Construction method of AC loop management system of electrical secondary system

Abstract

The invention discloses a construction method of an AC loop management system of an electrical secondary system, and the method comprises the following steps: dividing the structure of the AC loop management system of the electrical secondary system, and dividing the management system into a mutual inductor body module management module, a secondary connection cable management module and a secondary screen cabinet sampling unit management module; setting current and voltage transformer body management attributes, and checking the current and voltage transformer body management attributes; setting current and voltage transformer electrical secondary loop connection cable management attributes, and checking; setting attributes of a secondary circuit sampling unit of the current and voltage transformer, and checking the attributes; and checking and managing the correctness of the overall parameters of the staged electrical secondary alternating-current loop of the new energy construction project. By constructing the AC loop management system of the electrical secondary system, various problems caused by improper management in the rapid development process of the electrical secondary system of a new energy station are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical secondary system management, and particularly relates to a construction method for an AC circuit management system of an electrical secondary system. Background Art

[0002] In the photovoltaic power generation project of new energy power generation projects, due to the relatively simplified infrastructure compared with conventional thermal and hydropower, its development process and project cycle are shortened more and more. During the development process, planning, design, infrastructure construction, installation, and commissioning often proceed simultaneously. The connection between each link often becomes a blind spot in project management, bringing greater risks to the actual implementation of the project.

[0003] This is especially true for the development of photovoltaic projects during the development of new energy projects. During the development of photovoltaic power generation projects, the secondary system is an important part of the project. The correct use of voltage and current transformers, secondary system circuit connection cables, and secondary cabinet sampling units involved in relevant secondary cabinets is a prerequisite for the normal operation of the secondary system. However, due to the rapid development of photovoltaic power generation projects and the simultaneous progress of various processes in project management, insufficient attention is paid to the secondary system voltage and current signal sources, connection cables, and sampling units. Accidents and abnormal events caused by the lack of connection between each link and insufficient overall planning and management occur frequently. For example: The accuracy level of the current transformer used in the monitoring system is too low, resulting in a large deviation between the current data displayed by the monitoring system and the actual value during peak load; The accuracy level of the current transformer used in the electric energy metering system is insufficient, resulting in a low metering result and significant economic losses in the long-term operation; For the power quality detection system, due to the insufficient accuracy level of the used transformer, the actual power quality situation of the power station cannot be accurately detected, resulting in problems with the power generation quantity assessment of grid-connected photovoltaic power stations; The accuracy level of the voltage transformer selected for the relay protection device is inappropriate, causing the protection device to fail to operate correctly during voltage sags, affecting the stable operation of the power system. The accuracy level matching defect of the transformer leads to frequent misoperation and alarm of the protection device of newly commissioned photovoltaic power stations; In the power regulation system of photovoltaic power stations, the accuracy level of the used transformer is too low, resulting in the system being unable to accurately regulate during photovoltaic changes; In the automatic generation and voltage control system, the importance of the accuracy level of the transformer is ignored during the design and installation process, resulting in the system being unable to accurately control and regulate during actual operation and facing problems such as huge power generation quantity assessment losses in the power market. Summary of the Invention

[0004] The purpose of the present invention is: aiming at the above problems existing currently, a construction method for an AC circuit management system of an electrical secondary system is provided. By constructing an AC circuit management system of an electrical secondary system, various problems caused by improper management during the rapid development of the electrical secondary system in new energy power stations are solved.

[0005] The technical solution of the present invention is as follows:

[0006] A construction method for an AC circuit management system of an electrical secondary system, comprising the following steps:

[0007] Divide the structure of the AC circuit management system of the electrical secondary system, and divide the management system into management of the transformer body, management of secondary connection cables, and management module of the secondary panel sampling unit;

[0008] Set the management attributes of current and voltage transformer bodies, and conduct verification;

[0009] Set the management attributes of the connection cables of the electrical secondary circuits of current and voltage transformers, and conduct verification;

[0010] Set the attributes of the sampling units of the secondary circuits of current and voltage transformers, and conduct verification;

[0011] Overall parameter correctness verification management of the electrical secondary AC circuits in stages for new energy construction projects.

[0012] Furthermore, the content of the management attributes of the current transformer body includes:

[0013] Manufacturer of current transformer; model; winding distribution; rated current of primary winding; rated transformation ratio; rated voltage of primary winding; accuracy class; rated capacity of secondary winding; thermal stability current multiple; dynamic stability current multiple; excitation characteristic curve; change in excitation current; rated frequency; composite error; ratio error; phase error; spare winding;

[0014] Based on the design of the transformer, test data in the laboratory or on-site, verify the important attribute parameters of the current transformer with reference to the design values. The verification content includes:

[0015] Actual transformation ratio test and error verification of the current transformer, with the error within the allowable range of the specification;

[0016] Polarity terminal verification of the current transformer, with the verification target being subtractive polarity;

[0017] Measured excitation characteristic curve of the current transformer and the designed excitation curve;

[0018] Phase error verification of the current transformer, with the error within the allowable range of the specification;

[0019] Composite error verification of the current transformer, with the error within the allowable range of the specification.

[0020] Furthermore, the content of the management attributes of the voltage transformer body includes:

[0021] Manufacturer of voltage transformer; model; winding distribution; rated voltage of primary winding; rated transformation ratio; rated capacity of secondary winding; accuracy class; rated frequency; composite error; ratio error; phase error;

[0022] Based on the design of the instrument transformer and the test data in the laboratory or on-site, check the reference design values of the important attribute parameters of the voltage transformer. The checking contents include:

[0023] Test the actual transformation ratio of the voltage transformer and check the error, with the error within the allowable range of the specification;

[0024] Check the polarity terminal of the voltage transformer, with the checking target being subtractive polarity;

[0025] Check the transformation ratio error of the voltage transformer, with the error within the allowable range of the specification;

[0026] Check the phase error of the voltage transformer, with the error within the allowable range of the specification;

[0027] Check the composite error of the voltage transformer, with the error within the allowable range of the specification.

[0028] Furthermore, the content of the management attributes of the connection cables of the electrical secondary connection circuit of the voltage transformer includes:

[0029] The cable model of the secondary circuit connection; the resistance of the secondary circuit; the insulation level of the secondary circuit; the formation position of the neutral point of the secondary circuit; the sealing position of the three-phase current of the secondary circuit; the grounding position of the secondary circuit; the number of groundings of the secondary circuit;

[0030] Combined with the on-site application design results and on-site installation and commissioning results of the current transformer given by the design unit, the checking contents of the management attributes of the connection cables of the electrical secondary connection circuit include:

[0031] Combined with the secondary rated current of the current transformer, check the cross-sectional area of the conductor of the secondary current circuit;

[0032] Based on the secondary rated load parameters of the current transformer, check the resistance of the secondary current circuit of the transformer;

[0033] Based on the insulation level requirements of the secondary current circuit of the instrument transformer, check the insulation level of the secondary circuit of the transformer;

[0034] Based on the actual wiring situation of the secondary circuit of the instrument transformer and the impedance parameters of the secondary circuit, check the formation position of the neutral point of the secondary circuit to prevent the open circuit of the secondary circuit of the current transformer;

[0035] Based on the requirements of the secondary circuit grounding points of the current transformer in the specialties of relay protection, integrated automation, etc., check the actual grounding point position;

[0036] Based on the results of the review of the parasitic circuit in the secondary circuit, check the number of groundings of the secondary circuit of the current transformer to ensure that there is one and only one grounding point in the secondary circuit.

[0037] Furthermore, the content of the management attributes of the connection cables of the electrical secondary connection circuit of the voltage transformer includes:

[0038] Type of the secondary circuit connection cable; secondary circuit resistance; secondary circuit insulation level; required forming position of the neutral point of the secondary circuit; grounding position of the secondary circuit; number of secondary circuit groundings; capacity of the air switch in the secondary circuit;

[0039] Combined with the on-site design results of the application of voltage transformers and the on-site installation and commissioning results given by the design unit, the checking content of the management attributes of the electrical secondary connection circuit connection cables includes:

[0040] Check the cross-section of the conductor in the secondary voltage circuit in combination with the secondary rated current of the voltage transformer.

[0041] Check the capacity of the air switch in the secondary voltage circuit of the voltage transformer according to the secondary rated capacity of the voltage transformer.

[0042] Check the insulation level of the secondary circuit of the voltage transformer according to the insulation level requirements of the secondary voltage circuit of the voltage transformer.

[0043] Check the actual grounding position according to the requirements of the secondary circuit grounding points of the voltage transformer in the relay protection, integrated automation and other specialties.

[0044] Check the number of groundings of the secondary circuit of the voltage transformer according to the results of the review of the parasitic circuit in the secondary circuit to ensure that there is only one grounding point in the secondary circuit.

[0045] Furthermore, the management attributes of the secondary signal sampling unit of the current transformer include:

[0046] Required secondary rated current of the sampling unit; required transformation ratio of the transformer in the sampling unit; required capacity of the transformer in the sampling unit; required connection of the polarity terminal of the transformer in the sampling unit; required installation position of the transformer in the sampling unit; required frequency of the secondary current signal in the sampling unit; required overload capacity of the secondary current signal in the sampling unit;

[0047] According to the requirements of the current input signal specified in the AC signal sampling unit of the secondary switch cabinet, and the secondary circuit design results and actual wiring conditions of the current transformer given by the design unit, check the attribute information of each sampling unit connected in series in the secondary circuit item by item. The checking content includes:

[0048] Check the cross-section of the connection cable of the secondary circuit of the current transformer according to the rated current of the sampling unit in the secondary current circuit.

[0049] Check whether there is an open circuit in the secondary circuit according to the measured resistance of the secondary circuit, and check the secondary load in combination with the excitation characteristics of the current transformer.

[0050] Check the transformation ratio of the transformer set inside the sampling unit according to the actual transformation ratio of the current transformer connected.

[0051] Check the correctness of the polarity connection of the current transformer in the sampling unit according to the secondary polarity requirements of the current transformer in the sampling unit;

[0052] Check the overload capacity requirements of the secondary current signal in the sampling unit according to the measured results of the comprehensive overall load of the secondary current signal in the sampling unit.

[0053] Furthermore, the management attributes of the secondary signal sampling unit of the voltage transformer include:

[0054] The rated secondary voltage requirements of the sampling unit; the transformer ratio requirements of the transformer in the sampling unit; the capacity requirements of the transformer in the sampling unit; the requirements for connecting the polarity terminal of the transformer in the sampling unit; the installation position requirements of the transformer in the sampling unit; the frequency requirements of the secondary voltage signal in the sampling unit; the overvoltage capacity requirements of the secondary voltage signal in the sampling unit.

[0055] According to the specified voltage input signal requirements of the AC signal sampling unit in the secondary switch cabinet, as well as the design results of the secondary circuit of the voltage transformer given by the design unit and the actual wiring conditions, check the attribute information of each secondary switch cabinet sampling unit connected in parallel in the secondary circuit item by item. The check contents include:

[0056] Check the cross-sectional area of the connecting cable of the secondary circuit of the voltage transformer according to the capacity of the sampling unit in the voltage secondary circuit;

[0057] Check the transformer ratio set inside the sampling unit according to the actual access transformer ratio of the voltage transformer;

[0058] Check the correctness of the polarity connection of the voltage transformer in the sampling unit according to the secondary polarity requirements of the voltage transformer in the sampling unit;

[0059] Check the overvoltage capacity of the secondary voltage signal in the sampling unit according to the measured results of the comprehensive overall load of the secondary voltage signal in the sampling unit and the calculation results of the overvoltage system according to the location of the transformer;

[0060] Check the capacity of the air switch in the secondary voltage circuit according to the rated capacity of the voltage transformer in the sampling unit.

[0061] Furthermore, the new energy construction project includes the planning stage, the design stage, the installation and commissioning stage, and the production and operation stage;

[0062] The planning stage includes: determining the main wiring form and the voltage level of the outgoing line according to the project scale. On this basis, combined with the actual requirements of secondary switch cabinets such as relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency modulation and inertia, automatic generation control, automatic voltage and reactive power control, and metering, comprehensively count and give the quantity requirements and attribute requirements of the transformer body, and carry out the verification of the body;

[0063] The design phase includes: Based on the statistics and verification results of the quantity and attribute requirements of the transformer body in the planning phase, combined with the panel assembly results of the secondary switchgear cabinets given by the design unit of the new energy development project and the situation of the secondary AC circuit connection cables, adopt the typical secondary load design value of the panel sampling unit or the load range value of similar products given by the secondary switchgear cabinet manufacturer, estimate the impedance of the secondary connection cables, calculate the matching relationship between the secondary loads of current and voltage transformers and the load of the design circuit wiring, and on this basis, carry out the verification of the secondary circuit connection cables by referring to the typical secondary circuit data.

[0064] Furthermore, the installation and commissioning phase includes: Referring to the secondary circuit wiring design results given by the design unit of the new energy development project, based on the requirements of secondary switchgear cabinet sampling units such as relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency modulation and inertia, automatic generation control, automatic voltage and reactive power control, and metering for current and voltage input signals, conduct a two-way verification from both aspects of the actual secondary circuit load verified by the design parameters of the signal source according to the attribute contents such as quantity, accuracy level, polarity, excitation characteristics, ratio error, composite error, angle error, and load capacity, and then verify the correctness of the signal source input in reverse according to the signal input requirements of the secondary switchgear cabinet sampling units.

[0065] The production and operation phase includes: Conduct verification respectively for the transformer body of the electrical secondary AC circuit, the secondary connection cables, and the secondary switchgear cabinet sampling units based on the design, on-site test, and commissioning results, and conduct item-by-item verification for the load requirements of secondary switchgear cabinet sampling units such as relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency modulation and inertia, automatic generation control, automatic voltage and reactive power control, and metering, and the matching of the signal source attributes of current and voltage transformer bodies; and conduct separate verification for the reserved current transformer windings in the design by using the verification scheme for the attributes of the transformer body.

[0066] Furthermore, the secondary switchgear cabinets at least include relay protection cabinets, integrated automation cabinets, power quality cabinets, synchronous vector cabinets, fault recording cabinets, primary frequency modulation cabinets, automatic generation control cabinets, automatic voltage and reactive power control cabinets, and metering cabinets.

[0067] Compared with the existing technology, the beneficial effects of the present invention are:

[0068] 1. Enhanced systematicness and integrity: In the existing technology, the management of the electrical secondary system often relies on experience and commissioning, lacking a systematic management method; in this application, through modular management, the management of the transformer body, secondary connection cables, and secondary switchgear cabinet acquisition units is systematized, ensuring the comprehensiveness and accuracy of the attribute settings and verifications of each link, and avoiding management vacuum and repeated errors;

[0069] 2. Reduce errors and risks: In the prior art, due to the rapid development and multi-front engineering management methods, it is easy to cause incorrect connections, missing connections, and parameter mismatches in the secondary electrical system. Through detailed attribute definition and verification, this application ensures the correctness and rationality of the secondary electrical system, reduces errors and risks, and improves the stability and reliability of the system.

[0070] 3. Improve project quality and efficiency: Through systematic management methods, this application can gradually implement management requirements at all stages of new energy projects, ensuring that the work results of each stage provide the basis and boundaries for subsequent stages. This method not only improves project quality but also management efficiency, reducing rework and economic losses caused by improper management.

[0071] 4. Enhance the level of automation and intelligence: In the prior art, the management of the secondary electrical system relies on manual operation and empirical judgment, making it difficult to achieve automation and intelligence. Through modularization and attribute settings, this application simplifies the work process of professional technicians, facilitating its gradual implementation at all stages of new energy development and enhancing the level of automation and intelligence of management. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic diagram of the connection of the AC circuit of the secondary electrical system of this application.

[0073] Figure 2 It is a schematic diagram of the structure of the secondary AC circuit system of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0074] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0075] The features and performance of the present invention will be further described in detail below in conjunction with the embodiments.

[0076] In the actual operation of the secondary electrical circuit of a new energy power station, the typical connection structure of the AC current circuit of the secondary electrical system shown in Figure 1 is usually adopted.

[0077] The primary winding of the current transformer is connected to the primary system of the new energy power station. The secondary system uses secondary cables to connect the AC current sampling circuits in each secondary switch cabinet, and at the end of the secondary switch cabinet, the secondary cables are returned to connect to the secondary winding of the current transformer. And according to the regulations and design requirements, a circuit grounding point is set at a suitable location in the secondary circuit.

[0078] In the above schematic diagram, the secondary circuit of the current transformer is shown connected to two sets of relay protection devices and one new energy power station power regulation device in the secondary switch cabinet. In the actual application process, the number of secondary switch cabinets connected to the secondary circuit of the current transformer can be determined according to the actual situation on site.

[0079] The wiring schematic diagram of the voltage transformer is similar to the above figure and will not be elaborated here.

[0080] Please refer to Figure 1 and Figure 2 , a construction method for an AC circuit management system of an electrical secondary system, including the following steps:

[0081] Divide the structure of the AC circuit management system of the electrical secondary system, and divide the management system into the management of the transformer body module, the management of the secondary connection cables, and the management module of the secondary switch cabinet sampling unit; improve the systematicness and integrity of project management: by dividing the AC circuit management of the electrical secondary system into three modules: the management of the transformer body, the management of the secondary connection cables, and the management of the secondary switch cabinet sampling unit, ensure the comprehensiveness and accuracy of the attribute definition, organizational management, and verification of each link.

[0082] The structure diagram of the management system is as shown in Appendix Figure 2 . The management of the transformer body realizes the definition, organizational management, and verification of the important attribute parameters of the transformer; the management of the secondary connection cables realizes the definition, organizational management, and verification of the important attributes of the connection cables between the transformer and the AC signal sampling unit of the secondary switch cabinet; the management of the secondary switch cabinet signal sampling unit realizes the definition, organizational management, and verification of the important attribute parameters of the AC current and voltage sampling units for the secondary system-related switch cabinets including relay protection, stability control, power regulation, voltage and reactive power, power quality, and integrated automation systems.

[0083] Set the management attributes of the current and voltage transformer bodies and conduct verification;

[0084] The content of the current transformer body attributes includes:

[0085] The manufacturer of the current transformer; model; winding distribution; rated current of the primary winding; rated transformation ratio; rated voltage of the primary winding; accuracy class; rated capacity of the secondary winding; thermal stability current multiple; dynamic stability current multiple; excitation characteristic curve; change in excitation current; rated frequency; composite error; ratio error; phase error; spare winding;

[0086] Based on the design of the instrument transformer and the test data in the laboratory or on-site, check the reference design values of the important attribute parameters of the current transformer. The checking contents include:

[0087] Test the actual transformation ratio of the current transformer and check the error, with the error within the allowable range of the specification;

[0088] Check the polarity terminal of the current transformer, with the checking target being subtractive polarity;

[0089] The measured excitation characteristic curve and the designed excitation curve of the current transformer;

[0090] Check the phase error of the current transformer, with the error within the allowable range of the specification;

[0091] Check the composite error of the current transformer, with the error within the allowable range of the specification.

[0092] The content of the management attributes of the voltage transformer body includes:

[0093] The manufacturer of the voltage transformer; model; winding distribution; rated voltage of the primary winding; rated transformation ratio; rated capacity of the secondary winding; accuracy class; rated frequency; composite error; transformation ratio error; phase error;

[0094] Based on the design of the instrument transformer and the test data in the laboratory or on-site, check the reference design values of the important attribute parameters of the voltage transformer. The checking contents include:

[0095] Test the actual transformation ratio of the voltage transformer and check the error, with the error within the allowable range of the specification;

[0096] Check the polarity terminal of the voltage transformer, with the checking target being subtractive polarity;

[0097] Check the transformation ratio error of the voltage transformer, with the error within the allowable range of the specification;

[0098] Check the phase error of the voltage transformer, with the error within the allowable range of the specification;

[0099] Check the composite error of the voltage transformer, with the error within the allowable range of the specification.

[0100] Set the management attributes of the connection cables of the electrical secondary circuits of the current and voltage transformers, and conduct checks;

[0101] The content of the management attributes of the connection cables of the electrical secondary connection circuit of the current transformer includes:

[0102] The model of the connection cable of the secondary circuit; the resistance of the secondary circuit; the insulation level of the secondary circuit; the formation position of the neutral point of the secondary circuit; the sealing position of the three-phase current of the secondary circuit; the grounding position of the secondary circuit; the number of groundings of the secondary circuit;

[0103] Combined with the on-site current transformer application design results and on-site installation and commissioning results given by the design unit, the checking contents of the connection cable management attributes of the secondary electrical connection circuit include:

[0104] Combined with the secondary rated current of the current transformer, check the cross-sectional area of the conductors in the secondary current circuit;

[0105] Based on the secondary rated load parameters of the current transformer, check the resistance of the secondary current circuit of the transformer;

[0106] Based on the insulation level requirements of the secondary current circuit of the transformer, check the insulation level of the secondary circuit of the transformer;

[0107] Based on the actual wiring conditions of the secondary circuit of the transformer and the impedance parameters of the secondary circuit, check the formation position of the neutral point of the secondary circuit to prevent the open circuit of the secondary circuit of the current transformer;

[0108] Based on the requirements of specialties such as relay protection and integrated automation for the grounding point of the secondary circuit of the current transformer, check the position of the actual grounding point;

[0109] Based on the results of the review of parasitic circuits in the secondary circuit, check the number of grounding points in the secondary circuit of the current transformer to ensure that there is only one grounding point in the secondary circuit.

[0110] The contents of the connection cable management attributes of the secondary electrical connection circuit of the voltage transformer include:

[0111] The type of connection cable in the secondary circuit; the resistance of the secondary circuit; the insulation level of the secondary circuit; the required formation position of the neutral point of the secondary circuit; the grounding position of the secondary circuit; the number of grounding points in the secondary circuit; the capacity of the air switch in the secondary circuit;

[0112] Combined with the on-site voltage transformer application design results and on-site installation and commissioning results given by the design unit, the checking contents of the connection cable management attributes of the secondary electrical connection circuit include:

[0113] Combined with the secondary rated current of the voltage transformer, check the cross-sectional area of the conductors in the secondary voltage circuit;

[0114] Based on the secondary rated capacity of the voltage transformer, check the capacity of the air switch in the secondary voltage circuit of the transformer;

[0115] Based on the insulation level requirements of the secondary voltage circuit of the transformer, check the insulation level of the secondary circuit of the transformer;

[0116] Based on the requirements of specialties such as relay protection and integrated automation for the grounding point of the secondary circuit of the voltage transformer, check the position of the actual grounding point;

[0117] Based on the results of the review of parasitic circuits in the secondary circuit, check the number of grounding points in the secondary circuit of the voltage transformer to ensure that there is only one grounding point in the secondary circuit.

[0118] Set the attributes of the sampling units in the secondary circuits of current and voltage transformers and conduct verification.

[0119] The management attributes of the secondary signal sampling units of current transformers include:

[0120] The requirement for the secondary rated current of the sampling unit; the requirement for the transformation ratio of the transformer in the sampling unit; the requirement for the capacity of the transformer in the sampling unit; the requirement for the connection of the polarity terminal of the transformer in the sampling unit; the requirement for the installation position of the transformer in the sampling unit; the requirement for the frequency of the secondary current signal of the sampling unit; the requirement for the overload capacity of the secondary current signal of the sampling unit;

[0121] According to the requirements for the current input signal specified by the AC signal sampling units in the secondary switchgear cabinets, as well as the design results of the secondary circuit of the current transformer and the actual wiring situation given by the design unit, verify item by item the attribute information of each sampling unit connected in series in the secondary circuit. The verification contents include:

[0122] Verify the cross-sectional area of the connection cable in the secondary circuit of the current transformer based on the rated current of the sampling unit in the current secondary circuit.

[0123] Verify whether there is an open circuit in the secondary circuit based on the measured resistance of the secondary circuit, and verify the secondary load in combination with the excitation characteristics of the current transformer.

[0124] Verify the transformation ratio of the transformer set inside the sampling unit based on the actual transformation ratio of the current transformer connected.

[0125] Verify the correctness of the polarity connection of the current transformer in the sampling unit based on the requirements for the secondary polarity of the current transformer in the sampling unit.

[0126] Verify the requirement for the overload capacity of the secondary current signal of the sampling unit based on the measured results of the comprehensive overall load of the secondary current signal of the sampling unit.

[0127] The management attributes of the secondary signal sampling units of voltage transformers include:

[0128] The requirement for the secondary rated voltage of the sampling unit; the requirement for the transformation ratio of the transformer in the sampling unit; the requirement for the capacity of the transformer in the sampling unit; the requirement for the connection of the polarity terminal of the transformer in the sampling unit; the requirement for the installation position of the transformer in the sampling unit; the requirement for the frequency of the secondary voltage signal of the sampling unit; the requirement for the overvoltage capacity of the secondary voltage signal of the sampling unit.

[0129] According to the requirements for the voltage input signal specified by the AC signal sampling units in the secondary switchgear cabinets, as well as the design results of the secondary circuit of the voltage transformer and the actual wiring situation given by the design unit, verify item by item the attribute information of each sampling unit connected in parallel in the secondary circuit. The verification contents include:

[0130] Verify the cross-sectional area of the connection cable in the secondary circuit of the voltage transformer based on the capacity of the sampling unit in the voltage secondary circuit.

[0131] Check the transformer ratio set inside the sampling unit according to the actual transformer ratio of the voltage transformer connected.

[0132] Check the correctness of the polarity connection of the voltage transformer in the sampling unit according to the secondary polarity requirement of the voltage transformer in the sampling unit.

[0133] Check the overvoltage capacity of the secondary voltage signal in the sampling unit according to the comprehensive measured result of the overall load of the secondary voltage signal in the sampling unit and the calculation result of the overvoltage system of the transformer according to the location.

[0134] Check the capacity of the air switch in the secondary voltage circuit according to the rated capacity of the voltage transformer in the sampling unit.

[0135] Reduce the blind spots and risks in project management: By systematically sorting out and checking the key attributes of the electrical secondary circuit, avoid problems such as missed connections, wrong connections, and parameter mismatches caused by management vacuum, and improve the project quality.

[0136] Overall parameter correctness check and management of the electrical secondary AC circuit in new energy construction projects in phases.

[0137] New energy construction projects include the planning stage, design stage, installation and commissioning stage, and production operation stage;

[0138] The planning stage includes: determining the main wiring form and the voltage level of the outgoing line according to the project scale. On this basis, combined with the actual requirements of secondary switch cabinets such as relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency modulation and inertia, automatic generation control, automatic voltage and reactive power control, and metering, comprehensively statistically give the quantity requirements and attribute requirements of the transformer body, and carry out the verification of the body.

[0139] The design stage includes: According to the statistical and verification results of the quantity requirements and attribute requirements of the transformer body in the planning stage, combined with the panel assembly results of the secondary switch cabinets given by the design unit of the new energy development project and the connection cable situation of the secondary AC circuit, adopt the typical design value of the secondary load of the panel sampling unit or the load range value of similar products given by the secondary switch cabinet manufacturer, and estimate the impedance of the secondary connection cable, calculate the matching relationship between the secondary load of the current and voltage transformers and the load of the designed circuit connection, and on this basis, carry out the verification of the secondary circuit connection cable by referring to the typical secondary circuit data.

[0140] The installation and commissioning stage includes: referring to the wiring design results of the secondary circuit of the instrument transformer given by the design unit of the new energy development project, and based on the requirements of the current and voltage input signals of the sampling units of the secondary switchgear cabinets for relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency modulation and inertia, automatic generation control, automatic voltage and reactive power control, metering, etc., checking the actual secondary circuit load from the signal source design parameters in terms of attributes such as quantity, accuracy class, polarity, excitation characteristics, ratio error, composite error, angle error, load capacity, etc., and then reversely checking the correctness of the signal source input from the signal input requirements of the sampling units of the secondary switchgear cabinets.

[0141] The production and operation stage includes: separately checking the instrument transformer body, secondary connection cables, and sampling units of the secondary switchgear cabinets in terms of three aspects according to the design, on-site test and commissioning results; item-by-item checking the load requirements of the sampling units of the secondary switchgear cabinets for relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency modulation and inertia, automatic generation control, automatic voltage and reactive power control, metering, etc., and the matching of the signal source attributes of the current and voltage transformers; and separately checking the reserved current transformer windings for design with the management verification scheme for the attributes of the transformer body.

[0142] The secondary switchgear cabinets include at least relay protection cabinets, integrated automation cabinets, power quality cabinets, synchronous vector cabinets, fault recording cabinets, primary frequency modulation cabinets, automatic generation control cabinets, automatic voltage and reactive power control cabinets, and metering cabinets.

[0143] Three management system modules based on the basic working principle of the electrical secondary system circuit are clearly proposed. Item-by-item sorting is carried out from three aspects: the transformer body, secondary connection cables, and sampling units of the secondary switchgear cabinets, replacing the natural defects in the past that completely relied on commissioning as a "last resort", where the commissioning quality largely depended on engineering experience and construction was carried out according to the drawings. The proposed management system for the AC circuit of the electrical secondary system is comprehensive and can effectively improve the integrity and systematicness of the electrical secondary system, preventing "management vacuum"; the management attribute definitions of the three major modules of the management system for the AC circuit of the electrical secondary system comprehensively consider the engineering requirements of each electrical secondary specialty. The attribute definitions are comprehensive and detailed, and the provided attribute definitions are relatively concise and easy to execute for professional and technical personnel. Through the perfect attribute definitions of each module, the management system for the AC circuit of the electrical secondary system can be implemented step by step in each stage of the new energy project development and construction process, and the implementation results of the previous stage are the basis and boundary for the implementation of the subsequent stage, facilitating the division of responsibilities and the implementation of responsibilities for work management.

[0144] The above-described embodiments merely represent the specific implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the protection scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the technical solution of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application.

Claims

1. A method for constructing an AC circuit management system for an electrical secondary system, characterized in that: The following steps are involved: Divide the structure of the AC circuit management system of the electrical secondary system into transformer body management, secondary connection cable management and secondary panel cabinet sampling unit management modules; Set the management attributes of current and voltage transformers and perform verification; Set the cable management properties for the electrical secondary circuit connections of current and voltage transformers and perform verification; Set the properties of the current and voltage transformer secondary circuit sampling units and perform verification; Correctness verification management of overall parameters of electrical secondary AC circuits in phases for new energy construction projects.

2. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The current transformer main body attributes include: Current transformer manufacturer; model; winding distribution; primary winding rated current; rated change; primary winding rated voltage; accuracy level; secondary winding rated capacity; thermal stability current multiple; dynamic stability current multiple; excitation characteristic curve; excitation current change; rated frequency; composite error; ratio error; phase error; spare winding; Based on the transformer design, laboratory or field test data, the important attribute parameters of the current transformer are checked against the design values. The check includes: The actual change test machine error calibration of the current transformer is within the allowable range of the specification; The polarity end of the current transformer is checked, and the check target is to reduce the polarity; Measured excitation characteristic curve and designed excitation curve of current transformer; The current transformer phase error is checked and the error is within the allowable range of the specification; The composite error of the current transformer is calibrated and the error is within the allowable range of the specification.

3. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The voltage transformer body management attribute content includes: Voltage transformer manufacturer; model; winding distribution; primary winding rated voltage; rated transformation ratio; secondary winding rated capacity; accuracy level; rated frequency; composite error; transformation ratio error; phase error; Based on the transformer design, laboratory or field test data, the reference design values ​​of the important attribute parameters of the voltage transformer are checked. The check contents include: The actual transformation ratio test and error verification of the voltage transformer shall be within the allowable range of the specification; Voltage transformer polarity end calibration, the calibration target is polarity reduction; Voltage transformer ratio error calibration, the error is within the allowable range of the specification; Voltage transformer phase error calibration, the error is within the allowable range of the specification; The voltage transformer composite error is calibrated and the error is within the allowable range of the specification.

4. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The current transformer electrical secondary connection circuit connection cable management attribute content includes: Secondary circuit connection cable model; secondary circuit resistance; secondary circuit insulation level; secondary circuit neutral point formation position; secondary circuit three-phase current sealing position; secondary circuit grounding position; secondary circuit grounding number; Combined with the on-site current transformer application design results and on-site installation and commissioning results provided by the design unit, the electrical secondary connection circuit connection cable management attribute verification content includes: Combined with the secondary rated current of the current transformer, check the cross-section of the secondary current loop conductor; According to the secondary rated load parameters of the current transformer, check the secondary current loop resistance of the current transformer; According to the insulation level requirements of the transformer secondary current circuit, check the insulation level of the transformer secondary circuit; According to the actual wiring of the secondary circuit of the transformer and the impedance parameters of the secondary circuit, check the neutral point formation position of the secondary circuit to prevent the secondary circuit of the current transformer from being open; According to the requirements of relay protection and integrated automation for the grounding point of the secondary circuit of the current transformer, check the actual grounding point location; Based on the review results of the secondary circuit parasitic circuit, check the number of grounding points in the secondary circuit of the current transformer to ensure that the secondary circuit has only one grounding point.

5. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The voltage transformer electrical secondary connection circuit connection cable management attribute content includes: Secondary circuit connection cable model; secondary circuit resistance; secondary circuit insulation level; secondary circuit neutral point required position; secondary circuit grounding position; secondary circuit grounding number; secondary circuit air switch capacity; Combined with the on-site voltage transformer application design results and on-site installation and commissioning results provided by the design unit, the electrical secondary connection circuit connection cable management attribute verification content includes: Combined with the secondary rated current of the voltage transformer, check the cross-section of the secondary voltage circuit conductor; According to the rated capacity of the voltage transformer secondary circuit, check the capacity of the air switch of the transformer secondary voltage circuit; According to the insulation level requirements of the transformer secondary voltage circuit, check the insulation level of the transformer secondary circuit; According to the requirements of relay protection and integrated automation for the grounding point of the voltage transformer secondary circuit, check the actual grounding point location; Based on the review results of the secondary circuit parasitic circuit, check the number of grounding points in the secondary circuit of the voltage transformer to ensure that the secondary circuit has only one grounding point.

6. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The current transformer secondary signal sampling unit management attributes include: The sampling unit secondary rated current requirements; sampling unit transformer ratio requirements; sampling unit transformer capacity requirements; sampling unit transformer polarity terminal access requirements; sampling unit transformer installation position requirements; sampling unit secondary current signal frequency requirements; sampling unit secondary current signal overload capacity requirements; According to the current input signal requirements specified by the AC signal sampling unit of the secondary panel cabinet, as well as the secondary circuit design results and actual wiring conditions of the current transformer provided by the design unit, the attribute information of each secondary panel cabinet sampling unit connected in series in the secondary circuit is checked item by item. The check contents include: According to the rated current of the current secondary circuit sampling unit, check the cross-section of the cable connecting the secondary circuit of the current transformer; Check whether there is an open circuit in the secondary circuit based on the measured secondary circuit resistance, and check the secondary load based on the current transformer excitation characteristics; According to the actual connection ratio of the current transformer, check the transformer ratio set inside the sampling unit; According to the secondary polarity requirements of the sampling unit current transformer, check the correctness of the polarity wiring of the sampling unit current transformer; Based on the actual measurement results of the overall load of the sampling unit secondary current signal, the overload capacity requirements of the sampling unit secondary current signal are verified.

7. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The voltage transformer secondary signal sampling unit management attributes include: The sampling unit secondary rated voltage requirements; sampling unit transformer ratio requirements; sampling unit transformer capacity requirements; sampling unit transformer polarity terminal access requirements; sampling unit transformer installation position requirements; sampling unit secondary voltage signal frequency requirements; sampling unit secondary voltage signal overvoltage capacity requirements; According to the voltage input signal requirements of the AC signal sampling unit of the secondary panel cabinet, as well as the secondary circuit design results and actual wiring conditions of the voltage transformer provided by the design unit, the attribute information of each secondary panel cabinet sampling unit connected in parallel in the secondary circuit is checked item by item. The check contents include: According to the capacity of the voltage secondary circuit sampling unit, check the cross section of the cable connecting the voltage transformer secondary circuit; According to the actual access ratio of the voltage transformer, check the transformer ratio set inside the sampling unit; According to the secondary polarity requirements of the sampling unit voltage transformer, check the correctness of the polarity wiring of the sampling unit voltage transformer; Verify the overvoltage capacity of the secondary voltage signal of the sampling unit based on the overall load measurement results of the secondary voltage signal of the sampling unit and the calculation results of the transformer according to the overvoltage system at the location; According to the rated capacity of the sampling unit voltage transformer, check the capacity of the secondary voltage circuit air switch.

8. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The new energy construction project includes the planning stage, design stage, installation and commissioning stage, and production operation stage; The planning stage includes: determining the main wiring form and the voltage level of the transmission line according to the project scale, and on this basis, combining the actual requirements of relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency regulation and inertia, automatic generation control, automatic voltage and reactive power control, and metering secondary cabinets, comprehensively statistically giving the number and attribute requirements of the transformer body, and conducting body verification; The design stage includes: based on the statistical and verification results of the number and attribute requirements of the transformer body in the planning stage, combined with the secondary panel cabinet group results and secondary AC circuit connection cable conditions provided by the new energy development project design unit, using the typical panel cabinet sampling unit secondary load design value or the load range value of similar products provided by the secondary panel cabinet manufacturer, and estimating the secondary connection cable impedance, calculating the matching relationship between the current and voltage transformer secondary load and the design circuit wiring load, and on this basis, carrying out secondary circuit connection cable verification with reference to typical secondary circuit data.

9. The method for constructing an AC circuit management system for an electrical secondary system according to claim 8, characterized in that: The installation and commissioning phase includes: referring to the transformer secondary circuit wiring design results provided by the design unit of the new energy development project, based on the requirements of relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency modulation and inertia, automatic power generation control, automatic voltage and reactive power control, and metering secondary cabinet sampling unit for current and voltage input signals, the actual secondary circuit load is verified by the signal source design parameters from the content of quantity, accuracy level, polarity, excitation characteristics, ratio error, composite error, angle error, and load capacity attributes, and then the correctness of the signal source input is verified by the signal source design parameters in reverse by the signal input requirements of the secondary cabinet sampling unit; The production and operation stage includes: separately conducting verification on the electrical secondary AC circuit transformer body, secondary connecting cables, and secondary panel cabinet sampling unit based on the design, field test and debugging results; verifying the relay protection, integrated automation, power quality, synchronous vector, fault recording, primary frequency regulation and inertia, automatic generation control, automatic voltage and reactive power control, metering secondary panel cabinet sampling unit load demand, and current and voltage transformer body signal source attribute matching item by item; and separately verifying the current transformer windings reserved for spare use using the transformer body attribute management verification plan.

10. The method for constructing an AC circuit management system for an electrical secondary system according to claim 1, characterized in that: The secondary panel cabinet at least includes a relay protection cabinet, an integrated automation cabinet, a power quality cabinet, a synchronous vector cabinet, a fault recording cabinet, a primary frequency modulation cabinet, an automatic power generation control cabinet, an automatic voltage and reactive power control cabinet, and a metering cabinet.

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