A 10kv broadband voltage transformer for broadband voltage monitoring

Abstract

This invention discloses a 10 kV broadband voltage transformer for broadband voltage monitoring, comprising: a resistive-capacitive voltage divider main structure, consisting of a high-voltage arm unit and a low-voltage arm unit connected in series, wherein the impedance angles of the high-voltage arm unit and the low-voltage arm unit are equal, so that the voltage division ratio of the transformer is determined by the ratio of their impedance moduli; a high-voltage arm unit, comprising at least one or more high-voltage arm capacitors and high-voltage arm resistors connected in parallel or in series-parallel configuration, one end of the high-voltage arm unit being connected to the primary high-voltage side of the distribution network; a low-voltage arm unit, consisting of a low-voltage arm resistor and a low-voltage arm capacitor connected in parallel, one end of the low-voltage arm unit being connected to the output terminal of the high-voltage arm unit, and the other end being grounded; an insulating encapsulation shell, employing a fully enclosed insulating encapsulation structure, which encloses the high-voltage arm unit, the low-voltage arm unit, and the internal connecting components, forming the primary main insulation and structural support; and a signal output interface, connected to the low-voltage arm unit, for outputting the measured voltage signal to an external voltage monitoring terminal.

Description

Technical Field

[0001] This invention relates to the field of distribution network voltage monitoring technology, and more specifically, to a 10 kV broadband voltage transformer for broadband voltage monitoring. Background Technology

[0002] With the accelerated development of energy transition and new power systems, large-scale grid connection of new energy sources, distributed photovoltaic power generation, and offshore wind power transmission have caused a certain degree of harmonic pollution to the power grid. Meanwhile, high-end manufacturing and data center scenarios are placing higher demands on power quality. The large-scale integration of new energy sources has led to not only the existence of steady-state harmonics at traditional power frequencies in the power grid, but also the frequent occurrence of high-frequency harmonics, interharmonics, sub / supersynchronous oscillations, and complex transient events such as microsecond-level voltage sags and dips. However, existing traditional voltage monitoring equipment is limited by sensing and acquisition principles, with its operating frequency band typically restricted to within 3kHz. This makes it difficult to accurately capture and analyze the aforementioned wide-frequency, high-frequency transient signals, resulting in technical bottlenecks of "inability to measure accurately" and "inability to measure precisely."

[0003] As the core primary sensing device in a voltage monitoring system, the frequency transmission characteristics of a voltage transformer directly determine the overall bandwidth and accuracy of the monitoring system. Currently, while conventional electromagnetic voltage transformers are simple in structure and highly reliable, they suffer from magnetic saturation, resulting in limited dynamic range and poor high-frequency response characteristics, failing to meet the voltage transmission requirements of the DC-300kHz ultra-wide frequency range. While some existing electronic transformers with RC voltage divider structures can theoretically achieve voltage division from DC to high frequencies, in actual products, the high-voltage impedance and voltage divider impedance inevitably contain distributed inductance and capacitance, causing the voltage divider's bandwidth to narrow rapidly, limiting its measurement accuracy in the high-frequency range. Furthermore, existing transformers lack precise testing methods for wideband characteristics throughout their entire lifecycle, and methods for verifying amplitude-frequency characteristics in the high-frequency range and establishing quantitative transfer standards are still lacking.

[0004] Therefore, in order to overcome the limitations of traditional voltage transformers in terms of bandwidth, high-frequency response, and resistance to distributed parameter interference, it is urgent to propose a miniaturized voltage transformer with ultra-wideband operating capability based on a specially manufactured RC voltage divider structure. This transformer can be used to support wideband voltage monitoring and analysis systems and ensure voltage quality monitoring in complex power grid environments. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a 10 kV broadband voltage transformer for broadband voltage monitoring.

[0006] According to one aspect of the present invention, a 10 kV broadband voltage transformer for broadband voltage monitoring is provided, comprising: The main structure of the RC voltage divider consists of a high-voltage arm unit and a low-voltage arm unit connected in series. The impedance angles of the high-voltage arm unit and the low-voltage arm unit are equal, so that the voltage division ratio of the current transformer is determined by the ratio of the impedance moduli. A high-voltage arm unit includes at least one or more high-voltage arm capacitors and high-voltage arm resistors, which are connected in parallel or in series-parallel. One end of the high-voltage arm unit is connected to the primary high-voltage side of the distribution network. The low-voltage arm unit consists of a low-voltage arm resistor and a low-voltage arm capacitor connected in parallel. One end of the low-voltage arm unit is connected to the output terminal of the high-voltage arm unit, and the other end is grounded. The insulating enclosure adopts a fully enclosed insulating enclosure structure, which completely covers the high voltage arm unit, the low voltage arm unit and the internal connecting components, forming a primary main insulation and structural support. The signal output interface connects to the low-voltage arm unit and is used to output the measured voltage signal to an external voltage monitoring terminal.

[0007] Optionally, the principle of the resistive-capacitive voltage divider main structure is as follows: in This is the primary voltage of the distribution network; This is the secondary voltage output; The impedance of the high-voltage arm of the resistor-capacitor voltage divider; The impedance of the low-voltage arm of the resistor-capacitor voltage divider; This refers to the impedance modulus of the high-voltage arm of the impedance divider. This refers to the impedance modulus of the low-voltage arm of the impedance divider. This refers to the impedance angle of the high-voltage arm of the resistor-capacitor voltage divider. ω is the impedance angle of the low-voltage arm of the RC voltage divider [1], ω is the angular frequency, and ωt represents the phase angle of the sinusoidal quantity at time t.

[0008] Optionally, the voltage division ratio is 100:1, and the measured voltage signal is 100V.

[0009] Optionally, the capacitance of a single high-voltage arm capacitor is 50 to 500 pF, and the resistance of a single high-voltage arm resistor is 1 to 10 MΩ.

[0010] Alternatively, the high-voltage arm unit is fixed to the top of the inside of the insulating enclosure by a specially designed insulating bracket.

[0011] Optionally, the low-voltage arm resistor is a high-precision, low-temperature drift metal film resistor; the low-voltage arm capacitor is a mica capacitor or a polypropylene capacitor without residual voltage.

[0012] Optionally, the low-voltage arm unit is encapsulated in a metal shield with electromagnetic shielding and connected to the signal acquisition board of an external broadband voltage monitoring terminal via a signal output interface to achieve impedance matching.

[0013] Optionally, the insulating encapsulation shell is made of epoxy resin material, and the high-voltage arm unit, low-voltage arm unit and internal connection components are completely encapsulated in it through a process combining vacuum casting and heat curing.

[0014] Optionally, the signal output interface is a 50Ω BNC connector, and the measured voltage signal is directly input to the signal acquisition board of the voltage monitoring terminal through the 50Ω BNC connector.

[0015] Optionally, the frequency measurement range of the 10 kV wideband voltage transformer is DC to 300 kHz.

[0016] Optionally, the capacitance of the low-voltage arm capacitor is increased by tens of nF based on the calculated value to compensate for the effect of stray capacitance in the high-voltage arm.

[0017] Therefore, this invention proposes a 10 kV wideband voltage transformer for distribution network voltage monitoring. This voltage transformer has a resistive-capacitive voltage divider structure and can be used in conjunction with voltage monitoring terminals and analysis master stations to form a wideband voltage monitoring and analysis system. It is used for monitoring points with high voltage quality requirements, such as new energy grid connection points, distribution network areas with distributed photovoltaic access, and high-end manufacturing industries. It effectively suppresses the influence of distributed parameters, significantly improves the accuracy of high-frequency measurements, and greatly expands the frequency range of voltage measurement, extending the upper limit of the traditional voltage transformer's 3kHz frequency band to 300kHz. It can effectively capture complex voltage quality events such as high-frequency harmonics, interharmonics, and microsecond-level voltage sags / droops, solving the problem of "undetectable" high-frequency harmonics and transient events. Attached Figure Description

[0018] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures: Figure 1 This is a schematic diagram of a 10 kV wideband voltage transformer provided in an exemplary embodiment of the present invention; Figure 2 This is an overall schematic diagram of a 10 kV wideband voltage transformer provided in an exemplary embodiment of the present invention; Figure 3 This is a schematic diagram and wiring diagram of a dual-channel oscilloscope that simultaneously monitors the primary and secondary voltages, provided by an exemplary embodiment of the present invention. Figure 4 This is a schematic diagram of the result of a current transformer inputting 100V at a frequency of 50kHz, provided by an exemplary embodiment of the present invention; Figure 5 This is a schematic diagram of the result of a current transformer inputting 100V at a frequency of 500kHz, provided by an exemplary embodiment of the present invention. Figure 6 This is a schematic diagram of the result of a current transformer inputting 100V at a frequency of 3kHz, provided by an exemplary embodiment of the present invention; Figure 7 This is a schematic diagram of the result of a current transformer receiving a single 100V input at a frequency of 10kHz, provided by an exemplary embodiment of the present invention. Figure 8 This is a schematic diagram of the result of a current transformer receiving a single 100V input at a frequency of 100kHz, provided by an exemplary embodiment of the present invention. Figure 9 This is a schematic diagram of the result of a current transformer receiving a single input of 100V at a frequency of 300kHz, provided by an exemplary embodiment of the present invention. Detailed Implementation

[0019] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0020] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0021] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0022] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0023] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0024] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0025] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0026] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0027] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0028] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0030] Figure 1 This is a schematic diagram of the structure of a 10 kV broadband voltage transformer for broadband voltage monitoring provided in an exemplary embodiment of the present invention. Figure 1 As shown, a 10 kV broadband voltage transformer for broadband voltage monitoring includes: The main structure of the RC voltage divider consists of a high-voltage arm unit and a low-voltage arm unit connected in series. The impedance angles of the high-voltage arm unit and the low-voltage arm unit are equal, so that the voltage division ratio of the current transformer is determined by the ratio of the impedance moduli. A high-voltage arm unit includes at least one or more high-voltage arm capacitors and high-voltage arm resistors, which are connected in parallel or in series-parallel. One end of the high-voltage arm unit is connected to the primary high-voltage side of the distribution network. The low-voltage arm unit consists of a low-voltage arm resistor and a low-voltage arm capacitor connected in parallel. One end of the low-voltage arm unit is connected to the output terminal of the high-voltage arm unit, and the other end is grounded. The insulating enclosure adopts a fully enclosed insulating enclosure structure, which completely covers the high voltage arm unit, the low voltage arm unit and the internal connecting components, forming a primary main insulation and structural support. The signal output interface connects to the low-voltage arm unit and is used to output the measured voltage signal to an external voltage monitoring terminal.

[0031] Specifically, the purpose of this invention is to propose a 10 kV wideband voltage transformer for distribution network voltage monitoring. This invention aims to solve the problems of limited voltage monitoring bandwidth and insufficient high-frequency measurement accuracy caused by magnetic saturation and distributed parameters in traditional voltage transformers. It achieves high-precision voltage transfer from DC to an ultra-wideband frequency range to meet the needs of complex voltage quality monitoring in new power systems. On the one hand, it overcomes the limitations of traditional voltage monitoring equipment, which is limited to an operating range of less than 3 kHz and has difficulty capturing high-frequency harmonics and microsecond-level voltage dips, enabling effective monitoring of wideband signals from the power grid. On the other hand, while achieving wideband monitoring, the transformer is compact and miniaturized, allowing for flexible installation and deployment in various compact or complex field environments such as switchgear and ring main units.

[0032] This invention proposes a 10 kV wideband voltage transformer for distribution network voltage monitoring. To address the limitations of traditional voltage transformers in terms of bandwidth and high-frequency measurement accuracy, an optimized RC voltage divider structure is employed to achieve ultra-wideband voltage transfer. Its schematic diagram is shown below. Figure 1 As shown in the diagram, the overall schematic diagram is as follows: Figure 2 As shown.

[0033] The 10 kV wideband voltage transformer adopts a resistive-capacitive voltage divider structure and is mainly composed of a high-voltage arm unit, a low-voltage arm unit, an insulating encapsulation shell, and a signal output interface.

[0034] (1) Main structure of resistive-capacitive voltage divider The basic principle of a resistive-capacitive voltage divider is: in This is the primary voltage of the distribution network; This is the secondary voltage output; The impedance of the high-voltage arm of the resistor-capacitor voltage divider; The impedance of the low-voltage arm of the resistor-capacitor voltage divider; This refers to the impedance modulus of the high-voltage arm of the impedance divider. This refers to the impedance modulus of the low-voltage arm of the impedance divider. This refers to the impedance angle of the high-voltage arm of the resistor-capacitor voltage divider. This refers to the impedance angle of the low-voltage arm of the RC voltage divider.

[0035] When the impedance angles of the high-voltage and low-voltage arms are equal, the voltage division ratio of the transformer depends only on the ratio of the magnitudes of the impedances of the high-voltage and low-voltage arms. This structure avoids the magnetic saturation problem of traditional electromagnetic transformers in principle, has a wide dynamic range, no electromagnetic resonance, and a small size, making it suitable for accurate AC / DC voltage measurement. Considering that the input voltage of the power quality monitoring terminal is generally 100V, the secondary output of the transformer should be matched to this voltage; therefore, the voltage division ratio should be selected as 100:1.

[0036] (2) High-voltage arm unit The high-voltage arm unit consists of at least one or more high-voltage ceramic capacitors and high-voltage resistors connected in parallel or series-parallel. High-precision high-voltage ceramic capacitors are selected, with a single capacitor capacitance between 50-500pF, and the resistance of a single high-voltage resistor between 1-10MΩ. The high-voltage arm assembly should be fixed to the top of the insulating enclosure using a specially designed insulating bracket to increase the creepage distance between it and the low-voltage arm, meeting insulation strength requirements.

[0037] (3) Low-pressure arm unit The low-voltage arm unit consists of parallel low-voltage resistors and low-voltage capacitors. The low-voltage resistors are high-precision, low-temperature-drift metal film resistors, and the low-voltage capacitors are mica or polypropylene capacitors without residual voltage. One end of the low-voltage arm impedance unit is soldered to the output terminal of the high-voltage arm impedance unit, and the other end is grounded. The entire low-voltage arm impedance unit is encapsulated in a metal shield with electromagnetic shielding and connected to the signal acquisition board of an external broadband voltage monitoring terminal via a BNC interface to achieve impedance matching. The low-voltage arm resistor should be determined based on the voltage division ratio and the high-voltage arm unit. Since the stray capacitance of the high-voltage arm is on the same order of magnitude as its capacitance under actual operating conditions, while the stray capacitance of the low-voltage arm is much smaller, the low-voltage arm capacitance should be increased by tens of nF from the calculated value to meet the resistance-capacitance matching requirement.

[0038] (4) Insulating encapsulation shell The insulating enclosure is a component that provides high-voltage isolation, mechanical support, and long-term operational reliability. It adopts a fully enclosed insulating enclosure structure, uses epoxy resin, and employs a combination of vacuum casting and heat curing processes to completely encapsulate the high-voltage arm impedance unit, low-voltage arm impedance unit, and internal connection components. The cured enclosure serves as the primary insulation of the instrument transformer, achieving electrical isolation between the primary high-voltage side, the secondary low-voltage side, and the external environment, meeting the insulation strength requirements under rated voltage. In addition, it serves as the structural support of the instrument transformer, fixing the relative positions of the internal components and preventing displacement of components due to mechanical vibration or temperature changes, which could affect the voltage division accuracy.

[0039] (5) Signal output and interface The wideband voltage transformer outputs the measured voltage signal through a 50Ω BNC connector. This signal can be directly input to the signal acquisition board of the voltage monitoring terminal to achieve full-band measurement of DC-300kHz and high-speed sampling of 10MHz.

[0040] This embodiment provides a design and application scheme for a 10 kV wideband voltage transformer for distribution network voltage monitoring. It consists of a high-voltage arm unit, a low-voltage arm unit, an insulating encapsulation shell, and a signal output interface. Through a resistive-capacitive voltage divider structure, considering stray parameters, the voltage measurement range covers DC-300kHz. It is suitable for accurate monitoring of high-frequency harmonics, interharmonics, and transient voltage events in new power systems. The typical design parameters and application scheme are as follows.

[0041] The 10 kV wideband voltage transformer has a voltage division ratio of 100:1, a primary rated voltage of 10 / 3 kV, and a secondary rated voltage of 100 / 3 V. The capacitance of a single high-voltage arm unit is 50 pF, and the resistance of a single high-voltage resistor is 8 MΩ. There are 5 units in total. The measured resistance of the high-voltage arm is 40.2 MΩ, and the capacitance is 250 pF. The resistance of the low-voltage arm is taken as 400 kΩ, and the measured value is 406.06 kΩ. After considering stray parameters, the actual capacitance of the low-voltage arm is 43.05 nF. Epoxy resin mixture is used as the insulating encapsulation material. It is formed by vacuum casting and heat curing process to ensure that the partial discharge index meets the requirement of ≤20 pC and the power loss meets the requirement of <0.3 W.

[0042] The 10kV broadband voltage transformer provides installation options for three typical scenarios: switchgear, ring main unit, and outdoor tower. It adopts a typical Y / Y connection, consisting of three single-phase voltage transformers forming a three-phase voltage transformer group. The three-phase windings on the high-voltage side are connected to the three-phase busbars respectively, and the ends are connected in a star configuration to lead out the neutral point for reliable grounding. The three-phase windings on the low-voltage side are also connected in a star configuration, with the neutral point grounded. The output signal on the low-voltage side is connected to the subsequent broadband voltage monitoring terminal through a coaxial cable to achieve high-fidelity transmission and high-precision acquisition of DC-300kHz full-frequency voltage signals.

[0043] A small signal (maximum amplitude 20V, frequency adjustable from DC to 1MHz) is output from a signal generator, amplified 10 times by a power amplifier, and then used as the primary input of the current transformer (amplitude set to 100V). A dual-channel oscilloscope is used to simultaneously monitor the primary (attenuated by a 10:1 voltage probe) and secondary voltages. The schematic and wiring diagram are as follows. Figure 3 As shown.

[0044] (1) such as Figure 4 As shown, the frequency is 50Hz, and the primary input of the current transformer is 100V. First peak-to-peak value: 100V; Second peak-to-peak value: 0.99V; Amplitude error: 1%.

[0045] (2) such as Figure 5 As shown, the frequency is 500Hz, and the primary input of the current transformer is 100V. The first side peak-to-peak value is 100V, the second side peak-to-peak value is 1.02V, and the amplitude error is 2%.

[0046] (3) such as Figure 6 As shown, the frequency is 3kHz, and the primary input of the current transformer is 100V. The first side peak-to-peak value is 100V, the second side peak-to-peak value is 1.01V, and the amplitude error is 1%.

[0047] (4) such as Figure 7 As shown, the frequency is 10kHz, and the primary input of the current transformer is 100V. The first side peak-to-peak voltage is 100V, the second side peak-to-peak voltage is 1.00V, and the amplitude error is less than 1%.

[0048] (5) such as Figure 8 As shown, the frequency is 100kHz, and the primary input of the current transformer is 100V. The first side peak-to-peak value is 100V, the second side peak-to-peak value is 1.00V, and the amplitude error is less than 1%.

[0049] (6) For example Figure 9 As shown, the frequency is 300kHz, and the primary input of the current transformer is 100V. The first side peak-to-peak value is 100V, the second side peak-to-peak value is 1.02V, and the amplitude error is 2%.

[0050] Actual measurements show that within the range of 50 Hz to 300 kHz, the relative error of the transformer ratio coefficient is within ±2%, and the phase difference is negligible, indicating that its amplitude-frequency characteristics are good.

[0051] In summary, (1) proposes a 10 kV wideband voltage transformer for voltage monitoring of distribution networks. The voltage transformer is a resistive-capacitive voltage divider structure and can be used together with voltage monitoring terminals and analysis master stations to form a wideband voltage monitoring and analysis system for monitoring points with high voltage quality requirements, such as new energy grid connection points, distribution network areas with distributed photovoltaic access, and high-end manufacturing industries.

[0052] (2) The impedance angle of the high voltage arm of the RC divider is equal to that of the low voltage arm. The total resistance of the high voltage arm is between 10-100MΩ and the total capacitance is between 50pF and 500pF. Considering the influence of stray distribution parameters, the capacitance of the low voltage arm should be increased by about 18nF based on the theoretical value. The low frequency characteristics of the RC divider are better than those of the capacitor divider. After parameter adjustment, the high frequency characteristics can also meet the measurement accuracy.

[0053] Equivalent circuits for inter-turn and inter-layer capacitances were established, and calculation methods for inter-turn and inter-layer capacitances were proposed. Based on the calculation results, measures such as optimizing the width of the high-voltage coil wiring and increasing the number of coil layers were taken to increase the PT capacitance, change the volt-ampere characteristics of the electromagnetic voltage transformer, and avoid the generation of ferroresonant fields, which is of great significance for improving power grid safety.

[0054] Therefore, this invention proposes a 10 kV voltage transformer for voltage monitoring in distribution networks, which effectively suppresses the influence of distributed parameters, significantly improves the accuracy of high-frequency measurements, and greatly expands the frequency range of voltage measurement. It extends the upper limit of the traditional voltage transformer's 3 kHz frequency band to 300 kHz, and can effectively capture complex voltage quality events such as high-frequency harmonics, interharmonics, and microsecond-level voltage sags / droops, solving the problem of "undetectable" high-frequency harmonics and transient events.

[0055] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A 10 kV broadband voltage transformer for broadband voltage monitoring, characterized in that, include: The main structure of the resistive-capacitive voltage divider consists of a high-voltage arm unit and a low-voltage arm unit connected in series. The impedance angles of the high-voltage arm unit and the low-voltage arm unit are equal, so that the voltage division ratio of the current transformer is determined by the ratio of the impedance moduli. A high-voltage arm unit includes at least one or more high-voltage arm capacitors and high-voltage arm resistors, which are connected in parallel or in series-parallel connection. One end of the high-voltage arm unit is connected to the primary high-voltage side of the distribution network. The low-voltage arm unit consists of a low-voltage arm resistor and a low-voltage arm capacitor connected in parallel. One end of the low-voltage arm unit is connected to the output terminal of the high-voltage arm unit, and the other end is grounded. The insulating enclosure adopts a fully enclosed insulating enclosure structure, which completely covers the high-voltage arm unit, the low-voltage arm unit and the internal connecting components to form a primary insulation and structural support body; The signal output interface is connected to the low-voltage arm unit and is used to output the measured voltage signal to an external voltage monitoring terminal.

2. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The principle of the resistor-capacitor voltage divider main structure is as follows: in This is the primary voltage of the distribution network; This is the secondary voltage output; The impedance of the high-voltage arm of the resistor-capacitor voltage divider; The impedance of the low-voltage arm of the resistor-capacitor voltage divider; This refers to the impedance modulus of the high-voltage arm of the impedance divider. This refers to the impedance modulus of the low-voltage arm of the impedance divider. This refers to the impedance angle of the high-voltage arm of the resistor-capacitor voltage divider. Here, ω represents the impedance angle of the low-voltage arm of the RC voltage divider, ω is the angular frequency, and ωt represents the phase angle of the sinusoidal quantity at time t. j This is a virtual unit.

3. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The voltage division ratio is 100:1, and the measured voltage signal is 100V.

4. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The capacitance of a single high-voltage arm capacitor is 50 to 500 pF, and the resistance of a single high-voltage arm resistor is 1 to 10 MΩ.

5. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The high-voltage arm unit is fixed to the top of the inside of the insulating enclosure by a specially designed insulating bracket.

6. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The low-voltage arm resistor is a high-precision, low-temperature drift metal film resistor; the low-voltage arm capacitor is a mica capacitor or a polypropylene capacitor without residual voltage.

7. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The low-voltage arm unit is encapsulated in a metal cover with electromagnetic shielding function, and is connected to the signal acquisition board of an external broadband voltage monitoring terminal through the signal output interface to achieve impedance matching.

8. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The insulating encapsulation shell is made of epoxy resin material, and the high-voltage arm unit, the low-voltage arm unit, and the internal connecting components are completely encapsulated in it through a process combining vacuum casting and heat curing.

9. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The signal output interface is a 50Ω BNC connector, and the measured voltage signal is directly input to the signal acquisition board of the voltage monitoring terminal through the 50Ω BNC connector.

10. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The frequency measurement range of the 10 kV wideband voltage transformer is DC to 300 kHz.

11. The 10 kV wideband voltage transformer according to claim 1, characterized in that, The capacitance of the low-voltage arm capacitor is increased by tens of nF based on the calculated value to compensate for the influence of stray capacitance in the high-voltage arm.

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