Capacitor with buffer resistor

Abstract

The utility model discloses a capacitor with a buffer resistor, which belongs to the technical field of power electronics and comprises a capacitor body provided with a resistor assembly. The resistor assembly comprises a resistor; the framework is used for winding the resistor; wherein the resistor is connected with the capacitor body; according to the capacitor with the buffer resistor, the buffer resistor is directly combined with the capacitor through an integrated solution according to the application characteristics of a direct current bus capacitor of a frequency converter to form an integrated charging buffer resistor, so that the problems in the traditional design are effectively solved, the use cost of customers is saved, and the starting performance of the frequency converter is improved; and the improvement of the integration level and reliability of the system is promoted.

Description

Technical Field

[0001] The utility model belongs to the technical field of power electronics, and in particular relates to a capacitor with a buffer resistor. Background Art

[0002] With the development of industrial automation technology, frequency converters have become key equipment for motor speed regulation, energy saving and improvement of power quality. In the main circuit of the frequency converter, the capacitor of the DC link plays a vital role. It can store energy and smooth the rectified DC voltage. However, during the startup phase of the frequency converter or when the load suddenly changes, the DC bus capacitor may have a large charging current and discharge current, which will not only have a negative impact on the life of the capacitor itself, but also cause current shock and voltage fluctuation on the grid side, posing a threat to the stability and safety of the frequency converter and even the entire power system. At present, the common practice in the industry is to connect an external charging resistor or buffer resistor in series between the capacitor and the power supply to limit the starting current and reduce the current shock during sudden loading. However, the design of this external resistor has many limitations, such as increasing the complexity of the circuit and occupying space, which is not conducive to the miniaturization and modular design of the equipment, and will also increase the cost and maintenance difficulty. In view of this, it is necessary to develop a new capacitor with buffer resistor to solve the existing problems. Utility Model Content

[0003] The utility model aims to provide a capacitor with a buffer resistor to solve the problem that an external resistor increases the difficulty of maintenance.

[0004] To achieve the above object, the utility model provides the following technical solution: a capacitor with a buffer resistor, including a capacitor body, including:

[0005] The capacitor body is provided with a resistor component;

[0006] The resistor assembly comprises:

[0007] resistance;

[0008] A skeleton for winding the resistor;

[0009] Wherein, the resistor is connected to the capacitor body.

[0010] Preferably, the resistor assembly further includes:

[0011] Insulating material filled in the skeleton;

[0012] An insulating sleeve wrapping the resistor.

[0013] Preferably, the resistor is a resistance wire or an enameled wire.

[0014] Preferably,

[0015] The capacitor body comprises:

[0016] a second conductive part connected to one end of the resistor;

[0017] a metal electrode connected to the other end of the resistor;

[0018] A core package connected to the metal pole;

[0019] A shell that wraps and fixes the core package;

[0020] a third conductive part connected to the housing;

[0021] a first conductive part connected to the housing;

[0022] A cover plate connected to the housing for sealing protection.

[0023] Preferably,

[0024] The metal pole comprises:

[0025] a first metal electrode connected to the first conductive part;

[0026] and a second metal electrode connected to the third conductive part.

[0027] Preferably, the resistor assembly is filled with insulating material.

[0028] Preferably, the portions of the first conductive part, the second conductive part and the third conductive part exposed from the outer shell are coated with insulating material.

[0029] Preferably, the end surfaces of the first conductive part, the second conductive part and the third conductive part are respectively provided with connection terminals or connection points.

[0030] The technical effects and advantages of the utility model are as follows: the capacitor with a buffer resistor is designed with a series RC circuit structure formed by directly connecting the resistor and the metal pole, and is mainly used in capacitor pre-charging, filtering, delay and other links in the power system, and can also be widely used in power electronic products such as frequency converters, switching power supplies, inverters, etc.; at the same time, according to the application characteristics of the DC bus capacitor of the frequency converter, through an integrated solution, the buffer resistor is directly combined with the capacitor to form an integrated charging buffer resistor, which effectively solves the problems in the traditional design, saves customers' use costs, improves the starting performance of the frequency converter, and promotes the improvement of system integration and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a three-dimensional diagram of the utility model;

[0032] Figure 2 This is a wiring diagram of the utility model;

[0033] Figure 3 It is a front view of the utility model;

[0034] Figure 4 For this utility model Figure 3 Middle AA section view;

[0035] Figure 5 This is a schematic diagram of the structure of the utility model without the housing installed;

[0036] Figure 6 It is a three-dimensional diagram of the resistor assembly of the utility model;

[0037] Figure 7 This is a cross-sectional view of the utility model;

[0038] Figure 8 It is a cross-sectional view of the capacitor body of the utility model;

[0039] Fig. 9 It is a schematic diagram of the connection between the utility model and the switch and power supply.

[0040] In the figure: 1. Shell; 2. Conductive parts; 2.1. First conductive parts; 2.2. Second conductive parts; 2.3. Third conductive parts; 3. Cover plate; 4. Core package; 5. Frame; 6. Insulating sleeve; 7. Insulating material; 8. Resistor; 9. Metal pole; 9.1. First metal pole; 9.2. Second metal pole; 10. Resistor assembly; 11. Capacitor body. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0042] The utility model provides Figure 1 , Figure 3 , Figure 4 A capacitor with a buffer resistor is shown in FIG. , and the capacitor body 11 includes:

[0043] The conductive part 2 used to electrically connect the capacitor to the external circuit can also be called a lead pin, a shell 1, a core package 4 wrapped by the shell 1, a metal pole 9 connected to the core package 4 (a conductive part at both ends of the capacitor), and a cover plate 3 for sealing and protection; the top of the conductive part 2 is a threaded hole inlay, etc., which can be wired and is equivalent to a terminal;

[0044] The capacitor body 11 is provided with a resistor component 10;

[0045] The upper and lower ends of the resistor assembly 10 are connected to the second conductive part 2.2 and the first metal electrode 9.1 respectively;

[0046] The first conductive part 2.1 is connected to the first metal electrode 9.1, the third conductive part 2.3 is connected to the second metal electrode 9.2, and the metal electrode 9 is connected to the core package 4 to form a capacitor with a buffer resistor.

[0047] like Figure 5 As shown, the resistor 8 is provided with other parts to form a resistor assembly 10, and the resistor assembly 10 includes a skeleton 5, an insulating sleeve 6, an insulating material 7, and a resistor 8; the resistor 8 is wound on the skeleton 5, the insulating sleeve 6 wraps the resistor 8, and the skeleton 5 is filled with the insulating material 7; the upper and lower ends of the resistor 8 are respectively connected to the second conductive part 2.2 and one of the metal poles 9, and a sufficient insulation distance is ensured according to the capacitor withstand voltage, and this insulation distance is determined according to the minimum electrical clearance in the national standard 14048.1;

[0048] The resistor can be a resistance wire or enameled wire, etc. The resistance value of the resistor 8 is adjustable, and by changing the length and cross-sectional area of ​​the resistor 8 or selecting materials with different resistivity, it can adapt to different circuit application requirements, such as changing the pre-charging time, adjusting the filtering frequency or the delay time, etc.;

[0049] The capacitor may have a built-in or external resistor component 10. If the resistor component 10 is inside the capacitor, the space where the resistor component 10 is located may be filled with insulating materials 7 such as insulating glue; if the resistor component 10 is outside the capacitor, the exposed conductive parts 2 may be coated with insulating paint or the like for insulation treatment;

[0050] like Figure 2 , Figure 7 , Fig. 9 As shown, Figure 2In the embodiment, L1 and L2 are main circuit terminals; R is resistor 8; C is core package 4; A1 and A2 are external switch terminals. In this embodiment, terminal 2 is the resistor terminal. The capacitor has three terminals. One electrode L1 of the power supply is connected to terminal 2, and the other electrode L2 of the power supply is connected to terminal 3. The above-mentioned electrodes can be the positive or negative electrodes of the power supply without distinction. A switch is externally connected between terminal 2 and terminal 1 (the last terminal). In this embodiment, the switch is a contactor, which is connected in parallel with the resistor component 10. When the product is charged, the external switch is disconnected, and the current will charge the capacitor through resistor 8. When the charging is completed, the external switch is closed, and the current bypasses resistor 8 and flows into the capacitor from the last terminal, namely terminal 1, to bypass the resistor. The two terminals of the power supply terminal are connected to terminal 2 and terminal 3, and terminals 1 and 2 are externally connected to switches. Terminal 1 is indirectly connected to the power supply through an external switch, thereby completing the entire pre-charging process and realizing an integrated capacitor charging solution without impact current.

[0051] Finally, it should be noted that the above is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A capacitor with a buffer resistor, comprising a capacitor body (11), characterized in that: The capacitor body (11) is provided with a resistor component (10); The resistor assembly (10) comprises: Resistor(8); A skeleton (5) for winding the resistor (8); The resistor (8) is connected to the capacitor body (11).

2. A capacitor with a buffer resistor according to claim 1, characterized in that: The resistor assembly (10) further comprises: Insulating material (7) filled in the skeleton (5); An insulating sleeve (6) wrapping the resistor (8).

3. A capacitor with a buffer resistor according to claim 1 or 2, characterized in that: The resistor (8) is a resistance wire or an enameled wire.

4. A capacitor with a buffer resistor according to claim 1, characterized in that: The capacitor body (11) comprises: A second conductive part (2.2) connected to one end of the resistor (8); A metal electrode (9) connected to the other end of the resistor (8); A core package (4) connected to the metal electrode (9); A shell (1) encapsulating and fixing the core package (4); A third conductive part (2.3) connected to the housing (1); A first conductive part (2.1) connected to the housing (1); A cover plate (3) connected to the housing (1) for sealing protection.

5. A capacitor with a buffer resistor according to claim 4, characterized in that: The metal electrode (9) comprises: A first metal electrode (9.1) connected to the first conductive part (2.1); and a second metal pole (9.2) connected to the third conductive part (2.3).

6. A capacitor with a buffer resistor according to claim 4 or 5, characterized in that: The resistor component (10) is filled with insulating material (7).

7. A capacitor with a buffer resistor according to claim 4 or 5, characterized in that: The portions of the first conductive part (2.1), the second conductive part (2.2) and the third conductive part (2.3) exposed from the housing (1) are coated with insulating material (7).

8. A capacitor with a buffer resistor according to claim 7, characterized in that: The end surfaces of the first conductive part (2.1), the second conductive part (2.2) and the third conductive part (2.3) are respectively provided with connection terminals or connection points.

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