Method for controlling the number of turns of a winding of a magnetic induction power supply device

Abstract

The application provides a winding turn number transformation control method of a magnetic induction power taking device. Since the output power of the magnetic induction power taking device is related to the power transmission line current, the magnetic core turn number, the magnetic core cross-sectional area, the magnetic core material and the load, when the remaining parameters are fixed, the magnetic induction power taking device can be controlled to work in different states by controlling the secondary winding turn number, so as to meet the required power output requirement. Therefore, the application analyzes different power requirements respectively, configures different winding turn numbers under different power requirements, and realizes the self-adaptation of the load. The effect is that the winding turn number can be transformed according to different power requirements, the magnetic induction power taking system outputs corresponding power, has certain power supply flexibility, can change the power working point of the system under the condition that the load is determined, and improves the power supply reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to magnetic induction power supply technology, in particular to a winding turn number transformation control method of a magnetic induction power supply device. BACKGROUND

[0002] The electromagnetic induction phenomenon is one of the most important discoveries in electromagnetism, which reveals the mutual relationship between electric and magnetic phenomena. Faraday summarized the following law according to a large number of experimental facts: the size of the induced electromotive force in the circuit is proportional to the rate of change of the magnetic flux passing through the circuit. The importance of Faraday's law of electromagnetic induction lies in that, on the one hand, according to the principle of electromagnetic induction, people have manufactured generators, and large-scale production and long-distance transmission of electric energy have become possible; on the other hand, electromagnetic induction phenomena have been widely used in electrical engineering, electronic technology, and electromagnetic measurement.

[0003] In some application scenarios, the required power requirement does not match the output power of the magnetic induction power supply device system, which is too small to meet the power requirement, too large to cause waste of resources, and even can cause damage to the equipment. If a parameter can be adjusted to transform the power, this problem can be well solved.

[0004] The parameters that affect the system output power mainly include the transmission line current, the cross-sectional area of the magnetic core, the magnetic core material, the secondary winding turns, the load size, etc. In actual application scenarios, the transmission line current, the cross-sectional area of the magnetic core, the magnetic core material, and the load size are relatively fixed parameters and cannot be conveniently controlled by humans. Therefore, the secondary winding turns are selected as the control quantity, and the output power is adjusted by transforming the winding turns to meet the required power output requirement. However, the relationship between the winding turns and the output power is not thoroughly analyzed in the prior art, and there is no complete scheme to adapt to different load power requirements by changing the coil winding turns. SUMMARY

[0005] Based on the above needs, the purpose of the present application is to provide a winding turn number transformation control method of a magnetic induction power supply device. The number of turns of the coil winding is determined according to the output power requirement of the application scenario, the cross-sectional area of the magnetic core, the magnetic characteristic parameters of the magnetic core, and the load resistance, so as to improve the reliability of the system power supply.

[0006] In order to achieve the above purpose, the specific technical scheme adopted by the present application is as follows:

[0007] A winding turn number transformation control method of a magnetic induction power supply device, which is characterized by comprising the following steps:

[0008] S1: determining the transmission line current amplitude I, the angular frequency ω, the cross-sectional area A of the magnetic core, and the saturation magnetic induction B according to the magnetic core structure of the magnetic induction power supply device and the application scenario p .sat , the load resistance R and the power demand P;

[0009] S2: judging whether the following condition is met: N < sqrt (P / R), if yes, setting the winding number of the magnetic induction power taking device according to the winding number N; if no, going to step S3;

[0010] S3: judging whether the following condition is met: N > sqrt (P / R), if yes, setting the winding number of the magnetic induction power taking device according to the winding number N; if no, going to step S4;

[0011] setting the winding number of the magnetic induction power taking device according to the winding number N; otherwise, no effective winding number meets the condition.

[0012] Optionally, when no effective winding number meets the condition in step S3, the cross-sectional area A of the magnetic core is adjusted by changing the structure of the magnetic core, and the winding number of the magnetic induction power taking device is set again according to steps S2-S3.

[0013] Optionally, neither the magnetic loss inside the magnetic core nor the winding resistance or the switching loss of each device in the rectification and conversion circuit is considered in the design.

[0014] Optionally, the coil winding in the magnetic induction power taking device is provided with different connection taps according to different winding numbers, the winding number of the coil winding is determined according to the load resistance value and the power demand according to steps S1-S3, and the corresponding connection tap is controlled to be connected to the load.

[0015] Effects of the present application are as follows:

[0016] The present application can transform the winding number according to different power demands, so that the magnetic induction power taking system outputs corresponding power, has certain power supply flexibility, and can change the power working point of the system in the case of determined load, thereby improving the power supply reliability. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced.

[0018] Figure 1 Fig. 1 is a schematic diagram of the application scenario of the magnetic induction power taking device in the embodiments of the present application;

[0019] Figure 2 Fig. 2 is a structural schematic diagram of the magnetic induction power taking device in the embodiments of the present application;

[0020] Figure 3 Fig. 3 is a flow chart of the method in the embodiments of the present application. EMBODIMENT ​

[0021] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0022] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0023] This embodiment provides a method for controlling the number of turns of a magnetic induction energy harvesting device winding, in order to Figure 1 Taking the illustrated application scenario as an example, the magnetic induction energy harvesting device includes a magnetic core and a coil winding. A power conversion circuit is installed at the end of the coil winding. The power conversion circuit includes a rectifier circuit and a DC / DC converter module. The output of the power conversion circuit is connected to a load. Addressing the self-powering problem of high-voltage transmission line sensing equipment, the alternating magnetic field existing around the power line is collected by the magnetic induction energy harvesting device and supplied to the load with stable DC power through the power conversion circuit, thus achieving self-powering. Figure 1 For remote video monitoring equipment in the power grid, the load is the video monitoring device. In practical applications, excessively high or low output power of the magnetic induction energy harvesting device will affect the normal operation of the video monitoring device. The parameters affecting the system output power mainly include transmission line current, magnetic core cross-sectional area, magnetic core material, number of turns in the secondary winding, and load size. However, in actual applications, these parameters are relatively fixed and cannot be easily adjusted manually. Figure 2 For the magnetic induction energy harvesting device shown, only by selecting the number of turns of the secondary winding as the control quantity and adjusting the output power by changing the number of turns of the winding can the required power output requirements be met more conveniently.

[0024] like Figure 3 As shown in the embodiment, a method for controlling the number of turns of a magnetic induction energy harvesting device winding is provided, and the specific steps are as follows:

[0025] S1: Determine the transmission line current amplitude I based on the magnetic core structure and application scenario of the magnetic induction energy harvesting device. p Angular frequency ω, core cross-sectional area A, saturation magnetic induction intensity B sat , load resistance R and power requirement P;

[0026] S2: Judgment Whether it is true or not, if true, then according to the number of turns of the winding. Set the number of winding turns of the magnetic induction energy harvesting device; if not, proceed to step S3.

[0027] S3: Judgment If yes, the number of turns of the winding of the magnetic induction power taking device is set; otherwise, no effective number of turns meets the condition.

[0028] The number of turns of the winding of the magnetic induction power taking device is set; otherwise, no effective number of turns meets the condition.

[0029] For Figure 2 As shown in the magnetic induction power taking device, when no effective number of turns meets the condition in step S3, the cross-sectional area A of the magnetic core is adjusted by changing the magnetic core structure, and the number of turns of the winding of the magnetic induction power taking device is set again according to steps S2-S3. In specific implementation, the coil winding in the magnetic induction power taking device can also be provided with different connection taps according to different numbers of turns, and the number of turns of the coil winding is determined according to steps S1-S3 according to the load resistance and power demand, and the corresponding connection tap is controlled to be connected to the load.

[0030] As can be seen from the above method, the above method analyzes different working states corresponding to different power demands, and is specifically designed according to the working state. The number of turns of the winding is determined by the output power demand, the cross-sectional area of the magnetic core, the magnetic characteristic parameters of the magnetic core, and the load resistance. When designing, neither the magnetic loss inside the magnetic core nor the winding resistance or the switching loss of each device in the rectification and conversion circuit is considered.

[0031] In order to further understand the technical effect of the present application, the design process is further analyzed as follows:

[0032] The power line current i p is represented as:

[0033] i P = I P sin(ωt) (1)

[0034] The power obtained on the load is:

[0035]

[0036] The magnetic-electric equivalent relationship existing in the magnetic induction power taking device is:

[0037]

[0038] Under the condition that the cross-sectional area of the magnetic core and the load and the power line current are constant, the magnetic induction power taking device has a maximum output power, and different power outputs can be realized by changing the number of turns of the winding. Therefore, the number of turns of the secondary winding should be controlled according to different power output requirements.

[0039] When the magnetic core power taking time is greater than 10ms, that is, the magnetic induction power taking device is in an unsaturated state, t s is 10ms, so it can be found from formula (3) that:

[0040]

[0041] At this time, according to equation (2) and equation (4), P has the following relationship:

[0042]

[0043] Therefore, when the load power requirement satisfies equation (5), N is designed as:

[0044]

[0045] When the magnetic induction power supply device is in a saturated state, according to equation (2) and equation (3), the following equation can be obtained:

[0046]

[0047] According to equation (7), it is found that (2ωt s -sin(2ωt s )) / (4(1-cos(ωt s )) has a maximum value, that is:

[0048]

[0049] According to equation (7) and equation (8), another power node can be obtained, that is, the maximum power output that can be achieved by controlling N, that is:

[0050]

[0051] Therefore, when the load power requirement does not satisfy equation (9), at this time, no effective secondary turns can meet the power requirement.

[0052] When the power requirement is between the above two cases, another method can be used for the control design of the turns, that is, (2ωt s -sin(2ωt s )) / (4(1-cos(ωt s )) is simplified as the following equation:

[0053] 0.84sin(0.73ωt s ) (10)

[0054] Therefore, according to equation (7), ωt s at this time is:

[0055]

[0056] Combined with equation (2) and equation (11), it is found that the winding control design at this time is:

[0057]

[0058] At this time, the purpose of controlling and designing the number of turns of the winding for the power demand is completed.

[0059] In conclusion, the winding number transformation control method of the magnetic induction power supply device provided by the present application can transform the number of turns of the winding according to different power demands, so that the magnetic induction power supply system outputs corresponding power, has certain power supply flexibility, and can change the power operating point of the system under the condition that the load is determined, thereby improving the power supply reliability.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and such 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 present application, and such changes should be covered in the scope of the claims and the specification of the present application.

Claims

1. A method for controlling the number of turns of a winding of a magnetic induction power supply device, characterized in that, The method comprises the following steps: S1: Determine the current amplitude I of the power transmission line according to the magnetic induction power supply device core structure and application scenario p , angular frequency , core cross-sectional area A, saturation magnetic induction , load resistance R and power demand P; S2: Judgment Whether it is true or not, if true, then according to the number of turns of the winding. Set the number of winding turns of the magnetic induction energy harvesting device; if not, proceed to step S3. S3: judging whether the condition is met, and if so, according to the number of turns of the winding: Setting the number of turns of the winding of the magnetic induction power derivation device; Otherwise, no valid number of turns satisfies the condition.

2. The magnetic induction power sourcing equipment winding turn number transformation control method of claim 1, wherein, When no valid number of turns satisfies the condition in step S3, the cross-sectional area A of the magnetic core is adjusted by changing the magnetic core structure, and the number of turns of the winding of the magnetic induction power supply device is reconfigured according to steps S2-S3.

3. The magnetic induction power sourcing equipment winding turn number transformation control method of claim 1, wherein, Neither the magnetic loss inside the magnetic core nor the winding resistance or the switching loss of each device in the rectification and conversion circuit is considered in the design.

4. The method of claim 1-3, wherein the number of turns of the winding of the magnetic induction power supply device is transformed and controlled. The coil winding in the magnetic induction power supply device is provided with different wiring taps according to different numbers of turns, the number of turns of the coil winding is determined according to the load resistance and power demand according to steps S1-S3, and the corresponding wiring tap is controlled to be connected to the load.

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