals arranged side by side at at least one end, and the terminals being fitted with clips.

[0007] The latch includes a body and a locking foot. The locking foot is located at the end of the body, and the upper side of the locking foot is lower than the upper side of the body. The portion of the body that is higher than the upper side of the locking foot forms a stop. When the latch is inserted between the terminals, the locking foot engages between the terminals, and the stop abuts against the outer surface of the IGBT for limiting its position.

[0008] The buckle has a T-shaped body, and the buckle foot is located at the non-vertical end of the body. The upper side of the buckle foot is an arc surface that curves downward on both sides.

[0009] Preferably, the ends of the locking feet extend to both sides to form limiting protrusions, and the length of the locking feet is greater than the width of the terminals. When the latch is inserted between the terminals, the ends of the locking feet extend beyond the terminals. Furthermore, a through groove is provided in the middle of the locking feet to divide them into left and right parts.

[0010] Furthermore, the IGBT has a first terminal at its DC input terminal and a second terminal at its AC output terminal, and the latch is installed between the first terminals.

[0011] Furthermore, the rectifier module includes a rectifier connected to the second terminal of the AC output terminal of the IGBT, and a Hall switch is installed on the line between the rectifier and the IGBT.

[0012] Furthermore, the heat dissipation assembly includes a heat sink and a fan, the rectifier module and the inverter module are mounted on the heat sink, and several fans are provided and horizontally mounted on the top of the heat sink.

[0013] The heat dissipation assembly further includes a flow guide plate, which is installed on the rear side of the heat sink and has both ends bent outward.

[0014] Preferably, the housing has a plurality of heat dissipation holes arranged in an array at the bottom of the air guide plate, and the heat dissipation holes are located on the side plates and bottom plate on both sides of the housing.

[0015] Furthermore, the inverter also includes a capacitor, which is connected to the rectifier module and the inverter module respectively.

[0016] Preferably, the frequency converter further includes a contactor and a current-limiting resistor, wherein the contactor is connected to the rectifier module and the capacitor respectively, and the current-limiting resistor is connected to the rectifier module and the contactor respectively.

[0017] After adopting the above technical solution, the present invention has the following effects: The IGBT in this invention adopts an Economial package. While ensuring that the distance between conductive parts at different potentials of the IGBT meets international standards, insulating clips are installed between the conductive parts to increase the electrical distance and creepage distance. This prevents dust and other contaminants accumulated over long-term use from shortening the electrical distance and creepage distance between conductive parts at different potentials, thus preventing insulation breakdown and leakage under high voltage. Attached Figure Description

[0018] Figure 1 This is a 3D structural diagram of an IGBT in Economual packaging.

[0019] Figure 2 This is a three-dimensional structural diagram of the buckle in this utility model.

[0020] Figure 3 This is a three-dimensional structural diagram of the clip-on installation of the IGBT in this utility model.

[0021] Figure 4 This is a schematic diagram of the installation of the clip and the IGBT in this utility model.

[0022] Figure 5 This is a bottom structural diagram of the buckle mounted on the IGBT in this utility model.

[0023] Figure 6 This is a three-dimensional structural diagram of the present invention.

[0024] Figure 7 This is a bottom structural diagram of the present invention.

[0025] Figure 8 This is a top view of the present invention.

[0026] Figure 9 for Figure 8 AA section view.

[0027] Figure 10 for Figure 8 BB-direction cross-sectional view.

[0028] Figure 11 This is a diagram of the internal structure of this utility model.

[0029] Figure 12 for Figure 11 The C-direction view.

[0030] Figure 13 This is an elevation view of the internal structure of this utility model.

[0031] Main component symbols: 1: Housing; 11: Heat dissipation hole; 2: Rectifier module; 21: Rectifier; 3: Inverter module; 31: IGBT; 311: First terminal; 312: Second terminal; 32: Snap-in; 321: Main body; 322: Clip; 323: Limiting protrusion; 324: Abutment; 325: Through slot; 4: Heat dissipation assembly; 41: Heat sink; 42: Fan; 43: Air guide plate; 5: Hall switch; 6: Capacitor; 7: Contactor; 8: Current limiting resistor. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] like Figure 6 and Figure 11 As shown, this utility model discloses a frequency converter, including: a housing 1 and a rectifier module 2, an inverter module 3, and a heat dissipation component 4 installed inside the housing 1.

[0034] The rectifier module 2 is connected to the inverter module 3, and the heat dissipation component 4 is installed on the rear side of the rectifier module 2 and the inverter module 3.

[0035] The rectifier module 2 and the inverter module 3 are connected by wires or connecting plates (in this embodiment, all connections between electronic components are made using copper connecting plates, which can ensure good conductivity while avoiding short circuits or disconnections due to excessive moisture in the air). That is, the DC output terminal of the rectifier module 2 is connected to the copper connecting plate, and the DC input terminal of the inverter module 3 obtains power from the copper connecting plate.

[0036] Combination Figures 1 to 5 As shown, the inverter module 3 includes several sets of insulated gate bipolar transistors (IGBTs) 31. The IGBTs 31 are in economical packages, meaning that each IGBT 31 has a pair of terminals on its DC input terminal (DC terminal) and AC output terminal (AC terminal). The DC terminal is the first terminal 311, and the AC terminal is the second terminal 312. A latch 32 is installed between the first terminals 311.

[0037] The latch 32 includes a body portion 321 and a latch 322. The latch 322 is located at the end of the body portion 321, and the upper side of the latch 322 is lower than the upper side of the body portion 321. The portion of the body portion 321 that is higher than the upper side of the latch 322 forms a stop surface 324. When the latch 32 is inserted between the first terminals 311, the latch 322 engages between the first terminals 311, and the stop surface 324 abuts against the outer surface of the IGBT 31 for limiting its position.

[0038] In this embodiment, the body portion 321 of the latch 32 is T-shaped, and the latch foot 322 is disposed at the end of the vertical end of the body portion 321. The upper side of the latch foot 322 is an arc surface that curves downward on both sides. The T-shaped body portion 321 facilitates the insertion of the latch 32 between the terminals, and the horizontal end of the body portion 321 can better apply pressure to the latch 32.

[0039] Meanwhile, the ends of the retaining feet 322 extend to the left and right sides to form limiting protrusions 323, and the length of the retaining feet 322 is greater than the width of the first terminal 311. When the latch 32 is inserted between the first terminals 311, the ends of the retaining feet 322 extend beyond the first terminals 311. Furthermore, a through groove 325 is provided in the middle of the retaining feet 322 to divide the retaining feet 322 into two parts, left and right. When disassembling the latch 32, the two parts are pressed together and then the latch 32 is pulled out.

[0040] The principle behind installing a clip 32 between the first terminals 311 of the DC input terminal of the IGBT 31 in this invention to increase the electrical distance and creepage distance between the first terminals 311 is as follows: Under normal circumstances, no clips 32 are installed between the first terminals 311 of the DC input of the IGBT 31. In this case, the electrical distance and creepage distance between the first terminals 311 are the straight-line distance 'a' between them, which conforms to international standards. However, after long-term use, dust and other contaminants accumulate on the insulating shell of the first terminals 311, causing the electrical distance and creepage distance between them to shorten. This distance becomes less than the straight-line distance 'a', which does not conform to international standards and can easily lead to insulation breakdown and leakage under high voltage.

[0041] In this invention, a latch 32 is assembled between the first terminals 311, so that the electrons need to move along the surface of the latch 32, thereby increasing the actual electrical distance and creepage distance between the first terminals 311, and avoiding insulation breakdown and leakage under high voltage after long-term use.

[0042] Secondly, combining Figure 13 As shown, in this embodiment, the rectifier module 2 includes a rectifier 21, which is connected to the second terminal 312 of the AC output terminal of the IGBT 31, and a Hall switch 5 is installed on the line between the rectifier 21 and the IGBT 31.

[0043] The most critical function of Hall effect switch 5 in the frequency converter is main circuit current sampling and protection. When current flows through a wire or connector, a magnetic field is generated. Hall effect switch 5 detects the strength of this magnetic field and converts it into a voltage signal proportional to the current magnitude, which is then transmitted to the frequency converter's control unit. The control unit determines whether the current is normal based on the signal. If the current exceeds a set threshold, it immediately triggers protection, cutting off the drive signal of inverter module 3 to prevent IGBT 31 from burning out.

[0044] Furthermore, in this embodiment, the heat dissipation component 4 includes a heat sink 41 and a fan 42. The rectifier module 2 and the inverter module 3 are mounted on the heat sink 41, and two fans 42 are provided and are horizontally mounted on the top of the heat sink 41.

[0045] The heat dissipation assembly 4 further includes a guide plate 43, which is installed on the rear side of the radiator 41, and both ends of the guide plate 43 are bent outwards. Furthermore, the housing 1 has a plurality of arrayed heat dissipation holes 11 at the bottom of the guide plate 43, located on the side plates and bottom plate of the housing 1, such as... Figure 7 As shown.

[0046] Combination Figures 8 to 10 As shown, the working principle of the heat dissipation component 4 in this utility model is as follows: When the fan 42 in the heat dissipation assembly 4 starts running, it accelerates the downward movement of cold air, which enters the radiator 41 and exchanges heat with the interior of the radiator 41. At this time, the bending at the upper end of the guide plate 43 causes the cold air entering the inverter to gather towards the radiator 41, improving heat dissipation efficiency. After the heat exchange is completed, the hot air is discharged from the bottom of the radiator 41 and discharged outside the housing 1 through the heat dissipation holes 11. Since in this embodiment, the heat dissipation holes 11 are located on the side plates and bottom plate on both sides of the housing 1, the bending at the bottom end of the guide plate 43 guides the hot air discharged from the radiator 41 to the back plate of the housing 1, and then disperses and is discharged to both sides.

[0047] In addition, such as Figure 11 and Figure 12 As shown, in this embodiment, the frequency converter also includes: a capacitor 6, a contactor 7, and a current-limiting resistor 8.

[0048] Capacitor 6 is connected to both rectifier module 2 and inverter module 3. The DC output terminal of rectifier module 2 is connected to capacitor 6, with its positive output terminal connected to the positive terminal of capacitor 6 and its negative output terminal connected to the negative terminal of capacitor 6. The DC input terminal of inverter module 3 is connected to capacitor 6, with its positive input terminal connected to the positive terminal of capacitor 6 and its negative input terminal connected to the negative terminal of capacitor 6.

[0049] The purpose of installing capacitor 6 is to filter and smooth the DC voltage output by rectifier module 2. Then, inverter module 3 converts the stable DC power provided by capacitor 6 into AC power with adjustable frequency and voltage.

[0050] Typically, a current-limiting resistor 8 and a contactor 7 are connected between the rectifier module 2 and the capacitor 6. The contactor 7 is connected to both the rectifier module 2 and the capacitor 6, and the current-limiting resistor 8 is connected to both the rectifier module 2 and the contactor 7.

[0051] One end of the current-limiting resistor 8 is connected to the DC output terminal of the rectifier module 2, and the other end is connected to the contactor 7. The other end of the contactor 7 is connected to the capacitor 6. When the rectifier module 2 converts AC power to DC power, the current flows through the current-limiting resistor 8 to the capacitor 6, thus limiting the charging current. When the capacitor 6 is fully charged, the contactor 7 closes, short-circuiting the current-limiting resistor 8. This prevents the current from flowing directly through the contactor 7 to the capacitor 6 instead of through the current-limiting resistor 8, thereby avoiding the voltage drop of the current-limiting resistor 8 from affecting the inverter's output voltage and energy conversion efficiency.

[0052] The above description is only a preferred embodiment of the present utility model. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A frequency converter, characterized in that, include: The enclosure and the rectifier module, inverter module, and heat dissipation components installed inside the enclosure; The rectifier module is connected to the inverter module, and the heat dissipation component is installed on the rear side of the rectifier module and the inverter module; The inverter module includes: several groups of IGBTs, each IGBT having several terminals arranged side by side at at least one end, and the terminals being fitted with clips; The latch includes a body and a latch foot. The latch foot is located at the end of the body, and the upper side of the latch foot is lower than the upper side of the body. The portion of the body that is higher than the upper side of the latch foot forms a stop. When the latch is inserted between the terminals, the latch foot engages between the terminals, and the stop comes into contact with the outer surface of the IGBT for limiting the position.

2. The frequency converter as described in claim 1, characterized in that: The main body of the buckle is T-shaped, the buckle foot is located at the vertical end of the main body, and the upper side of the buckle foot is an arc surface that curves downward on both sides.

3. The frequency converter as described in claim 2, characterized in that: The end of the latch extends to the left and right sides to form a limiting protrusion, and the length of the latch is greater than the width of the terminal. When the buckle is inserted between the terminals, the end of the latch extends beyond the terminal. Furthermore, a through groove is provided in the middle of the latch to divide the latch into two parts, left and right.

4. The frequency converter as described in claim 1, characterized in that: The IGBT has a first terminal at its DC input terminal and a second terminal at its AC output terminal, and the latch is installed between the first terminals.

5. A frequency converter as described in claim 4, characterized in that: The rectifier module includes a rectifier connected to the second terminal of the AC output terminal of the IGBT, and a Hall switch is installed on the line between the rectifier and the second terminal.

6. A frequency converter as described in claim 1, characterized in that: The heat dissipation assembly includes a heat sink and a fan. The rectifier module and the inverter module are mounted on the heat sink, and several fans are provided and horizontally mounted on the top of the heat sink.

7. A frequency converter as described in claim 6, characterized in that: The heat dissipation assembly further includes a flow guide plate, which is installed on the rear side of the heat sink and has both ends bent outward.

8. A frequency converter as described in claim 7, characterized in that: The housing has several arrayed heat dissipation holes at the bottom of the air guide plate, and the heat dissipation holes are located on the side plates and bottom plate of the housing.

9. A frequency converter as described in any one of claims 1-8, characterized in that: Also includes: The capacitors are connected to the rectifier module and the inverter module, respectively.

10. A frequency converter as described in claim 9, characterized in that: Also includes: A contactor and a current-limiting resistor are provided, wherein the contactor is connected to the rectifier module and the capacitor respectively, and the current-limiting resistor is connected to the rectifier module and the contactor respectively.

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