Vector jump protection function block description
Contents
1. EURO PRO TT Vector jump protection function block description HE es aa IED EP Vector jump protection User s manual version information Version Date Modification Compiled by Version 1 0 07 03 2012 First edition Petri VERSION 1 0 2 10 IED EP Vector jump protection CONTENTS 1 Vector jump protection function ss 4 del APPICAUON Esten eneen eerd 4 1 2 Mode of operation eran cnrrsneeernen eren eiaa a aie annen kn da annee 4 1 3 Structure of the vector jump protection algorithm nennen ennen enen ennnenennenen 5 1 3 1 The Fourier calculation isa 7 1 3 2 The symmetrical component calculation 7 1 3 3 The frequency calculation 7 1 3 4 The vector jump calculation 8 1 3 5 Thedecision OGIER dede ten leeds Gecteed ened 8 1 4 Technical SUMMATY erneer nergens ihinniteestihe ntm tiihnminterelteentitenttietes 9 1 4 1 Technical data ssssnneitihesiunes pese ed deena the aenedmebesien as 9 1 42 _Th parameters ss ssssss sienne een ne ett eme 9 1 4 3 Binary output status signal 10 1 4 4 Binary input status signals nnn anneer neenenenneerennnneerensnneenenenneenenenn 10 1 45 _Thefunecton BlOCk nzsn aren eere sinus ers enden evet er eenen teeven 10 VERSION 1 0 3 10 IED EP Vector jump protection 1 Vector jump protection function 1 1 Application The modern electric power systems include an increasing number2. Vector jump protection Modules for processing the input signals Fourier calculations These modules calculate the basic Fourier components of the phase voltages individually They are not part of the Vector jump function Positive sequence component calculation This module calculates the positive sequence voltage component based on the basic Fourier components of the phase voltages It is not part of the Vector jump function The magnitude of the positive sequent voltage component must be above the setting to enable the operation Negative sequence component calculation This module calculates the negative sequence voltage component based on the basic Fourier components of the phase voltages It is not part of the Vector jump function If the magnitude of the negative sequent voltage component is above the setting then an asymmetrical fault is supposed and the operation of the vector jump protection function is blocked Zero sequence component calculation This module calculates the zero sequence voltage component based on the basic Fourier components of the phase voltages It is not part of the Vector jump function If the magnitude of the zero sequent voltage component is above the setting then an asymmetrical fault is supposed and the operation of the vector jump protection function is blocked Frequency calculation This module calculates the frequency It is not pa
3. manual delivered with the device The accurate frequency measurement is performed by measuring the time period between two rising edges at zero crossing of a voltage signal For the acceptance of the measured frequency at least four subsequent identical measurements are needed Similarly four invalid measurements are needed to reset the measured frequency to zero The basic criterion is that the evaluated voltage should be above 30 of the rated voltage value The inputs of this module are assigned voltages channels according to the device configuration The output of this module is the calculated frequency in mHz units VERSION 1 0 7 10 IED EP Vector jump protection 1 3 4 The vector jump calculation The vector jump is the difference between the phase angle of the actual positive sequence component and the angle measured two network periods earlier A vector jump is detected if the absolute value of the calculated angle difference is above the setting value The inputs of this module are the data of the positive sequence voltage the frequency and the setting value of the vector jump The module stores the angles of the positive sequence voltage component in the memory for two network periods and calculates the raw vector jump This value is corrected if the frequency deviates from the rated network frequency The binary output of this module is true if the corrected vector jump is above the setting value 1 3 5 The deci
4. of small generators distributed generation system There can be several events in the network resulting that the small generators get disconnected from the system and the small generator supplies some consumer only remaining in the electric island unintended islanding If a small generator remains in an island with some consumers it is highly possible that the balance of the generated and consumed active and reactive power is not fulfilled This results changing of the frequency and or voltage accordingly the voltage vector position of the island is changing related to that of the disconnected grid An automatic reclosing of the circuit breaker at an unfavorable vector position can result high currents and serious damages To prevent these damages a protection is needed to detect the islanding and to disconnect the generator from the island One of the protection methods to detect unintended islanding is this vector jump protection function 1 2 Mode of operation When an unintended islanding occurs then the induced voltage inside the generator EMF may not change abruptly As a consequence on other locations within the island at the connection point of the generator at the bus bar or at the consumer a sudden change of the voltage vector can be detected It means that the vector jumps the time period of the sinusoid at the moment of the change can be shorter or longer than the previous or subsequent ones The main task
5. of the vector jump protection function 1 4 2 The parameters Enumerated parameters Parameter name Title Selection range Default Enabling or disabling the vector jump protection function VectJmp_ Oper EPar_ Operation Off On Off Table 1 2 The enumerated parameters of the vector jump protection function Integer parameters Parameter name Title Unit Min Max Step Default Starting phase difference level setting If the vector jum function generates a start signal p is above the setting value the VectJmp_PhDiff Par __ PhaseDiff Limit deg 5 25 1 10 Enabling positive voltage level setting If the measured is above the setting value the function enables the trip positive signal sequence voltage component VectUmp_UposLim_I Par_ Min PosSeg Voltage 10 100 1 30 Blocking negative sequence voltage level setting If the component is above the setting value the function bloc measured negative sequence ks the trip signal voltage VectUmp_UnegLim_IPar_ Max NegSeq Voltage 5 50 1 10 Blocking zero sequence voltage level setting If the measured voltage value the function blocks the trip signal is above the setting VectUmp_UoLim_ Par_ Max ZeroSeq Voltage 1 30 1 5 Table 1 3 Integer parameters of the vector jump protection function Timer parameter Parameter
6. he function must be enabled and the measured voltage must be above a minimum value For disabling the operation in case of low voltage an additional undervoltage binary input is provided VERSION 1 0 4 10 IED EP Vector jump protection If the network frequency is deviating from the nominal frequency then the voltage vector rotates slowly in the complex coordinate system As the vector jump detection function is based on comparison of the vectors of the actual and some previous states the vector rotation caused by the frequency deviation must be compensated For this purpose also the network frequency is measured continuously 1 3 Structure of the vector jump protection algorithm The scheme of operation of the vector jump protection function is shown in Figure 1 1 Fourier Symmetrical calculation component calculation Bin inputs Parameter Figure 1 1 Structure of the vector jump protection algorithm The inputs are e the three phase voltages e parameters e status signals NOTE in some device configurations also the residual voltage is measured separately In this case the zero sequence voltage component is calculated directly from the residual voltage For the actual realization please consult the configuration manual delivered with the device The output is e the binary output status signal for tripping The software modules of the vector jump protection function are VERSION 1 0 5 10 IED EP
7. lculation calculate the magnitudes and phase angles of the symmetrical components based on the theory of the component calculation The magnitude of the positive sequent component is used to enable the vector jump decision The magnitudes of the negative and zero sequence components can disable the vector jump decision The angle of the vector jump is calculated based on the angle of the positive sequence component and the angle of this component two periods before The rotation of the vector caused by the frequency deviation is compensated based on the frequency input NOTE in some device configurations also the residual voltage is measured separately In this case the zero sequence voltage component is calculated directly from the residual voltage For the actual realization please consult the configuration manual delivered with the device The inputs of this module are the basic Fourier components of the phase voltages UL1Four UL2Four IUL3Four The outputs of this module are the basic Fourier components of the positive negative and zero sequence voltage components given in terms of magnitudes and phase angles 1 3 3 The frequency calculation Depending on the hardware software configuration the frequency measurement is usually based on channel No 1 of the voltage input module In some applications the frequency is measured based on the weighted sum of the phase voltages For the actual realization please consult the configuration
8. name Title Unit Min Max Step Default Trip command pulse duration VectJmp_Pulse TPar_ Pulse Duration msec 150 500 1 150 Table 1 4 Timer parameter of the vector jump protection function VERSION 1 0 9 10 IED EP Vector jump protection 1 4 3 Binary output status signal The binary output status signal of vector jump protection function is shown in Table 7 5 Binary status signal Title Explanation VectUmp_Trip_Grl_ Trip Trip command of the function Table 1 5 The binary output status signals of the vector jump protection function 1 4 4 Binary input status signals Binary input signals The vector jump protection function has binary input signals which serve the purpose of disabling the function The conditions of disabling are defined by the user applying the graphic equation editor Binary status signal Title Explanation VectUmp_Blk_GrO_ Blk General blocking status signal External under voltage blocking VectUmp_UVBIk_GrO_ UVBIk status signal Table 1 6 The binary input signal of vector jump protection function 1 4 5 The function block The function block of vector jump protection function is shown in Figure 7 2 This block shows all binary input and output status signals that are applicable in the graphic logic editor Blk Trip UBlk Figure 1 2 The function block of vector jump protection function VERSION 1 0 10 10
9. of the vector jump protection function is to detect the unintended islanding when the generator with some consumer area is disconnected from the electric power grid The application of the vector jump function needs careful setting One of the problems is caused by the scenario when the balance of the electric power before and after the islanding is not changing significantly the generated and consumed power within the island is balanced Accordingly the limit for jump detection must be set to a low angle value but there is no guarantee that the islanding is detected by this method At the same time however a switching of a relatively large consumer can cause also a vector jump To prevent the unwanted trip in this scenario the setting limit for the vector jump angle should be selected large For vector jump detection the function must be enabled and the measured positive sequence voltage component must be above a minimum value If a fault occurs on the network the voltage vector jumps In this case a decision is needed if the role of the vector jump function is the fault protection or the fault is to be cleared at other locations of the network For excluding the operation in case of asymmetrical faults the negatives sequence and zero sequence voltage components must be supervised If they are above the setting asymmetrical fault is detected and the operation of the vector jump protection function is blocked For vector jump detection t
10. rt of the Vector jump function Based on the frequency value the calculated angle of the vector jump is corrected if the frequency deviates from the rated frequency Modules for vector jump detection and decision Vector jump calculation This module calculates the vector jump based on the Fourier components of the positive sequence voltage component Decision logic The decision logic module combines the status signals to generate the trip command of the function The following description explains the details of the individual components VERSION 1 0 6 10 IED EP Vector jump protection 1 3 1 The Fourier calculation These modules calculate the basic Fourier components of the phase voltages individually They are not part of the vector jump function they belong to the preparatory phase The inputs are the sampled values of the three phase voltages UL1 UL2 UL3 The outputs are the basic Fourier components of the analyzed voltages UL1Four UL2Four UL3Four NOTE in some device configurations also the residual voltage is measured separately In this case the zero sequence voltage component is calculated directly from the residual voltage For the actual realization please consult the configuration manual delivered with the device 1 3 2 The symmetrical component calculation These modules Positive sequence component calculation negative sequence component calculation zero sequence component ca
11. sion logic The decision logic module combines the status signals and parameters to generate the trip command of the function The performed logic is a simple one a trip command is generated if e The calculated vector jump is above the setting value e The magnitude of the positive sequence voltage component is above the setting value e The magnitude of the negative sequence voltage component is below the setting value e The magnitude of the zero sequence voltage component is below the setting value e The Blk binary input does not block the function and e The UVBIk binary input does not block the function The vector jump means that one network frequency period of the voltage sinusoid is shorter or longer than the previous periods or that of the subsequent periods This binary information must be prolonged to generate the trip pulse The minimum duration of the trip command is set by a parameter NOTE when checking the pulse duration please consider that the timer parameter defines the prolongation the operating time span is added to the pulse duration VERSION 1 0 8 10 IED EP Vector jump protection 1 4 Technical summary 1 4 1 Technical data Function Value Accuracy Pick up starting accuracy lt 0 5 Blocking voltage U gt 0 2Un lt 5 Operate time i Jump gt 2 setting SOE Minimum operate time 40 ms Pulse duration 150 500 ms lt 10 ms Table 1 1 Technical data
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