Hybrid quadrature controllable wide-range tunable filtering device and method

Abstract

The application discloses a hybrid orthogonal controllable wide-range adjustable filtering device and method, and relates to the technical field of power equipment. The device comprises a hybrid orthogonal controllable reactor, a filtering capacitor, a harmonic detection module, a control module and a DC control power supply. The reactor and the capacitor are connected in series to form a filtering unit and are connected in parallel to a harmonic source side. The reactor comprises a symmetric core assembly and a winding assembly. The AC winding is provided with multiple taps, and is matched with a DC excitation winding to realize combined inductance adjustment. The method calculates the target inductance by detecting the harmonic frequency and combining a resonance formula, and then switches the taps to coarsely adjust the number of turns, and then adjusts and controls the DC current to finely adjust the inductance, so that the capacitor and the inductance are always resonant and matched. The application breaks through the traditional adjustment limitation, realizes wide-range continuous linear inductance adjustment, adapts to mobile harmonic treatment, improves filtering stability and power quality, and has compact structure, less magnetic flux leakage and high application value.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, specifically to a hybrid orthogonal controllable wide-range adjustable filter device and method. Background Technology

[0002] In power system operation, harmonic pollution severely impacts power quality, especially frequency-shifting harmonics present in scenarios such as wind and solar power integration systems, leading to decreased equipment efficiency and shortened lifespan. Traditional filter structures are fixed and cannot adapt to changes in harmonic frequencies; when harmonic frequencies deviate from design values, the filtering effect significantly diminishes. Furthermore, existing adjustable filter devices combining orthogonal controllable reactors and capacitors suffer from limited inductance adjustment ranges, only effectively managing harmonics with small frequency shifts, failing to meet the needs of harmonic mitigation across a wide frequency range. Therefore, developing a filtering technology capable of continuous inductance adjustment over a wide range and adapting to harmonic frequency variations under different operating conditions has become an important research direction in the field of power equipment. Summary of the Invention

[0003] The purpose of this invention is to provide a hybrid orthogonal controllable wide-range adjustable filter device and method to solve the technical problems of traditional filters having a narrow filtering frequency range and being unable to effectively deal with moving harmonics.

[0004] To solve the above problems, the technical solution of the present invention is as follows: A hybrid orthogonal controllable wide-range adjustable filter device includes a hybrid orthogonal controllable reactor, a filter capacitor, a harmonic detection module, a control module, and a DC control power supply. The hybrid orthogonal controllable reactor and the filter capacitor are connected in series to form an adjustable filter unit, which is connected in parallel to the harmonic source side. The harmonic detection module is signal-connected to the control module and is used to detect and output the harmonic frequency at the harmonic source side. The control module is signal-connected to the harmonic detection module and the DC control power supply, and is indirectly controlled by the hybrid orthogonal controllable reactor. After receiving the harmonic frequency signal, the control module outputs a turns switching signal to the hybrid orthogonal controllable reactor and an output current adjustment signal to the DC control power supply, which provides excitation current to the hybrid orthogonal controllable reactor.

[0005] Furthermore, the hybrid orthogonal controllable reactor includes symmetrically arranged core assemblies and winding assemblies. The core assembly includes an AC core section and a DC core section. The AC core section has a closed frame structure with air gaps on both sides of the core columns, while the DC core section has an open structure and is vertically mounted on both sides of the AC core section. The winding assembly includes AC windings and DC windings, which are wound on the AC core section and the DC core section, respectively. This symmetrical structural design can improve magnetic field utilization and reduce leakage flux and electromagnetic interference.

[0006] Furthermore, the AC winding is an adjustable-turn structure, including two sets of symmetrically arranged AC coils, which are connected in series to form an AC working winding; the DC winding includes two sets of symmetrically arranged DC coils, which are connected in series to form a DC excitation winding; the AC coils are provided with multiple taps at intervals along the winding axis, and the number of turns connected can be adjusted in stages by switching the taps.

[0007] Furthermore, the inductance value of the hybrid quadrature controllable reactor satisfies: ,in, This is the inductance value. For harmonic frequencies, The capacitance value of the filter capacitor; the hybrid quadrature controllable reactor, through a combination of turns adjustment and DC current adjustment, is used to adjust the inductance value at... Continuously adjustable within the range.

[0008] Furthermore, the inductance adjustment range of the hybrid quadrature controllable reactor satisfies the following conditions: the inductance reaches its maximum value when the maximum number of turns is connected and the DC control current is 0A, and the inductance reaches its minimum value when the minimum number of turns is connected and the DC control current is the set maximum value; the inductance range of each setting satisfies the following conditions. And the maximum inductance value of the nth stage satisfies .

[0009] Furthermore, the capacitance value of the filter capacitor satisfies: ,in, This is the effective value of the power frequency filter branch voltage. The reactive power capacity compensated by the filter. The power frequency. The capacitance value is selected as a solution greater than 0, where the intermediate frequency is the harmonic frequency variation.

[0010] Furthermore, the side length of the cross-section of the AC core satisfies: ,in, This is an empirical coefficient. For reactor capacity, The number of AC core columns with coils wound around them is given, and the length of the orthogonal region is equal to the side length of the cross section.

[0011] Furthermore, the magnetic induction intensity of the core assembly satisfies: And the maximum magnetic flux density satisfies ,in, For the number of turns of the AC winding, For the cross-sectional area, , These are the fundamental current and the maximum value of the harmonic current, respectively. For safety reasons, The saturation magnetic induction intensity of the core material.

[0012] Furthermore, the inductance value of the hybrid quadrature controllable reactor satisfies: ,in, To exchange the total length of the non-orthogonal region of the iron core, The length of a single orthogonal region. The length of the air gap. The permeability of free space, , These represent the permeability of the AC core and the orthogonal region, respectively. The air gap length l... g Based on the target minimum inductance value Minimum number of access turns And the calculation and determination of magnetic permeability parameters A method for a hybrid orthogonal controllable wide-range adjustable filter device includes the following steps: S1: Harmonic signals from the harmonic source side are acquired through the harmonic detection module, and the harmonic frequencies are obtained through analysis. And transmit it to the control module; S2: The control module determines the harmonic frequency. , combined Calculate the target inductance value, generate a turns-level switching command, and control the hybrid quadrature controllable reactor to connect to the AC coil with the corresponding number of turns; S3: The control module adjusts the output current of the DC control power supply based on the deviation between the target inductance value and the current detected value, combined with... Fine-tuning of the inductor is performed to ensure that the filter capacitor and inductor meet the resonance matching condition, thereby achieving harmonic filtering.

[0013] The beneficial effects of this invention are as follows: 1. Wide and continuous inductance adjustment range: By combining the adjustment of turns and magnetic control, and with parameter matching supported by multiple formulas, continuous linear adjustment of the inductance is achieved in a wide range, breaking through the limitations of the traditional single adjustment method, and can adapt to the needs of mobile harmonic control in a wide range of 300~400Hz.

[0014] 2. Stable and reliable filtering effect: Through the coordinated work of the harmonic detection module and the control module, the harmonic frequency changes are tracked in real time, and the inductance value is precisely adjusted to keep the capacitor and inductor in a resonant matching state. This avoids the problem of filter effect attenuation caused by frequency offset in traditional filters, and significantly improves the power quality of the power grid.

[0015] 3. Scientific and reasonable structural design: The symmetrical iron core structure and winding design significantly improve the magnetic field utilization rate, reduce leakage flux and electromagnetic interference, and at the same time reduce the equipment size and installation space requirements, thereby reducing the cost of engineering applications.

[0016] 4. Precise and controllable design process: The structural parameters, inductance adjustment and reactive power compensation of the reactor are all supported by clear formulas, which can precisely customize the equipment parameters according to the harmonic frequency range and reactive power compensation requirements of the actual application scenario, thereby improving the applicability and reliability of the device. Attached Figure Description

[0017] The invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of the present invention. Figure 2 This is a schematic diagram of the hybrid orthogonal controllable reactor structure of the present invention. Figure 3 This is a schematic diagram of the adjustable winding structure of the hybrid orthogonal controllable reactor of the present invention. Figure 4 This is a schematic diagram illustrating the working principle of the hybrid orthogonal controllable reactor of the present invention. Figure 5 This is a schematic diagram of the inductance adjustment characteristics of the hybrid orthogonal controllable reactor of the present invention. Figure 6 This is a schematic diagram of the current waveform after the application of the wide-range adjustable filter of the present invention. Figure 7 This is a schematic diagram of the filtering performance of the adjustable filter of the present invention within the harmonic frequency shift range. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] A hybrid orthogonal controllable wide-range adjustable filter device includes a hybrid orthogonal controllable reactor, a filter capacitor, a harmonic detection module, a control module, and a DC control power supply. The hybrid orthogonal controllable reactor and the filter capacitor are connected in series to form an adjustable filter unit. The adjustable filter unit is connected in parallel to the harmonic source side, such as a wind-solar convergence point with a frequency shifting from 300 to 400 Hz. The reactive power compensation required per phase of the system is 1 Mvar. The harmonic detection module is installed near the harmonic source and is signal-connected to the control module. It is used to detect and output the harmonic frequency at the harmonic source side. The control module is controlled by the DC control power supply, which is electrically connected to the hybrid orthogonal controllable reactor. After receiving the harmonic frequency signal, the control module outputs a turns-switching signal to the hybrid orthogonal controllable reactor and an output current adjustment signal to the DC control power supply. By adjusting the turns ratio first and then the DC current, the filter capacitor and inductor meet the resonance matching condition, achieving wide-range harmonic filtering and significantly improving the power quality of the power grid.

[0020] Furthermore, the hybrid orthogonal controllable reactor includes symmetrically arranged core and winding assemblies. The symmetrical structure can improve magnetic field utilization, reduce leakage flux and electromagnetic interference, and reduce equipment size and installation space. The core assembly consists of an AC core and a DC core. The AC core is a "U-shaped" closed frame structure with two air gaps in the middle of the core columns on both sides. The DC core has two "C-shaped" open structures, which are respectively vertically assembled on both sides of the AC core. The winding assembly includes AC windings and DC windings, which are wound on the AC core and DC core respectively.

[0021] Furthermore, the AC winding is an adjustable-turn structure, comprising two symmetrically arranged AC coils, with the same-name terminals of the two AC coils connected end-to-end and connected in series to form an AC working winding; the DC winding comprises two symmetrically arranged DC coils, with the same-name terminals of the two DC coils connected end-to-end and connected in series to form a DC excitation winding; the AC coils are provided with multiple taps at intervals along the winding axis, with 3 to 5 taps divided into 3 levels, each tap being equipped with a terminal block, which is connected to an external switching switch, and the switching switch is connected to the control module signal, thereby realizing the graded adjustment of the number of turns connected by switching the taps, providing a structural basis for wide-range inductance adjustment.

[0022] Furthermore, the inductance value of the hybrid quadrature controllable reactor satisfies: ,in, This is the inductance value. For harmonic frequencies, The capacitance value of the filter capacitor is selected as 22uF; the hybrid quadrature controllable reactor achieves continuous adjustment of the inductance value in the range of 7.48~13.30mH through a combination of turns adjustment and DC current adjustment, which is suitable for wide range of mobile harmonic control requirements.

[0023] Furthermore, the inductance adjustment range of the hybrid quadrature controllable reactor satisfies the following condition: maximum number of turns connected. Furthermore, the inductance reaches its maximum value when the DC control current is 0A, requiring the minimum number of turns to be connected. Furthermore, the inductance reaches its minimum value when the DC control current reaches its set maximum value; the inductance range for each gear position meets the requirements. And the maximum inductance value of the nth stage satisfies This achieves continuous coverage of the inductance range of 7.48~13.30mH, ensuring no blind spots in adjustment.

[0024] Furthermore, the capacitance value of the filter capacitor satisfies: ,in, This is the effective value of the power frequency filter branch voltage. The reactive power capacity compensated by the filter. The power frequency is 50Hz. The capacitor value is selected as the intermediate frequency of the harmonic frequency variation, with a value greater than 0. This provides a theoretical basis for accurate capacitor selection and ensures resonance matching with the inductor.

[0025] Furthermore, the side length of the cross-section of the AC core satisfies: ,in, This is an empirical coefficient (taken as 1.2). For reactor capacity, The number of AC core columns with wound coils, and the length of the orthogonal region. The core cross-sectional dimensions are determined by this formula to ensure that the core meets the requirements for magnetic permeability and structural strength.

[0026] Furthermore, the magnetic induction intensity of the core assembly satisfies: And the maximum magnetic flux density satisfies ,in, For the number of turns of the AC winding, For the cross-sectional area, , These are the fundamental current and the maximum value of the harmonic current, respectively. For the safety factor (taken as 0.9), The saturation magnetic induction intensity of the core material; combining the two equations, the minimum number of turns of the AC winding is obtained. This ensures that the iron core operates in an unsaturated state, preventing the reactor performance from deteriorating.

[0027] Furthermore, the inductance value of the hybrid quadrature controllable reactor also satisfies: ,in, To exchange the total length of the non-orthogonal region of the iron core, The length of a single orthogonal region. The length of the air gap. The permeability of free space, , These represent the permeability of the AC core and the orthogonal region, respectively. When the control current is at its maximum, the permeability of the orthogonal region reaches its minimum. Air gap length Based on the target minimum inductance value of 7.48mH and the minimum number of connected turns The permeability characteristic parameters were calculated and determined to optimize the linearity of inductor adjustment.

[0028] A method for a hybrid orthogonal controllable wide-range adjustable filter device achieves wide-frequency harmonic filtering through a four-step closed-loop process: harmonic detection, coarse inductor adjustment, fine inductor adjustment, and resonance matching. Based on real-time harmonic frequency detection, this method dynamically matches the inductance value of the hybrid orthogonal controllable reactor using a combination of "turn-by-turn graded adjustment + DC magnetic control fine adjustment," ensuring that the inductor and filter capacitor meet the resonance condition. This method filters out mobile harmonics of different frequencies while also addressing reactive power compensation requirements. The specific steps are as follows: S1: Harmonic signal acquisition and frequency analysis; S11. Install the harmonic detection module near the harmonic source (such as the bus side of the wind-solar power convergence point), collect the three-phase current / voltage signals at the harmonic source side in real time, and separate the fundamental and harmonic components using algorithms such as Fourier transform to extract the harmonic frequencies. (e.g., 300~400Hz moving harmonics), and transmit the frequency data to the control module in real time.

[0029] S12. The sampling frequency of the detection module must be higher than twice the harmonic frequency (satisfying the Nyquist sampling theorem), and the frequency detection error must be ≤ ±1Hz to ensure the accuracy of subsequent inductor matching.

[0030] S13. Single detection cycle ≤ 5ms, output harmonic frequency RMS value of harmonic current RMS value of fundamental current Core parameters, etc.

[0031] S2: Target inductance calculation and coarse adjustment of turns range; S21. Control module receives harmonic frequencies. Then, combined with the preset filter capacitor capacitance value Through formula Calculate the target inductance value corresponding to the current harmonic frequency. If the system needs to compensate for reactive power... Then first pass Determine the appropriate capacitance value (select a positive value solution), and then work backward to deduce the target inductance.

[0032] S22. The control module determines the target inductance value. This is for matching the AC coil turns of a hybrid quadrature controllable reactor. The AC coil has multiple taps (e.g., 3-5 taps), each corresponding to a fixed range of turns. By switching the external wiring switch, the number of turns matched to the target inductor can be connected. (For example, a target inductance of 10mH corresponds to 200 turns).

[0033] S23. The inductance range of each gear position meets the requirements. ( This ensures there are no inductor blind spots during switching. For example, the inductance range is 7.48-9.5mH for level 1, 8.8-11.2mH for level 2, and 10.5-13.3mH for level 3, covering a total range of 7.48-13.30mH.

[0034] S3: DC current regulation and fine inductor calibration; S31. By using an inductance sensor connected in series in the reactor branch, the actual inductance value at the current number of turns connected is detected in real time. And feed it back to the control module.

[0035] S32. Control module calculates target inductance. With actual inductance If the deviation is greater than 0.1mH, the adjustment is initiated, and a current adjustment signal is output to the DC control power supply to change the excitation current of the DC excitation winding. .

[0036] S33. Using the formula The permeability of the orthogonal region can be changed by altering the direct current. (The larger the current, the better) The smaller the value, the smaller the inductance, enabling fine inductance calibration and ultimately making... .

[0037] S34. The adjustment range of the DC control current is 0~5A, and the maximum current shall not exceed the rated current of the DC winding to avoid overheating of the winding.

[0038] S4: Resonance matching maintenance and dynamic adaptation; S41. The harmonic detection module continuously collects harmonic frequencies. If a harmonic frequency is detected... For changes (such as from 320Hz to 350Hz), repeat steps S2-3 to dynamically update the target inductance value and adjust the number of turns and DC current to ensure that the inductor and capacitor always meet the resonance condition. ( ).

[0039] S42. While adjusting the inductance, use the formula Ensure that the reactive power compensation meets the system requirements (e.g., 1 Mvar per phase) to achieve coordinated optimization of harmonic filtering and reactive power compensation.

[0040] Using this method, the filter device achieves a harmonic filtering rate of ≥95% within the 300~400Hz harmonic frequency range, and the current waveform after commissioning is close to a standard sine wave; at the same time, the reactive power compensation accuracy is ≤±5%, the system power factor is improved to above 0.95, the equipment operating efficiency is ≥98%, and the leakage magnetic interference is ≤5mT, meeting the power system's requirements for power quality and equipment stability.

[0041] The embodiments described in this specification are merely examples of implementations of the inventive concept. The scope of protection of this invention should not be considered as limited to the specific forms stated in the embodiments. The scope of protection of this invention also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A hybrid orthogonal controllable wide-range adjustable filter device, characterized in that, The system includes a hybrid quadrature controllable reactor, a filter capacitor, a harmonic detection module, a control module, and a DC control power supply. The hybrid quadrature controllable reactor and the filter capacitor are connected in series to form an adjustable filter unit, which is connected in parallel to the harmonic source side. The harmonic detection module is signal-connected to the control module and is used to detect and output the harmonic frequency at the harmonic source side. The control module is signal-connected to the harmonic detection module and the DC control power supply, and is indirectly controlled by the hybrid quadrature controllable reactor. After receiving the harmonic frequency signal, the control module outputs a turns switching signal to the hybrid quadrature controllable reactor and an output current adjustment signal to the DC control power supply, which provides excitation current to the hybrid quadrature controllable reactor.

2. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 1, characterized in that, The hybrid orthogonal controllable reactor includes symmetrically arranged core assemblies and winding assemblies; the core assembly includes an AC core section and a DC core section, the AC core section is a closed frame structure with air gaps on both sides of the core columns, and the DC core section is an open structure, vertically assembled on both sides of the AC core section; the winding assembly includes AC windings and DC windings, respectively wound on the AC core section and the DC core section.

3. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 2, characterized in that, The AC winding is an adjustable-turn structure, including two sets of symmetrically arranged AC coils, which are connected in series to form an AC working winding; the DC winding includes two sets of symmetrically arranged DC coils, which are connected in series to form a DC excitation winding; the AC coils are provided with multiple taps at intervals along the winding axis, and the number of turns connected can be adjusted in stages by switching the taps.

4. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 3, characterized in that, The inductance value of the hybrid quadrature controllable reactor satisfies: ,in, This is the inductance value. For harmonic frequencies, The capacitance value of the filter capacitor; the hybrid quadrature controllable reactor, through a combination of turns adjustment and DC current adjustment, is used to adjust the inductance value at... Continuously adjustable within the range.

5. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 4, characterized in that, The inductance adjustment range of the hybrid quadrature controllable reactor satisfies the following conditions: the inductance reaches its maximum value when the maximum number of turns is connected and the DC control current is 0A; the inductance reaches its minimum value when the minimum number of turns is connected and the DC control current is the set maximum value; the inductance range of each setting satisfies the following conditions. And the maximum inductance value of the nth stage satisfies .

6. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 1, characterized in that, The capacitance value of the filter capacitor satisfies: ,in, This is the effective value of the power frequency filter branch voltage. The reactive power capacity compensated by the filter. The power frequency. The capacitance value is selected as a solution greater than 0, where the intermediate frequency is the harmonic frequency variation.

7. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 2, characterized in that, The side length of the cross section of the AC core satisfies: ,in, This is an empirical coefficient. For reactor capacity, The number of AC core columns with coils wound around them is given, and the length of the orthogonal region is equal to the side length of the cross section.

8. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 2, characterized in that, The magnetic induction intensity of the core assembly satisfies: And the maximum magnetic flux density satisfies ,in, For the number of turns of the AC winding, For the cross-sectional area, , These are the fundamental current and the maximum value of the harmonic current, respectively. For safety reasons, The saturation magnetic induction intensity of the core material.

9. The hybrid orthogonal controllable wide-range adjustable filter device according to claim 2, characterized in that, The inductance value of the hybrid quadrature controllable reactor satisfies: ,in, To exchange the total length of the non-orthogonal region of the iron core, The length of a single orthogonal region. The length of the air gap. The permeability of free space, , These are the permeabilities of the AC core and the orthogonal region, respectively.

10. A method for using the hybrid orthogonal controllable wide-range adjustable filter device according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Harmonic signals from the harmonic source side are acquired through the harmonic detection module, and the harmonic frequencies are obtained through analysis. And transmit it to the control module; S2: The control module determines the harmonic frequency. , combined Calculate the target inductance value, generate a turns-level switching command, and control the hybrid quadrature controllable reactor to connect to the AC coil with the corresponding number of turns; S3: The control module adjusts the output current of the DC control power supply based on the deviation between the target inductance value and the current detected value, combined with... Fine-tuning of the inductor is performed to ensure that the filter capacitor and inductor meet the resonance matching condition, thereby achieving harmonic filtering.

Images