A transformer skeleton, laminated design and flyback power supply for electric energy metering

Abstract

This invention provides a transformer frame, a stacked design, and a flyback power supply for electricity metering. The transformer frame includes a primary side and a secondary side. The primary side has primary winding pins and auxiliary winding pins for the flyback power supply. The secondary side has power supply winding pins for the electricity metering chip and power supply winding pins for the low-voltage functional module. In the stacked design, the primary and secondary windings within the transformer frame are stacked. The flyback power supply includes a transformer and operates on a three-phase four-wire power grid. The power supply winding for the electricity metering chip supplies power to the metering circuit, and the power supply winding for the low-voltage functional module supplies power to the load circuit. This solution has the advantages of simple structure, low cost, meeting power requirements, strong noise immunity, low system noise, and low conducted and radiated interference. Furthermore, it reduces near-field radio frequency noise and improves radio frequency communication sensitivity through special design.

Description

Technical Field

[0001] This invention relates to the field of electrical energy metering technology, and more specifically, to a transformer frame, transformer stack design, and flyback power supply for electrical energy metering. Background Technology

[0002] Electricity metering typically uses shunts or current transformers / Rogowski coils for current sampling; however, because shunts provide non-isolated sampling, the power supply design for multiphase electricity meters becomes extremely difficult. Current solutions include:

[0003] RC power supply: low cost, but very low power output, which cannot meet the needs of current multi-functional smart meters;

[0004] Isolated DC-DC: An additional isolated DC-DC converter is added to the main power output to supply multiple power supplies to the current sampling chip; this method is more expensive and occupies a larger size.

[0005] Power ICs or isolation devices have their own power supply; this method has a high degree of integration, integrating the isolation DC-DC converter into the IC, which is costly and makes EMC design more difficult.

[0006] It is evident that the existing power supply design solutions for multiphase energy meters all have certain shortcomings. Therefore, a power supply system design with high integration, high power, low cost, and simple EMC design is needed to replace the previous design methods. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems in the prior art of power supply system design with low integration, insufficient power, high cost and complex EMC design.

[0008] Therefore, the first aspect of the present invention provides a transformer frame for electricity metering.

[0009] A second aspect of the present invention provides a transformer stacking design for electricity metering.

[0010] A third aspect of the present invention provides a flyback power supply for electricity metering.

[0011] The present invention provides a transformer frame for power metering, comprising: a primary side and a secondary side, wherein the primary side is provided with a flyback power supply primary winding pin and an auxiliary winding pin, and the secondary side is provided with a power supply winding pin for a power metering chip and a power supply winding pin for a low-voltage function module.

[0012] According to the above-described technical solution of the present invention, a transformer frame for electricity metering may further have the following additional technical features:

[0013] Furthermore, two pins of the same power supply winding of the power metering chip are grouped together, and several groups of power supply winding pins of the power metering chip are arranged adjacently, with a first air gap between two adjacent groups of power supply winding pins.

[0014] Two pins of the power supply winding of the same low-voltage function module are grouped together. Several groups of power supply windings of power metering chips are arranged adjacently and there is a second air gap between two adjacent groups of power supply windings of power metering chips.

[0015] There is a third air gap between the nearest pair of power metering chip power supply winding pins and the pair of low-voltage function module power supply winding pins.

[0016] Furthermore, the first air gap is not less than 3 mm, and the third air gap is not less than 6.3 mm.

[0017] The present invention also provides a transformer stacked design for electricity metering, wherein the primary winding and secondary winding disposed in the transformer frame as described in any of the above technical solutions are stacked, the primary winding includes: flyback power supply primary windings N1 and N5, auxiliary winding N2, and shielding windings N6 and N11; the secondary winding includes an electricity metering chip power supply winding and a low-voltage function module power supply winding.

[0018] The pins of the shielding winding are located on the primary side, and N6 and N11 are connected in parallel.

[0019] The auxiliary winding N2 and the power supply winding for the low-voltage function module are located between the primary windings N1 and N5 of the flyback power supply.

[0020] The primary winding N5 of the flyback power supply is arranged adjacent to the shielding winding N6.

[0021] The power supply winding of the power metering chip is located between the shielding windings N6 and N11.

[0022] Furthermore, the power supply windings for the four power metering chips are located between the shielding windings N6 and N11, with each pair of power supply windings for the power metering chips located on the same layer.

[0023] The present invention also provides a flyback power supply for electricity metering, including a transformer, wherein the transformer adopts the transformer frame as described in the above technical solution and the transformer winding adopts the transformer stacked design as described in the above technical solution; the flyback power supply operates on a three-phase four-wire power grid, the power supply winding of the electricity metering chip is used to supply power to the metering circuit, and the power supply winding of the low-voltage function module is used to supply power to the load circuit.

[0024] Furthermore, the same-named and different-named terminals of the power supply winding of the power metering chip are provided with ferrite suppressors.

[0025] Furthermore, a Y capacitor is connected between the ground of the metering circuit and the load circuit.

[0026] Furthermore, a Y capacitor is connected between the ground of the load circuit and the primary rectifier ground of the transformer; a Y capacitor is also connected between the primary rectifier ground of the transformer and the N line.

[0027] Furthermore, it also includes a flyback controller, one end of which is connected to the primary rectified ground of the transformer, and the other end is connected to the auxiliary winding. The output terminal of the power MOSFET in the flyback controller is connected to the primary winding of the flyback power supply via a ferrite suppressor.

[0028] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are:

[0029] With a simple structure, low cost, and high power, it can meet power requirements and achieve a three-phase four-wire manganese copper power metering scheme through special transformer design and flyback power supply design.

[0030] It has strong anti-noise interference capability, low system noise, low conducted and radiated interference, and reduces radio frequency near-field noise through special design, thereby improving radio frequency communication sensitivity.

[0031] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0033] Figure 1 This is one of the three-dimensional structural diagrams of a transformer frame for electricity metering according to an embodiment of the present invention;

[0034] Figure 2 This is a second three-dimensional structural diagram of a transformer frame for electricity metering according to an embodiment of the present invention;

[0035] Figure 3 This is a bottom view of a transformer frame for electricity metering according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of a transformer stack-up design for electricity metering according to an embodiment of the present invention;

[0037] Figure 5 This is a stacked structure diagram of a transformer stacked design for electricity metering according to an embodiment of the present invention;

[0038] Figure 6This is a schematic diagram of a flyback power supply for electricity metering according to an embodiment of the present invention. Detailed Implementation

[0039] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0041] The following reference Figures 1 to 6 This describes a transformer frame, stacked design, and flyback power supply for power metering provided according to some embodiments of the present invention.

[0042] Some embodiments of this application provide a transformer frame for electricity metering.

[0043] The first embodiment of this invention proposes a transformer frame for electricity metering, such as... Figures 1 to 3 As shown, it includes a primary side and a secondary side. The primary side is provided with primary winding pins and auxiliary winding pins of the flyback power supply, i.e., pins 1-5 in the figure. The secondary side is provided with power supply winding pins for the energy metering chip and power supply winding pins for the low-voltage function module. In the figure, pins 10-11, 12-13, 14-15, and 16-17 are four sets of power supply winding pins for the energy metering chip, mainly used to power the energy metering chip, i.e., the metering circuit; pins 6-7 and 8-9 are power supply winding pins for the low-voltage function module, mainly used to power the communication module, MCU, and other low-voltage function modules, i.e., the load circuit.

[0044] Two pins of the same power supply winding of the power metering chip are grouped together. Several groups of power supply winding pins of the power metering chip are arranged adjacently and there is a first air gap between two adjacent groups of power supply winding pins; that is, pins 10-11, 12-13, 14-15, and 16-17 are arranged adjacently, and there is a first air gap E between each pair of 10-11, 12-13, 14-15, and 16-17 arranged adjacently in sequence.

[0045] Two pins of the power supply winding of the same low-voltage function module are grouped together. Several groups of power supply windings of power metering chips are set up adjacently and there is a second air gap between two adjacent groups of power supply windings of power metering chips; that is, pins 6-7 and 8-9 are set up adjacently, and there is a second air gap E1 between each pair of 6-7 and 8-9 set up adjacently in sequence.

[0046] There is also an air gap between pins 1-5, and the distance of the air gap is the same as that of the first air gap E;

[0047] There is a third air gap between the nearest pair of power metering chip power supply winding pins and the pair of low-voltage function module power supply winding pins, namely, there is a third air gap E2 between pins 8-9 and pins 10-11.

[0048] The first air gap E is not less than 3mm, the second air gap E1 can be equal to the first air gap, or slightly smaller or larger, but not less than 2.5mm; the third air gap E2 is not less than 6.3mm. This ensures sufficient isolation between the high-voltage phases, as well as sufficient isolation between high-voltage and low-voltage circuits and ensures the safety of low-voltage circuits.

[0049] The second embodiment of the present invention proposes a transformer stacked design for electricity metering. Based on the first embodiment, the primary and secondary windings within the transformer frame as described in the previous embodiment are stacked, meaning that each winding is stacked and wound on a single layer. Figure 2 The transformer skeleton shown is on the iron core; the primary winding includes: flyback power supply primary windings N1 and N5, auxiliary winding N2, and shielding windings N6 and N11; the secondary winding includes power supply windings for the power metering chip and power supply windings for the low-voltage function module.

[0050] The primary windings N1 and N5 are used to store energy for the flyback power supply, such as Figure 4 As shown, pins 1 and 2 of N1 and pins 2 and 3 of N5 are connected. N1 and N5 share pin 2.

[0051] The pins of the shielding winding are located on the primary side to shield noise. N6 and N11 are connected in parallel. The pins of N6 and N11 are 3 and NC, where NC indicates an empty pin, meaning that N6 and N11 share pin 3 with N5.

[0052] The auxiliary winding is used to supply power to the power converter;

[0053] like Figure 5 As shown in the figure, the left side is the primary side, with pins 1-5; the right side is the secondary side, with pins 6-17; the auxiliary winding N2 and the power supply windings N3 and N4 of the low-voltage function module are located between the primary windings N1 and N5 of the flyback power supply; as... Figure 4 As shown, N1, N2, N3, N4, and N5 are stacked sequentially from bottom to top;

[0054] The primary winding N5 of the flyback power supply is arranged adjacent to the shielding winding N6; N6 is stacked on top of N5;

[0055] The four power supply windings of the power metering chip, namely N7, N8, N9, and N10, are located between the shielding windings N6 and N11.

[0056] The power supply windings for every two power metering chips are arranged on the same layer. N7 and N8 are arranged on the same layer and stacked on top of N6. N9 and N10 are arranged on the same layer and stacked on top of N7 and N8. N11 is stacked on top of N9 and N10. This transformer stacking design reduces noise from the primary to the secondary side of the power supply, playing a crucial role in improving the conducted interference performance of the power supply.

[0057] The third embodiment of the present invention proposes a flyback power supply for electricity metering, and based on any of the above embodiments, such as... Figure 6 As shown, the system includes a transformer, which adopts the transformer frame as described in the first embodiment above and the transformer winding adopts the transformer stacked design as described in the second embodiment; the flyback power supply operates on a three-phase four-wire power grid, the power supply winding of the power metering chip is used to supply power to the metering circuit, and the power supply winding of the low-voltage function module is used to supply power to the load circuit.

[0058] Figure 6 The dashed line represents the noise path.

[0059] The three-phase four-wire power grid includes L1, L2, L3, and N. The flyback power supply includes a rectifier unit, a filter unit, a transformer, and a flyback controller. L1, L2, L3, and N are connected to the primary side of the transformer after passing through the rectifier unit and the filter unit in sequence. One terminal of the output of the filter unit is connected to the opposite-name terminal of the primary winding N5 of the flyback power supply, i.e., pin 3, and the other terminal is connected to the primary rectified ground P_GND of the transformer.

[0060] One end of the flyback controller is connected to the primary rectified ground of the transformer, and the other end is connected to the same-name terminal (pin 4) of the auxiliary winding N2. The opposite-name terminal (pin 5) of the auxiliary winding N2 is connected to the primary rectified ground P_GND of the transformer. The output terminal of the power MOSFET in the flyback controller is connected to the opposite-name terminal (pin 1) of the primary winding N1 of the flyback power supply via a ferrite suppressor PL12. PL12 is used to suppress noise in the CATM 450M band and improve RF sensitivity.

[0061] The same-name and different-name terminals of the power supply winding of the power metering chip are equipped with ferrite suppressors. That is, the same-name and different-name terminals of the power supply winding N7-N10 of the power metering chip, namely pins 10, 11, 12, 13, 14, 15, 16, and 17, are connected to the metering circuit after passing through ferrite suppressors PL1, PL11, PL3, PL4, PL5, PL6, PL7, and PL8, respectively.

[0062] Among them, pin 17 is connected to the L1 metering circuit via PL1, and pin 16 is connected to the L1 metering circuit via PL11; pin 15 is connected to the L2 metering circuit via PL3, and pin 14 is connected to the L2 metering circuit via PL4; pin 13 is connected to the L3 metering circuit via PL5, and pin 12 is connected to the L3 metering circuit via PL6; pin 11 is connected to the N metering circuit via PL7, and pin 10 is connected to the N metering circuit via PL8; PL1, PL11, PL3, PL4, PL5, PL6, PL7, and PL8 are used to suppress high-frequency noise and reduce conducted and radiated interference.

[0063] Ferrite suppressors are provided at the same-named or different-named ends of the power supply winding of the low-voltage functional module. Specifically, ferrite suppressors are provided at the same-named or different-named ends of the power supply winding N3-N4 of the low-voltage functional module, i.e., pins 9 or 8, 7 or 6. Specifically, pin 9 is connected to load circuit 1 via ferrite suppressor PL9, pin 8 is connected to ground P1_GND after being connected to load circuit 1, pin 7 is connected to load circuit 2 via ferrite suppressor PL10, and pin 6 is connected to ground P1_GND after being connected to load circuit 2.

[0064] The ground terminal of load circuit 1 is connected to the ground terminal of load circuit 2 via capacitor PC4; PC4 is used to reduce conducted noise between load circuit 1 and load circuit 2.

[0065] A Y capacitor is connected between the ground of the metering circuit and the load circuit.

[0066] One end of the L1 metering circuit is grounded, and the ground of the L1 metering circuit is represented as L1_GND; one end of the L2 metering circuit is grounded, and the ground of the L2 metering circuit is represented as L2_GND; one end of the L3 metering circuit is grounded, and the ground of the L3 metering circuit is represented as L3_GND; one end of the N metering circuit is grounded, and the ground of the N metering circuit is represented as N_GND; L1_GND.

[0067] The ground L1_GND of the L1 metering circuit is connected to load circuit 1 and load circuit 2 via Y capacitor PC10; the ground L2_GND of the L2 metering circuit is connected to load circuit 1 and load circuit 2 via Y capacitor PC1; the ground L3_GND of the L3 metering circuit is connected to load circuit 1 and load circuit 2 via Y capacitor PC2; the ground N_GND of the N metering circuit is connected to load circuit 1 and load circuit 2 via Y capacitor PC3; the ends of PC10, PC1, PC2, and PC3 connected to the load circuits are grounded and represented as P3_GND. PC10, PC1, PC2, and PC3 are used to reduce the differential mode noise of the transformer output.

[0068] A Y capacitor is connected between the load circuit ground P1_GND and the transformer primary rectified ground P_GND; that is, a Y capacitor PC5 is placed between pin 6 and the transformer primary rectified ground P_GND; that is, a Y capacitor PC6 is placed between pin 8 and the transformer primary rectified ground P_GND.

[0069] A Y capacitor PC7 is connected between the primary rectifier ground P_GND and the N line of the transformer.

[0070] The above design can reduce radio frequency noise and improve radio frequency communication sensitivity, especially for low-frequency radio frequency communication of 450M-1G, where the noise will be partially absorbed by the neutral line.

[0071] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A transformer layering design for electrical energy metering, characterized by, The setup is based on a transformer frame for power metering; the transformer frame for power metering includes a primary side and a secondary side, the primary side is provided with a flyback power supply primary winding pin and an auxiliary winding pin, and the secondary side is provided with a power metering chip power supply winding pin and a low-voltage function module power supply winding pin. The primary and secondary windings within the transformer frame are designed in a stacked manner. The primary windings include: flyback power supply primary windings N1 and N5, auxiliary winding N2, and shielding windings N6 and N11. The secondary windings include power supply windings for the power metering chip and power supply windings for the low-voltage function module. The pins of the shielding winding are located on the primary side, and N6 and N11 are connected in parallel. The auxiliary winding N2 and the power supply winding for the low-voltage function module are located between the primary windings N1 and N5 of the flyback power supply. The primary winding N5 of the flyback power supply is arranged adjacent to the shielding winding N6. The power supply winding of the power metering chip is located between the shielding windings N6 and N11; Two pins of the same power supply winding of the power metering chip are grouped together. Several groups of power supply winding pins of the power metering chip are arranged adjacently and there is a first air gap between two adjacent groups of power supply winding pins. Two pins of the power supply winding of the same low-voltage function module are grouped together. Several groups of power supply windings of power metering chips are arranged adjacently and there is a second air gap between two adjacent groups of power supply windings of power metering chips. There is a third air gap between the nearest pair of power metering chip power supply winding pins and the pair of low-voltage function module power supply winding pins.

2. A transformer layering design for electrical energy metering according to claim 1, characterized in that, The first air gap is not less than 3 mm, and the third air gap is not less than 6.3 mm.

3. The transformer stacking design for electricity metering according to claim 1, characterized in that, The power supply windings for the four power metering chips are located between the shielding windings N6 and N11, with each pair of power supply windings for the power metering chips located on the same layer.

4. A flyback power supply for electricity metering, characterized in that, The device includes a transformer, which adopts a transformer stacked design as described in any one of claims 1 to 3; the flyback power supply operates on a three-phase four-wire power grid; the power supply winding of the power metering chip is used to supply power to the metering circuit; and the power supply winding of the low-voltage function module is used to supply power to the load circuit.

5. A flyback power supply for electricity metering according to claim 4, characterized in that, Ferrite suppressors are provided at the same-name and different-name terminals of the power supply winding of the power metering chip.

6. A flyback power supply for electricity metering according to claim 4, characterized in that, A Y capacitor is connected between the ground of the metering circuit and the load circuit.

7. A flyback power supply for electricity metering according to claim 4, characterized in that, A Y capacitor is connected between the ground of the load circuit and the primary rectifier ground of the transformer; a Y capacitor is also connected between the primary rectifier ground of the transformer and the N line.

8. A flyback power supply for electricity metering according to claim 4, characterized in that, It also includes a flyback controller, one end of which is connected to the primary rectified ground of the transformer, and the other end is connected to the auxiliary winding. The output terminal of the power MOSFET in the flyback controller is connected to the primary winding of the flyback power supply via a ferrite suppressor.

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