A transformer integrated with an lc filter
By integrating the inductor inside the transformer to form an integrated LC filter, the problems of high installation space and cost caused by the split structure are solved, achieving space and cost savings.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DONGGUAN LEADER ELECTRONICS
- Filing Date
- 2025-10-14
- Publication Date
- 2026-08-04
AI Technical Summary
In existing inverter power supply systems, the separate structure of transformers, inductors, and capacitors leads to problems such as large installation space occupation and high cost.
By integrating the inductor inside the transformer and fixing the capacitor by installing a capacitor bracket on the top of the transformer body, an integrated LC filter is formed, and the inductor and capacitor are combined into a single structure.
It achieves a reduction of approximately 30% in installation space and a reduction of approximately 30% in cost, while also integrating the filtering function.
Smart Images
Figure CN224595337U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of transformer technology, and in particular to a transformer with an integrated LC filter. Background Technology
[0002] In inverter power supply systems, DC is typically inverted to AC, then stepped up and isolated by a transformer, and finally filtered to produce voltage and current that meet power quality standards. Examples include UPS systems, frequency converters, and inverters. Usually, the transformer, inductor, and capacitor are connected separately in the circuit, forming an LC filter. This structure results in space-consuming installations and higher costs. Utility Model Content
[0003] This utility model discloses a transformer with an integrated LC filter. It adopts an integrated approach, integrating the inductor inside the transformer and installing a capacitor bracket on the top of the transformer body to fix the capacitor connected to the transformer output. This makes the transformer, inductor and capacitor combined into a whole structure, which greatly saves installation space and cost compared to the original separate structure.
[0004] The technical solution of this utility model is as follows:
[0005] A transformer with an integrated LC filter includes an iron core, a fastening bracket, a coil, and a capacitor. The iron core includes a main magnetic circuit core and a leakage inductance core. The fastening bracket clamps the main magnetic circuit core. The main magnetic circuit core is fitted with an inner winding and an outer winding, which are respectively a secondary coil and a primary coil. The leakage inductance core is inserted into a window between the inner secondary winding and the outer primary winding to form an inductive effect. The capacitor is fixed on the fastening bracket and electrically connected to the secondary coil and the primary coil.
[0006] Furthermore, the fastening bracket is divided into an upper bracket that clamps the top of the main magnetic circuit core and a lower bracket that clamps the bottom of the main magnetic circuit core.
[0007] Furthermore, the iron core is a three-phase rectangular iron core, including three sets of main magnetic circuit iron cores and leakage inductance iron cores. The cylinders of the three sets of main magnetic circuit iron cores are wrapped with coils, namely coil A, coil B and coil C. Coil A, coil B and coil C are each divided into a secondary coil of the inner winding and a primary coil of the outer winding.
[0008] Furthermore, an air duct support bar is provided between the secondary coil and the primary coil to facilitate ventilation and heat dissipation, while also forming a core window, with a leakage inductance core inserted inside.
[0009] Furthermore, the transformer has a terminal block on the front for easy connection of input and output lines, and a capacitor mounting bracket on the top for easy fixing of capacitors.
[0010] Furthermore, the capacitors include phase A capacitors, phase B capacitors, and phase C capacitors. One end of each capacitor is connected to the transformer output terminals a, b, and c, and the other end is shorted to form a Y connection. The n-line is led to the transformer output n-line.
[0011] Furthermore, relative to the front of the transformer, the main magnetic circuit core is composed of multiple layers of silicon steel sheets stacked vertically with the front facing forward, and the leakage inductance core is composed of multiple layers of silicon steel sheets stacked vertically with the front facing right.
[0012] Furthermore, each layer of the leakage inductance core includes four silicon steel sheets with air gaps between them. The overall height is equal to the height of the secondary coil, and the width is equal to the thickness of the main magnetic circuit core. Epoxy plates are provided on both sides of the front. The thickness of the epoxy plates plus the thickness of the silicon steel sheets is the thickness of the gap between the secondary coil and the primary coil.
[0013] The transformer with integrated LC filter of this invention has the following advantages compared with the prior art:
[0014] A typical inverter circuit output structure consists of a transformer, a reactor, and a capacitor, providing isolation, step-up / step-down voltage adjustment, and filtering. This patented utility model integrates an LC filter transformer with both inductor and capacitor. The inductor is built into the coil, reducing installation space and wiring while maintaining the same effect. No additional inductor and capacitor are needed for filtering; the transformer itself performs the filtering function, significantly reducing installation space and cost. Furthermore, a capacitor bracket is installed on top of the transformer to secure the capacitor connection to the transformer output. This integrates the transformer, inductor, and capacitor into a single structure, reducing installation space by approximately 30% compared to the common separate structure. Similarly, costs can be reduced by 30%. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the external structure of the transformer that integrates the LC filter according to this utility model;
[0016] Figure 2 The transformer is shown in its top view, front view, and left view.
[0017] Figure 3 This is a schematic diagram of the internal structure of a transformer cross-section;
[0018] Figure 4 A schematic diagram of the main magnetic circuit core and leakage inductance core structure;
[0019] Figure 5 This is a schematic diagram of the leakage inductor core structure;
[0020] Figure 6 This is the circuit schematic of an inverter power supply system.
[0021] The markings in the attached diagram are as follows: 1. Upper stand; 2. Lower stand; 3. Main magnetic circuit core; 4. A coil; 5. B coil; 6. C coil; 61. Secondary coil; 62. Primary coil; 7. Terminal block; 8. Capacitor; 81. A-phase capacitor; 82. B-phase capacitor; 83. C-phase capacitor; 9. Leakage inductor core; 10. Air duct support bar; 11. Epoxy board; 12. Air gap of leakage inductor core; h, single piece height of leakage inductor core; H, overall height of leakage inductor core; W, width of leakage inductor core; L, stack thickness of leakage inductor core. Detailed Implementation
[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, but these descriptions are not intended to limit the scope of the present invention.
[0023] In inverter power supply systems, DC is typically inverted to AC, then stepped up by a transformer for isolation, and finally filtered to produce voltage and current that meet power quality standards. Examples include UPS systems, frequency converters, and inverters. Usually, the transformer, inductor, and capacitor are separate components connected in the circuit. A UPS schematic diagram is shown below. Figure 6 As shown. See also Figure 6 The part shown in the middle frame is: A is the transformer connected to the inverter output terminal, B is the inductor connected to the transformer output terminal, and C is the capacitor. The capacitor and the inductor are combined to form an LC filter.
[0024] This invention provides a transformer with an integrated LC filter. The inductor is integrated inside the transformer, and a capacitor bracket is installed on the top of the transformer body to fix the capacitor and connect it to the transformer output. In this way, the transformer, inductor and capacitor are combined into a whole structure.
[0025] See Figure 1-3 A transformer with an integrated LC filter includes an iron core, a fastening bracket, coils, and a capacitor 8. The fastening bracket is divided into an upper bracket 1 that clamps the top of the main magnetic circuit iron core 3 and a lower bracket 2 that clamps the bottom of the main magnetic circuit iron core 3. The iron core is a three-phase rectangular iron core, including three sets of main magnetic circuit iron cores 3 and leakage inductance iron cores 9. The cylinders of the three sets of main magnetic circuit iron cores 3 are wrapped with coils, namely coil A 4, coil B 5, and coil C 6. Coil A 4, coil B 6, and coil C 6 are each divided into an inner winding secondary coil 61 and an outer winding primary coil 62.
[0026] An air channel support bar 10 is provided between the inner winding secondary coil 61 and the outer winding primary coil 62, and a leakage inductance core 9 is inserted into the window formed to form an inductance effect.
[0027] A terminal block 7 is provided on the front of the transformer for easy connection of input and output lines; a capacitor mounting bracket is provided above the transformer's upper stand 1 for easy fixing of capacitors, including phase A capacitor 81, phase B capacitor 82, and phase C capacitor 83. Each capacitor is electrically connected to the secondary coil 61 and the primary coil 62, with one end connected to the transformer output terminals a, b, and c, and the other end shorted to form a Y connection, with the n-line led to the transformer output n-line.
[0028] The positions of the main magnetic circuit core 3 and the leakage inductance core 9 are shown in the specific structure. Figure 3-5 , Figure 3 This is a top view of the transformer cross-section, showing the relative positions of the main magnetic circuit core 3 and the leakage inductance core 9. Figure 4 The diagram shows the front view of the main magnetic circuit core 3 and the leakage inductance core 9. Compared to the front view of the transformer, the main magnetic circuit core 3 is composed of multiple layers of silicon steel sheets stacked vertically with the front facing forward, and the leakage inductance core 9 is composed of multiple layers of silicon steel sheets stacked vertically with the front facing right. Figure 5 The left image shows a view of the leakage inductance core 9 relative to the front of the transformer, and the right image shows a view of the leakage inductance core 9 relative to the right side of the transformer. (See also...) Figure 5 Each layer of the leakage inductance core consists of four silicon steel sheets with air gaps between them. The overall height is equal to the height of the secondary coil, and the width is equal to the thickness of the main magnetic circuit core. Epoxy plates are provided on both sides of the front. The thickness of the epoxy plates plus the thickness of the silicon steel sheets is the thickness of the gap between the secondary coil and the primary coil.
[0029] Leakage inductance core refers to the inductance generated by the leakage of magnetic flux in a transformer due to incomplete closure of the magnetic flux lines. This invention utilizes the principle of leakage inductance core to integrate the inductance of a UPS circuit into the transformer. By inserting a leakage inductance core between the secondary and primary coils, the resulting inductance effect produces inductance B. The magnitude of this inductance is adjusted by modifying the number, size, and air gap width of the silicon steel sheets in the leakage inductance core.
[0030] The integrated LC filter transformer provided by this utility model adopts an integrated approach, integrating the inductor inside the transformer. The inductance is generated by adding a leakage inductance iron core. A capacitor bracket is installed on the top of the transformer body to fix the capacitor and connect it to the transformer output, so that the transformer, inductor and capacitor are combined into a whole structure. Compared with the split structure shown in the original circuit diagram, the installation space can be reduced by about 30%, and similarly, the cost can also be reduced by 30%.
[0031] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any form or substance. All technical solutions within the scope of the present utility model's concept are protected by the present utility model. Any equivalent changes and modifications made to the above embodiments based on the substantive technology of the present utility model should also be considered within the scope of protection of the present utility model.
Claims
1. A transformer with an integrated LC filter, characterized in that: The device includes an iron core, a fastening bracket, a coil, and a capacitor. The iron core comprises a main magnetic circuit iron core and a leakage inductance iron core. The fastening bracket clamps the main magnetic circuit iron core. The main magnetic circuit iron core is fitted with an inner winding and an outer winding, which are respectively a secondary coil and a primary coil. The leakage inductance iron core is inserted into the window between the inner secondary coil and the outer primary coil to form an inductive effect. The capacitor is fixed on the fastening bracket and electrically connected to the secondary coil and the primary coil.
2. The transformer with an integrated LC filter according to claim 1, characterized in that: The fastening bracket is divided into an upper bracket that clamps the top of the main magnetic circuit core and a lower bracket that clamps the bottom of the main magnetic circuit core.
3. The transformer with an integrated LC filter according to claim 1, characterized in that: The core is a three-phase rectangular core, including three sets of main magnetic circuit cores and leakage inductance cores. The cylinders of the three sets of main magnetic circuit cores are fitted with coils, namely coil A, coil B and coil C. Coil A, coil B and coil C are each divided into a secondary coil of the inner winding and a primary coil of the outer winding.
4. The transformer with an integrated LC filter according to claim 1, characterized in that: An air passage support bar is provided between the secondary coil and the primary coil.
5. The transformer with an integrated LC filter according to claim 1, characterized in that: A terminal block is provided on the front of the transformer, and a capacitor mounting bracket is provided on the top of the transformer.
6. The transformer with an integrated LC filter according to claim 1, characterized in that: The capacitors include phase A, phase B, and phase C capacitors. One end of each capacitor is connected to the transformer output terminals a, b, and c, and the other end is shorted to form a Y connection. The n-line is led to the transformer output n-line.
7. The transformer with an integrated LC filter according to claim 1, characterized in that: Relative to the front of the transformer, the main magnetic circuit core is composed of multiple layers of silicon steel sheets stacked vertically with the front facing forward, and the leakage inductance core is composed of multiple layers of silicon steel sheets stacked vertically with the front facing right.
8. The transformer with an integrated LC filter according to claim 7, characterized in that: Each layer of the leakage inductance core consists of four silicon steel sheets with air gaps between them. The overall height is equal to the height of the secondary coil, and the width is equal to the thickness of the main magnetic circuit core. Epoxy boards are provided on both sides of the front. The thickness of the epoxy boards plus the thickness of the silicon steel sheets is the thickness of the gap between the secondary coil and the primary coil.