CN109755009B - A dual-magnetic-core single-winding line inductive energy-capturing device and its configuration method - Google Patents

Abstract

The invention discloses a dual-magnetic-core single-winding line inductive energy-capturing device and a configuration method thereof, comprising a high-voltage transmission line and a load. A magnetic core group is sleeved on the outer side of the high-voltage transmission line, and a winding is wound on the outside of the magnetic core group. Both ends of the winding are respectively connected to the load, and the magnetic core group is formed by superimposing two or more magnetic cores. In order to significantly improve the initial permeability and saturation characteristics of the composite magnetic core topology and expand the effective working current range of the energy extraction device, appropriate core lengths of the first magnetic core and the second magnetic core are selected. The invention can solve the inherent problem that the traditional feed-through line inductive energy acquisition topology cannot have the advantages of high permeability and high saturation at the same time. Its parameter design method is simple and diverse, easier to implement, and has good economy and practicability.

Description

A dual-magnetic-core single-winding line inductive energy-capturing device and its configuration method

technical field

The invention belongs to the field of equipotential potential on-site power supply of on-line monitoring equipment for high-voltage transmission lines, and particularly relates to a dual-magnetic-core single-winding line inductive energy acquisition device and a configuration method thereof.

Background technique

With the wide application of online monitoring technology for power transmission and transformation lines and equipment in power systems, the monitoring functions and scope of power sensor networks are becoming wider and wider, such as insulator pollution flashover monitoring, temperature measurement of cable joints, etc. These monitoring sensors are usually arranged in the field, with many nodes and harsh working environment, so the operation and maintenance work is extremely complicated and difficult. In order to ensure the stable and effective operation of the monitoring device, the problem of energy acquisition and power supply needs to be solved urgently. Due to the alternating magnetic field energy around the transmission line, many scholars at home and abroad have carried out extensive research on the way of line induction energy. This method has the advantages of high stability of power supply performance and little external influence. The power level of energy extraction is generally several watts to several tens of watts. It is convenient and safe to supply equipotential power supply for monitoring equipment directly connected to the line. However, the traditional inductive energy acquisition method has a fatal weakness, that is, the magnetic core material cannot be compatible with the advantages of high initial permeability and high saturation characteristics, which must be compatible in the process of line energy acquisition. Therefore, when the line current fluctuates in a wide range, the energy-fetching device may not be able to obtain a certain amount of energy at a certain moment, or at another moment due to the oversaturation of the magnetic core, it may cause serious heat generation and damage the energy-fetching device itself.

SUMMARY OF THE INVENTION

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a dual-magnetic core single-winding line inductive energy-fetching device and a configuration method thereof. By improving the energy-fetching topology and parameter configuration method, the energy-fetching device can be Simultaneous improvements in both startup characteristics and saturation characteristics.

Technical solution: In order to achieve the above purpose, the present invention provides a dual-magnetic-core single-winding line inductive energy-capturing device, including a high-voltage transmission line and a load, a magnetic core group is sleeved outside the high-voltage transmission line, and a magnetic core group is wound on the outside of the magnetic core group. Winding, the two ends of the winding are respectively connected with the load, and the magnetic core group is formed by superposing two or more magnetic cores.

Further, the size and thickness of each magnetic core in the magnetic core group are the same.

Further, the magnetic core group is composed of a first magnetic core and a second magnetic core, and a second magnetic core is superimposed on the first magnetic core.

Further, the windings are wound clockwise.

Further, the windings are wound counterclockwise.

A configuration method of a dual-magnetic-core single-winding line inductive energy-fetching device: the specific steps are as follows:

(4) Obtain the initial permeability of the first magnetic core μ _i(1#) , the initial magnetic permeability of the second magnetic core μ _i(2#) , μ ₀ is the vacuum permeability, the first magnetic core The inner and outer radii of the second magnetic core are the same as D _in and D _out , respectively; the load is represented by R _L ; the magnetic core lengths of the first magnetic core and the second magnetic core are l ₁ and l ₂ respectively;

为等效拓扑中的阻抗角；(5) The induced voltages on the secondary side of the first magnetic core and the second magnetic core are obtained as e _1# ¹ (t) and e _2# ¹ (t), respectively, and the number of turns of the secondary winding is taken as N, two The equivalent inductance and loss resistance of the first winding on the secondary side are L ₂ (1 ^# ) and R ₂ (1 ^# ), respectively, and the equivalent inductance and loss resistance of the second winding on the secondary side are L ₂ (2 ^# ) and R ₂ (2 ^# ), the effective value of the load current is I ₂ , and the load terminal voltage is

is the impedance angle in the equivalent topology;

其中l₃为任意取能装置磁芯长度；选取第一磁芯与第二磁芯的磁芯长度l₁和l₂，最后获取配置好的线路感应取能装置。In order to significantly improve the initial permeability and saturation characteristics of the composite magnetic core topology and expand the effective working current range of the energy harvesting device, according to the conditions

Wherein l ₃ is the length of the magnetic core of any energy taking device; select the magnetic core lengths l ₁ and l ₂ of the first magnetic core and the second magnetic core, and finally obtain the configured line inductive energy taking device.

Beneficial effect: The present invention has the following advantages compared with the prior art:

1. The equipotential potential real-time power supply of the online monitoring device of the transmission line can be realized through the line induction energy acquisition device;

2. By improving the magnetic core structure of the energy extraction device and configuring appropriate parameters, the inherent problem of the traditional energy extraction device can be solved, that is, the magnetic core material cannot have the two advantages of high initial permeability and high saturation characteristics at the same time, which effectively improves the induction extraction. Effective working range that can withstand large-scale fluctuations in current;

3. In applications such as real-time power supply of high-voltage transmission line equipotential attachment devices, this parameter configuration method is simple and easier to implement, has good economy and practicability, and is very convenient to implement in practice.

Description of drawings

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the structural schematic diagram of the magnetic core group in Fig. 1;

Fig. 3 is the sectional view of the A-A surface of the magnetic core group in Fig. 2;

4 is a cross-sectional view of the B-B plane of the magnetic core group in FIG. 3;

5 is a circuit model diagram in a specific embodiment;

6 is a comparison diagram of the effect of the dual-magnetic-core single-winding line induction energy-fetching device according to the present invention and the traditional energy-fetching device under the condition of the same line current of 20A in a specific embodiment;

FIG. 7 is a comparison diagram of the effect of the dual-magnetic-core single-winding line inductive energy-capturing device according to the present invention and the traditional energy-capturing device under the same line current of 300A in a specific embodiment.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1-5, the present invention includes a high-voltage transmission line and a load ^, and a magnetic core is ^sleeved outside the high-voltage transmission line; Initial permeability and high saturation magnetic flux density; load terminals are represented by ⑦, ⑧; winding terminals matched with composite cores are represented by ⑤ and ⑥; the connection method of this topology is: ⑤-⑦, ⑧-⑥. The load is denoted by _RL .

According to the working principle of the line inductive energy extraction device, the composite magnetic core structure can be equivalent to an equivalent circuit diagram as shown in FIG. 1 .

In accompanying drawing 1, the secondary side induced voltage of the composite magnetic core structure energy taking device ^# is E _{12 #} ^III , the number of turns of the secondary side winding is all taken as N, and its equivalent inductance and loss resistance are respectively L ₂ ( 12 ^# ) and R ₂ (12 ^# ), the effective value of the load current is I ₂ ^III , the load terminal voltage is u _L ³ (σ), and σ is the impedance angle in the equivalent topology. From this, it can be obtained that the induced voltage on the secondary side of the energy-receiving device of the composite magnetic core structure is:

Assuming that the induced voltage E _12# ^III in Fig. 1 is provided by a single energy-receiving device, and the winding method and inner and outer diameter of the energy-receiving device are the same as those of any magnetic core in the composite magnetic core, in order to ensure that the load power supply is not Under the premise of change, it is necessary to meet the

μ _i ¹² =[μ _i ( _1# )l ₁ +μ _i ( _2# )l ₂ ]/l ₃

At this time, the initial magnetic permeability of the energy harvesting device can be significantly improved by only configuring the magnetic core length of the composite magnetic core topology to satisfy the conditions in the following formula

At the same time, the primary and secondary relational expressions in the composite core topology can be calculated

By changing the length of the composite magnetic core, the proportional coefficients of the primary and secondary side currents can be changed, thereby further affecting the saturation depth of the magnetic core, broadening the working current range of the energy extraction device, and greatly improving the ability of the energy extraction device to resist primary current fluctuations . The specific comparison effect is shown in Figure 6 and Figure 7.

It can be seen from FIG. 6 and FIG. 7 that the composite magnetic core topology protected in the present invention has great advantages both in start-up characteristics and saturation characteristics, and can significantly increase the power of the energy extraction device, thereby improving the extraction The practical level of the energy device has high application value.

The above is only the preferred embodiment of the present invention, it should be pointed out: for those skilled in the art, under the premise of not departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (6)

1. a configuration method of a dual-magnetic-core single-winding line induction energy-fetching device: it is characterized in that: the concrete steps are as follows: (1) Obtain the initial permeability of the first magnetic core μ _i(1#) , the initial magnetic permeability of the second magnetic core μ _i(2#) , μ ₀ is the vacuum permeability, the first magnetic core The inner and outer radii of the second magnetic core are the same as D _in and D _out , respectively; the load is represented by R _L ; the magnetic core lengths of the first magnetic core and the second magnetic core are l ₁ and l ₂ respectively; (2) Obtain the secondary side induced voltages of the first magnetic core and the second magnetic core as e _1# ¹ (t) and e _2# ¹ (t), respectively, and the number of turns of the secondary winding is taken as N, two The equivalent inductance and loss resistance of the first winding on the secondary side are L ₂ (1 ^# ) and R ₂ (1 ^# ), respectively, and the equivalent inductance and loss resistance of the second winding on the secondary side are L ₂ (2 ^# ) and R ₂ (2 ^# ), the effective value of the load current is I ₂ , and the load terminal voltage is

is the impedance angle in the equivalent topology; (3) The induced voltage E _12# ^III is provided by a single energy taking device, and the winding method and inner and outer diameter of the energy taking device are the same as any one of the composite magnetic cores. Under the premise, it is necessary to meet the μ _i ¹² =[μ _i ( _1# )l ₁ +μ _i ( _2# )l ₂ ]/l ₃ At this time, it is only necessary to configure the magnetic core length of the composite magnetic core topology so that it satisfies the conditions in the following formula to improve the initial permeability of the energy harvesting device

or

Wherein, l ₃ is the length of the magnetic core of the energy taking device, and its length and the initial permeability μ _i ¹² of the energy taking device satisfy μ _i ¹² l ₃ =μ _i ( _1# )l ₁ +μ _i ( _2# )l ₂ ; Select the magnetic core lengths l ₁ and l ₂ of the first magnetic core and the second magnetic core, and finally obtain the configured line inductive energy-taking device. 2. An inductive energy-receiving device using the configuration method of the dual-magnetic-core single-winding line inductive energy-receiving device according to claim 1, characterized in that it comprises a high-voltage transmission line and a load, and the outer side of the high-voltage transmission line is sleeved with a magnetic A core group, the outer part of the magnetic core group is wound with a winding, the two ends of the winding are respectively connected with the load, and the magnetic core group is formed by superposing two or more magnetic cores. 3 . The inductive energy taking device according to a configuration method of a dual magnetic core single winding line inductive energy taking device according to claim 2 , wherein the size and thickness of each magnetic core in the magnetic core group are the same. 4 . 4 . The inductive energy-receiving device of a method for configuring a dual-magnetic-core single-winding line inductive energy-receiving device according to claim 2 , wherein the magnetic core group is composed of a first magnetic core and a second magnetic core. 5 . , a second magnetic core is superimposed on the first magnetic core. 5 . The inductive energy extracting device of a method for configuring a dual-magnetic-core single-winding line inductive energy extracting device according to claim 2 , wherein the windings are wound clockwise. 6 . 6 . The inductive energy extracting device of a method for configuring a dual magnetic core single winding line inductive energy extracting device according to claim 2 , wherein the windings are wound counterclockwise. 7 .

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