Brake cooling resistor of frequency converter

Abstract

The utility model discloses a brake cooling resistor of a frequency converter. The brake cooling resistor comprises a cooling unit and a resistor unit, the cooling unit comprises a plurality of stacked cooling shells, resistor cavities are formed in the cooling shells, cooling cavities located on the two sides of the resistor cavities are formed in the cooling shells, the resistor unit comprises a plurality of spring-shaped resistor monomers which are located in the resistor cavities and arranged, and the adjacent resistor monomers are isolated through mica partition plates; the resistor cavity is internally provided with fixing porcelain pieces which are arranged at intervals front and back and allow the resistor monomers to pass through. The resistor provided by the utility model is formed by superposing a plurality of groups of resistor unit modules, so that the integral structure is compact and stable; the cooling structure adopts a parallel structure and is fully isolated from an electric appliance structure, so that the cooling effect is good, and higher safety and reliability are realized; and meanwhile, the resistor monomer adopts a spring-shaped structure and is fixed through the porcelain piece and the mica partition plate, so that the resistor has the advantages of high insulating property, strong combination universality, large energy density, good impact resistance, high production efficiency, low cost and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of resistors, in particular to a frequency converter braking cooling resistor. Background Art

[0002] When the motor stops quickly, a large amount of regenerative energy will be generated due to inertia. If this part of regenerative energy is not consumed in time, it will directly act on the DC circuit part of the inverter, which may cause the inverter to malfunction or be damaged. The above situation involves the problem of energy consumption braking of the inverter.

[0003] When the motor or other load driven by the inverter stops, it is generally realized by energy consumption braking, that is, the kinetic energy of the motor after stopping and the magnetic energy in the coil are consumed through another energy-consuming element, so as to achieve rapid stopping. When the power supply stops, the inverter circuit of the inverter conducts in the reverse direction, and feeds back the remaining electric energy to the DC bus of the inverter. The voltage on the DC bus will increase as a result. When it increases to a certain value, the braking resistor of the inverter will be put into operation, so that this part of the electric energy is consumed by the heating of the resistor, while maintaining the voltage on the DC bus at a normal level.

[0004] When inverter brake resistors are used in special environments, they require frequent braking, high voltage, and water cooling to remove the heat generated by energy-consuming braking. Existing resistors are difficult to meet the requirements. For example, due to their structural characteristics, winding resistors have small thermal capacity and large volume, which cannot meet the requirements; steel sheet resistors have the disadvantage of being large in volume and expensive, and can only dissipate heat naturally; other water-cooling structures make electric heating alloys into electric heating tubes, which are immersed in water and use water circulation to remove heat. Not only is the water circulation system structure complex and the maintenance cost high, but the service life is also short and the insulation performance is poor. Utility Model Content

[0005] In view of the defects in the prior art, the purpose of the utility model is to provide a frequency converter brake cooling resistor with water-electricity separation, good insulation performance, small size, simple structure; as well as the advantages of strong combination versatility, good impact resistance, low temperature drift, and low cost.

[0006] The technical solution adopted by the utility model is: a frequency converter braking cooling resistor, including a cooling unit and a resistance unit; the cooling unit includes a plurality of stacked cooling shells, a resistance cavity is arranged in the cooling shells, cooling cavities located on both sides of the resistance cavity are arranged in the cooling shells, and a circulating cooling mechanism connected to the cooling cavity is arranged outside the cooling shells; the resistance unit includes a plurality of spring-shaped resistance monomers located in and arranged in each resistance cavity, adjacent resistance monomers are isolated by mica partitions, front and rear spacing arrangements are arranged in the resistance cavity for the resistance monomers to pass through fixed porcelain parts, and front and rear ends of the resistance cavity are also provided with front porcelain parts and rear porcelain parts for fixing the resistance monomers.

[0007] The resistor provided in the technical solution has a cooling structure and an insulating structure. The resistor unit adopts a superimposed installation structure to install the resistor monomer in the resistor cavity of each cooling shell. The cooling cavity located inside the cooling shell adopts a circulating cooling structure to achieve liquid cooling heat dissipation. The cooling structure with water and electricity separation has a better cooling effect. At the same time, the resistor monomer adopts a spring-like structure and is fixed by porcelain parts and mica partitions. It is beneficial to improve the compactness of the resistor, and at the same time has the advantages of high insulation performance, strong combination versatility, high energy density, good impact resistance, low temperature drift, simple structure, high production efficiency, and low cost.

[0008] Preferably, the circulating cooling mechanism includes a water inlet joint and a water outlet joint located at the end of the cooling shell, the water inlet joint is connected to the cooling chamber on one side of each cooling shell through a diverter, and the water outlet joint is connected to the cooling chamber on the other side of each cooling shell through a diverter, and each cooling shell is provided with parallel water pipes connecting the cooling chambers on both sides of the resistance chamber on both sides of one end away from the water inlet joint and the water outlet joint.

[0009] Preferably, the end of the cooling shell is provided with a front installation port for leading out the resistor unit wire, and the front installation port is provided with a front welding plate, a front sealing wet sand, a front mica baffle and a front aluminum plate arranged from the inside to the outside, and both ends of the aluminum plate are provided with lead-out porcelain parts sleeved on the wire.

[0010] Preferably, a heat insulation board and an insulating board arranged from inside to outside are provided on the outside of the cooling shell corresponding to the front installation opening, and a wiring copper busbar installed on the insulating board through an insulator is provided on the outside of the insulating board.

[0011] Preferably, a rear mounting opening is provided at one end of the cooling shell away from the front mounting opening, and the rear mounting opening is provided with a rear mica baffle, a rear sealing wet sand, and a rear aluminum plate arranged from inside to outside.

[0012] Preferably, the top wall and side walls of the resistor cavity are provided with wide pads and narrow pads respectively.

[0013] Preferably, it also includes an installation unit, which includes a base located below the cooling shell, and the base has an inverted U-shaped fixed frame on both sides corresponding to the front and rear ends of the cooling shell, and the fixed frame is provided with a joint bracket connecting the water inlet joint and the water outlet joint.

[0014] Preferably, a bottom plate is provided between the base and the cooling shell.

[0015] The beneficial effects of the utility model are as follows: the resistor provided by the utility model is formed by stacking a plurality of groups of resistor unit modules, and the overall structure is compact and stable through the assembly of the installation units; the cooling structure adopts a parallel structure and is fully isolated from the electrical structure, which not only has a good cooling effect but is also safer and more reliable; at the same time, the resistor monomer adopts a spring-like structure and is fixed by a porcelain part and a mica partition, which is beneficial to improving the compactness of the resistor, and at the same time has the advantages of high insulation performance, strong combination versatility, high energy density, good impact resistance, low temperature drift, simple structure, high production efficiency, low cost, etc.; it has high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the specific implementation or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0017] Figure 1 The three-dimensional structure of the inverter brake cooling resistor provided in the embodiment of the utility model Figure 1 .

[0018] Figure 2 The three-dimensional structure of the inverter brake cooling resistor provided in the embodiment of the utility model Figure 2 .

[0019] Figure 3 The resistor monomer explosion of the inverter brake cooling resistor provided in the embodiment of the utility model Figure 1 .

[0020] Figure 4 The resistor monomer explosion of the inverter brake cooling resistor provided in the embodiment of the utility model Figure 2 .

[0021] Figure numerals: cooling shell 100, resistor monomer 200, mica partition 300, fixed porcelain part 400, front porcelain part 500, rear porcelain part 600, water inlet joint 700, water outlet joint 800, diverter 900, parallel water pipe 1000, front welding plate 1100, front sealing wet sand 1200, front mica baffle 1300, front aluminum plate 1400, outlet porcelain part 1500, conductor 1600, heat insulation board 1700, insulating board 1800, insulator 1900, wiring copper bus 2000, rear mica baffle 2100, rear sealing wet sand 2200, rear aluminum plate 2300, wide pad 2400, narrow pad 2500, base 2600, fixed frame 2700, joint bracket 2800. DETAILED DESCRIPTION

[0022] The following embodiments of the technical solution of the utility model are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and are therefore only used as examples, and cannot be used to limit the protection scope of the utility model.

[0023] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by technicians in the field to which the utility model belongs.

[0024] Embodiment 1

[0025] like Figures 1 to 4 As shown, a specific embodiment of the utility model provides a frequency converter braking cooling resistor, which has good cooling effect, compact size and good insulation; specifically comprises a cooling unit and a resistance unit; the cooling unit comprises a plurality of stacked cooling shells 100, a resistance cavity is arranged in the cooling shell 100, cooling cavities located on both sides of the resistance cavity are arranged in the cooling shell 100, and a circulating cooling mechanism connected to the cooling cavity is arranged outside the cooling shell 100; the resistance unit comprises a plurality of spring-shaped resistance monomers 200 located and arranged in each resistance cavity, adjacent resistance monomers 200 are isolated by mica partitions 300, front and rear intervals are arranged in the resistance cavity for the resistance monomers 200 to pass through the fixed porcelain parts 400, and front and rear ends of the resistance cavity are also provided with front porcelain parts 500 and rear porcelain parts 600 for fixing the resistance monomers 200.

[0026] like Figures 1 to 4 As shown, through the above arrangement, the resistor in this embodiment has a cooling structure and an insulating structure. The cooling shell 100 adopts a stacking arrangement so that each resistor monomer 200 of the resistor unit can be installed in each resistor cavity. The cooling cavity located inside the cooling shell 100 adopts a circulating cooling structure to achieve liquid cooling heat dissipation, and the cooling structure with water and electricity separation has a better cooling effect; at the same time, the resistor monomer 200 adopts a spring-like structure and is fixed by a porcelain part and a mica partition 300; it is beneficial to improve the compactness of the resistor, and at the same time, the insulation performance is high, the combination of the stacking structure is strong in versatility, high in energy density, good in impact resistance, and low in temperature drift; the overall structure is simple and reasonable, and has the advantages of high production efficiency and low cost.

[0027] like Figures 1 to 4As shown, in this embodiment, the resistor monomer 200 is wound into a spring shape, which has high strength and is easy to process in batches. The desired resistance value can be achieved by adjusting the number of winding turns and spacing parameters, especially the iron-chromium alloy material has a low temperature drift characteristic; the mica partition 300 is made of insulating and high-temperature resistant mica material, and the fixed porcelain part 400 is made of 95 porcelain material. The two are used together to fix the spring-shaped resistor, and the isolation between the spring-shaped resistors prevents the spring-shaped resistors from contacting each other due to thermal deformation after the resistor energy impact; in addition, the cooling shell 100 is formed by extrusion and drawing, and then welded by stir friction welding of the water channel, and then finely processed.

[0028] like Figures 1 to 4 As shown in the figure, in actual application, the above resistor has the working characteristics of short time (millisecond level) and large energy (megajoule level): when the inverter is braking, the motor regenerative energy is directly converted into heat energy, which is quickly absorbed and dissipated by the water-cooled resistor to prevent the motor regenerative energy from damaging the inverter. The resistor body is located inside the aluminum shell and is completely isolated from the water circuit. The resistor can also conduct heat to the outside of the cooling shell by arranging magnesium oxide powder, and the heat is taken away by the coolant in the cooling cavity; due to the full separation of water and electricity, the cooling structure has high safety performance.

[0029] like Figures 1 to 4 As shown, the circulating cooling mechanism for cooling the resistor unit in this embodiment includes a water inlet joint 700 and a water outlet joint 800 located at the end of the cooling shell 100. The water inlet joint 700 is connected to the cooling cavity on one side of each cooling shell 100 through a diverter 900, and the water outlet joint 800 is connected to the cooling cavity on the other side of each cooling shell 100 through a diverter 900. Parallel water pipes 1000 are provided on both sides of one end of each cooling shell 100 away from the water inlet joint 700 and the water outlet joint 800, which are connected to the cooling cavities on both sides of the resistor cavity. In this way, the coolant can circulate through the water inlet joint 700 and the water outlet joint 800 through the diverter 900 structure, and a complete parallel water circuit is formed under the action of the parallel water pipe 1000; the resistor in each cooling shell 100 can be cooled and dissipated at the same time, and the cooling effect is better. In the drawings of this embodiment, four layers of cooling shells 100 are superimposed, and the water circuit adopts a parallel structure to reduce the pressure difference and flow resistance of the water inlet and outlet, which is suitable for standard design and mass production.

[0030] like Figures 1 to 4As shown, in this embodiment, a wiring structure is provided on the cooling housing 100, specifically, a front installation port for leading out the wire 1600 of the resistor monomer 200 is provided at the end of the cooling housing 100, and the front installation port is provided with a front welding plate 1100, a front sealing wet sand 1200, a front mica baffle 1300 and a front aluminum plate 1400 arranged from the inside to the outside, and a lead-out porcelain piece 1500 sleeved on the wire 1600 is provided at both ends of the aluminum plate; in addition, a heat insulation plate 1700 and an insulating plate 1700 arranged from the inside to the outside are provided on the outer side of the cooling housing 100 corresponding to the front installation port. The insulating plate 1800 is provided with a copper busbar 2000 installed on the insulating plate 1800 through an insulator 1900 on the outside of the insulating plate 1800; when installing, the copper busbar 2000 is connected with a cable, which is more convenient for wiring and assembly, and the connection safety is higher; in order to assemble the rear end of the cooling shell 100, the cooling shell 100 of this embodiment is provided with a rear installation opening at one end away from the front installation opening, and the rear installation opening is provided with a rear mica baffle 2100, a rear sealing wet sand 2200, and a rear aluminum plate 2300 arranged from the inside to the outside. The top wall and side wall of the resistor cavity are respectively provided with a wide pad 2400 and a narrow pad 2500 to further improve the resistor insulation effect and installation stability.

[0031] Embodiment 2

[0032] like Figures 1 to 4 As shown, this embodiment also provides an installation unit structure for fixing and assembling the entire resistance structure, and the installation unit includes a base 2600 located below the cooling housing 100, and the base 2600 is provided with an inverted U-shaped fixed frame 2700 on both sides corresponding to the front and rear ends of the cooling housing 100, and the fixed frame 2700 is provided with a joint bracket 2800 connecting the water inlet joint 700 and the water outlet joint 800, and a bottom plate is provided between the base 2600 and the cooling housing 100. In actual application, the fixed frame 2700 can be fixed from all sides of the cooling housing 100 with the core-pulling rivets 13, and the base 2600 is also fixed from the bottom with the core-pulling rivets.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model, and they should all be included in the scope of the claims and specification of the utility model.

Claims

1. A frequency converter braking cooling resistor, characterized in that; including a cooling unit and a resistance unit; The cooling unit comprises a plurality of stacked cooling shells (100), a resistance cavity is provided in the cooling shell (100), cooling cavities located on both sides of the resistance cavity are provided in the cooling shell (100), and a circulating cooling mechanism connected to the cooling cavity is provided outside the cooling shell (100); The resistor unit comprises a plurality of spring-shaped resistor monomers (200) arranged in each resistor cavity, adjacent resistor monomers (200) are isolated by mica partitions (300), front and rear spacing arrangements are provided in the resistor cavity for the resistor monomers (200) to pass through a fixed porcelain piece (400), and front and rear ends of the resistor cavity are also provided with a front porcelain piece (500) and a rear porcelain piece (600) for fixing the resistor monomers (200).

2. The inverter braking cooling resistor according to claim 1, characterized in that; The circulating cooling mechanism comprises a water inlet joint (700) and a water outlet joint (800) located at the end of the cooling shell (100); the water inlet joint (700) is connected to the cooling cavity on one side of each cooling shell (100) through a flow divider (900); the water outlet joint (800) is connected to the cooling cavity on the other side of each cooling shell (100) through the flow divider (900); and parallel water pipes (1000) are provided on both sides of one end of each cooling shell (100) away from the water inlet joint (700) and the water outlet joint (800) for connecting the cooling cavities on both sides of the resistance cavity.

3. The inverter braking cooling resistor according to claim 1, characterized in that; The end of the cooling shell (100) is provided with a front installation opening for leading out the wire (1600) of the resistor monomer (200), the front installation opening is provided with a front welding plate (1100), a front sealing wet sand (1200), a front mica baffle (1300) and a front aluminum plate (1400) arranged from the inside to the outside, and both ends of the aluminum plate are provided with lead-out porcelain parts (1500) sleeved on the wire (1600).

4. The inverter braking cooling resistor according to claim 1, characterized in that; The cooling shell (100) is provided with a heat insulation plate (1700) and an insulation plate (1800) arranged from the inside to the outside on the outside of the front installation opening, and the insulation plate (1800) is provided with a connection copper bus (2000) installed on the insulation plate (1800) through an insulator (1900) on the outside.

5. The inverter braking cooling resistor according to claim 1, characterized in that; The cooling shell (100) is provided with a rear installation opening at one end away from the front installation opening, and the rear installation opening is provided with a rear mica baffle (2100), a rear sealing wet sand (2200), and a rear aluminum plate (2300) arranged from the inside to the outside.

6. The inverter braking cooling resistor according to claim 1, characterized in that; The top wall and side walls of the resistor cavity are respectively provided with wide pads (2400) and narrow pads (2500).

7. The inverter braking cooling resistor according to any one of claims 1 to 6, characterized in that: The cooling device further comprises an installation unit, wherein the installation unit comprises a base (2600) located below the cooling shell (100), and a fixing frame (2700) with an inverted U-shaped structure is provided on both sides of the base (2600) corresponding to the front and rear ends of the cooling shell (100), and a joint bracket (2800) is provided on the fixing frame (2700) for connecting the water inlet joint (700) and the water outlet joint (800).

8. The inverter braking cooling resistor according to claim 7, characterized in that; A bottom plate is provided between the base (2600) and the cooling shell (100).

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