CN108364775B - Energy taking device based on converter valve bus bar square wave current and design method thereof - Google Patents
Energy taking device based on converter valve bus bar square wave current and design method thereof Download PDFInfo
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/14—Inductive couplings
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
Abstract
The invention relates to an energy taking device based on converter valve busbar square wave current and a design method thereof, wherein the method comprises the following steps: s1: extracting a square wave current key parameter of a converter valve busbar; s2: calculating the power characteristic of a coil of the energy-taking device; s3: selecting a magnetic core material and a shape of the energy taking device according to the shape of the converter valve busbar, and analyzing and calculating the energy taking device; s4: simulating the designed energy taking device, and setting up a test platform to carry out performance test on the energy taking device. The invention provides a design method of a high-performance high-voltage side induction energy-taking device by performing theoretical analysis, simulation research and experimental test on various parameters of a magnetic core and a signal processing circuit based on an electromagnetic induction principle.
Description
Technical Field
The invention belongs to the technical field of electric energy conversion equipment, and relates to a method for designing an energy taking device based on converter valve bus square wave current.
Background
With the continuous development and perfection of power systems and the high-speed development of power grids, the scale of the power grids in China currently leaps the world first, but the inverse distribution contradiction exists between the energy resource distribution and the energy demand in China, so that the distribution of power generation energy and power utilization load in China is extremely unbalanced. In order to overcome the contradiction of energy structure, the strategic target of building a unified strong intelligent power grid is provided by national power grid companies, an extra-high voltage power grid is used as a backbone grid frame of the strong intelligent power grid, the key link of realizing the strong and intelligent power grid is realized, and the special high voltage direct current power grid has a series of advantages of large transmission capacity, small loss, long transmission distance and the like and is determined to be used as an important carrier for large-capacity long-distance power transmission in a strong intelligent power grid framework.
The converter valve is a core device of an extra-high voltage direct current transmission system, and once a fault occurs, the operation reliability of an extra-high voltage direct current power grid is greatly influenced.
The converter valve operates in complex environments with interwoven multi-physical fields of electricity, magnetism, heat and the like for a long time, and the characteristic of relatively weak operation reliability of the converter valve is determined. Due to the fact that the operating voltage level of the converter valve is too high, the operating state of the converter valve equipment cannot be directly observed in a short distance, so that operating personnel cannot know the operating conditions of all parts of the converter valve equipment at the first time, and the converter valve equipment can possibly run with diseases. This poses a great risk to the operation of the converter valve, which may cause great economic losses even if the probability of failure is extremely small.
In order to make timely state evaluation and fault diagnosis for the converter valve equipment and better guarantee the normal operation of the equipment, a perfect on-line monitoring and state evaluation diagnosis system needs to be established. The sensor of the on-line monitoring system and the processing and transmission of the monitoring data all need a stable energy-taking device, so that the research on a set of high-practicability energy-taking device for the on-line monitoring system is of great significance.
At present, the on-line energy-taking device reported in the literature is mainly applied to an on-line monitoring system under the working condition of sinusoidal current of an alternating current transmission system. However, since the current flowing through the direct-current transmission converter valve busbar is square wave current, in order to provide a long-term reliable low-voltage power supply for an online monitoring system of the converter valve, it is of great significance to analyze and design the square wave current of the converter valve busbar, which is an induction energy-taking method under special working conditions.
Disclosure of Invention
In view of the above, the present invention provides an energy obtaining device based on a converter valve bus bar square wave current and a design method thereof, and the energy obtaining device is designed by performing theoretical analysis, simulation research and experimental test on various parameters of a magnetic core and a signal processing circuit based on an electromagnetic induction principle, so as to design a high-performance high-voltage side induction energy obtaining device.
In order to achieve the purpose, the invention provides the following technical scheme:
the method for designing the energy taking device based on the square wave current of the converter valve busbar comprises the following steps:
s1: extracting a square wave current key parameter of a converter valve busbar;
s2: calculating the power characteristic of a coil of the energy-taking device;
s3: selecting a magnetic core material and a shape of the energy taking device according to the shape of the converter valve busbar, and analyzing and calculating the energy taking device;
s4: simulating the designed energy taking device, and setting up a test platform to carry out performance test on the energy taking device.
Further, step S2 specifically includes the following steps:
s21: calculating the effective value of the secondary side voltage of the energy taking device;
s22: and calculating the secondary side power characteristic of the energy taking device.
Further, the iron core is shaped into a U-shaped ring or a circular ring in step S3.
Further, step S3 specifically includes:
s31: selecting a magnetic core material according to the magnetic conductivity, the coercive force, the resistivity and the saturation magnetic induction intensity of the magnetic core material;
s32: analyzing the magnetic resistance and the magnetic saturation of the magnetic core, and determining the size of the magnetic core;
s33: calculating the number of turns of a coil of the energy taking device;
s34: and designing turn-to-turn insulation of the coil of the energy taking device.
Further, step S32 specifically includes:
s321: selecting a circular magnetic core, and calculating the magnetic conductance of the magnetic core on the assumption that the magnetic core works in a linear region;
s322: calculating the maximum exciting current just entering a saturation state;
s323: the core is dimensioned in such a way that the sum of the average magnetic path length and the perimeter of the cross-sectional area is minimized.
Further, the number of turns of the coil of the energy-taking device in step S33 satisfies:
wherein e is induced potential, n is number of turns of coil, mueqFor equivalent permeability, w is the width of the inner and outer diameters of the core, and s is the thickness of the core.
Further, step S4 specifically includes:
s41: modeling the magnetic core according to the magnetic core parameters, and connecting the magnetic core into an excitation source;
s42: setting an excitation source as a power frequency current, changing the amplitude of the applied power frequency current, carrying out no-load test on the primary side of the magnetic core, and testing and recording the amplitude of the output voltage of the secondary side of the magnetic core;
s43: replacing the power frequency current with a square wave current with a fixed amplitude, carrying out no-load test on the primary side of the magnetic core, and testing and recording the amplitude of the output voltage of the secondary side of the magnetic core;
s44: connecting the secondary side of the magnetic core with a signal processing module to form an energy taking circuit and connecting the energy taking circuit with a load equivalent circuit;
s45: applying excitation and changing the resistance value of the load equivalent resistor, testing the voltage change condition of the load terminal, and carrying out statistics to obtain a conclusion;
s46: and (3) building a test platform, debugging a test circuit, testing the designed energy-taking device, and acquiring the performance of the energy-taking device in a real environment.
Further, the signal processing module comprises a rectifying circuit, a filter capacitor and a voltage stabilizing circuit which are connected in sequence, the rectifying circuit is connected to the secondary side of the magnetic core, and the voltage stabilizing circuit is connected to the load equivalent circuit.
The energy taking device based on the converter valve busbar square wave current is characterized in that a magnetic core of the energy taking device is in a split-opening annular shape and is divided into a primary side magnetic core and a secondary side magnetic core which are wound with a primary side coil and a secondary side coil respectively, the magnetic cores are made of silicon steel sheets, air gap sheets are arranged at two openings and are compressed through spring clamp springs, and the energy taking device is used for extracting line parameters in a high-voltage line.
Furthermore, the coil turn-to-turn insulation of the primary side coil and the secondary side coil is formed by winding polyester films.
The invention has the beneficial effects that: by carrying out theoretical analysis, simulation research and experimental test on various parameters of the energy-taking magnetic core and the signal processing circuit based on the electromagnetic induction energy-taking principle, the high-voltage side induction energy-taking power supply structure with better performance is designed.
(1) Modeling simulation is carried out on the magnetic core, C-shaped and U-shaped closed magnetic core models and open air gap magnetic core models are respectively established by adopting AnsoftMaxwell, main factors influencing output electric energy are simulated and analyzed, and a scheme that an air gap with a proper width is added at the interface of the magnetic core is adopted to inhibit the magnetic core from entering a saturated state prematurely. When the bus current is large, the energy-taking magnetic core still works in a non-saturated state, so that sufficient energy is provided for back-end equipment.
(2) The designed induction power supply signal processing module is subjected to experimental test, an experimental platform is built in a laboratory, and a processing circuit is welded and debugged. And analyzing the experimental waveform to determine the feasibility of the circuit.
Drawings
In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:
FIG. 1 is a flow chart of the present invention;
FIG. 2 is a schematic diagram of the energy-extracting device of the present invention;
FIG. 3 is a schematic view of a magnetic core according to an embodiment of the present invention;
FIG. 4 is a schematic diagram illustrating simulation of a magnetic core shape according to an embodiment of the present invention;
FIG. 5 is a schematic cross-sectional view of a circular magnetic core according to an embodiment of the present invention;
FIG. 6 is a schematic diagram illustrating a no-load current-voltage relationship of an energy-extracting device according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of an energy-extracting circuit according to an embodiment of the present invention;
FIG. 8 is a circuit diagram of an embodiment of a power circuit;
FIG. 9 is a graph of load output power of an energy-extracting device according to an embodiment of the present invention;
fig. 10 is a schematic view illustrating an installation of the energy-taking device according to the embodiment of the invention.
Detailed Description
Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in fig. 1, which is a flow chart of the present invention, the embodiment of the present invention includes the following steps:
step one, extracting key parameters of square wave current of converter valve busbar
The 800kV converter valve thyristor busbar square wave current is a square wave current with constant amplitude of 4500A, frequency of 50Hz, duty ratio of 1/3 and rising edge and falling edge of about 0.8 ms. The square wave current can generate a variable magnetic field at the rising edge and the falling edge, and the closed coil can be used for inducing voltage according to the electromagnetic induction law, so that electric energy is obtained.
Step two, the power characteristic of the energy induction coil is obtained, as shown in figure 2,
the energy-taking CT is used as an energy-taking front end of an energy-taking power supply for obtaining energy from a power transmission line, and the power transmission characteristics of the energy-taking CT need to be researched. Because the magnetic hysteresis loop of the iron core of the energy-taking CT is narrow by adopting the cold-rolled silicon steel sheet, the iron core loss is very low, and in order to reflect the power change rule of the energy-taking CT, the resistance of the exciting current is ignored
Wherein, ImFor exciting current, IFeIs an effective value of a resistive component of the exciting current, I1Is an effective value of the primary side current, N2Number of turns of secondary winding, I2The effective value of the secondary side current.
According to the electromagnetic induction principle, when the primary side input is sine wave, the effective value of the voltage of the secondary CT is
Wherein, U2Effective value of voltage of two times, E2Effective value of induced electric potential of secondarymf is the excitation magnetic flux, f is the system frequency, η is the lamination coefficient of the iron core, S is the cross-sectional area of the iron core, mu is the relative permeability of the iron core with air gaps, and l is the average magnetic path length of the iron core.
The output power expression of the available energy-taking CT secondary side is as follows
where K is 2 pi f μ S η/l, K is a parameter reflecting the core material and structure, and so on
When the load resistance is effective, the output power of the energy-taking CT obtains the maximum value,
the power characteristics of the energy-taking CT secondary side mainly include the following two points:
the maximum value of the output power is related to the current of the transmission line, the material and the size of the iron core and is unrelated to the number of turns of the secondary winding.
② when
Secondary side power output reaches maximum
in this case, the frequency f of the line current and the following parameters of CT determine S, mu, l, eta, N2。
For the current containing harmonic waves, the power superposition theorem is respectively applied to multiple times of harmonic current, and the maximum power is as follows:
magnetic permeability mu-mu of air-core coil0
Step three, analyzing the shape of the magnetic core
As shown in fig. 3, according to the shape of the converter valve bus bar, the magnetic core can be selected to have an annular iron core and a U-shaped iron core, and the iron cores with the two structures are subjected to electric field simulation by using ansys, so that the appearance design of the magnetic core with an air gap is optimized, and the influence of the converter valve bus bar on electric field discharge at the air gap of the magnetic core is reduced.
As shown in fig. 4, it is found through simulation that: the air gap of the annular iron core is far away from the busbar, and the distortion of an electric field at the air gap is small, so that the annular iron core is selected as the magnetic core in the embodiment of the invention.
Step four, selecting magnetic core material
When selecting the core material, the main considerations are:
the magnetic permeability is higher when the magnetic field intensity in the magnetic core around the bus is constant, the magnetic induction intensity depends on the magnetic permeability of the material, and under the condition of the same bus square wave current, the material with the high magnetic permeability induces a higher voltage value, so that the volume of the magnetic core can be reduced by reducing the sectional area of the magnetic core.
The smaller the coercive force, the narrower the hysteresis loop, the easier the magnetization and demagnetization the smaller the coercive force of the magnetic core material, and the smaller the hysteresis loop, the less heat is generated by the hysteresis loss.
The electrical resistivity is required to have eddy current loss when the magnetic core works, and the heat generation caused by the eddy current loss can be reduced due to the higher electrical resistivity.
The saturation magnetic induction intensity is high, so that when the square wave current of the bus is large, the magnetic core does not enter a saturation state prematurely, the heat produced by iron loss is reduced, and meanwhile, the generation of peak voltage is avoided.
Ferromagnetic materials are further classified into soft, hard, and rectangular magnetic materials according to the magnitude of their coercive force. The soft magnetic material has small coercive force, and the magnetic hysteresis loop is slender, compared with other materials, the magnetic hysteresis loop has small surrounding area, namely, less energy dissipation in the magnetization process, and in addition, the magnetic material also has the characteristics of easy magnetization, easy demagnetization, large saturation magnetic induction intensity, easy removal of residual magnetism in an alternating magnetic field and the like, so the magnetic material is suitable for being used as a magnetic core material.
TABLE 1 magnetic core Material Property parameter Table
As shown in table 1, the permalloy has a high squareness ratio of the magnetization curve, a high magnetic permeability and a very low coercive force, but is expensive, has a low saturation magnetic induction, and has a significant influence of mechanical stress on magnetic properties, and a protective shell is usually required. The microcrystal alloy has high initial relative magnetic conductivity and low cost, and is suitable for high frequency device. Compared with alloy materials, the saturation magnetic induction intensity of the silicon steel sheet is much higher, the range of the energy-taking magnetic core adapting to the bus square wave current can be greatly increased, the Curie temperature reaches 740 ℃, and the material can completely meet the requirement of the energy-taking magnetic core. In addition, the price of the silicon steel sheet is much lower than that of an alloy material, so that the cost performance is better.
Comprehensively considering, the magnetic core made of the silicon steel sheet material is selected, and on the basis, the electric energy meeting the requirement of a rear-end device can be induced by designing various parameters such as the size of the magnetic core, the number of turns of the coil and the like, and the embodiment of the invention selects the ultrathin B23P085 silicon steel sheet.
Step five, designing the anti-magnetic saturation of the iron core
It can be seen from the basic magnetization curve of the magnetic core material that when the bus square wave current is small, the magnetic induction field intensity in the magnetic core is small, and the magnetic induction intensity is gradually increased along with the increase of the bus square wave current.
The sizes of the energy-taking magnetic core are mainly as follows: inner diameter, outer diameter, height. Assuming that the core is a circular ring with a rectangular cross section, the inner diameter of the core is a, the outer diameter is b, the height is h, and the cross-sectional area is S, as shown in fig. 5.
Assuming that the magnetic core works in a linear region, the relative magnetic permeability is constant, the magnetic lines of force are uniformly distributed on the section of the magnetic core, and mu at each position on SrThe same applies to the formula G ═ mu defined by the flux guide0μrS/L, the magnetic core permeance can be obtained as follows:
magnetic induction at saturation of the magnetic core is BsMagnetic flux of phi in the corem＝BsS, according to the ohm law of the magnetic circuit, the maximum exciting current when the magnetic core just enters the saturation state can be obtained as
The maximum exciting current is determined by three parameters of the size of the magnetic core, the saturation magnetic induction intensity and the relative magnetic permeability of the magnetic core. Therefore, the maximum exciting current of the magnetic core can be increased by changing the magnitudes of the three parameters, and the magnetic core is prevented from entering a saturation state prematurely during operation.
When calculating the magnetic core, the cross-sectional area, average magnetic path length L and cross-sectional perimeter of the magnetic core are generally taken as Lc
Wherein the average magnetic path length mainly affects the consumption of material, the sectional area perimeter mainly affects the copper consumption of coil winding, and in order to reduce consumption as much as possible, the size of the magnetic core is designed according to the principle that the sum of the average magnetic path length and the sectional area perimeter is minimum, that is
Lc+L＝2S/d+(2+π)d+πa (9)
When a is determined, the above formula has a minimum value, and the size of each parameter is calculated to be
Therefore, when the size of the magnetic core is determined, the consumed material amount can be reduced as much as possible according to the size determined by the formula relation under the condition that the requirement of output electric energy is also met, and the purpose of optimizing the magnetic core is achieved.
b magneto-resistance analysis
For the convenience of installation, two C-shaped or U-shaped magnetic cores can be selected when the magnetic cores are designed. When an air gap is present at the core interface, the reluctance of the entire magnetic circuit will change.
If the length of the air gap D is large, the magnetic lines of the magnetic field in the air gap will expand outward, causing edge diffusion. The magnetic lines of force at the edge of the air gap are not straight lines, but are convex outwards, so that the effective area of the air gap is larger than the sectional area of the magnetic core, and the edge diffusion phenomenon is more obvious when the air gap is larger. Only when the cross-sectional area of the core is much larger than the air gap (D <0.2D and D <0.2h) the edge diffusion is negligible and the magnetic field distribution in the air gap is considered to be the same as in the core.
The core reluctance is defined by reluctance
R1＝L/μ0μrS (11)
Let δ be 2D, the air gap reluctance is
R2＝δ/μ0S0(12)
Wherein S0Is the air gap effective area.
When D is small, the edge diffusion is not considered, i.e. S is considered0S. When the air gap D is larger, the influence of edge diffusion needs to be considered, a correction coefficient k can be added into the formula, and the formula is changed into
R＝δ/μ0(d+kδ)(h+kδ) (13)
Wherein k is 0.307/pi, d is h and the air gap reluctance is
R＝δ/μ0(d+kδ)2(14)
When the cross-sectional area is circular, D>At 0.4r, edge diffusion is considered. Equating the area of a circle to a square, i.e. d2＝πr2Bringing into the above formula
Assuming that the relative permeability of the whole magnetic core with air gap is, there is the following principle according to ampere loop theorem and magnetic path ohm's law
When S is0When the magnetic flux is approximately equal to S, the magnetomotive force is substituted into the magnetic flux relational expression, and the relative magnetic permeability is obtained
Since in general L/delta < murTherefore, the relative permeability of the whole magnetic circuit is greatly reduced, namely the corresponding magnetization intensity is greatly increased when the magnetic core reaches the saturation magnetic induction intensity.
The relative permeability of magnetic materials is generally large (10)3～104) When L/δ is equal to μrWhen R is1＝R2Despite the narrow air gap, the reluctance of the entire magnetic circuit is doubled. Under the condition that the magnetomotive force is not changed, the magnetic flux in the magnetic core becomes half of the original magnetic flux, namely the magnetic induction intensity becomes half of the original magnetic induction intensity. Therefore, under the condition that the bus bar square wave current is the same, the air gap magnetic resistance can be increased by increasing the air gap width, so that the magnetic resistance in the whole magnetic circuit is increased, and the magnetic flux is reduced, namely the magnetic induction intensity is reduced. The introduction of air gap reluctance avoids premature saturation of the core, thereby reducing core losses. Therefore, in the magnetic core with air gaps, the exciting current when the magnetic core is in a saturated state is greatly improved compared with the original exciting current.
Under the condition of larger current of the bus, the magnetic core can work in a non-saturated state by increasing the air gap at the magnetic core interface, so that the generation of overhigh peak voltage is avoided, and a back-end processing circuit is effectively simplified and protected.
According to the embodiment of the invention, the air gap width delta can be obtained according to the designed maximum saturation current.
Step six, calculating the number of turns of the coil
According to
The simulation of the energy taking of the bus bar current to the induction coil can be realized as long as the slope of the rising edge and the slope of the falling edge of the mathematical function waveform of the bus bar square wave current are consistent.
According to a simulation of the current function, from the formula
The secondary induced voltage can be calculated. The waveform of the induced voltage can be replaced by a mathematical function identifying M as 1, having
y＝4500(cos(x))-cos(5x)-cos(7x)+cos(11x)+cos13(x)-cos(17x)-cos(19x)(21)
According to the waveform drawn by matlab, the maximum value of y is 6.1, namely, the bus current can induce a spike wave with the amplitude 6.1 times of the fundamental wave induced voltage on the secondary side. Formula based on sinusoidal current induced voltage
Wherein mueqAt 157, N is 34 turns for an equivalent rectangular voltage wave 15V. The primary side current is much larger than the secondary side current, so the induced voltage at load is the same as that at no load.
Load requirements: maximum power PmaxThe load and the processing circuit resistance of the embodiment of the invention are 20 Ω in consideration of margin, wherein the rated power is 2.5W, the rated voltage U is 12V, the obtained equivalent resistance R is 28.8 Ω, and the current I is 0.42A.
The load power is 7.2W >5W, and the maximum power requirement of the load is met.
Step seven, designing turn-to-turn insulation of coil
The energy-taking iron core coil adopts a transformer purple copper foil, the insulating material wound on the outer layer is a polyester film, the withstand voltage level reaches 5.5kV, the voltage difference delta U of pulse square waves at two ends of the energy-taking iron core coil is 30V, the number of turns N is 40, and the voltage difference between turns is 0.75V <5.5kV, so that the breakdown phenomenon cannot occur between the turns of the energy-taking iron core coil.
Step eight, simulation analysis and performance test
A, magnetic core simulation modeling
The circuit of the energy-taking device is simulated by Saber. The magnetic core is first modeled, including the B-H curve of the magnetic core, the shape and size of the magnetic properties, the number of turns of the coil, the stray parameters of the coil, etc., and then the magnetic core is tested for anti-saturation performance with a sinusoidal current source applied. The material parameters are set according to the selected magnetic core, the B-H curve can be led in according to the curve given by the magnetic core, and the saturation magnetic induction intensity and the saturation magnetic field intensity are specified.
The magnetic core shape parameter setting comprises magnetic path length, silicon steel sheet thickness, lamination coefficient and rectangular section parameter of the magnetic core.
The primary side winding is set to be n1The value of the number of turns of the secondary winding is determined according to the designed output voltage, and the wire diameter of the winding is determined by the effective value of the current flowing. At this time, the modeling of the entire energy-extracting core is completed.
B, magnetic core no-load simulation test
Sine current no-load simulation test
According to the established model, a power frequency sinusoidal current source is added to the primary side of the magnetic core, the current amplitude is continuously changed from 100A to 6000A, no-load output is set at the secondary side, and the output voltage amplitude and the waveform distortion degree are observed. When the busbar current is 100-4500A, the output voltage is sine wave, when the current value is increased to 5000A, the magnetic core enters a saturated state in part of time, namely the magnetic flux in the magnetic core changes slowly, and the induced electromotive force is almost zero at the moment; however, near the bus square wave current zero crossing point, the magnetic induction intensity in the magnetic core reaches saturation quickly, that is, the magnetic flux in the magnetic core changes quickly, the induced electromotive force generated at this time is large, and the test result is shown in fig. 6.
Pulse square wave current no-load simulation test
Next, no-load test was performed on the primary side injected pulse square wave current, the amplitude of the square wave current was 4500A, and the rising edge and the falling edge were set to 0.8 ms. The simulation shows that: the amplitude of the no-load voltage is about 30V and is consistent with the theoretical calculation result
Integral simulation test of energy taking circuit
As shown in fig. 7, a signal processing module is connected to the rear of the no-load energy-taking circuit, and a rectifying circuit, a filter capacitor, a voltage stabilizing circuit and a load equivalent circuit are sequentially arranged from left to right. Considering that the load power is larger, the filter capacitor should satisfy the power conservation law, i.e. the load power is larger
In order to make the voltage drop during discharging meet the requirement of 10%, the embodiment of the present invention selects a capacitance of 10000uF through a simulation circuit diagram as shown in FIG. 8. The voltage-stabilizing input is electrically connected with a 100uF capacitor, and the output is connected with a 10uF capacitor to form a DC/DC output circuit.
When the load resistance is greater than 9 Ω, the load voltage is stabilized at 12V, that is, the maximum power that can be stably output by the energy obtaining device is 16W. The relation of load power and voltage approximately satisfies
The power curve of the load output is shown in fig. 9.
When the load equivalent resistance is set to 5 Ω, the load terminal voltage is as shown in the waveforms of fig. 5-22 (red). Since the primary side capacitance is not sufficient to support the energy output of the load, the voltage across the terminals has dropped to zero during the discharge phase.
Step nine, performance test and material object manufacture
According to the no-load output voltage waveform of the energy taking device, an IGBT full-bridge switching circuit is used for simulating and generating a bipolar pulse square wave, the pulse width and the frequency are consistent with those of the integral simulation test of the energy taking circuit, and the pulse width and the frequency are used for testing the electrical performance of the power supply processing module.
Making corresponding object according to the circuit diagram of the performance test, and performing shell appearance design and material selection according to the bus bar size and the insulation strength
As shown in fig. 10, the schematic diagram of the installation of the energy-taking device in real object is that the energy-taking device is installed on the busbar close to the reactor of the converter valve, and the buckle at the air gap connection of the energy-taking device is placed at the farthest position from the busbar, so that the influence of the busbar on the electric field of the energy-taking iron core is reduced, and the surface flashover is prevented. The output of the energy taking device is connected to the sensor through the power supply processing module on the left side. The whole device is supported and fixed by installing two buckles on the cylindrical surface of the energy taking device.
Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.
Claims (8)
1. The energy taking device design method based on the converter valve bus bar square wave current is characterized in that: the method comprises the following steps:
s1: extracting a square wave current key parameter of a converter valve busbar;
s2: calculating the power characteristic of a coil of the energy-taking device;
s3: selecting a magnetic core material and a shape of the energy taking device according to the shape of the converter valve busbar, and analyzing and calculating the energy taking device;
in the step S3, the magnetic core is in a U-shaped or circular ring shape;
step S3 specifically includes:
s31: selecting a magnetic core material according to the magnetic conductivity, the coercive force, the resistivity and the saturation magnetic induction intensity of the magnetic core material;
s32: analyzing the magnetic resistance and the magnetic saturation of the magnetic core, and determining the size of the magnetic core;
s33: calculating the number of turns of a coil of the energy taking device;
s34: designing turn-to-turn insulation of a coil of the energy taking device;
s4: simulating the designed energy taking device, and setting up a test platform to carry out performance test on the energy taking device.
2. The converter valve busbar square wave current-based energy taking device design method according to claim 1, characterized in that: step S2 specifically includes the following steps:
s21: calculating the effective value of the secondary side voltage of the energy taking device;
s22: and calculating the secondary side power characteristic of the energy taking device.
3. The converter valve busbar square wave current-based energy taking device design method according to claim 1, characterized in that: step S32 specifically includes:
s321: selecting a circular magnetic core, and calculating the magnetic conductance of the magnetic core on the assumption that the magnetic core works in a linear region;
s322: calculating the maximum exciting current just entering a saturation state;
s323: the core is dimensioned in such a way that the sum of the average magnetic path length and the perimeter of the cross-sectional area is minimized.
4. The converter valve busbar square wave current-based energy taking device design method according to claim 3, characterized in that: the number of turns of the coil of the energy-taking device in the step S33 satisfies the following conditions:
wherein e is induced potential, n is number of turns of coil, mueqFor equivalent permeability, w is the width of the inner and outer diameters of the core, s is the thickness of the core, ImFor the excitation current, l is the average magnetic path length of the core.
5. The converter valve busbar square wave current-based energy taking device design method according to claim 4, wherein the method comprises the following steps: step S4 specifically includes:
s41: modeling the magnetic core according to the magnetic core parameters, and connecting the magnetic core into an excitation source;
s42: setting an excitation source as a power frequency current, changing the amplitude of the applied power frequency current, carrying out no-load test on the primary side of the magnetic core, and testing and recording the amplitude of the output voltage of the secondary side of the magnetic core;
s43: replacing the power frequency current with a square wave current with a fixed amplitude, carrying out no-load test on the primary side of the magnetic core, and testing and recording the amplitude of the output voltage of the secondary side of the magnetic core;
s44: connecting the secondary side of the magnetic core with a signal processing module to form an energy taking circuit and connecting the energy taking circuit with a load equivalent circuit;
s45: applying excitation and changing the resistance value of the load equivalent resistor, testing the voltage change condition of the load terminal, and carrying out statistics to obtain a conclusion;
s46: and (3) building a test platform, debugging a test circuit, testing the designed energy-taking device, and acquiring the performance of the energy-taking device in a real environment.
6. The converter valve busbar square wave current-based energy taking device design method according to claim 5, characterized in that: the signal processing module comprises a rectifying circuit, a filter capacitor and a voltage stabilizing circuit which are sequentially connected, the rectifying circuit is connected to the secondary side of the magnetic core, and the voltage stabilizing circuit is connected to the load equivalent circuit.
7. The energy taking device based on the converter valve busbar square wave current manufactured by the design method according to any one of claims 1 to 6, is characterized in that: the magnetic core of the energy taking device is in a split-opening annular shape and is divided into a primary side magnetic core and a secondary side magnetic core, a primary side coil and a secondary side coil are wound on the primary side magnetic core and the secondary side magnetic core respectively, the magnetic cores are made of silicon steel sheets, air gap sheets are arranged at two openings and are tightly pressed through spring clamp springs, and the energy taking device is used for extracting line parameters in a high-voltage line.
8. The converter valve busbar square wave current-based energy taking device according to claim 7, wherein: and the coil turn-to-turn insulation of the primary side coil and the secondary side coil is formed by winding a polyester film.
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| CN110704962B (en) * | 2019-08-29 | 2022-11-18 | 石家庄科林电气股份有限公司 | Manufacturing method of double-power output energy-taking magnetic core |
| CN111337803A (en) * | 2020-03-20 | 2020-06-26 | 国网陕西省电力公司电力科学研究院 | Built-in high-voltage cable intermediate joint partial discharge detection and self-energy-taking integrated system and operation method thereof |
| CN113933630A (en) * | 2021-10-12 | 2022-01-14 | 全球能源互联网欧洲研究院 | Measuring method and device for embedded sensor of converter valve |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2007097358A (en) * | 2005-09-30 | 2007-04-12 | Toshiba Corp | Information collecting device and method therefor |
| CN101923593A (en) * | 2010-08-23 | 2010-12-22 | 中国电力科学研究院 | Performance analysis method of saturated reactor for converter valve in thyristor impedance state |
| CN105024460A (en) * | 2015-07-27 | 2015-11-04 | 东南大学 | Design method for 110 kV high-voltage line wireless power supply system used online induction energy-obtaining device |
| CN105182123A (en) * | 2015-09-02 | 2015-12-23 | 国网智能电网研究院 | Converter valve saturable reactor thermal property test apparatus and test method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2007097358A (en) * | 2005-09-30 | 2007-04-12 | Toshiba Corp | Information collecting device and method therefor |
| CN101923593A (en) * | 2010-08-23 | 2010-12-22 | 中国电力科学研究院 | Performance analysis method of saturated reactor for converter valve in thyristor impedance state |
| CN105024460A (en) * | 2015-07-27 | 2015-11-04 | 东南大学 | Design method for 110 kV high-voltage line wireless power supply system used online induction energy-obtaining device |
| CN105182123A (en) * | 2015-09-02 | 2015-12-23 | 国网智能电网研究院 | Converter valve saturable reactor thermal property test apparatus and test method thereof |
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