Auxiliary power system relay protection setting value accounting method and device

Abstract

The invention provides an auxiliary power system relay protection constant value accounting method and device, and relates to the technical field of power grids, and the method comprises the steps: obtaining nameplate parameters of a related transformer of an auxiliary power system and a main self-starting load table of a power supply system; a power supply system constant value is calculated according to the power supply system main self-starting load meter, a station service power constant value is calculated according to the nameplate parameters, and the station service power constant value comprises bus upper short-circuit reactance per unit value, transformer low-voltage side short-circuit reactance, transformer low-voltage side three-phase short-circuit current and current quick-break related parameters in various operation modes. Setting time-limit overcurrent related parameters and overload related parameters; and summarizing the power supply system constant value and the auxiliary power constant value. Through the nameplate parameter calculation of the main self-starting load meter of the power supply system and the transformer related to the auxiliary power system, the setting calculation of the relay protection fixed value is realized, the calculation efficiency is improved, and the operation safety of the power plant is improved.

Description

Technical Field

[0001] The present application relates to the field of power grid technology, and in particular to a method and device for calculating relay protection constant values ​​of a factory power system. Background Art

[0002] The main tasks of the relay protection setting calculation of the power supply system are: to determine the technical specifications of the protection device when selecting the protection device in the engineering design stage; to determine the operating parameters (given the fixed value) of the protection device actually used on site through setting calculation. In this way, the relay protection device can play its role correctly, prevent the accident from expanding, and maintain the stable operation of the power supply system. At present, the setting calculation efficiency of the power supply relay protection device is low. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the first purpose of this application is to propose a method for calculating relay protection settings for a factory power system.

[0005] The second object of the present application is to provide a device.

[0006] The third objective of the present application is to provide an electronic device.

[0007] A fourth objective of the present application is to provide a computer-readable storage medium.

[0008] A fifth object of the present application is to provide a computer program product.

[0009] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a method for calculating relay protection setting values ​​of a power supply system of an auxiliary power plant, comprising:

[0010] Obtain the nameplate parameters of the transformers related to the plant power system and the main self-starting load table of the power supply system;

[0011] The power supply system constant is calculated according to the main self-starting load table of the power supply system, wherein the power supply system constant includes: avoiding the maximum value Iop and In multiples of the rated current on the low-voltage side of the low-voltage plant transformer, the maximum value Iop and In multiples of the measured normal load current, and the In multiple is the multiple relationship between the rated current and the actual operating current;

[0012] Calculate the factory power setting value according to the nameplate parameters, wherein the factory power setting value includes the per unit value of the short-circuit reactance on the bus under various operating modes, the short-circuit reactance on the low-voltage side of the transformer, the three-phase short-circuit current on the low-voltage side of the transformer, current quick-break related parameters, time-limited overcurrent related parameters, and overload related parameters;

[0013] The power supply system set value and the factory power set value are summarized.

[0014] Optionally, the nameplate parameters of the transformer related to the auxiliary power system include at least one of the following:

[0015] Switch number, equipment name, transformer capacity, short-circuit impedance, rated voltage, rated current, current transformer ratio, zero-sequence CT ratio;

[0016] The main self-starting load table of the power supply system includes at least one of the following: circuit breaker rated current, normal operating single-phase load current, main self-starting load name, main self-starting load power, and main self-starting load rated current.

[0017] Optionally, the calculating of the power supply system constant value according to the main self-starting load table of the power supply system includes:

[0018] Determine the reliability coefficient Krel and feedback coefficient Kr of the long-time overcurrent protection, and calculate the maximum value Iop of the rated current on the low-voltage side of the low-voltage plant transformer according to the rated current. The formula is:

[0019] Avoid the maximum value of the rated current on the low-voltage side of the low-voltage plant transformer Iop = rated current × reliability coefficient Krel / feedback coefficient Kr;

[0020] The multiple In of the low-voltage side rated current of the low-voltage plant transformer to be avoided is calculated according to the maximum value Iop of the low-voltage side rated current of the low-voltage plant transformer to be avoided and the rated current of the circuit breaker, and the formula is:

[0021] Avoid the In multiple of the rated current of the low-voltage side of the low-voltage transformer = Iop / rated current of the circuit breaker;

[0022] The reliability coefficient Krel in actual measurement is determined, and the maximum value Iop in actual measurement is calculated according to the normal operating single-phase load current, and the formula is as follows:

[0023] The maximum value Iop in actual measurement = the reliability coefficient Krel in actual measurement / (single-phase load current in normal operation of section a + single-phase load current in normal operation of section b);

[0024] The In multiple in the actual measurement is calculated according to the maximum value Iop in the actual measurement and the rated current of the circuit breaker, and the formula is:

[0025] The In multiple in actual measurement = the maximum value Iop in actual measurement / rated current of circuit breaker.

[0026] Optionally, the operation mode includes:

[0027] In the first operation mode, 2GB is powered via circuit breaker 002;

[0028] In the second operation mode, 3GB is supplied with power through Section II via 020 circuit breaker;

[0029] In the third operation mode, 4GB is supplied with power through the 020 circuit breaker via Section II;

[0030] In the fourth operation mode, 0B supplies power through section IV via circuit breaker 043;

[0031] The calculating of the factory power set value according to the nameplate parameters comprises:

[0032] Determine the calculation reference capacity, calculate the reference voltage, and calculate the 7B short-circuit reactance per unit value according to the maximum value of the rated voltage and the transformer capacity. The formula is:

[0033] 7B short-circuit reactance per unit value = maximum value of rated voltage × calculation base capacity / transformer capacity;

[0034] According to the short-circuit impedance of the transformer used in the operation mode and the transformer capacity, the corresponding short-circuit reactance per unit value on the bus section I is calculated. The formula is:

[0035] The unit value of short-circuit reactance on section I busbar = short-circuit impedance × calculated benchmark capacity / transformer capacity.

[0036] Optionally, the method further includes:

[0037] The smallest per-unit short-circuit reactance value on the bus section I under each operation mode is taken as the per-unit short-circuit reactance value of the bus section in the maximum operation mode, and the largest per-unit short-circuit reactance value on the bus section I under each operation mode is taken as the per-unit short-circuit reactance value of the bus section in the maximum operation mode;

[0038] According to the busbar short-circuit reactance standard value in the maximum operation mode, short-circuit impedance and transformer capacity, the transformer low-voltage side short-circuit reactance under the maximum operation mode of the power plant section I is calculated. The formula is:

[0039] The short-circuit reactance of the transformer low-voltage side under the maximum operation mode of the power supply section I of the auxiliary power supply = short-circuit impedance × calculated reference capacity / transformer capacity + the per-unit value of the busbar short-circuit reactance under the maximum operation mode;

[0040] According to the short-circuit reactance of the transformer low-voltage side under the maximum operation mode of the power supply section I, the reference capacity and reference voltage are calculated to calculate the three-phase short-circuit current of the transformer low-voltage side under the maximum operation mode of the power supply section I. The formula is:

[0041]

[0042] According to the busbar short-circuit reactance standard value in the minimum operation mode, short-circuit impedance and transformer capacity, the transformer low-voltage side short-circuit reactance in the minimum operation mode of the power plant section I is calculated. The formula is:

[0043] The short-circuit reactance of the transformer low-voltage side under the minimum operation mode of the power supply section I = short-circuit impedance × calculated reference capacity / transformer capacity + the per-unit value of the busbar short-circuit reactance under the minimum operation mode;

[0044] According to the short-circuit reactance of the transformer low-voltage side under the minimum operation mode of the power plant section I, the reference capacity and reference voltage are calculated to calculate the two-phase short-circuit current on the low-voltage side of the transformer under the minimum operation mode of the power plant section I. The formula is:

[0045] The two-phase short-circuit current on the low-voltage side of the transformer under the minimum operating mode of the plant power section I = calculated reference capacity / (2×short-circuit reactance on the low-voltage side of the transformer under the minimum operating mode of the plant power section I×calculated reference voltage).

[0046] Optionally, the method further includes:

[0047] Determine the reliability coefficient Krel and the excitation inrush current coefficient of the current quick-break, and calculate the three-phase short-circuit current at the low-voltage side of the transformer under the maximum operation mode of the power supply section I and the current transformer ratio on the high-voltage side of the low-voltage power supply transformer to avoid the three-phase short-circuit current at the low-voltage side outlet. The formula is:

[0048] Avoid the three-phase short-circuit current at the low-voltage side outlet = the reliability coefficient of the current quick-break Krel × the three-phase short-circuit current at the low-voltage side of the transformer under the maximum operation mode of the power supply section I / the current transformer ratio at the high-voltage side of the low-voltage power supply transformer;

[0049] The sensitivity coefficient Ksen is calculated based on the three-phase short-circuit current at the low-voltage side outlet and the two-phase short-circuit current at the low-voltage side of the transformer under the minimum operation mode of the power supply stage I. The formula is:

[0050] Sensitivity coefficient Ksen = two-phase short-circuit current on the low-voltage side of the transformer under the minimum operating mode of plant power section I / (current transformer ratio on the high-voltage side of the low-voltage plant transformer × three-phase short-circuit current at the low-voltage side outlet).

[0051] To achieve the above-mentioned purpose, the second embodiment of the present application proposes a relay protection setting value calculation device for a power supply system of a factory, comprising:

[0052] Parameter acquisition module, used to obtain the nameplate parameters of the transformers related to the plant power system and the main self-starting load table of the power supply system;

[0053] The first calculation module is used to calculate the power supply system set value according to the main self-starting load table of the power supply system, wherein the power supply system set value includes: avoiding the maximum value Iop and In multiples of the rated current on the low-voltage side of the low-voltage plant transformer, and the maximum value Iop and In multiples of the measured normal load current, wherein the In multiple is the multiple relationship between the rated current and the actual operating current;

[0054] A second calculation module is used to calculate the factory power setting value according to the nameplate parameters, wherein the factory power setting value includes the per unit value of the short-circuit reactance on the bus under various operating modes, the short-circuit reactance on the low-voltage side of the transformer, the three-phase short-circuit current on the low-voltage side of the transformer, current quick-break related parameters, time-limited overcurrent related parameters, and overload related parameters;

[0055] A summarizing module is used to summarize the power supply system set value and the factory power set value.

[0056] To achieve the above-mentioned purpose, the third aspect of the present application provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0057] The memory stores computer-executable instructions;

[0058] The processor executes the computer-executable instructions stored in the memory to implement the method as described in any one of the first aspects.

[0059] To achieve the above-mentioned purpose, the fourth aspect embodiment of the present application proposes a computer-readable storage medium, in which computer-readable storage medium is stored computer execution instructions, and when the computer execution instructions are executed by a processor, they are used to implement the method as described in any one of the first aspects.

[0060] To achieve the above-mentioned purpose, the fifth aspect of the present application proposes a computer program product, which implements any method in the first aspect when executed by a processor.

[0061] The method, device, electronic device and storage medium for calculating the relay protection constant value of the power plant system provided in this application realize the setting calculation of the relay protection constant value by calculating the nameplate parameters of the main self-starting load table of the power supply system and the related transformers of the power plant system, thereby improving the calculation efficiency and the safety of power plant operation.

[0062] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0064] Figure 1 A flow chart of a method for calculating relay protection setting values ​​of a power plant system provided in an embodiment of the present application;

[0065] Figure 2 A schematic diagram of the structure of a relay protection constant value calculation device for a factory power system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0066] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0067] The main tasks of the relay protection setting calculation of the power supply system are: to determine the technical specifications of the protection device when selecting the protection device in the engineering design stage; to determine the operating parameters (given the fixed value) of the protection device actually used on site through setting calculation. In this way, the relay protection device can play its role correctly, prevent the accident from expanding, and maintain the stable operation of the power supply system. At present, the setting calculation efficiency of the power supply relay protection device is low.

[0068] To address this problem, the present application provides a method for calculating relay protection setting values ​​of a power plant system. Figure 1 The following is a flow chart of a method for calculating relay protection setting values ​​of a power plant system provided in an embodiment of the present application. Figure 1 As shown, the method comprises the following steps:

[0069] Step 101, obtaining the nameplate parameters of the transformers related to the plant power system and the main self-starting load table of the power supply system;

[0070] Step 102, calculating the power supply system constant value according to the main self-starting load table of the power supply system, wherein the power supply system constant value includes: avoiding the maximum value Iop and In multiples of the rated current on the low-voltage side of the low-voltage plant transformer, the maximum value Iop and In multiples of the measured normal load current, and the In multiple is the multiple relationship between the rated current and the actual operating current;

[0071] Step 103, calculating the factory power setting value according to the nameplate parameters, wherein the factory power setting value includes the per unit value of the short-circuit reactance on the bus under various operating modes, the short-circuit reactance on the low-voltage side of the transformer, the three-phase short-circuit current on the low-voltage side of the transformer, current quick-break related parameters, time-limited overcurrent related parameters, and overload related parameters;

[0072] Step 104, summarizing the power supply system set value and the factory power set value.

[0073] Optionally, the nameplate parameters of the transformer related to the auxiliary power system include at least one of the following:

[0074] Switch number, equipment name, transformer capacity, short-circuit impedance, rated voltage, rated current, current transformer ratio, zero-sequence CT ratio;

[0075] Table 1 is the nameplate parameter table corresponding to a transformer.

[0076]

[0077] Table 1

[0078] Transformer capacity refers to the capacity that the transformer can deliver when it is in continuous operation under the specified conditions of use, at the rated voltage and rated current; short-circuit impedance is to short-circuit the secondary winding of the transformer and slowly increase the voltage on the primary winding. When the short-circuit current of the secondary winding is equal to the rated value, the voltage applied on the primary side is generally expressed as a percentage of the rated voltage; the rated voltage is the working voltage that the transformer can withstand when it is in operation for a long time. In order to meet the needs of grid voltage changes, the high-voltage side of the transformer has taps, and the output voltage on the low-voltage side is adjusted by adjusting the number of turns of the high-voltage winding; the rated current is the current that the transformer is allowed to pass for a long time at the rated capacity. The CT ratio refers to the ratio of the current transformer, that is, the ratio of the current on the primary side to the secondary side of the current transformer. This ratio determines the output signal size of the current transformer, that is, the accuracy of measuring current.

[0079] The function of CT ratio is to convert large current into small current. It is mainly used as a current measuring element in the current loop of the secondary circuit such as metering, measurement, relay protection, monitoring, etc. Generally, the secondary rated current of CT is 5A or 1A, and the primary rated current is selected according to the power load.

[0080] Zero-sequence CT ratio refers to the ratio of the zero-sequence current transformer, which is used to measure the zero-sequence current in the system. Zero-sequence current refers to the vector sum of the three-phase currents in a three-phase power system, and is usually used to detect unbalanced faults in the system. In a three-phase power system, since the three-phase currents are balanced with each other, the algebraic sum of the three-phase currents is zero, which is the so-called zero-sequence current. In a switch, if it is necessary to detect or measure zero-sequence current, a zero-sequence current transformer is required, and its ratio is the zero-sequence ratio. The size of the zero-sequence ratio determines the detection or measurement accuracy of the switch for zero-sequence current.

[0081] The main self-starting load table of the power supply system includes at least one of the following: circuit breaker rated current, normal operating single-phase load current, main self-starting load name, main self-starting load power, and main self-starting load rated current.

[0082] In a possible embodiment, the main self-starting load table of the power supply system is shown in Table 2.

[0083]

[0084] Table 2

[0085] Optionally, the calculating of the power supply system constant value according to the main self-starting load table of the power supply system includes:

[0086] Determine the reliability coefficient Krel and feedback coefficient Kr of the long-time overcurrent protection, and calculate the maximum value Iop of the rated current on the low-voltage side of the low-voltage plant transformer according to the rated current. In the setting calculation of the action current (Iop) constant, the action current is set according to the rated current on the low-voltage side of the low-voltage plant transformer. The formula is:

[0087] Avoid the maximum value of the rated current on the low-voltage side of the low-voltage plant transformer Iop = rated current × reliability coefficient Krel / feedback coefficient Kr;

[0088] The reliability coefficient Krel can be 1.1~1.2, and the feedback coefficient Kr can be 0.85~0.95.

[0089] The multiple In of the low-voltage side rated current of the low-voltage plant transformer to be avoided is calculated according to the maximum value Iop of the low-voltage side rated current of the low-voltage plant transformer to be avoided and the rated current of the circuit breaker, and the formula is:

[0090] Avoid the In multiple of the rated current of the low-voltage side of the low-voltage transformer = Iop / rated current of the circuit breaker;

[0091] The reliability coefficient Krel in actual measurement is determined, and the maximum value Iop in actual measurement is calculated according to the normal operating single-phase load current, and the formula is as follows:

[0092] The maximum value Iop in actual measurement = the reliability coefficient Krel in actual measurement / (single-phase load current in normal operation of section a + single-phase load current in normal operation of section b);

[0093] The In multiple in the actual measurement is calculated according to the maximum value Iop in the actual measurement and the rated current of the circuit breaker, and the formula is:

[0094] The In multiple in actual measurement = the maximum value Iop in actual measurement / rated current of circuit breaker.

[0095] In the setting calculation of the action time constant, the following two principles should be considered in the setting calculation of the fixed-time action time: Calculate in coordination with the longest action time of the lower protection. Calculate according to the maximum self-starting time of the motor on the PC segment. The action time is the sum of the maximum values ​​of the above time, and the step time can be 0.2~0.3s. The calculation of the integral of the time constant of the inverse time action characteristic is based on the selected inverse time characteristic and is calculated in coordination with the lower protection.

[0096] Optionally, the setting calculation method for short-time overcurrent protection is as follows:

[0097] The operating current can be calculated as follows and the maximum value is taken:

[0098] Cooperate with the maximum operating current of the lower level instantaneous or short-time delay protection, that is:

[0099] Iop=Kco*Iopmax

[0100] Kco is the coordination coefficient, which is between 1.15 and 1.20; Iopmax is the maximum primary value of the self-starting current of the motor.

[0101] Action time setting calculation: The fixed-time action is calculated in coordination with the longest action time of the lower-level short-time delay protection. The inverse time action time is set. According to the selected inverse time characteristic, it is calculated in coordination with the next level of protection. If it cannot be coordinated with the next level of protection, this protection will be exited.

[0102] Sensitivity check: The sensitivity coefficient of the two busbars in the PC section should not be less than 2.

[0103] Optionally, the operation mode includes:

[0104] In the first operation mode, 2GB is powered via circuit breaker 002;

[0105] In the second operation mode, 3GB is supplied with power through Section II via 020 circuit breaker;

[0106] In the third operation mode, 4GB is supplied with power through the 020 circuit breaker via Section II;

[0107] In the fourth operation mode, 0B supplies power through section IV via circuit breaker 043;

[0108] The calculating of the factory power set value according to the nameplate parameters comprises:

[0109] Determine the calculation reference capacity, calculate the reference voltage, and calculate the 7B short-circuit reactance per unit value according to the maximum value of the rated voltage and the transformer capacity. The formula is:

[0110] 7B short-circuit reactance per unit value = maximum value of rated voltage × calculation base capacity / transformer capacity;

[0111] According to the short-circuit impedance of the transformer used in the operation mode and the transformer capacity, the corresponding short-circuit reactance per unit value on the bus section I is calculated. The formula is:

[0112] The unit value of short-circuit reactance on section I busbar = short-circuit impedance × calculated benchmark capacity / transformer capacity.

[0113] Optionally, the method further includes:

[0114] The smallest per-unit short-circuit reactance value on the bus section I under each operation mode is taken as the per-unit short-circuit reactance value of the bus section in the maximum operation mode, and the largest per-unit short-circuit reactance value on the bus section I under each operation mode is taken as the per-unit short-circuit reactance value of the bus section in the maximum operation mode;

[0115] According to the busbar short-circuit reactance standard value in the maximum operation mode, short-circuit impedance and transformer capacity, the transformer low-voltage side short-circuit reactance under the maximum operation mode of the power plant section I is calculated. The formula is:

[0116] The short-circuit reactance of the transformer low-voltage side under the maximum operation mode of the power supply section I of the auxiliary power supply = short-circuit impedance × calculated reference capacity / transformer capacity + the per-unit value of the busbar short-circuit reactance under the maximum operation mode;

[0117] In this embodiment, the per-unit value of the busbar short-circuit reactance in the maximum operation mode refers to the reactance value when a short circuit occurs on the busbar under the maximum operation mode of the power system, which is expressed as a per-unit value. The per-unit value is a relative value used to compare electrical parameters under different devices or different conditions, and is calculated by dividing the actual value by the reference value. For reactors, the calculation of the per-unit value is usually based on the rated voltage and rated current. In the power system, the calculation of the per-unit value of the short-circuit reactance involves the system reactance, the overhead line reactance, and the power transformer reactance.

[0118] Optionally, the three-phase short-circuit current on the low-voltage side of the transformer under the maximum operation mode of the power supply section I of the plant can be calculated based on the short-circuit reactance on the low-voltage side of the transformer under the maximum operation mode of the power supply section I of the plant, the reference capacity and the reference voltage, and the formula is:

[0119]

[0120] According to the busbar short-circuit reactance standard value in the minimum operation mode, short-circuit impedance and transformer capacity, the transformer low-voltage side short-circuit reactance in the minimum operation mode of the power plant section I is calculated. The formula is:

[0121] The short-circuit reactance of the transformer low-voltage side under the minimum operation mode of the power supply section I = short-circuit impedance × calculated reference capacity / transformer capacity + the per-unit value of the busbar short-circuit reactance under the minimum operation mode;

[0122] According to the short-circuit reactance of the transformer low-voltage side under the minimum operation mode of the power plant section I, the reference capacity and reference voltage are calculated to calculate the two-phase short-circuit current on the low-voltage side of the transformer under the minimum operation mode of the power plant section I. The formula is:

[0123] The two-phase short-circuit current on the low-voltage side of the transformer under the minimum operating mode of the plant power section I = calculated reference capacity / (2×short-circuit reactance on the low-voltage side of the transformer under the minimum operating mode of the plant power section I×calculated reference voltage).

[0124] In a possible embodiment, the calculated short-circuit reactance per unit value is shown in Table 3.

[0125]

[0126] Table 3

[0127] Optionally, the method further includes:

[0128] Determine the reliability coefficient Krel and excitation inrush current coefficient of the current quick-break, and calculate the three-phase short-circuit current at the low-voltage side outlet to be avoided based on the three-phase short-circuit current on the low-voltage side of the transformer under the maximum operating mode of plant power section I and the current transformer ratio on the high-voltage side of the low-voltage plant transformer.

[0129] In this embodiment, each branch of the low-voltage side of the high-voltage plant transformer can be provided with two-stage overcurrent protection as a backup protection for the interphase short-circuit fault of the branch bus and adjacent components. The setting calculation method of the time-limited current quick-break protection is: a) Setting calculation of the action current constant value. The action current constant value can be calculated as follows and the maximum value is taken: I) Setting according to the sum of the self-starting currents of the motors connected to the branch bus that need to participate in the self-starting, that is:

[0130] Avoid the three-phase short-circuit current at the low-voltage side outlet = the reliability coefficient of the current quick-break Krel × the three-phase short-circuit current at the low-voltage side of the transformer under the maximum operation mode of the power supply section I / the current transformer ratio at the high-voltage side of the low-voltage power supply transformer;

[0131] Krel is 1.15~1.2;

[0132] Optionally, the sensitivity coefficient Ksen is calculated based on the three-phase short-circuit current at the low-voltage side outlet and the two-phase short-circuit current at the low-voltage side of the transformer under the minimum operation mode of the power supply stage I. The formula is:

[0133] Sensitivity coefficient Ksen = two-phase short-circuit current on the low-voltage side of the transformer under the minimum operating mode of plant power section I / (current transformer ratio on the high-voltage side of the low-voltage plant transformer × three-phase short-circuit current at the low-voltage side outlet).

[0134] Under the minimum operating mode, the two-phase metallic short-circuit current of the high and low-voltage side branches of the transformer is converted to the high-voltage side to obtain the two-phase short-circuit current on the low-voltage side of the transformer under the minimum operating mode of the plant power section I.

[0135] In order to implement the above-mentioned embodiment, the present application also proposes a relay protection setting calculation device for a factory power system. Figure 2 This is a schematic diagram of the structure of a relay protection setting value calculation device for a power plant system provided in an embodiment of the present application. Figure 2 As shown, the device comprises:

[0136] The parameter acquisition module 210 is used to obtain the nameplate parameters of the transformers related to the factory power system and the main self-starting load table of the power supply system;

[0137] The first calculation module 220 is used to calculate the power supply system set value according to the main self-starting load table of the power supply system, wherein the power supply system set value includes: avoiding the maximum value Iop and In multiples of the rated current on the low-voltage side of the low-voltage plant transformer, and the maximum value Iop and In multiples of the measured normal load current, wherein the In multiple is the multiple relationship between the rated current and the actual operating current;

[0138] The second calculation module 230 is used to calculate the factory power setting value according to the nameplate parameters, wherein the factory power setting value includes the per unit value of the short-circuit reactance on the bus under various operating modes, the short-circuit reactance on the low-voltage side of the transformer, the three-phase short-circuit current on the low-voltage side of the transformer, current quick-break related parameters, time-limited overcurrent related parameters, and overload related parameters;

[0139] The summarizing module 240 is used to summarize the power supply system set value and the factory power set value.

[0140] In order to implement the above embodiments, the present application also proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method provided by the above embodiments.

[0141] In order to implement the above embodiments, the present application also proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0142] In order to implement the above embodiments, the present application also proposes a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0143] The collection, storage, use, processing, transmission, provision and disclosure of user personal information involved in this application are in compliance with relevant laws and regulations and do not violate public order and good morals.

[0144] It should be noted that personal information from users should be collected for legitimate and reasonable purposes and should not be shared or sold outside of these legitimate uses. In addition, such collection / sharing should be carried out after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign the agreement / authorization including authorization of relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others who have access to personal information data comply with its privacy policy and procedures.

[0145] The present application is expected to provide an implementation scheme for users to selectively block the use or access of personal information data. That is, the present disclosure is expected to provide hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, the risk can be minimized by limiting data collection and deleting the data. In addition, when applicable, such personal information is de-identified to protect the privacy of the user.

[0146] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0147] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0148] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0149] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0150] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0151] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0152] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0153] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for calculating relay protection setting values ​​of a power plant system, characterized in that: The following steps are involved: Obtain the nameplate parameters of the transformers related to the plant power system and the main self-starting load table of the power supply system; The power supply system constant is calculated according to the main self-starting load table of the power supply system, wherein the power supply system constant includes: avoiding the maximum value Iop and In multiples of the rated current on the low-voltage side of the low-voltage plant transformer, the maximum value Iop and In multiples of the measured normal load current, and the In multiple is the multiple relationship between the rated current and the actual operating current; Calculate the factory power setting value according to the nameplate parameters, wherein the factory power setting value includes the per unit value of the short-circuit reactance on the bus under various operating modes, the short-circuit reactance on the low-voltage side of the transformer, the three-phase short-circuit current on the low-voltage side of the transformer, current quick-break related parameters, time-limited overcurrent related parameters, and overload related parameters; The power supply system set value and the factory power set value are summarized.

2. The method according to claim 1, characterized in that The nameplate parameters of the transformers related to the auxiliary power system include at least one of the following: Switch number, equipment name, transformer capacity, short-circuit impedance, rated voltage, rated current, current transformer ratio, zero-sequence CT ratio; The main self-starting load table of the power supply system includes at least one of the following: circuit breaker rated current, normal operating single-phase load current, main self-starting load name, main self-starting load power, and main self-starting load rated current.

3. The method according to claim 2, characterized in that The calculating of the power supply system constant value according to the main self-starting load table of the power supply system comprises: Determine the reliability coefficient Krel and feedback coefficient Kr of the long-time overcurrent protection, and calculate the maximum value Iop of the rated current on the low-voltage side of the low-voltage plant transformer according to the rated current. The formula is: Avoid the maximum value of the rated current on the low-voltage side of the low-voltage plant transformer Iop = rated current × reliability coefficient Krel / feedback coefficient Kr; The multiple In of the low-voltage side rated current of the low-voltage plant transformer to be avoided is calculated according to the maximum value Iop of the low-voltage side rated current of the low-voltage plant transformer to be avoided and the rated current of the circuit breaker, and the formula is: Avoid the In multiple of the rated current of the low-voltage side of the low-voltage transformer = Iop / rated current of the circuit breaker; The reliability coefficient Krel in actual measurement is determined, and the maximum value Iop in actual measurement is calculated according to the normal operating single-phase load current, and the formula is as follows: The maximum value Iop in actual measurement = the reliability coefficient Krel in actual measurement / (single-phase load current in normal operation of section a + single-phase load current in normal operation of section b); The In multiple in the actual measurement is calculated according to the maximum value Iop in the actual measurement and the rated current of the circuit breaker, and the formula is: The In multiple in actual measurement = the maximum value Iop in actual measurement / rated current of circuit breaker.

4. The method according to claim 3, characterized in that The operation mode includes: In the first operation mode, 2GB is powered via circuit breaker 002; In the second operation mode, 3GB is supplied with power through Section II via 020 circuit breaker; In the third operation mode, 4GB is supplied with power through the 020 circuit breaker via Section II; In the fourth operation mode, 0B supplies power through section IV via circuit breaker 043; The calculating of the factory power set value according to the nameplate parameters comprises: Determine the calculation reference capacity, calculate the reference voltage, and calculate the 7B short-circuit reactance per unit value according to the maximum value of the rated voltage and the transformer capacity. The formula is: 7B short-circuit reactance per unit value = maximum value of rated voltage × calculation base capacity / transformer capacity; According to the short-circuit impedance of the transformer used in the operation mode and the transformer capacity, the corresponding short-circuit reactance per unit value on the bus section I is calculated. The formula is: The unit value of short-circuit reactance on section I busbar = short-circuit impedance × calculated benchmark capacity / transformer capacity.

5. The method according to claim 4, characterized in that The method further comprises: The smallest per-unit short-circuit reactance value on the bus section I under each operation mode is taken as the per-unit short-circuit reactance value of the bus section in the maximum operation mode, and the largest per-unit short-circuit reactance value on the bus section I under each operation mode is taken as the per-unit short-circuit reactance value of the bus section in the maximum operation mode; According to the busbar short-circuit reactance standard value in the maximum operation mode, short-circuit impedance and transformer capacity, the transformer low-voltage side short-circuit reactance under the maximum operation mode of the power plant section I is calculated. The formula is: The short-circuit reactance of the transformer low-voltage side under the maximum operation mode of the power supply section I of the auxiliary power supply = short-circuit impedance × calculated reference capacity / transformer capacity + the per-unit value of the busbar short-circuit reactance under the maximum operation mode; According to the short-circuit reactance of the transformer low-voltage side under the maximum operation mode of the power supply section I, the reference capacity and reference voltage are calculated to calculate the three-phase short-circuit current of the transformer low-voltage side under the maximum operation mode of the power supply section I. The formula is: According to the busbar short-circuit reactance standard value in the minimum operation mode, short-circuit impedance and transformer capacity, the transformer low-voltage side short-circuit reactance in the minimum operation mode of the power plant section I is calculated. The formula is: The short-circuit reactance of the transformer low-voltage side under the minimum operation mode of the power supply section I = short-circuit impedance × calculated reference capacity / transformer capacity + the per-unit value of the busbar short-circuit reactance under the minimum operation mode; According to the short-circuit reactance of the transformer low-voltage side under the minimum operation mode of the power plant section I, the reference capacity and reference voltage are calculated to calculate the two-phase short-circuit current on the low-voltage side of the transformer under the minimum operation mode of the power plant section I. The formula is: The two-phase short-circuit current on the low-voltage side of the transformer under the minimum operating mode of the plant power section I = calculated reference capacity / (2×short-circuit reactance on the low-voltage side of the transformer under the minimum operating mode of the plant power section I×calculated reference voltage).

6. The method according to claim 5, characterized in that The method further comprises: Determine the reliability coefficient Krel and the excitation inrush current coefficient of the current quick-break, and calculate the three-phase short-circuit current at the low-voltage side of the transformer under the maximum operation mode of the power supply section I and the current transformer ratio on the high-voltage side of the low-voltage power supply transformer to avoid the three-phase short-circuit current at the low-voltage side outlet. The formula is: Avoid the three-phase short-circuit current at the low-voltage side outlet = the reliability coefficient of the current quick-break Krel × the three-phase short-circuit current at the low-voltage side of the transformer under the maximum operation mode of the power supply section I / the current transformer ratio at the high-voltage side of the low-voltage power supply transformer; The sensitivity coefficient Ksen is calculated based on the three-phase short-circuit current at the low-voltage side outlet and the two-phase short-circuit current at the low-voltage side of the transformer under the minimum operation mode of the power supply stage I. The formula is: Sensitivity coefficient Ksen = two-phase short-circuit current on the low-voltage side of the transformer under the minimum operating mode of plant power section I / (current transformer ratio on the high-voltage side of the low-voltage plant transformer × three-phase short-circuit current at the low-voltage side outlet).

7. A relay protection setting value calculation device for a power plant system, characterized in that: include: Parameter acquisition module, used to obtain the nameplate parameters of the transformers related to the plant power system and the main self-starting load table of the power supply system; The first calculation module is used to calculate the power supply system set value according to the main self-starting load table of the power supply system, wherein the power supply system set value includes: avoiding the maximum value Iop and In multiples of the rated current on the low-voltage side of the low-voltage plant transformer, and the maximum value Iop and In multiples of the measured normal load current, wherein the In multiple is the multiple relationship between the rated current and the actual operating current; A second calculation module is used to calculate the factory power setting value according to the nameplate parameters, wherein the factory power setting value includes the per unit value of the short-circuit reactance on the bus under various operating modes, the short-circuit reactance on the low-voltage side of the transformer, the three-phase short-circuit current on the low-voltage side of the transformer, current quick-break related parameters, time-limited overcurrent related parameters, and overload related parameters; A summarizing module is used to summarize the power supply system set value and the factory power set value.

8. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 6 when executed by a processor.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 6 when being executed by a processor.

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