Background
With the demand of energy internet, more and more communication, monitoring and big data analysis energy technologies are applied to a power grid, but the application of the technologies is limited by the aspects of a voltage system, an electromagnetic environment, environmental temperature and the like in a power system, most of the technologies are often applied to a secondary system of a transformer substation, for example, equipment such as an online monitoring device runs on the high-voltage side of primary equipment of the transformer substation, and the provided data can only be used as reference assistance and cannot be used as reference for protection judgment.
The mutual inductor is used as equipment for monitoring primary voltage and current in a transformer substation, and the condition of a primary voltage and current signal is fed back to secondary metering, measuring, protecting and other devices to be used as a judgment basis for the condition of the transformer substation, so that the secondary equipment can make judgment such as normal operation, fault short circuit, overrun trip and the like, and the action of a protection system is determined.
Therefore, the requirements on the accuracy and timeliness of the information output of the mutual inductor per se are high, and along with the development of the technology, the maturity, the performance and the use requirements of the transformer substation can be met. In a transformer substation and a power transmission and distribution system, a current transformer and a voltage transformer are often additionally arranged at key nodes to monitor voltage and current in a stage and judge the state of the system, so that the number of the transformers used in the transformer substation is the largest. The traditional mutual inductor has limited sampling frequency and lagged data acquisition technology, so that the mutual inductor is only used for monitoring primary power frequency voltage current, the position advantage of key nodes of the mutual inductor is not fully exerted, and the meaning expressed by a plurality of current voltage signals capable of representing different working conditions in the primary power frequency voltage current is not really reflected.
With the further development of the signal acquisition and transmission communication technology, the development of the transformer measurement technology, and the continuous deep analysis and application of the monitored current and voltage signals in the equipment state monitoring technology, the application of the transformer in the transformer substation needs to be further expanded, and the signals output by the primary current and voltage monitored by the transformer are further developed and utilized.
Disclosure of Invention
In order to solve the above problem, the present invention provides a transformer for multi-node station domain information fusion, including:
the high-voltage side signal conditioning module comprises an air core coil, an energy taking coil, a high-voltage side signal conditioning module and a receiving coil which are positioned on the primary high-voltage side of a target node, and a low-voltage side communication module and a transmitting coil which are positioned on the secondary ground potential of the target node;
the hollow coil converts primary large current in the power system into a small voltage signal which can be input by a collection target node;
the high-voltage side signal conditioning module converts the differential small voltage signal into a digital signal; the high-voltage side signal conditioning module supplies power through an energy taking coil or a wireless power supply mode formed by a transmitting coil and a receiving coil through a magnetic resonance coupling principle;
and the low-voltage side communication module transmits the data signal to an external APN wireless private network.
Optionally, the high-voltage side signal conditioning module converts the differential small-voltage signal into a digital signal, and the specific conversion process includes: and integrating, filtering, amplifying and sampling the differential small voltage signal, and converting the differential small voltage signal into a digital signal.
Optionally, the low-voltage side communication module sends the data signal to an external APN wireless private network in a wireless communication manner.
Optionally, the air-core coil is a primary current sensing coil, the measurement frequency range is 50Hz-20MHz, the measurement current range is 20A-120kA, and the measurement current range is changed by changing the number of turns of the winding.
Optionally, when the target node is a transformer substation of 110kV or above, when the target node can take a primary current of less than or equal to 10% of the rated current, the high-voltage side signal conditioning module is powered by using a wireless power supply mode, if the primary current can be taken to be greater than 10% of the rated current, the high-voltage side signal conditioning module is powered by using an energy taking coil, the target node is a transformer substation below 35kV, and the high-voltage side signal conditioning module is powered by using a wireless energy supply mode.
The invention also provides a method for data acquisition by using the mutual inductor, which comprises the following steps:
converting primary large current in the power system into a small voltage signal which can be input by a collection target node through an air-core coil;
controlling a high-voltage side signal conditioning module to convert the differential small voltage signal into a digital signal;
and transmitting the data signal to an external APN wireless private network by using the low-voltage side communication module.
Optionally, the converting the differential small voltage signal into a digital signal includes: and integrating, filtering, amplifying and sampling the differential small voltage signal, and converting the differential small voltage signal into a digital signal.
The invention uses an energy supply mode combining wireless energy supply and an energy self-taking coil to replace the laser energy supply mode of the conventional high-voltage electronic transformer, has the advantages of high reliability, no influence of bus current change and the like, realizes the electrical isolation of a high-voltage side power supply, and is not influenced by primary high-voltage side electromagnetic disturbance.
The system is sent to a server in a wireless data transmission mode, can realize the synchronous time synchronization acquisition of the whole station, can be applied to the synchronous time synchronization acquisition of the whole line by matching with a Beidou satellite system, can be applied to transformer substations in a distribution network system and a high-voltage transmission system, has wireless transmission of output signals, does not have electrical connection, can be conveniently networked, and overcomes the problem that the conventional electronic transformer cannot be compatible with electromagnetism.
The mutual inductor can realize real-time synchronous data comparison among the node mutual inductors of the total station and real-time data comparison among stations, and realize the functions of equipment state monitoring among the nodes, mutual inductor state self-detection, line state monitoring among the stations, station-area protection, fault accurate positioning and the like through modeling of the whole station.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
The invention provides a mutual inductor for information fusion of multi-node station domains, as shown in fig. 1, comprising:
the high-voltage side signal conditioning module comprises an air core coil, an energy taking coil, a high-voltage side signal conditioning module and a receiving coil which are positioned on the primary high-voltage side of a target node, and a low-voltage side communication module and a transmitting coil which are positioned on the secondary ground potential of the target node;
the mutual inductor uses a coil based on an air-core coil principle as a primary current sensing coil, the air-core coil converts primary large current in a power system into a small-voltage signal which can be input by a collection target node, the measurement frequency range of the air-core coil is 50Hz-20MHz, and the measurement current range can reach 20A-120kA by changing the number of turns of a winding.
The high-voltage side signal conditioning module integrates, filters, amplifies and samples the output differential small-voltage signal of the hollow coil, converts the signal into a digital signal, and transmits the digital signal to the low-voltage side communication module through 4G/5G or optical fiber communication and then transmits the digital signal to an external network through the low-voltage side communication module. Wherein, dispose the insulator between high pressure side signal conditioning module and the low pressure side communication module.
The high-voltage side signal conditioning module needs to supply power, and the invention adopts a mode of combining a wireless power supply mode based on a magnetic resonance coupling principle and a high-voltage energy-taking coil energy supply mode to supplement each other. The wireless power supply mode is realized through a receiving coil and a transmitting coil.
In a transformer substation with the voltage of 110kV or above, when the primary current of the system is small and the primary current is less than or equal to 10% of rated current, wireless power supply is adopted. When the primary current of the system is large and the primary current can be larger than 10% of rated current, the energy-taking coil is adopted to supply power, and seamless switching and reliable energy supply are realized. In a power system below 35kV, a high-voltage energy-taking coil is not needed for supplying energy, and only a wireless energy supply module is adopted.
The mutual inductor can be applied to a multi-node station domain information fusion technology, a networking application schematic diagram is shown in figure 2, and networking is divided into a sensing layer, a network layer, a platform layer and an application layer.
The number of the measuring terminals is 2, data are sent to an APN (access point name) wireless private network in a wireless 4G/5G data transmission mode, an APN wireless private network sub-center monitor receives the data and then sends the data to an APN private network sub-center server, acquired current and voltage signals are finally connected to the Internet and can be inquired by a mobile operation terminal and an information intranet terminal, a Beidou satellite system is matched in a transformer substation, time synchronization acquisition among multiple measuring terminals on the whole line is realized, real-time synchronous data comparison among all-station node transformers is realized, real-time data comparison among stations is realized, and functions of inter-node equipment state monitoring, mutual inductor state self-detection, inter-station line state monitoring, station domain protection, fault accurate positioning and the like are realized through whole station modeling.
In practical application, as shown in fig. 3, the invention is applied to sampling data of current and voltage at relevant intervals when a fault occurs in a dual-power system, and performs station domain protection automatic switching. When the 220kV side line and the 110kV line 1 are powered on, the rest 110kV lines are loaded, and the 110kV bus II and III section sectional switches are switched on. The measuring terminal 1 outputs sampling values of voltage transformers at the II section and the III section of the 110kV bus, the measuring terminal 2 outputs sampling values of current transformers at the medium voltage side of a main transformer, and the measuring terminal 3 outputs sampling values of the current transformers at the 1 kV circuit. And sending the collected line current and voltage values in a 4G/5G network mode, transmitting the line current and voltage values to a switch, observing an action message by the station domain protection device, and judging.
The invention also provides a method for data acquisition by using the mutual inductor, as shown in fig. 4, comprising the following steps:
converting primary large current in the power system into a small voltage signal which can be input by a collection target node through an air-core coil;
controlling a high-voltage side signal conditioning module to convert the differential small voltage signal into a digital signal;
and transmitting the data signal to an external APN wireless private network by using the low-voltage side communication module.
Wherein, convert differential small voltage signal into digital signal, specific conversion process includes: and integrating, filtering, amplifying and sampling the differential small voltage signal, and converting the differential small voltage signal into a digital signal.
The invention uses an energy supply mode combining wireless energy supply and an energy self-taking coil to replace the laser energy supply mode of the conventional high-voltage electronic transformer, has the advantages of high reliability, no influence of bus current change and the like, realizes the electrical isolation of a high-voltage side power supply, and is not influenced by primary high-voltage side electromagnetic disturbance.
The system is sent to a server in a wireless data transmission mode, can realize the synchronous time synchronization acquisition of the whole station, can be applied to the synchronous time synchronization acquisition of the whole line by matching with a Beidou satellite system, can be applied to transformer substations in a distribution network system and a high-voltage transmission system, has wireless transmission of output signals, does not have electrical connection, can be conveniently networked, and overcomes the problem that the conventional electronic transformer cannot be compatible with electromagnetism.
The mutual inductor can realize real-time synchronous data comparison among the node mutual inductors of the total station and real-time data comparison among stations, and realize the functions of equipment state monitoring among the nodes, mutual inductor state self-detection, line state monitoring among the stations, station-area protection, fault accurate positioning and the like through modeling of the whole station.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. The scheme in the embodiment of the invention can be realized by adopting various computer languages, such as object-oriented programming language Java and transliterated scripting language JavaScript.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.