RU2823576C1 - Method of forming adaptive actuation parameters in relay with one summed value - Google Patents

Abstract

FIELD: electric power industry.

SUBSTANCE: invention relates to electric power engineering, in particular to formation of actuation parameters for protections with one supplied value. According to the invention, the network mode change is determined based on the values of the phase currents or voltages of the filter of orthogonal components, determined from the readings of the current instantaneous values of the currents or voltages, and according to the stored data of the previous mode, the protection settings are formed, which are adaptive to the load mode of the power system, directly in the protection terminal.

EFFECT: providing maximum sensitivity of protection in the whole range of operating modes of a power facility.

1 cl, 1 dwg

Description

The invention relates to the electric power industry, in particular to relay protection and automation (RPA) of power facilities in complex and transient modes. Solves the problem of forming adaptive response parameters in the protection terminal based on the results of measuring values in the mode preceding the accident.

According to [1], it is necessary to install relay protection and automation devices (RPA) at power facilities. The calculation of response parameters (settings) of relay protection and automation devices is carried out according to guidelines developed for each type of protection (for example, [2]). The bulk of the calculation of settings is the determination and calculation of operating modes of the power system, characteristic of the protections under consideration. The variety of design modes practically excludes obtaining optimal settings that ensure selectivity of action in all modes. The problem of using optimal response parameters in adaptive protections, in which response parameters are determined based on the current previous load mode, is effectively solved.

The closest to the claimed technical solution is the method described in [3], which considers an adaptive method for generating settings for protection.

However, in [3] a method is described in which the calculation of the mode and the formation of settings for the new mode occur on an external computer, from which the data is transferred to the protection device. It should be noted that in emergency mode, a number of processes occur one after another, for example, a short circuit in load mode, a transition from one type of fault to another, a phase disconnection, unsuccessful automatic phase reconnection, a three-phase disconnection, a line reconnection, a short circuit in transit with transition to a new load mode. For each of these modes it is necessary to obtain a new group of settings in the protection device. When changing modes quickly, a situation may arise when the protection operates with response parameters that are irrelevant for the current mode.

The purpose of the invention is the continuous formation of protection response parameters adaptive to the current mode in the protection terminal. This goal is achieved by introducing a module into the functional logic of protection, which, upon activation of the triggering element, instantly generates new response parameters (setpoints), adaptive to the newly emerged mode. The protection relay response parameters are formed from the phase complex values of the current and previous load conditions Where obtained from instantaneous measured values of current and voltage of the current i _v , u _v and the previous modes i _{v previous} , u _{v previous} from the output of the orthogonal components filter. Based on the complex values of phase quantities, respectively, in the filters of symmetrical and emergency components, symmetrical components are determined where μ=1,2,0 and emergency symmetrical components of currents and voltages.

The implementation of the method is illustrated in Fig. 1 block diagram of the logical module for generating the adaptive setpoint in the protection device. Block diagram of Fig. 1 contains the following functional channels and blocks: filter block of orthogonal components (OCF) of complex current values and voltage where v=A,B,C (element 1) and two identical channels for generating adaptive settings (elements 9 and 10), each of which includes a current symmetrical components filter unit (SCF) or voltage where μ=1,2,0 - index of current or voltage, respectively, direct, negative and zero sequences (element 2), emergency components filter unit (FAS) current values (item 3) or voltage values (element similar to element 3 in channel 10), memory block (element 4), block for generating adaptive response parameters (settings block, element 5), triggering element (software) of positive and negative sequence current relay (element 6), comparison block with adaptive setting (element 7), output signal of the current measuring element (element 8), channel for generating adaptive current settings (element 9), channel for generating adaptive voltage settings (element 10) and output signal of the voltage measuring element (element 11 ).

The method is carried out as follows.

The algorithm for calculating the adaptive setting assumes, based on the instantaneous values of currents i _v , or voltages u _v by the FOS block (element 1), the formation of orthogonal current components and voltage current mode, which enter the channels for generating adaptive current (element 9) and voltage (element 10) settings, respectively. The operating algorithms for the channels for generating adaptive current (element 9) and voltage (element 10) settings are identical. Next, we consider an algorithm based on the current channel (element 9).

Current current value in the channel for generating adaptive current settings (element 9) it simultaneously enters the FSS unit (element 2) and upon activation of the trigger (element 6) is stored in the memory module (element 4). Symmetrical current components from the FSS block enter the FAS block (element 3), at the output of which emergency current components are formed for example, according to algorithm [3]. Output values of emergency current components from the FAS unit (element 3) enter the software (element 6), which is triggered when the emergency components of the positive or negative sequence exceed predetermined settings, adjusted from the switching currents for the direct and unbalances arising from the current values in asymmetrical previous modes, for the negative sequence . The trigger element (element 6) performs the functions of a mode selector and its operation means the appearance of a new mode. In this case, new current parameters are stored and voltage in the memory block (element 4) and the formation of adaptive settings according to the parameters of the previous mode, which were previously recorded in the memory block (element 4). For example, for maximum current protection (overcurrent protection) in the settings block (element 5), adaptive settings will be generated based on the magnitude of phase currents and/or the magnitude of the positive sequence current:

Where

- respectively, the maximum effective values of phase currents and the value of positive sequence current;

To _ots - detuning coefficient; It is recommended, depending on the size of the switched load and the number of the protection stage, to take it equal to K _ots = 1.2÷2.0.

From the output of the setpoint block (element 5), the adaptive setpoint, calculated using formulas (1) or (2), is supplied to the input of the “Comparison with setpoint” block (element 7). The other inputs of this block from the FOS block (element 1) receive current phase current values or their symmetrical and emergency components.

The algorithm for calculating the adaptive setting based on the negative sequence current value for the software (element 6) or for the negative sequence relay (RTOP) will be as follows:

Where - current value of the emergency component of the negative sequence current;

- adaptive setting of the emergency component of the negative sequence current at the moment of mode change;

k _ots =1.2 - detuning coefficient;

k _in =0.95 - relay return coefficient;

I _2nb =k _nb ⋅I _{m precursor} - negative sequence unbalance current, formed based on the measurement results of the previous mode. It is possible to use a non-adaptive setting, calculated based on the currents of the maximum load mode: I _2nb =k _nb ⋅I _rab.max ;

- maximum value of phase currents;

k _nb = 0.05 - unbalance coefficient;

I _2ns =0 - in the emergency component there is no value due to the asymmetry of the previous load mode.

The peculiarity of emergency components is that IOs based on them are triggered both when the current surges and when it decreases, for example, when a short circuit is turned off. Therefore, an EUT based on emergency components must always be controlled by an additional negative sequence EUT, the setting of which is determined by the unbalance value calculated from the maximum load current:

where the coefficients for calculating formula (4) are taken equal to the coefficients of formula (3);

k _carried =0.03 - asymmetry coefficient of the previous mode.

Triggering of the EUT by negative sequence current will occur under the following conditions:

where Ω is a mathematical step (jump) function.

Thus, according to the principle of its operation, the proposed method makes it possible in real time to generate operating settings for relays with one supplied value, adaptive to the mode preceding the accident.

Information sources

1. Rules for electrical installations, 7th ed., approved. By Order of the Ministry of Energy of Russia dated July 8, 2002 No. 204.

2. Guidelines for relay protection." Issue 12. Zero sequence current protection against ground faults of 110-500 kV lines. Calculations M.: Energy, 1980. - 88 p.

3. Sharygin M.V., Kulikov A.L., Falkov A.A. Automation of calculations of adaptive multiparameter relay protection for reconfigurable distribution networks // Releyshchik. 2022. No. 1(42). pp. 12-16.

4. Patent 2035815 Russian Federation, MKI N02N 3/38. Method for isolating the emergency term of short circuit current / Yu.Ya. Lyamets, V.A. Efremov, V.A. Ilyin. Publ. 05/20/1995.

Claims (1)

A method for generating adaptive response parameters in a relay with one supplied value, characterized in that the response parameters for protecting power facilities are formed according to the values of the design operating modes of the power facility, characterized in that in order to ensure protection sensitivity parameters, a module for generating adaptive response parameters is introduced, which includes a block starting element, a memory block, a block for generating current settings and a setting comparison block, which is based on the output complex values of phase currents or voltages of the filter of orthogonal components, calculated by measuring the current instantaneous values of currents or voltages, and on the basis of the output values of the filter of orthogonal components by filters of symmetrical components and emergency components, complex values of symmetrical and emergency components are formed, the latter of which, when exceeding the values calculated from the unbalance values from the values of the previous mode, trigger the triggering element of the module for generating adaptive response parameters, from the output of which commands are simultaneously received to store the current complex ones in the memory block values of phase currents or voltages, their symmetrical and emergency components, and for the formation in the block for generating the current settings of adaptive response parameters based on the phase values of the current or voltage of the previous mode recorded in the memory block, their symmetrical and emergency components, which enter the settings comparison block, where the generated adaptive response parameters are compared based on phase complex values of current and voltage, their symmetrical and emergency components with similar values of the current mode coming from the filters of orthogonal, symmetrical and emergency components, and, if the current values exceed the previously generated adaptive response parameters, at the output In the setting comparison block, an operation signal appears, which is an output protection signal with adaptive operation parameters.

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