A composite wideband synergic measurement type high-voltage current transformer device and method

Abstract

The application discloses a composite broadband cooperative measurement type high-voltage current transformer device and method, and belongs to the technical field of high-voltage power equipment and smart grid. A composite broadband current sensing unit is constructed, and a high-permeability alloy magnetic core and a Rogowski coil are fused, wherein the alloy magnetic core is used for outputting a first voltage signal under a steady-state working condition, and the Rogowski coil is used for outputting a second voltage signal under a transient-state working condition; a signal processing unit is used for conditioning, synchronously sampling and data fusing two voltage signals respectively, so as to generate a digital current signal suitable for a new type of power line protection algorithm interface; and a power management unit is used for taking energy from primary current and supplying power to the whole, so as to form a self-powered operation architecture. Through the cooperative measurement of the alloy magnetic core and the Rogowski coil, the fusion mechanism of the signal processing unit and the adaptive power supply of the power management unit, the steady-state precision and the transient-state response are considered, and the accuracy, the response speed and the power supply reliability of current measurement are improved.

Description

Technical Field

[0001] This invention relates to the field of high-voltage power equipment and smart grid technology, and in particular to a composite broadband collaborative measurement type high-voltage current transformer device and method. Background Technology

[0002] In high-voltage power systems, current transformers serve as a crucial interface between primary equipment and secondary protection and control devices. Their measurement accuracy and dynamic response characteristics directly impact the safe and stable operation of the power grid. Traditional 500kV high-voltage current transformers are primarily electromagnetic in structure, operating based on the principle of electromagnetic induction. They consist of a primary winding, a toroidal core, and a secondary winding. The primary winding is connected in series in the primary circuit. When a primary current flows through it, an alternating magnetic flux is generated in the core, inducing an electromotive force proportional to the primary current in the secondary winding. This electromotive force, through the secondary load, forms a secondary current, thus achieving current transformation and electrical isolation. This type of transformer has a simple structure and high long-term operational reliability, making it widely used in traditional power systems.

[0003] However, electromagnetic current transformers have inherent technical limitations in engineering applications. Firstly, the core material has nonlinear magnetization characteristics, making it prone to saturation when the primary current is too large or contains a significant DC component. Magnetic saturation leads to a sharp drop in excitation impedance, distortion of the secondary current, and a significant increase in measurement error, potentially causing maloperation or failure of protection devices. This is particularly pronounced during transient processes such as short-circuit faults, where non-periodic components are often superimposed on the primary current. Secondly, the measurement response of electromagnetic transformers is limited by the core excitation inductance and secondary circuit parameters, exhibiting inherent hysteresis for high-frequency transient components and rapidly changing current signals, making it difficult to achieve wideband, low-delay signal transmission. With the construction of new power systems, large-scale integration of new energy sources, increasingly complex grid structures, and highly nonlinear fault characteristics, protection algorithms place higher demands on the fidelity, bandwidth, and real-time performance of current signals. The limitations of traditional electromagnetic transformers in terms of measurement accuracy and response rate are becoming increasingly apparent, making them unable to meet the needs of modern power line protection.

[0004] Therefore, there is an urgent need to propose a new type of high-voltage current transformer device that can balance steady-state high accuracy with transient fast response, has wide-band measurement capability, and is adaptable to digital protection algorithms. Summary of the Invention

[0005] The present invention aims to at least partially solve one of the technical problems in the related art.

[0006] To address this issue, this invention proposes a composite broadband collaborative measurement type high-voltage current transformer device. It constructs a composite broadband current sensing unit, integrating a high-permeability alloy core and a Rogowski coil, used for voltage signal output under steady-state and transient conditions respectively. A signal processing unit conditions, synchronously samples, and fuses the two signals to generate a digital current signal adapted to the interface of a new power line protection algorithm. A power management unit extracts energy from the primary current and supplies power to the entire device, forming an adaptive power supply architecture. This invention, through the collaborative measurement of the alloy core and Rogowski coil, combined with the fusion mechanism of the signal processing unit and the adaptive power supply of the power management unit, achieves a balance between steady-state accuracy and transient response, improving the accuracy of current measurement and the reliability of power supply.

[0007] Another objective of this invention is to propose a method for a composite broadband collaborative measurement type high voltage current transformer.

[0008] To achieve the above objectives, the present invention provides a composite broadband collaborative measurement type high-voltage current transformer device, comprising:

[0009] A composite broadband current sensing unit includes: a high permeability alloy magnetic core, used to output a first voltage signal through electromagnetic induction under steady-state conditions of primary current; and a Rogowski coil, coaxially or parallel to the high permeability alloy magnetic core, used to output a second voltage signal through electromagnetic induction under transient conditions of primary current. The signal processing unit is electrically connected to the secondary winding of the high permeability alloy magnetic core and the output terminal of the Rogowski coil, respectively, and is used to condition, synchronously sample and fuse the first voltage signal and the second voltage signal to generate a digital current signal adapted to the interface of the new power line protection algorithm. The power management unit is electrically connected to the composite broadband current sensing unit and the signal processing unit, and is used to draw energy from the primary current and supply power to the composite broadband current sensing unit and the signal processing unit.

[0010] A composite broadband collaborative measurement type high-voltage current transformer device according to an embodiment of the present invention may also have the following additional technical features: In one embodiment of the present invention, the high permeability alloy core is made of iron-based amorphous alloy or nanocrystalline alloy material, and its saturation magnetic induction intensity is not less than 1.2T and its coercivity is not greater than 1.5A / m.

[0011] In one embodiment of the invention, the Rogowski coil includes a ring-shaped frame and enameled wire uniformly wound on the ring-shaped frame, the ring-shaped frame being made of an insulating material.

[0012] In one embodiment of the present invention, the signal processing unit includes: The first conditioning circuit is electrically connected to the secondary winding of the high permeability alloy magnetic core and is used to filter and amplify the first voltage signal. The second conditioning circuit is electrically connected to the output of the Rogowski coil and is used to integrate, filter and amplify the second voltage signal. An analog-to-digital converter is electrically connected to the first conditioning circuit and the second conditioning circuit respectively, and is used to synchronously convert the conditioned first voltage signal and the second voltage signal into digital signals. The data fusion module, electrically connected to the analog-to-digital converter, is used to synthesize digital signals into a single digital current signal and output it according to the interface format of the new power line protection protocol.

[0013] In one embodiment of the present invention, the data fusion module uses the digital signal corresponding to the high permeability alloy core as the output reference under steady-state conditions, and the digital signal corresponding to the Rogowski coil as the output reference under transient conditions. Under transitional conditions, the two digital signals are weighted and fused, and the weighting coefficient is dynamically adjusted according to the rate of change of the primary current.

[0014] In one embodiment of the present invention, the power management unit includes: The resonant compensation energy harvesting module is coupled to the primary current loop and is used to extract electrical energy from the primary current. A supercapacitor energy storage device, electrically connected to a resonant compensation energy harvesting module, is used for short-term energy storage. A lithium battery backup power supply, connected in parallel with a supercapacitor energy storage device, is used to provide continuous power supply when the primary current is lower than the energy extraction threshold. The power management controller is used to monitor the status of each power supply branch and automatically switch the power source.

[0015] In one embodiment of the present invention, the high permeability alloy core and the Rogowski coil are arranged in a coaxial nested structure.

[0016] To achieve the above objectives, another aspect of the present invention proposes a method for a composite broadband collaborative measurement type high-voltage current transformer, comprising: A primary current signal is acquired through a composite broadband current sensing unit, including outputting a first voltage signal through a high permeability alloy core and outputting a second voltage signal through a Rogowski coil. The signal processing unit processes the first voltage signal and the second voltage signal, including conditioning the two signals respectively, synchronously sampling and converting them into digital signals, and performing data fusion on the digital signals to generate a digital current signal adapted to the interface of the new power line protection algorithm. The power management unit draws energy from the primary current and supplies power, including drawing energy from the primary current and performing energy storage management.

[0017] In one embodiment of the present invention, the step of data fusion of the first voltage signal and the second voltage signal includes: Determine the current operating condition type, which includes steady-state operating condition, transient operating condition, and transitional operating condition; Under steady-state conditions, the digital signal corresponding to the first voltage signal is used as the output reference. Under transient conditions, the digital signal corresponding to the second voltage signal is used as the output reference. Under transient operating conditions, the two digital signals are weighted and fused, and the weighting coefficients are dynamically adjusted according to the rate of change of the primary current.

[0018] In one embodiment of the present invention, the step of extracting energy from primary current and performing energy storage management through a power management unit includes: When the primary current exceeds the preset energy extraction threshold, the extracted electrical energy is simultaneously supplied to the load and stored in the supercapacitor energy storage device. When the primary current drops below the preset energy harvesting threshold, the supercapacitor energy storage device supplies power to the load. When the primary current is lower than the power outage threshold, the load is switched to the lithium battery backup power supply.

[0019] This invention discloses a composite broadband collaborative measurement high-voltage current transformer device and method. It constructs a composite broadband current sensing unit composed of a high-permeability alloy core and a Rogowski coil, used for voltage signal output under steady-state and transient conditions. A signal processing unit conditions, synchronously samples, and fuses the two signals to generate a digital current signal adapted to the interface of a new power line protection algorithm. Simultaneously, a power management unit enables adaptive power harvesting and supply. This effectively solves the problems of large measurement errors, delayed transient response, and insufficient power supply reliability caused by magnetic saturation in existing electromagnetic current transformers under high-current conditions. It achieves an integrated architecture from broadband signal acquisition and multi-source data fusion to digital output and self-powered assurance, significantly improving the measurement accuracy and response speed of the high-voltage current transformer under complex conditions, and enhancing its adaptability and operational reliability to new power system protection algorithms.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart illustrating a specific implementation according to an embodiment of the present invention; Figure 2 This is a flowchart of a composite broadband collaborative measurement type high voltage current transformer method according to an embodiment of the present invention. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0024] The following description, with reference to the accompanying drawings, describes a composite broadband collaborative measurement type high-voltage current transformer device and method according to an embodiment of the present invention.

[0025] The core idea of ​​this invention is to address the abnormal transient creep behavior exhibited by high-temperature alloys during service by constructing a creep life assessment method covering the entire process of "curve acquisition—behavior identification—rate correction—model establishment," thus resolving the prediction bias caused by the traditional method's approximation of the steady-state rate using the minimum creep rate. First, creep tests under different temperature and stress conditions are conducted to obtain the creep curve and its differential rate curve of the target material. Based on this, abnormal transient behavior is identified according to the morphological characteristics of the rate curve, and the curve is classified into three categories: normal state, transition state, and abnormal state. For each category, the minimum creep rate point, the inflection point after the abnormal behavior, or the stable process point after the inflection point are used as characteristic values ​​of the steady-state creep rate, thereby correcting the traditional minimum rate method. Finally, the corrected steady-state creep rate is introduced into the Monkman-Grant relation and the Norton equation to establish a prediction model coupling stress and life, and stress exponential analysis is used to verify the deformation mechanism. By integrating the above-mentioned technical path of "anomaly identification - classification correction - model reconstruction", this invention transforms the traditional experience prediction based on a single rate into an intelligent evaluation system that can adapt to the abnormal creep evolution law of materials, fully explore the curve morphology characteristics, and realize multi-mechanism collaborative characterization, which significantly improves the accuracy, robustness and engineering applicability of high-temperature alloy creep life prediction.

[0026] The following description, with reference to the accompanying drawings, describes a composite broadband collaborative measurement type high-voltage current transformer device and method according to an embodiment of the present invention.

[0027] The present invention provides a composite wideband collaborative measurement type high voltage current transformer device, comprising: The composite broadband current sensing unit includes: a high permeability alloy magnetic core, used to output a first voltage signal through electromagnetic induction under steady-state conditions of primary current; and a Rogowski coil, coaxially or parallel to the high permeability alloy magnetic core, used to output a second voltage signal through electromagnetic induction under transient conditions of primary current.

[0028] In one embodiment of the present invention, a high-permeability, low-loss alloy is used as the core material. This material has excellent soft magnetic properties, which can effectively reduce hysteresis loss and eddy current loss, thereby improving the measurement accuracy and stability of the transformer. The coil part adopts a Rogowski coil design, which realizes non-contact measurement of the primary current by uniformly winding enameled wire on a ring frame. This design not only effectively isolates the high-voltage side from the low-voltage side, but also significantly improves the anti-interference capability of the transformer.

[0029] The signal processing unit is electrically connected to the secondary winding of the high permeability alloy magnetic core and the output terminal of the Rogowski coil, respectively, and is used to condition, synchronously sample and fuse the first voltage signal and the second voltage signal to generate a digital current signal adapted to the interface of the new power line protection algorithm.

[0030] In one embodiment of the invention, the signal processing unit is responsible for converting the electromotive force induced by the coil into a digital signal and sending it to the power line protection system through a data transmission interface. This unit integrates a high-precision amplifier and an analog-to-digital converter to ensure high accuracy and low distortion in signal processing.

[0031] The power management unit is electrically connected to the composite broadband current sensing unit and the signal processing unit, and is used to draw energy from the primary current and supply power to the composite broadband current sensing unit and the signal processing unit.

[0032] In one embodiment of the invention, the power management unit extracts energy from the primary current using resonant compensation energy harvesting technology to provide continuous power for the normal operation of the current transformer. Furthermore, the power management unit is equipped with a supercapacitor energy storage device and a lithium battery backup power supply to cope with low current or sudden power outages.

[0033] Furthermore, such as Figure 1 As shown, the specific working process of this composite broadband collaborative measurement type high voltage current transformer device is as follows: primary current An alternating magnetic field is generated around the toroidal nanocrystalline magnetic core, which is one of the core components of the composite broadband current sensing unit. The Rogowski coil, nested coaxially with it, cuts magnetic field lines in an alternating magnetic field, generating an induced electromotive force at its output that is proportional to the rate of change of the primary current. ,in The mutual inductance coefficient is used. This induced electromotive force, as the second voltage signal input signal processing unit, is first integrated by an integrating circuit to restore it to a small signal proportional to the primary current. The signal is then sequentially filtered to remove high-frequency noise, amplified to increase its amplitude, and isolated from the high-voltage side by an isolation circuit. The conditioned analog signal is then synchronously sampled and converted into a digital signal by an analog-to-digital converter. In the data fusion module, a digital current data stream is generated according to a preset fusion algorithm and encapsulated into a sampled value message format.

[0034] Finally, the digital current signal is transmitted in real time to the intelligent electronic equipment for line protection via an optical fiber communication interface. This allows new power line protection algorithms, such as differential protection and distance protection, to utilize it as the basis for fault diagnosis and protection actions. This completes the entire collaborative measurement process of primary current, from analog signal acquisition, broadband signal fusion, digital processing to the application of protection algorithms.

[0035] The device of this invention effectively solves the problems of large measurement error, slow transient response, and insufficient power supply reliability caused by magnetic saturation in existing electromagnetic current transformers under high current conditions. It realizes integrated and coordinated measurement from wideband signal acquisition and digital processing to protection algorithm application, which significantly improves the measurement accuracy, response speed and operational reliability of high-voltage current transformers under complex power grid conditions.

[0036] To achieve the above invention, such as Figure 2 As shown, this embodiment also provides a method for a composite broadband collaborative measurement type high-voltage current transformer, including: A primary current signal is acquired through a composite broadband current sensing unit, including outputting a first voltage signal through a high permeability alloy core and outputting a second voltage signal through a Rogowski coil. The signal processing unit processes the first voltage signal and the second voltage signal, including conditioning the two signals respectively, synchronously sampling and converting them into digital signals, and performing data fusion on the digital signals to generate a digital current signal adapted to the interface of the new power line protection algorithm. The power management unit draws energy from the primary current and supplies power, including drawing energy from the primary current and performing energy storage management.

[0037] The method of this invention effectively solves the problems of magnetic saturation measurement error, transient response lag and insufficient power supply reliability caused by a single electromagnetic structure in the prior art. It realizes integrated collaborative measurement from broadband signal acquisition and multi-source data fusion to digital output and self-power supply guarantee, which significantly improves the measurement accuracy, response speed and operational reliability of high-voltage current transformers under complex power grid conditions.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A composite broadband collaborative measurement type high-voltage current transformer device, characterized in that, include: A composite broadband current sensing unit includes: a high permeability alloy magnetic core, used to output a first voltage signal through electromagnetic induction under steady-state conditions of primary current; and a Rogowski coil, coaxially or parallel to the high permeability alloy magnetic core, used to output a second voltage signal through electromagnetic induction under transient conditions of primary current. The signal processing unit is electrically connected to the secondary winding of the high permeability alloy magnetic core and the output terminal of the Rogowski coil, respectively, and is used to condition, synchronously sample and fuse the first voltage signal and the second voltage signal to generate a digital current signal adapted to the interface of the new power line protection algorithm. The power management unit is electrically connected to the composite broadband current sensing unit and the signal processing unit, and is used to draw energy from the primary current and supply power to the composite broadband current sensing unit and the signal processing unit.

2. The composite broadband collaborative measurement type high-voltage current transformer device according to claim 1, characterized in that, The high permeability alloy core is made of iron-based amorphous alloy or nanocrystalline alloy material, with a saturation magnetic induction intensity of not less than 1.2T and a coercivity of not more than 1.5A / m.

3. The composite broadband collaborative measurement type high-voltage current transformer device according to claim 1, characterized in that, A Rogowski coil consists of a toroidal frame and enameled wire uniformly wound on the toroidal frame, the toroidal frame being made of insulating material.

4. The composite broadband collaborative measurement type high-voltage current transformer device according to claim 1, characterized in that, The signal processing unit includes: The first conditioning circuit is electrically connected to the secondary winding of the high permeability alloy magnetic core and is used to filter and amplify the first voltage signal. The second conditioning circuit is electrically connected to the output of the Rogowski coil and is used to integrate, filter and amplify the second voltage signal. An analog-to-digital converter is electrically connected to the first conditioning circuit and the second conditioning circuit respectively, and is used to synchronously convert the conditioned first voltage signal and the second voltage signal into digital signals. The data fusion module, electrically connected to the analog-to-digital converter, is used to synthesize digital signals into a single digital current signal and output it according to the interface format of the new power line protection protocol.

5. The composite broadband collaborative measurement type high-voltage current transformer device according to claim 4, characterized in that, The data fusion module uses the digital signal corresponding to the high permeability alloy core as the output reference under steady-state conditions, and the digital signal corresponding to the Rogowski coil as the output reference under transient conditions. Under transient conditions, the two digital signals are weighted and fused, and the weighting coefficient is dynamically adjusted according to the rate of change of the primary current.

6. The composite broadband collaborative measurement type high-voltage current transformer device according to claim 1, characterized in that, The power management unit includes: The resonant compensation energy harvesting module is coupled to the primary current loop and is used to extract electrical energy from the primary current. A supercapacitor energy storage device, electrically connected to a resonant compensation energy harvesting module, is used for short-term energy storage. A lithium battery backup power supply, connected in parallel with a supercapacitor energy storage device, is used to provide continuous power supply when the primary current is lower than the energy extraction threshold. The power management controller is used to monitor the status of each power supply branch and automatically switch the power source.

7. The composite broadband collaborative measurement type high-voltage current transformer device according to any one of claims 1 to 6, characterized in that, The high-permeability alloy core and the Rogowski coil are coaxially nested.

8. A method for a composite broadband collaborative measurement type high-voltage current transformer based on the device described in claim 1, characterized in that, include: A primary current signal is acquired through a composite broadband current sensing unit, including outputting a first voltage signal through a high permeability alloy core and outputting a second voltage signal through a Rogowski coil. The signal processing unit processes the first voltage signal and the second voltage signal, including conditioning the two signals respectively, synchronously sampling and converting them into digital signals, and performing data fusion on the digital signals to generate a digital current signal adapted to the interface of the new power line protection algorithm. The power management unit draws energy from the primary current and supplies power, including drawing energy from the primary current and performing energy storage management.

9. The method for a composite broadband collaborative measurement type high-voltage current transformer according to claim 8, characterized in that, The steps for data fusion of the first voltage signal and the second voltage signal include: Determine the current operating condition type, which includes steady-state operating condition, transient operating condition, and transitional operating condition; Under steady-state conditions, the digital signal corresponding to the first voltage signal is used as the output reference. Under transient conditions, the digital signal corresponding to the second voltage signal is used as the output reference. Under transient operating conditions, the two digital signals are weighted and fused, and the weighting coefficients are dynamically adjusted according to the rate of change of the primary current.

10. The method for a composite broadband collaborative measurement type high-voltage current transformer according to claim 8, characterized in that, The steps of extracting energy from primary current and managing energy storage through a power management unit include: When the primary current exceeds the preset energy extraction threshold, the extracted electrical energy is simultaneously supplied to the load and stored in the supercapacitor energy storage device. When the primary current drops below the preset energy harvesting threshold, the supercapacitor energy storage device supplies power to the load. When the primary current is lower than the power outage threshold, the load is switched to the lithium battery backup power supply.

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