Voltage sampling interface protection device for doubly fed induction generator of wind turbine generator set

Abstract

This utility model discloses a voltage sampling interface protection device for a doubly-fed induction generator (DFIG) converter in a wind turbine generator set, relating to the field of wind power equipment technology. It includes a fusible link fuse, a DC bus voltage sampling interface, a capacitor voltage sampling interface, a stator voltage sampling interface, and cables. It also includes a DIN rail bracket. The fusible link fuse is fixedly installed in the external terminal box of the DFIG converter control box via the DIN rail bracket. Three sets of fusible link fuses are connected in series on the voltage divider circuit side at the front end of the DC bus voltage sampling interface, the capacitor voltage sampling interface, and the stator voltage sampling interface, respectively. A protective component is installed at the cable through-hole. This device features an optimized structure, with the addition of fusible link fuses to enhance the protection characteristics of the converter grid-side voltage sampling interface, quickly cutting off short-circuit current and preventing fault propagation. The cable through-hole uses a special protective sleeve to prevent cable damage due to vibration or external force. The modular design of the fuse via the DIN rail and bracket simplifies the fuse replacement process and facilitates maintenance.

Description

Technical Field

[0001] This utility model relates to the field of wind power generation equipment technology, and in particular to a voltage sampling interface protection device for a doubly fed converter of a wind turbine generator set. Background Technology

[0002] The voltage sampling interface of the wind turbine generator converter provides accurate electrical parameters for the control system by monitoring the voltage signals of key nodes of the converter in real time. Existing voltage sampling interfaces for wind-cooled doubly-fed induction generators mainly include grid voltage sampling interfaces, DC bus voltage sampling interfaces, filter capacitor voltage sampling interfaces, and stator voltage sampling interfaces, but they generally suffer from the following shortcomings:

[0003] 1. Insufficient protection: Only the grid voltage sampling interface is equipped with a fuse, while other interfaces rely on the main circuit for protection, which cannot quickly cut off the short-circuit current;

[0004] 2. Weak cable protection: The cable passage hole is not equipped with a special protective sleeve, and the cable is easily cut by vibration or external force;

[0005] 3. Fault propagation: Metal debris generated by short-circuit arcing contaminates the insulation environment, leading to cascading failures.

[0006] Therefore, there is an urgent need for a device that integrates fuse protection and cable protection to overcome the shortcomings of existing technologies. Utility Model Content

[0007] The purpose of this invention is to provide a voltage sampling interface protection device for a wind turbine generator doubly fed converter with optimized structure, capable of quickly cutting off short-circuit current, immediately preventing fault propagation, and enhanced cable protection, thus preventing cable damage due to vibration or external force.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] The voltage sampling interface protection device for the doubly-fed induction generator of a wind turbine includes a fuse, a DC bus voltage sampling interface, a capacitor voltage sampling interface, a stator voltage sampling interface, and cables, and also includes:

[0010] The DIN rail bracket is used to fix the fuse in the external terminal box of the doubly fed converter control box.

[0011] The three sets of fuse-type fuses are connected in series on the voltage divider circuit side at the front end of the DC bus voltage sampling interface, the capacitor voltage sampling interface, and the stator voltage sampling interface, respectively.

[0012] A protective component is installed at the cable through-hole.

[0013] Furthermore, the protective component includes:

[0014] Corrugated pipe, double-layer silicone rubber protective sleeve and snap-on insulating sleeve;

[0015] The double-layer silicone rubber protective sleeve covers the outside of the corrugated pipe;

[0016] The snap-on insulating sleeve covers the outside of the double-layer silicone rubber protective sleeve;

[0017] The snap-on insulating sleeve is fixed to the external terminal box of the doubly fed converter control box by bolts.

[0018] The cable is threaded through the corrugated pipe;

[0019] The contact surface between the corrugated pipe and the cable is coated with an anti-wear coating.

[0020] Furthermore, the hardness of the double-layer silicone rubber protective sleeve is 60±5 Shore A.

[0021] Furthermore, the outer diameter of the cable is R1, the bending radius of the cable is R2, and R2 > 5R1.

[0022] Furthermore, the PCB trace width connecting the fuse terminals is 2mm, and the copper foil thickness is 70μm.

[0023] Furthermore, the fuse element material of the fusible core fuse is a silver alloy quartz sand filled structure;

[0024] The rated voltage of the fuse is 1500V and the rated current is 5A.

[0025] The maximum permissible short-circuit current that the fuse-type circuit breaker can reliably interrupt is 3000A, and its response time t < 10ms.

[0026] Furthermore, the fuse is covered with a protective sleeve.

[0027] The sheath is made of polyimide.

[0028] The thickness of the sheath is 0.5 mm;

[0029] The sheath can withstand an instantaneous arc temperature of T, where T > 1200℃.

[0030] In the above technical solution, the voltage sampling interface protection device of the doubly fed converter of the wind turbine generator set of this utility model has the following beneficial effects:

[0031] The device features an optimized structure with the addition of a fuse-type circuit breaker, enhancing the protection characteristics of the converter grid-side voltage sampling interface. This allows for rapid interruption of short-circuit current, preventing fault propagation. Cable protection is enhanced with dedicated protective components in the cable passage holes, preventing cable damage from vibration or external forces. The modular design of the fuse, achieved through DIN standard guide rails and brackets, simplifies the fuse replacement process, facilitates maintenance, and significantly reduces the converter failure rate. It is suitable for doubly-fed converter systems operating in high-vibration and high-humidity environments. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0033] Figure 1 Circuit diagram of the voltage sampling interface protection device for the doubly fed converter of the wind turbine generator set provided in this embodiment of the utility model;

[0034] Figure 2 A schematic diagram of the protective components in the voltage sampling interface protection device of the doubly fed converter of the wind turbine generator set provided in this embodiment of the utility model;

[0035] Figure 3 A front view of the installation position of the fuse-type circuit breaker and the DIN rail bracket in the voltage sampling interface protection device of the doubly fed converter of the wind turbine generator set provided in this embodiment of the utility model;

[0036] Figure 4 A cross-sectional view of the installation position of the fuse-type circuit breaker and the DIN rail bracket in the voltage sampling interface protection device of the doubly fed converter of the wind turbine generator set provided in this embodiment of the utility model.

[0037] Figure 5 A top view of the installation position of the fuse-type circuit breaker and the DIN rail bracket in the voltage sampling interface protection device of the doubly fed wind turbine converter provided in this embodiment of the utility model.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Fuse-type fuse; 2. DC bus voltage sampling interface; 3. Capacitor voltage sampling interface; 4. Stator voltage sampling interface; 5. Cable; 6. DIN rail bracket; 7. Protective components; 8. Sheath;

[0040] 71. Corrugated pipe; 72. Double-layer silicone rubber protective sleeve; 73. Snap-on insulating sleeve. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0042] It should be noted that the terms "front end", "external", "both ends", etc. used in this document indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of describing this utility model and simplifying the description. Similar expressions are only for illustrative purposes and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this utility model.

[0043] See Figure 1-5 As shown;

[0044] The voltage sampling interface protection device for the doubly fed converter of the wind turbine generator set includes a fuse 1, a DC bus voltage sampling interface 2, a capacitor voltage sampling interface 3, a stator voltage sampling interface 4, a cable 5, a DIN rail bracket 6, and a protective component 7. The three fuses 1 are connected in series on the voltage divider circuit side at the front end of the DC bus voltage sampling interface 2, the capacitor voltage sampling interface 3, and the stator voltage sampling interface 4, respectively. The fuses 1 are fixedly installed in the external terminal box of the doubly fed converter control box through the DIN rail bracket 6. The DIN rail bracket 6 adopts a modular bracket for mounting on DIN standard rails. The protective component 7 is installed at the through hole of the cable 5, which can effectively prevent the cable 5 from being cut or falling off.

[0045] Specifically, the protective component 7 includes a corrugated pipe 71, a double-layer silicone rubber protective sleeve 72, and a snap-on insulating sleeve 73. The corrugated pipe 71, the double-layer silicone rubber protective sleeve 72, and the snap-on insulating sleeve 73 are arranged sequentially from the inside to the outside. The cable 5 is inserted into the corrugated pipe 71. The snap-on insulating sleeve 73 is fixed to the external terminal box by bolts. The inner wall of the corrugated pipe 71 that contacts the cable 5 is coated with an anti-wear coating, which can reduce the friction coefficient generated by the direct contact between the cable 5 and the corrugated pipe 71 and extend the service life.

[0046] The double-layer silicone rubber protective sleeve 72 has a hardness of 60±5 Shore A, which meets the vibration protection standard of IEC60068-2-6; the outer diameter of the cable 5 is R1, the bending radius of the cable 5 is R2, and R2>5R1.

[0047] Furthermore, the fuse 1 can be Schneider Electric's AC10XLgPV5 model.

[0048] The PCB trace width for connecting terminal 1 of the fuse is 2mm, and the copper foil thickness is 70μm.

[0049] The fuse element material of the fusible element type 1 is a silver alloy quartz sand filled structure;

[0050] The rated voltage of fuse 1 is 1500V and the rated current is 5A;

[0051] The maximum permissible short-circuit current that the fuse-type circuit breaker 1 can reliably interrupt is 3000A, and its response time t < 10ms.

[0052] Specifically, the fuse 1 is covered with a sheath 8, which is made of polyimide and has a thickness of 0.5mm. The sheath 8 can withstand an instantaneous arc temperature of T, where T > 1200℃. The polyimide material has high insulation performance and can withstand high temperatures of over 400℃, effectively protecting the fuse 1 for use.

[0053] The working principle and usage procedure of the voltage sampling interface protection device for the doubly fed converter of the wind turbine generator set: When the fuse protection is activated, if a short circuit or overload occurs at the DC bus voltage sampling interface 2, capacitor voltage sampling interface 3, and stator voltage sampling interface 4, the fuse 1 will melt within 10ms, cutting off the fault current and preventing arcing from spreading; the double-layer silicone rubber protective sleeve 72 buffers vibration through the inner corrugated pipe 71 and works with the outer snap-on insulating sleeve 73 to fix the cable 5, preventing the cable 5 from being cut or falling off; after the fuse 1 fails, it can be quickly replaced through the DIN rail bracket 6, effectively shortening the downtime.

[0054] The voltage sampling interface protection device of this wind turbine generator set enhances the protection characteristics of the grid-side voltage sampling interface by adding fuse-type fuses 1 to the DC bus voltage sampling interface 2, capacitor voltage sampling interface 3 and stator voltage sampling interface 4 respectively, and optimizes the protection of cable 5 by setting a double-layer silicone rubber protective sleeve 72. The DIN rail bracket 6 is formed by DIN standard rails and brackets to realize the modular design of fuses, which significantly reduces the failure rate of the converter and is suitable for doubly fed converter systems in high vibration and high humidity environments.

[0055] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A voltage sampling interface protection device for a doubly-fed converter of a wind turbine generator set, comprising a fuse (1), a DC bus voltage sampling interface (2), a capacitor voltage sampling interface (3), a stator voltage sampling interface (4), and cables (5), characterized in that, Also includes: DIN rail bracket (6), the fuse (1) is fixedly installed in the external terminal box of the doubly fed converter control box through the DIN rail bracket (6); The three sets of fuses (1) are connected in series in the voltage divider circuits at the front end of the DC bus voltage sampling interface (2), the capacitor voltage sampling interface (3), and the stator voltage sampling interface (4); The protective component (7) is installed at the through-hole of the cable (5).

2. The wind turbine DFIG voltage sampling interface protection device of claim 1, wherein, The protective component (7) includes: Corrugated pipe (71), double-layer silicone rubber protective sleeve (72) and snap-on insulating sleeve (73); The double-layer silicone rubber protective sleeve (72) covers the outside of the corrugated pipe (71); The snap-on insulating sleeve (73) covers the outside of the double-layer silicone rubber protective sleeve (72); The snap-on insulating sleeve (73) is fixed to the external terminal box of the doubly fed converter control box by bolts; The cable (5) is inserted into the corrugated pipe (71); The contact surface between the corrugated pipe (71) and the cable (5) is coated with an anti-wear coating.

3. The voltage sampling interface protection device for a doubly-fed converter of a wind turbine generator set according to claim 2, characterized in that: The hardness of the double-layer silicone rubber protective sleeve (72) is 60±5 Shore A.

4. The voltage sampling interface protection device for a doubly-fed converter of a wind turbine generator set according to claim 1, characterized in that: The outer diameter of the cable (5) is R1, and the bending radius of the cable (5) is R2, where R2 > 5R1.

5. The voltage sampling interface protection device for a doubly-fed converter of a wind turbine generator set according to claim 1, characterized in that: The PCB trace width connecting the terminals of the fuse (1) is 2mm and the copper foil thickness is 70μm.

6. The voltage sampling interface protection device for a doubly-fed converter of a wind turbine generator set according to claim 1, characterized in that: The fuse core material of the fuse (1) is a silver alloy quartz sand filled structure; The rated voltage of the fuse (1) is 1500V and the rated current is 5A; The maximum permissible short-circuit current that the fuse (1) can reliably cut off is 3000A, and its response time t < 10ms.

7. The voltage sampling interface protection device for a doubly-fed converter of a wind turbine generator set according to claim 1, characterized in that: The fuse (1) is covered with a protective sleeve (8). The sheath (8) is made of polyimide. The thickness of the sheath (8) is 0.5 mm; The sheath (8) can withstand an instantaneous arc temperature of T, where T > 1200℃.

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