RU2316099C1 - Method of finding and liquidation of async mode in electric power by automatic control system - Google Patents

Abstract

FIELD: electric engineering.

SUBSTANCE: method can be used in aids of anti-alarm automatics of electric-power system. According to method, full resistance Z , calculated from local information (current and voltage in unit to be controlled) due to reduction its angle for correcting angle. Correcting angle is found during process through relation of increased reactive and active components of full resistance. Resistance is fixed till electric center of oscillations by using reactive component of transformed resistance Z. Active component of transformed resistance, which component is multiplied by electric transmission current, allows finding voltage Um in center. On base of voltage Um, angle δ_m of electric transmission is calculated on base trigonometric transform. From specified range of modeled voltage, range of angles of electric transmission is fixed beyond limits of working mode, in which mode the calculated angle more precisely corresponds to real one and async mode is revealed. By using angle of electric transmission and its derivatives and by defining location of center of oscillations in relation to unit to be controlled, threat, moment and fact of arise of async mode is fixed to form optimal action of automatic system.

EFFECT: improved adaptation; higher stability.

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Description

The invention relates to electrical engineering, in particular to emergency automation (PA) of electric power systems (ES), and can be used, for example, in automatic equipment for eliminating asynchronous operation (ALAR) or automatic equipment for preventing instability (APNU).

A known method for detecting asynchronous mode (AR) by an automation device based on fixing the transition of the phase angle φ between voltage and current in the ES unit from one region to another, provided that the angle δ of the power transmission equivalent to the ES relative to this node is significantly different from zero and is in the range of values, including δ = 180 ° [1, p.40-45]. In the automation device, the implementation of this method is carried out by fixing the reorientation of the power relay in the zone of operation of the resistance relay. In this case, the characteristic of the power relay corresponds to the boundary dividing the range of values of the angle φ, and the response of the resistance relay determines the required range of angles δ and the network section controlled by the placement of the electric swing center (ECC).

The disadvantage of this method is the low selectivity and stability of operation due to the dependence of φ on changes in the angle φ _{e of the} equivalent transmission resistance in the range (60-110) ° with a tight connection between the characteristics of the power relay and the calculated value of φ _e , as well as due to the uncertainty of the fixed range δ, caused by the ambiguity of its relationship with the measured resistance. For the same reason, the considered method does not allow to selectively identify the threat and the time of occurrence of AR.

The invention relates to a group of methods using direct simulation of the angle of power transmission 5 according to local information.

The known method [2], according to which the angle δ is modeled through the angle δ ₁₂ between the voltages at the ends of the monitored network section. These voltages themselves are obtained by modeling on the basis of current and voltage measured in the ES unit (the place where automation is connected). The moment of occurrence of AR is determined by the coincidence of the signs of the angle δ ₁₂ with the sign of its first and second derivatives with respect to time.

The location of the ECC in the controlled area is fixed when the resistance reaches the point of minimum voltage (TMN) in the range of values limited by the resistance from the measurement point to the boundaries of this area.

The obvious advantages of the method are the acceptable speed of response, the detection of AR at the time of its occurrence (δ <180 °), the minimum setpoints and their design support, which increases the stability of operation.

However, this method has several significant disadvantages:

1. Violation of selectivity in deep synchronous swings (SC) due to the non-linear dependence of δ ₁₂ on δ, leading to an earlier change in sign of the second derivative of δ ₁₂ with respect to the moment of synchronism violation.

2. Violation of selectivity at close external ARs due to the difference between the real angle φ _e and the one specified as a constant (the line resistance angle φ _{l is} proposed).

3. Lack of adaptability to the structure adjacent to the controlled network node, because its interconnectedness, the presence of intermediate taps and power inflows dramatically reduce the modeling capabilities.

4. Limited response speed (AR threat is not detected), which limits the choice and reduces the effectiveness of control actions (HC) by the automation device.

The closest in technical essence and the achieved results to the claimed method is a method for identifying and eliminating an asynchronous mode in an electric power system using an automation device [3]. The method consists in measuring currents and voltages in the power transmission node, converting the measured values into current and voltage vectors, determining, based on the information about the resistances of the two-machine power transmission equivalent circuit, the modules and angles of voltage vectors in the ES nodes limiting the ECC placement area, forming voltage trajectories in the AR the measurement node and the nodes limiting the controlled zone relative to the selected coordinates, the calculation of the complex values of the centers and radii of the arcs of circles forming these the trajectory, determining, according to these values of the transmission angle δ, between the EMF vectors of the equivalent generators of the two-machine equivalent circuit of the ES, comparing the obtained values of δ with the preset settings and fixing the AR according to the results of this comparison, calculating for each trajectory a parameter in the form of the ratio of the module of the circle radius vector to its vector module center, comparing the specified parameters for the stress trajectories at the boundaries of the controlled zone and in the measurement node, fixing the hit of the ECC on the transmission section for which dynes parameter is greater and the other smaller one, and in case of equality of the parameters of the node voltage path unit is fixed ETSK entering this node.

In addition, when the critical angle δ _{cr is} used as the setpoint, the transmission angle δ is calculated from its change outside the operating mode angles, the mutual sliding of the EMF vectors of the equivalent generators (the first derivative of δ in time) and the derivative of sliding (second derivative of δ in time) and by changing the sign of the derivative of the slip, the presence of AR in the ES is recorded.

The described method has significant disadvantages.

The first drawback is the lack of adaptability to the structure of the controlled area adjacent to the network measurement node. Strengthening the multiplicity of the network and the variability of the design schemes, the presence of intermediate taps and power inflows make it difficult or impossible to simulate with acceptable accuracy the voltages in the nodes that bound the controlled area. At the same time, the reliability of calculating the angle δ of the power transmission and determining the zone of placement of the ECC decreases.

The second drawback is the complexity of the procedure for calculating δ, which, in addition to modeling stresses, includes steps that introduce an additional error that is difficult to predict when the circuit-mode conditions change during the AR.

First of all, these are the stages of formation of stress trajectories in AR along arcs of circles and determination of the complex values of their centers and radii. Here, the error is related to the number of measurements for each arc. However, their increase reduces the detection rate of AR and enhances the influence of fluctuations in the ratio of EMF equivalent generators.

In general, these shortcomings adversely affect the selectivity and stability of the method, and also limit its use in networks of complex configuration.

In addition, the lack of detection of AR at the stage of its threat limits the ability of automation to effectively eliminate AR by increasing the intensity of hydrocarbons.

The task to which the stated proposal is directed is to increase adaptability, selectivity, and stability of functioning.

The technical result obtained is manifested in a decrease in the number of failures, unnecessary and false positives of automation (for example, ALAR), where this invention can be used, as well as an increase in the efficiency of hydrocarbons carried out by this automation. This technical result reduces the damage from possible accidents in modern multi-connected power systems.

The problem is solved in that in a method for identifying and eliminating an asynchronous mode in an electric power system, an automation device consisting in measuring currents and voltages in a power transmission unit, converting the measured values into voltage and current vectors, determining a transmission angle between electromotive force vectors of equivalent generators of a two-machine equivalent circuit power systems, comparing the obtained values with preset settings, determining the position of the electric swing center, determining the deficient and excess parts of the power system in an asynchronous mode, calculating the first and second derivatives of the power transmission angle with respect to time when its values are in the specified range outside the working mode angles, using the change in the sign of the second derivative as a sign of the occurrence of the asynchronous mode, and shaping the action of automatic detection and elimination asynchronous mode according to the results of comparing the angle of power transmission with preset settings, additionally through the ratio of vectors n Of voltages and currents, the impedance is calculated and the parameters characterizing it, including the modulus, angle, active and reactive components, are calculated, the correction angle is calculated as the inverse tangential function of the ratio of the increments of the reactive and active components of the impedance at time intervals between successive calculations of their current values, and the impedance is converted by reducing its angle by a correction angle, the active and reactive components of the converted resistance are calculated; They simulate the voltage as the product of the active component of the converted resistance by the absolute value of the power transmission current, determine the angle of transmission through the doubled inverse cosine function of the modeled voltage assigned to the specified voltage, fix the sign of the modeled voltage at the moment of its value entering the specified range corresponding to the specified range of transmission angle, increase by 2π the preset settings of the negative sign with the same fixed sign of the model voltage, if the values of the reactive component of the converted resistance are within the specified limits, indicating the placement of the electric swing center in the controlled section of the network, the threat of an asynchronous mode is detected by comparing it with the settings functionally related to the first time derivative of the transmission angle in accordance with the phase “slip-angle” trajectories, fix the moment of occurrence of the asynchronous mode when the second derivative of the angle changes sign power transmission in time in the direction of coincidence with the signs of its first derivative and simulated voltage, determine the existence of an asynchronous mode by comparing the angle of transmission with other constant settings, and depending on the stage of development of the asynchronous mode, form the optimal action of automation in order to prevent and eliminate the asynchronous mode in power system for asynchronous operation with acceleration with a positive sign of the first derivative of the angle of transmission over time, and for asynchronous Foot braking mode when it is a negative sign.

A comparative analysis of the essential features of the proposed technical solution and the essential features of analogues and prototype indicate its compliance with the criterion of "novelty."

The essential features of the distinguishing part of the formula of the invention solve the following functional tasks:

1. The set of signs "... in addition, through the ratio of the voltage and current vectors, the impedance is calculated and the parameters characterizing it, including the modulus, angle, active and reactive components, the correcting angle is calculated as the inverse tangential function of the ratio of the increments of the reactive and active components of the impedance the time intervals between successive calculations of their current values, convert the impedance by reducing its angle by a correction angle ... "allows you to calculate drain common complex parameter (transformed impedance), on which the components can be determined accurately enough power angle δ and the section AP in any circuit-operation conditions, regardless of the angle of power equivalent resistance.

2. The signs "... calculate the active and reactive components of the converted resistance, calculate the simulated voltage as the product of the active component of the converted resistance by the absolute value of the power transmission current, determine the transmission angle through the doubled inverse cosine function of the simulated voltage assigned to the given ..." allow get the parameters that determine the resistance to the ECC modulo and direction of measurement (the magnitude and sign of the reactive component of the converted of resistance), the voltage at ETSK (simulated voltage) and the angle transmission through a simple trigonometric function of the voltage in ETSK.

3. The signs "... fix the sign of the simulated voltage at the moment of its value entering the specified range corresponding to the set range of transmission angles, increase the set negative sign by 2π with the same fixed sign of the simulated voltage ..." allow to obtain the range of angles δ for the limits of the operating mode, in which the calculated values of the transmission angle and the reactive component of the converted resistance with acceptable accuracy correspond to the real values of the angle δ and the resistance down to the ECC, respectively, and also allow you to adapt the settings to the sign of this angle.

4. The sign "... if the values of the reactive component of the converted resistance are within the specified limits, indicating the placement of the electric swing center on the controlled section of the network ..." allows you to record the hit of the ECC on the controlled section for a given section of the AR.

5. The sign "... identify the threat of an asynchronous mode according to the results of comparisons with the settings functionally related to the first derivative of the power transmission angle in time in accordance with the slip-angle phase paths ..." allows you to detect the threat of the occurrence of AR and proactively form the device automation necessary HC.

6. The sign “... record the moment of occurrence of the asynchronous mode when the sign of the second derivative of the angle of transmission over time changes in the direction of coincidence with the signs of its first derivative and the simulated voltage ...” allows you to create additional HC for its elimination at the time of occurrence of the AR.

7. The set of signs "... determine the fact of the existence of an asynchronous mode according to the results of comparing the transmission angle with other constant settings, and depending on the stage of development of the asynchronous mode, the optimal action of automation is formed to prevent and eliminate the asynchronous mode in the power system for asynchronous operation with acceleration at the positive sign of the first derivative of the angle of transmission over time, and for the asynchronous mode with braking when it is negative ... "allows increase of HC in the transition from one AP to another stage (growth angle δ), and change their composition and intensity depending on the relative slip sign.

для контролируемого узла и преобразованного сопротивления

а также показаны составляющие этих сопротивлений и касательная к годографу

при его минимальном значении. На фиг.4 и 5 показаны зависимости активной и реактивной составляющих (R_m, Х_m) преобразованного сопротивления от угла электропередачи δ. На фиг.6 показано изменение моделируемого напряжения в зависимости от угла δ. На фиг.7 приведена кривая, показывающая изменение корректирующего угла Δφ в функции угла электропередачи. На фиг.8 приведена зависимость вычисляемого угла δ_m электропередачи от реального угла δ.Figure 1 presents the equivalent circuit of the power transmission for a two-machine AR relative to the monitored node 0. Figure 2 shows a vector diagram in relation to this equivalent circuit. Figure 3 shows the hodographs of the impedance

for controlled node and transformed resistance

and also shows the components of these resistances and the tangent to the hodograph

at its minimum value. Figures 4 and 5 show the dependences of the active and reactive components (R _m , X _m ) of the converted resistance on the transmission angle δ. Figure 6 shows the change in the simulated voltage depending on the angle δ. 7 is a curve showing the change in the correction angle Δφ as a function of the transmission angle. On Fig shows the dependence of the calculated angle δ _m power transmission from the actual angle δ.

и

(α=0,35) в о.е., а также заданных углах этих сопротивлений (φ₁=φ₂=70°).All the curves shown in figures 3-8 correspond to the equivalent circuit (figure 1) for a given ratio of EMF E ₁ and E ₂ (k = 1, 2) and resistances

and

(α = 0.35) in pu, as well as the given angles of these resistances (φ ₁ = φ ₂ = 70 °).

The essence of the proposed method is as follows.

The combination of distinctive features allows us to solve a number of basic tasks:

1. Calculation with acceptable accuracy from the local information of the angle of transmission δ.

2. Determining the location of the ECC (section of the AR).

3. The consistent identification of the threat, the moment and the fact of the occurrence of AR in order to form with increasing intensity the optimal action of automation to eliminate AR.

в ТМН электропередачи, соответствующей ЭЦК в заданном диапазоне δ (от 90° до 270°) при двухмашинном АР.Detection of δ is carried out through the simulated voltage

in the TMN of a power transmission corresponding to an ECC in a given range of δ (from 90 ° to 270 °) with a two-machine AR.

The location of the ECC is determined by the absolute value of the resistance from the measurement point to the TMN, and the fact of the placement of the ECC to the left or to the right of the controlled area is fixed depending on the sign of this resistance.

In this regard, we first consider some relationships between circuit-mode parameters inherent in a two-machine AR.

и

по ее концам и сопротивлениями

и

от точек приложения этих ЭДС до контролируемого узла 0 с напряжением

и током I (фиг.1). На векторной диаграмме электропередачи (фиг.2) кроме упомянутых параметров показан вектор напряжения

в ТМН, совпадающий по направлению с осью, перпендикулярной вектору

При этом проекция U_m вектора

на эту ось, совпадающая по модулю с

может быть найдена какWith a two-machine AR, the energy system can be represented as an equivalent power transmission with EMF

and

at its ends and resistances

and

from the points of application of these EMFs to the controlled node 0 with voltage

and current I (figure 1). In the vector power transmission diagram (Fig. 2), in addition to the mentioned parameters, a voltage vector is shown

in TMN, coinciding in direction with the axis perpendicular to the vector

Moreover, the projection U _{m of the} vector

on this axis, coinciding modulo with

can be found as

и

γ - угол, дополняющий до 90° угол φ_э эквивалентного сопротивления электропередачи

where φ is the angle between the vectors

and

γ - angle complementary to 90 ° angle φ _e equivalent transmission resistance

и

с учетом угла электропередачи

можно определить U_m как высоту этого треугольника:Solving Triangle Vectors

and

taking into account the angle of power transmission

U _m can be defined as the height of this triangle:

where m = 2 · k / (1 + k ² ), if we denote k = E ₁ / E ₂ .

In the real range, k = 0.8–1.25 [1, p.19], the difference between m and 1 is no more than 2.5%. Therefore, in the operating range δ = (60 ÷ 300) °, this error can be neglected. Then

в контролируемом узле для однородной электропередачи можно вычислить следующим образом:Voltage

in a monitored node for homogeneous power transmission can be calculated as follows:

.where α = Z ₁ / Z _e ;

.

в ЭЦК определяется при α=α_ц=k/(k+1) [1, с.23]. При этом его проекция на ось, совпадающую с биссектрисой угла δ с учетом (4), равнаVoltage

in ECC is determined for α = α _c = k / (k + 1) [1, p.23]. Moreover, its projection onto the axis coinciding with the bisector of the angle δ, taking into account (4), is equal to

Therefore, in accordance with (3) and (5) and taking into account the fact that U _m.max and U _c.max differ by no more than ± 0.7% in the real range of E ₁ and E ₂ (0.9 ÷ 1.1 in pu) [1, p.17], it is possible _to use U _m instead of U _c .

по (1), можно с учетом (3) определить угол электропередачи по локальной информации:By computing

according to (1), taking into account (3), it is possible to determine the angle of power transmission from local information:

на ось, совпадающую с

:The resistance ΔZ to TMN can be determined through the projection ΔU of the vector

on the axis coinciding with

:

Obviously, ΔZ will have a positive sign when placing the TMN (ECC) to the right of node 0 and negative otherwise.

According to the proposed method, the impedance is calculated through the vector of voltages and currents at the measurement point and the parameters characterizing it (modulus Z, angle φ, active R and reactive X components):

в комплексной плоскости R, jX при k≠1 имеет в цикле АР форму окружности (фиг.3), причем угол φ_э минимального значения

сопротивления

соответствует углу φ_э эквивалентного сопротивления электропередачи и значению δ=180°.Hodograph

in the complex plane R, jX for k ≠ 1 has a circle shape in the AP cycle (Fig. 3), and the angle φ _{e of the} minimum value

resistance

corresponds to the angle φ _{e of the} equivalent transmission resistance and the value δ = 180 °.

Further, according to the method, the correction angle Δφ is calculated as the inverse tangential function of the ratio of the increments of the reactive dX and active dR of the impedance components:

, к оси R (фиг.3).At infinitely small increments, dX / dR is the derivative, and Δφ determines the slope of the tangent at the hodograph point corresponding to

, to the axis R (figure 3).

When calculating the inverse tangent function, the angle Δφ is determined in the range of ± 90 ° and then

This relation is valid for all hodograph points for k = 1 (hodograph is a straight line). In the real range of 0.8 <k <1.25, relation (11) can be used with an acceptable error in the range of angles δ outside the operating mode (90 ° <δ <270 °).

Then, according to the claims, the converted resistance and its components are calculated:

.where R _m and X _m - active and reactive components of the converted resistance

.

The simulated voltage U _{m is} calculated by the method as follows:

и его составляющие показаны на фиг.3.Hodograph

and its components are shown in figure 3.

When, taking into account (11), γ is replaced by -Δφ, we obtain the correspondence of formulas (1) and (15), as well as formulas (8) and (14).

Thus, in the range of angles 90 ° <δ <270 ° in the proposed method, through the components R _m and X _{m of the} converted resistance Z _{m, the} voltage U _{m is} calculated in the TMN, which practically coincides with the ECC, and the resistance ΔZ = X _m to this point. The angle δ _m corresponding to the transmission angle δ is calculated according to (6).

The adaptability of the method in a package of real circuit-mode conditions is manifested in the absence of dependence of the calculation results on changes in the angle φ _e and their acceptable error when k deviates from 1. This is illustrated by the dependences of R _m , X _m , U _m , Δφ and δ _m on the angle δ, shown in Fig.4 - Fig.8.

So, in the range of angles 100 ° <δ <260 ° outside the operating mode, where the detection of AR occurs, the deviation of X _m from Z _min does not exceed 4% of Z _e (Fig. 5), the deviations modulo Δφ and γ are no more than 8 °, and the deviation of δ _m from δ is within ± 15 °, decreasing almost to zero as δ approaches 180 °. A series of calculations with different parameters of the circuit confirms these figures.

After calculating the angle of electrical transmission δ and the resistance to the ESC through δ _m and X _m, respectively, are fixed according to the method, the sign of U _m at the moment when its values enter the set range of angles δ outside the operating mode.

This range meets the condition

where δ _gr is the angle defining the boundaries of the range (90 ° -120 °).

In view of (5), the range δ is fixed according to the established range U _m :

where U _cp is the operating voltage corresponding to δ _gr and shown in Fig.6.

The fixed sign U _m uniquely determines the sign of δ and the sign of mutual sliding s = dδ / dt. Since when the δ changes from 0 to -360 °, the calculated angle δ _m decreases from 360 ° to 0 (it is always positive), then the set negative sign settings should be increased by 2π.

The detection of AR at different stages occurs only when the ECC is placed on a controlled section of the network, when X _m values fall within the established range:

where X _up and X _down are the values of X _m defining the upper and lower bounds of the range.

At the earliest stage, the threat of AR is detected before stability is violated when δ is less than the critical value of δ _cr . In this case, δ _{m is} compared with the settings functionally related to the first derivative δ (δ _m ) in time (slip) in accordance with the slip-angle phase trajectories.

Boundary phase trajectories can be specified, for example, by an approximating function, as in [4, f.173 on p.144] with δ ₀ = 0. Then the mentioned settings for positive δ ⁺ _sr and negative δ ^- _sr values of δ are defined as follows:

where δ _cf - a certain value of δ that determines the approximation parameters (δ _cf ≈180 °); k ₁ is a constant coefficient that provides the greatest correspondence of phase trajectories and function (19).

The threat of AR is fixed with

The identification of the threat of AR occurrence at δ <δ _cr allows timely organization of the action of automation aimed at its prevention.

If the volume of control actions (HC) or the time of their implementation was insufficient, then according to the method, the moment of occurrence of AR (δ = δ _cr ) is recorded for the formation of additional HC for resynchronization (PCX).

The moment of occurrence of the AR is fixed by changing the sign of the second derivative of the angle δ _m in time in the direction of coincidence with the signs of its first derivative and the simulated voltage U _m :

Since the sign of U _m at δ <180 ° always coincides with the sign of δ (see Figs. 6 and 8), condition (22) is adequate to condition (5) in [2].

Next, the fact of the existence of AR in the second half of the oscillation cycle (δ> 180 °) is revealed, comparing δ _m with constants that are independent of the parameters of the AR settings:

where δ ⁺ _cp1 and δ ^- _cp1 are constant settings for positive and negative values of δ.

Confirmation of the existence of AR in the first and subsequent cycles indicates the lack of effectiveness of PCX measures and allows you to direct the action of automation on the division of the system (DS) through a given number of cycles of AR in order to eliminate it.

The nature and volume of hydrocarbons formed by automation is set depending on the sign of mutual sliding (the first derivative of the angle δ _m with respect to time), as, for example, in standard automation [1, p. 45].

The implementation of the considered method according to conditions (6), (9) - (15), where simple mathematical operations and trigonometric functions are used, as well as according to logical conditions (17) - (24) does not cause difficulties on the basis of modern microprocessor devices, for example, ALAR- Ts [2] or ALAR-M [3].

.Thus, the proposed method has a high selectivity and stability of operation in comparison with the prototype, due to a more accurate calculation of the transmission angle δ through the simulated angle δ _m and the resistance to the ECC through the reactive component X _m resistance

.

The adaptability of the method removes the restrictions on its use in complex, multiply connected networks due to the refusal to simulate stresses in adjacent nodes of ES and from binding operating conditions to a given value of the angle φ _e .

Information sources

1. Gonik Y.E., Iglitsky E.S. Automatic elimination of asynchronous mode. - M.: Energoatomizdat, 1988 .-- 112 p.: Ill.

2. Patent RU 2199807 C2. A method for detecting asynchronous mode / ed. M.A. Edlin, P.Ya. Katz, A.V. Strukov, MKP H02J 3/24. Publ. 02/27/2003.

3. Patent RU 2204807 C2. A method for identifying and eliminating an asynchronous mode in an electric power system using an automation device / ed. I.V. Yakimets, A.A. Nalevin, A.V. Vaganov, MKP H02J 3/24. Publ. 05/20/2003.

4. Rosenblum F.M. Measuring bodies of emergency automation of power systems. - M .: Energoatomizdat, 1981. - 159 p.: Ill.

Claims (1)

A method for detecting and eliminating the asynchronous mode in an electric power system using an automation device, which consists in measuring currents and voltages in a power transmission node, converting the measured values into voltage and current vectors, determining the angle of transmission between the electromotive force vectors of the equivalent generators of a two-machine power system equivalent circuit, comparing the obtained values with the set ones settings, determining the position of the electric swing center, determining the deficit and excess hours power systems in asynchronous mode, calculating the first and second derivatives of the angle of transmission over time when its values are in the specified range outside the angles of the operating mode, using the change in sign of the second derivative as a sign of the occurrence of the asynchronous mode and forming the action of the automatic detection and elimination of the asynchronous mode according to the results comparing the angle of power transmission with preset settings, characterized in that it is additionally through the ratio of the voltage and current vectors in calculate the impedance and its characteristic parameters, including modulus, angle, active and reactive components, calculate the correction angle as the inverse tangential function of the ratio of the increments of the reactive and active components of the impedance at time intervals between successive calculations of their current values, convert the impedance by reducing it angle to the correcting angle, calculate the active and reactive components of the converted resistance, calculate simulated on the voltage as the product of the active component of the converted resistance by the absolute value of the power transmission current, determine the transmission angle through the doubled inverse cosine function of the simulated voltage, assigned to the given, fix the sign of the simulated voltage at the moment of its values entering the specified range corresponding to the specified range of transmission angles, increase by 2π setpoints of the negative sign with the same fixed sign of the simulated voltage, if the values of the reactive component of the converted resistance are within the specified limits, indicating the placement of the electric swing center in the controlled section of the network, the threat of an asynchronous mode is revealed by comparing with settings functionally related to the first time-derivative of the transmission angle in accordance with the slip sliding paths angle ”, fix the moment of occurrence of the asynchronous mode when the sign of the second derivative of the angle of transmission over time in the direction of coincidence with the signs of its first derivative and simulated voltage, determine the existence of an asynchronous mode by comparing the angle of transmission with other constant settings, and depending on the stage of development of the asynchronous mode, form the optimal action of automation in order to prevent and eliminate the asynchronous mode in the power system for asynchronous mode with acceleration with a positive sign of the first derivative of the angle of transmission over time, and for asynchronous mode with a brake zheniem when it has a negative sign.

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