JP4874824B2 - Distance relay device - Google Patents

Description

  The present invention relates to a distance relay device used for protection of a power system.

  The distance relay is one of the most important relays among the various relays used to protect the electric power system, and it is a bus line from a short-circuit accident and a ground fault in the transmission line only with its own electricity information. And is widely used in power systems. However, as shown in, for example, Japanese Patent Application Laid-Open No. 2004-48855 (Patent Document 1), the conventional distance relay device uses the entire amount of voltage / current after failure (failure voltage current itself) to reach the failure point. Since the impedance is calculated, various measures are taken to prevent malfunctions due to system outages or heavy loads, and it is difficult to achieve high-speed relay operation (specifically, the main protective operation of conventional distance relays) The time is one cycle (50ms system is 20ms or more). Also, it is said that when the system breaks down or shakes, the stripping of the circuit breaker due to the malfunction of the distance relay device is the cause of the large-scale power outage of the power system. In the worst case, the system collapses. It can happen. A dedicated step-out relay device may be installed to eliminate system step-out.

JP 2004-48855 A (paragraph numbers 0002 to 0010)

  Conventional distance relays calculate the impedance up to the point of failure using the total amount of voltage / current after the failure (failure current / voltage itself) as described above. Various measures have been taken so that it is difficult to achieve high-speed relay operation. Further, the conventional distance relay device is easily affected by the magnitude of the ground resistance at the failure point.

  The present invention has been made in view of the above-described circumstances, and aims to realize high-speed relay operation.

  The distance relay device according to the present invention comprises a voltage time series instantaneous value sampled from a voltage and a current detected from the power system and a voltage / current measuring means for taking in the current time series instantaneous value, and a voltage rotation vector from the voltage time series instantaneous value. Voltage rotation vector change calculation means for calculating the change, current rotation vector change calculation means for calculating the current rotation vector change from the current time series instantaneous value, up to an assumed point that is a predetermined distance away from the detection location Starting voltage calculating means for calculating a starting voltage at the time of failure start of the assumed point using the transmission line impedance, the current rotation vector change amount and the bus voltage rotation vector change amount of the protection target line, the protection target line current and the bus voltage Pre-failure voltage calculation means for calculating a pre-failure voltage at the assumed point using the transmission line impedance up to the assumed point, and the start-up A failure determination means for determining a failure in the protected area by comparing the pressure and the voltage before the failure, the determination result in the failure determination means in the area, when the starting voltage is larger than the voltage before the failure The trip output to the circuit breaker of the line to be protected is output.

  The present invention provides a voltage time series instantaneous value sampled from a voltage and current detected from a power system and a voltage / current measuring means for taking in a current time series instantaneous value, and a voltage for calculating a voltage rotation vector change from the voltage time series instantaneous value. Rotation vector change calculation means, current rotation vector change calculation means for calculating current rotation vector change from current time-series instantaneous values, transmission line impedance and protection to an assumed point that is a predetermined distance away from the detection location Starting voltage calculation means for calculating a starting voltage at the time of failure start of the assumed point using the current rotation vector change and the bus voltage rotation vector change of the target line, the protection target line current and the bus voltage and the assumption point A pre-failure voltage calculating means for calculating a pre-failure voltage at the assumed point using a transmission line impedance; and the starting voltage and the pre-failure power And a fault breakdown determination unit for determining a fault in the protection zone by comparing with the circuit breaker of the protection target line when the start-up voltage is larger than the pre-failure voltage Since the trip output to is output, there is an effect that high-speed relay operation can be realized.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS. 1 is a diagram of a model system to be protected, FIG. 2 is a connection diagram showing an equivalent circuit for a rotation vector change in a short-circuit fault, FIG. 3 is a connection diagram showing an equivalent circuit for a rotation vector change in a ground fault, and FIG. 4 is a complex number. FIG. 5 is a diagram showing an example of a functional block diagram of a distance relay, FIG. 6 is a flowchart showing a failure determination processing flow, and FIG. FIG. 8 is a diagram showing a typical electric society EAST10 model system adopted at the time of performing a simulation simulation of relay operation, FIG. 8 is a diagram showing a voltage waveform of a certain case A at the time of executing the verification simulation, and FIG. FIG. 10 is a diagram illustrating a current waveform of case A, FIG. 10 is a diagram illustrating a phase A operation voltage waveform of a certain case A when a verification simulation is performed, and FIG. FIG. 12 is a diagram illustrating a current waveform of a certain case B when the verification simulation is performed, and FIG. 13 is a diagram illustrating a phase A operating voltage waveform of the certain case B when the verification simulation is performed. 14 is a diagram showing a voltage waveform of a certain case C when the verification simulation is performed, FIG. 15 is a diagram showing a current waveform of a certain case C when the verification simulation is performed, and FIG. 16 is a certain case when the verification simulation is performed. FIG. 17 is a diagram showing a phase A operating voltage waveform of C, FIG. 17 is a diagram showing a voltage waveform of a certain case D when the verification simulation is performed, FIG. 18 is a diagram showing a current waveform of a certain case D when the verification simulation is performed, FIG. 20 is a diagram showing an A-phase operating voltage waveform of a certain case D when the verification simulation is performed, and FIG. 20 is a diagram showing a voltage waveform of a certain case E when the verification simulation is performed. 21 is a diagram showing a current waveform of a certain case E at the time of the verification simulation implementation, FIG. 22 is a diagram showing an A-phase operating voltage waveforms of a certain case D at the time of the verification simulation performed. In addition, in each figure, the same code | symbol shows the same part.

  FIG. 1 shows a model system diagram and its equivalent circuit for explaining the basic concept of the distance relay device of the present invention. FIG. 1 (a) is a model system diagram of a power system to be protected, FIG. 1 (b) and (c) are obtained by dividing the model system (FIG. 1 (a)) into two equivalent circuits by the superposition theorem of electric circuits, (b) is a steady circuit including a power source and a load, c) is a rotation vector change equivalent circuit (also referred to as a fault component equivalent circuit), and the rotation vector change equivalent circuit of FIG. 1C further includes a short-circuit fault rotation vector change in the case of a short-circuit fault shown in FIG. Equivalent circuits (applicable to short-circuit faults) and ground fault fault rotation vector change equivalent circuits (applicable to ground faults) in the case of a ground fault shown in FIG. In the variation circuit, it is assumed that a voltage source is inserted at the failure point. Based on these two types of rotation vector variation circuits, a theoretically new distance relay device that responds at high speed to at least one of a short circuit fault and a ground fault is realized in the present invention.

In FIG. 2 showing the equivalent circuit for the short-circuit fault rotation vector change, it is assumed that the distance relay device is installed at the M bus end and the N bus end, and in the distance relay device according to the first embodiment of the present invention, the short circuit fault (AB (Phase-phase failure, BC-phase failure, AC-phase failure, ABC-phase failure), line current rotation vector change, line voltage rotation vector change, and assumption point (detection of detection voltage / detection current of transmission line between bus MN) A point away from the location, for example, 80% of the transmission line that is the protection range of the first stage operation of the conventional distance relay device (80% from the detection location of the detection voltage / detection current of the transmission line between the buses MN) ) Is used to calculate the starting voltage, and when the starting voltage is higher than the voltage before the failure at the assumed point, it is determined as a failure within the area (internal failure), and a trip command is issued to the line breaker.
The distance relay device at the end of the M bus and the distance relay device at the end of the N bus are the same, and in the case of a short-circuit fault described later, the distance relay installed at the end of the M bus is used. Do it to the center.

  In FIG. 3 showing the equivalent circuit for the ground fault fault rotation vector change, it is assumed that the distance relay device is installed at the end of the M bus. In the distance relay device according to the first embodiment of the present invention, the ground fault (A phase ground) Phase current rotation vector change and phase voltage in fault fault, phase B ground fault, phase C ground fault, phase AB ground fault, phase BC ground fault, phase AC ground fault, phase ABC fault) Using the rotation vector variation, the self-zero phase current rotation vector variation, the mutual zero-phase current rotation vector variation and the impedance up to the assumed point, the starting voltage is calculated, and the starting voltage is the voltage before the failure of the assumed point. If it is larger, it is judged as a failure within the city (internal failure), and a trip command is issued to the line breaker.

  Further, in the distance relay device according to Embodiment 1 of the present invention, when calculating the rotation vector change, sampling corresponding to one cycle time and an electrical angle of 90 degrees is performed, and the sampling time is the characteristic invented by the present inventor. By setting based on the actual measurement frequency obtained by the high-accuracy frequency measurement method described in Japanese Unexamined Patent Application Publication No. 2004-361124, it is possible to calculate the rotation vector change and the start-up voltage with high accuracy.

  In addition, the starting voltage calculated by the distance relay device according to Embodiment 1 of the present invention is directional, and a large starting voltage is generated only in the forward failure of the transmission line to be protected. In this case, a starting voltage exceeding the operating voltage threshold is not generated.

  Further, the distance relay device according to the first embodiment of the present invention does not erroneously start during system oscillation / step out, and starts at high speed when a failure occurs during step out.

  Further, in the distance relay device according to Embodiment 1 of the present invention, even when a ground fault occurs through the ground resistance, an accurate start-up voltage is calculated regardless of the value of the ground resistance, and the highly accurate distance relay is performed. A device can be realized.

  Hereinafter, Embodiment 1 of the present invention will be described in detail.

1 (a), (b) and (c) described above,
M and N are bus lines, mn1 and mn2 are two transmission lines of A, B and C3 phases,
G and G2 are power supplies,
F is the failure point,
V _F is the contingency voltage source is a constant voltage immediately before the failure,
It is.

In FIG. 2 showing the equivalent circuit for the short-circuit fault rotation vector change, it is assumed that the distance relay device is installed at the M bus end and the N bus end, and the distance relay device at the M bus end and the distance relay device at the N bus end are The same thing shall be used, and the concrete description about the case of the short circuit failure mentioned later is given centering on the distance relay apparatus installed in the M bus-line end.
In FIG. 2 described above,
Z _M is the impedance behind the M bus, Z _L is the impedance between the buses MN (for one line),
_ZLM is the impedance between bus M and fault point F,
Z _LN is the impedance between bus N and fault point F,
V _F is an assumed fault voltage source (the magnitude of which is the fault point voltage immediately before the fault, and its existence time is one cycle),
Δi _M is the amount of change in rotation vector current of the line MF on the bus M side,
Δi _N is the amount of change in the rotation vector current of the line NF on the side of the bus N (the line between the bus N and the failure point F),
Δv _M is the change in rotation vector voltage of bus M,
These symbols are also used in the same meaning in each formula described later.

  In FIG. 3 showing the equivalent circuit for the ground fault fault rotation vector change, it is assumed that the distance relay device is installed at the end of the M bus.

In FIG. 3 described above,
z _1M is the positive phase impedance behind the M bus, z _1L is the positive phase impedance (for one line) between the buses MN,
z _1LM is the positive phase impedance between the bus M and the fault point F,
z _1LN is the positive phase impedance between the bus N and the fault point F,
v ₁ is the assumed fault positive phase voltage source (its existence time is one cycle),
Δi _M1 is the amount of change in the positive phase rotation vector current of the line MF on the bus M side (the line between the bus M and the failure point F),
Δi _N1 is the amount of change in the positive phase rotation vector current of the line NF on the bus N side (the line between the bus N and the failure point F),
Δv _1M is a change amount of the positive phase rotation vector voltage of the bus M,
z _2M is the reverse phase impedance behind the M bus,
z _2L is the negative phase impedance (for one line) between the buses MN,
z _2LM is the negative phase impedance between the bus M and the fault point F,
z _2LN is the negative phase impedance between the bus N and the fault point F,
v ₂ is a contingent fault reverse phase voltage source (the existence time is one cycle),
Δi _M2 is the amount of change in the reverse phase rotation vector current of the line MF on the bus M side,
Δi _N2 is the amount of change in the reverse phase rotation vector current of the line NF on the bus N side,
Δv _2M is the amount of change in the reverse phase rotation vector voltage of the bus M.
z _0M is the zero phase impedance behind the M bus,
z _0L is the zero-phase impedance (for one line) between the buses MN,
z _0LM is the zero-phase impedance between the bus M and the fault point F,
z _0LN is the zero-phase impedance between the bus N and the fault point F,
v ₀ is an assumed fault zero-phase voltage source (its existence time is one cycle),
_ΔiM0 is a change in the zero-phase rotation vector current of the line MF on the bus M side (the line between the bus M and the failure point F),
Δi _NO is the amount of change in the zero-phase rotation vector current of the line NF on the side of the bus N (the line between the bus N and the failure point F),
Δv20 is the amount of change in the zero-phase rotation vector voltage of bus M,
These symbols are also used in the same meaning in each formula described later.

In FIG. 4 showing the voltage rotation vector change amount and current rotation vector change amount of the relay arrangement point on the complex plane,
v _N is the voltage rotation vector before the failure (voltage rotation vector one cycle time before the current time),
v _F is a voltage rotation vector after the failure (current voltage rotation vector) (however, the voltage before the failure is expressed except in FIG. 4),
Δv is a change in voltage rotation vector (difference between both v _N and v _F ),
i _N is the current rotation vector before the failure (current rotation vector one cycle time before the current time), i _F is the current rotation vector after the failure (current current rotation vector),
Δi is a change in current rotation vector (difference between both i _N and i _F ),
These symbols are also used in the same meaning in each formula described later.

The voltage rotation vector and the current rotation vector rotate counterclockwise on the complex number plane, and the instantaneous measured values of voltage and current correspond to the real part of the voltage rotation vector and the current rotation vector.
In a steady state, the voltage rotation vector change and the current rotation vector change are both zero (Δv = 0, Δi = 0).
Only when there is a failure, there is a rotation vector change voltage and a rotation vector conversion current.

  In FIG. 5, which is a functional block diagram of the distance relay device according to the first embodiment of the present invention, 1 is the distance relay device, and its six calculation blocks are calculated in parallel. The six calculation blocks are the short-circuit fault calculation block AB-phase calculation block, the BC-phase calculation block, the AC-phase calculation block, and the ground-fault calculation block A-phase calculation block, B-phase calculation block, and C-phase, respectively. It is a calculation block.

2 is a voltage / current measuring means that samples and measures the detection voltage / current that is an output of PT / CT, etc., and measures the instantaneous value of the voltage and current of the power system in time series. It captures current time series instantaneous values.
A / D conversion means 3 performs A / D conversion of the time-series instantaneous values of the voltage / current measured by the voltage / current measurement means 2.

Reference numeral 4 denotes voltage rotation vector change calculating means for calculating the voltage rotation vector change from the voltage time series instantaneous value.
Reference numeral 5 denotes current rotation vector change calculation means for calculating the current rotation vector change from the current time series instantaneous value.

6 is a pre-failure voltage calculation means for the assumed point. The line current to be protected, the bus voltage, and the impedance to the assumed point (for example, 80% of the transmission line that is the protection range of the first stage operation of the conventional distance relay device) (Impedance up to 80% from the detection location of the detection voltage / detection current of the transmission line between the buses MN) is used to calculate the pre-failure voltage v _F at the assumed point.
Reference numeral 7 denotes a starting voltage calculation means for the assumed point, which uses a current rotation vector change amount, a bus voltage rotation vector change amount of the protection target line, and an impedance to the assumption point to start voltage v _S at the time of failure of the assumption point. Is calculated.
Reference numeral 8 denotes a failure activation determination means for determining whether or not a failure activation has occurred. For example, the activation determination is performed based on a difference in current instantaneous value around one cycle.
Reference numeral 9 denotes an in-zone fault discriminating means for discriminating a fault in the protected zone (also referred to as an internal fault) by comparing the calculated pre-failure voltage and the starting voltage.

Reference numeral 10 denotes an interface for outputting the above calculation result to an external device.
Reference numeral 11 denotes storage means for storing the above-described calculation results.
A control execution means 12 issues a command to trip the circuit breakers at both ends of the protection target section.
Reference numeral 13 denotes a circuit breaker CB, and only a single phase is displayed for omission.
Reference numeral 14 denotes a voltage measuring transformer PT, and only a single phase is displayed for the sake of omission.
Reference numeral 15 denotes a current measuring transformer CT, and only a single phase is displayed for omission.

  Hereinafter, a specific procedure in which steps 101 to 111 are executed in the order of the flow indicated by the arrows shown in FIG. 6 will be described in detail with reference to the flowchart shown in FIG. 6. In addition, subscripts (suffixes) re, im, A, B, and C in the following expressions respectively mean a real number, an imaginary number, an A phase, a B phase, and a C phase. Further, (t−T) means a time point a predetermined time T before the time point t.

但し、Ｖ_Ａは電圧の振幅、ωは角回転速度、φ_Ａは初期位相角である。ｖ_Ａre(t)は電圧瞬時値で、Ａ相電圧回転ベクトルの実数部である。ｖ_Ａim(t)はＡ相電圧回転ベクトルの虚数部で、電気角度90度前の電圧瞬時値である。
角回転速度ωは次の(2)式のように計算される。

但し、fは実測系統周波数で、本発明者が発明した高精度周波数測定手法(特開２００４−３６１１２４号公報を参照)で計測された値である。T は所定時間であり、所定サンプリング数に相当する時間であり、例えば１サイクル時間である。１サイクル時間の場合は、例えば、或る基本波50Hz系統において、実測周波数は49.5Hzであれば、Tは0.02020秒となり、電気角度90度に対応する時間は0.00505秒となる。 In step 101, voltage / current time-series instantaneous value data is measured by PT / CT, which is a voltage / current measuring means of the power system, and A / D conversion of the output is performed.
The general formula of the instantaneous value of the A phase voltage (real part and imaginary part) is as shown in the following formula (1).

Where V _A is the voltage amplitude, ω is the angular rotation speed, and φ _A is the initial phase angle. v _Are (t) is an instantaneous voltage value, which is the real part of the phase A voltage rotation vector. v _Aim (t) is an imaginary part of the A-phase voltage rotation vector, which is an instantaneous voltage value 90 degrees before the electrical angle.
The angular rotation speed ω is calculated as in the following equation (2).

However, f is an actually measured system frequency, which is a value measured by a high-accuracy frequency measurement method invented by the present inventor (see Japanese Patent Application Laid-Open No. 2004-361124). T is a predetermined time, which is a time corresponding to a predetermined number of samplings, for example, one cycle time. In the case of one cycle time, for example, if a measured frequency is 49.5 Hz in a certain fundamental wave 50 Hz system, T is 0.02020 seconds, and a time corresponding to an electrical angle of 90 degrees is 0.00505 seconds.

Similarly, general formulas of instantaneous values of the B-phase and C-phase voltages are as shown in the following formulas (3) and (4).

但し、I_Ａは電流の振幅、θ_Ａは初期位相角である。ｉ_Ａre(t)は電流瞬時値で、Ａ相電流回転ベクトルの実数部である。ｉ_Ａim(t)はＡ相電流回転ベクトルの虚数部で、電気角度90度前の電流瞬時値である。 Similarly, each phase current calculation formula is as follows.
The general formula for the instantaneous value of the A-phase current is as shown in the following formula (5).

However, I _A is the amplitude of the current, and θ _A is the initial phase angle. i _Are (t) is an instantaneous current value, which is a real part of the A-phase current rotation vector. i _Aim (t) is an imaginary part of the A-phase current rotation vector, which is an instantaneous current value 90 degrees before the electrical angle.

Similarly, general formulas of instantaneous values of B-phase and C-phase currents are as shown in the following formulas (6) and (7).

The general formula for the real part of the zero-phase current is as follows:

The general formula of the zero-phase current imaginary part is as shown in the following formula (9).

  In step 102, the voltage rotation vector change calculation means 4 uses the voltage rotation vector change calculation unit 4 to change the voltage rotation vector (a time (t-T) before the time t immediately after the accident by a predetermined time T (a time corresponding to a predetermined sampling number, for example, one cycle). ) To the time t immediately after the accident).

Here, changes in the voltage rotation vector of the A phase, B phase, and C phase are as shown in the following equations (10) to (12). The voltage rotation vector change calculation means 4 calculates the instantaneous value equation (1). (3) Calculated from (4).

  In step 103, the current rotation vector change calculation means 5 causes the current rotation vector change (time t-T before a predetermined time T (a time corresponding to a predetermined sampling number, for example, one cycle) from the time t immediately after the accident. ) To the time t immediately after the accident).

Here, changes in the current rotation vector of the A phase, B phase, and C phase are as shown in the following equations (13) to (15). The current rotation vector change calculation means 5 calculates the instantaneous value equation (5). (6) Calculated from (7).

The change amount of the zero-phase current rotation vector is as shown in the following equation (16), and is obtained from the instantaneous value equations (8) and (9) by the current rotation vector change amount calculation means 5.

In step 104, an instantaneous value of the pre-failure voltage at the assumed point is calculated by the pre-failure voltage VF calculating means 6 at the assumed point.
The calculation formula of the pre-failure voltage to be calculated is as the following formula (17).

但し、Ｒ_１は前記想定点までの送電線抵抗、Ｘ_１は前記想定点までの送電線インダクタンスである。
なお、これまでの本実施の形態１での説明は、Ｒ_１を省略して式を展開したが、省略しない場合、同じ手法で式を展開することができる。 The transmission line impedance up to the assumed point is expressed by the following equation (18).

However, the transmission line resistance R ₁ until the assumed point, X ₁ is a transmission line inductance to the assumed point.
In the above description of the first embodiment, R ₁ is omitted and the expression is expanded. However, if not omitted, the expression can be expanded by the same method.

  In step 105, the starting voltage calculation means 7 calculates the failure starting voltage at the assumed point.

但し、ｖ_Ｓは起動電圧、Δｖ_Ｍは母線Ｍの電圧回転ベクトル変化分(線間電圧)、Δｉ_Ｍは線路ＭＮ(故障線)の電流回転ベクトル変化分、Ｚ１は前記想定点までのインピーダンス(例えば送電線の80%地点までのインピーダンス(例えば従来の距離継電装置の第１段動作の保護範囲である送電線の80%（母線ＭＮ間の送電線の検出電圧・検出電流の検出場所から80%）までのインピーダンス))である。 In the case of a short-circuit fault, the calculation formula of the short-circuit fault start-up voltage v _S is as the following formula (19).

However, v _S is the starting voltage, Δv _M is the voltage rotation vector change (line voltage) of the bus M, Δi _M is the current rotation vector change of the line MN (fault line), and Z1 is the impedance ( For example, the impedance up to 80% of the transmission line (for example, 80% of the transmission line that is the protection range of the first stage operation of the conventional distance relay device (from the detection location of the detection voltage / detection current of the transmission line between the buses MN) Impedance up to 80%))).

The general formula of the line voltage is as the following formula (20).

The general formula of the line-to-line current is as the following formula (21).

The change amount of the current rotation vector is as shown in the following equation (22), and is obtained by the current rotation vector change amount calculation means 5.

The change amount of the voltage rotation vector is expressed by the following equation (23), and is obtained by the voltage rotation vector change amount calculation means 4.

When the equation of the current rotation vector change and impedance is expanded, the following equation (24) is obtained.

The real part of the starting voltage is calculated according to the following equation (25).

The imaginary part of the starting voltage is calculated according to the following equation (26).

短絡故障時の短絡故障起動電圧の実効値Ｖ_Ｓ(t)は、以下の(28)式の手法で計算することもできる。

但し、Ｎは、基準波の１周期を４Ｎ（Ｎは正の整数）等分したサンプリング手法を使用した場合におけるＮである。（リレーの一般的な手法であり、日本の場合、Ｎ＝３、４Ｎ＝１２、３０度サンプリング手法を使用している）
前記二つ実効値計算式(27)(28)を比較した場合、式(27)の方式は、式(28)の方式より高速性がよい。式(28)の方式の起動は少し遅れているが、1サイクルの範囲で積分をしているため、数値の安定性はよい。
距離継電装置のデジタルフィルタの性能により、前記実効値計算式(27)(28)を選択する。デジタルフィルタの性能が高い装置では、式(27)の方式を使用する。デジタルフィルタの性能が低い装置では、式(28)の方式を使用する。 The effective value V _S (t) of the short-circuit fault start-up voltage at the time of the short-circuit fault is calculated by the start-up voltage calculation means 7 by the following equation (27).

The effective value V _S (t) of the short-circuit failure start-up voltage at the time of the short-circuit failure can also be calculated by the following equation (28).

However, N is N in the case of using a sampling method in which one period of the reference wave is equally divided by 4N (N is a positive integer). (This is a general relay method. In Japan, N = 3, 4N = 12, 30 degree sampling method is used.)
When comparing the two RMS calculation formulas (27) and (28), the formula (27) is faster than the formula (28). Although the start of the method of Equation (28) is slightly delayed, the numerical stability is good because the integration is performed within the range of one cycle.
The effective value calculation formulas (27) and (28) are selected according to the performance of the digital filter of the distance relay device. For a device with high digital filter performance, the method of Equation (27) is used. In a device with a low digital filter performance, the method of Equation (28) is used.

但し、Δｉは相電流変化分、Δｖは相電圧変化分、ｋ_１は自己零相補償係数、Δｉ_０は自己零相電流回転ベクトル変化分、ｋ_２は相互零相補償係数(並行2回送電線の隣送電線の零相補償係数)、Δｉ_ｍｏは相互零相電流回転ベクトル変化分である。
ここで図２を用いて、電力系統で広く使用された対称座標法における電圧回転ベクトル変化分(正相／逆相／零相)、電流回転ベクトル変化分(正相／逆相／零相)と三相(Ａ相／Ｂ相／Ｃ相)間の関係を示す(説明はＡ相を例としている)。以下の展開に相互零相成分は省略している。相互零相成分を考慮する場合、同じ手法を用いて、式を展開することができる。
Ａ相電圧回転ベクトル変化分は、以下の式(30)のように、正相電圧回転ベクトル変化分、逆相電圧回転ベクトル変化分、零相電圧回転ベクトル変化分に分解することができる。

In the case of a ground fault, the calculation formula of the ground fault starting voltage v _S is as the following formula (29).

Where Δi is the phase current change, Δv is the phase voltage change, k ₁ is the self-zero phase compensation coefficient, Δi ₀ is the self-zero phase current rotation vector change, and k ₂ is the mutual zero phase compensation coefficient (two parallel transmission lines ), Δi _mo is the mutual zero-phase current rotation vector variation.
Here, with reference to FIG. 2, voltage rotation vector change (normal phase / reverse phase / zero phase) and current rotation vector change (normal phase / reverse phase / zero phase) in the symmetric coordinate method widely used in power systems And the three phases (A phase / B phase / C phase) are shown (the explanation is based on the A phase). The mutual zero phase component is omitted in the following development. When considering the mutual zero phase component, the same technique can be used to develop the equation.
The change amount of the A phase voltage rotation vector can be decomposed into a change amount of the positive phase voltage rotation vector, a change amount of the negative phase voltage rotation vector, and a change amount of the zero phase voltage rotation vector as in the following equation (30).

The change amount of the A phase current rotation vector can be decomposed into the change amount of the positive phase current rotation vector, the change amount of the negative phase current rotation vector, and the change amount of the zero phase current rotation vector as in the following equation (31).

The pre-accident voltage at the A phase fault point can be decomposed into a normal phase voltage rotation vector, a negative phase voltage rotation vector, and a zero phase voltage rotation vector as shown in the following equation (32).

但し、ｋ_１は自己零相補償係数で、以下の(34)式により求める。

このように、(29)式は正しいことであると言える。 In the case of a ground fault, the ground fault start voltage up to the fault assumption point is calculated as in the following equation (33) based on FIG.

However, k ₁ is a self zero phase compensation coefficients, obtained by the following equation (34).

Thus, it can be said that equation (29) is correct.

相互零相補償係数を零とする起動電圧の虚数部は以下の(36)式の通りである。

相互零相補償係数は零でない場合，上式と同じやり方で展開することができる。ここでは省略する。 The real part of the starting voltage where the mutual zero-phase compensation coefficient is zero is given by the following equation (35).

The imaginary part of the starting voltage where the mutual zero-phase compensation coefficient is zero is expressed by the following equation (36).

If the mutual zero-phase compensation coefficient is not zero, it can be expanded in the same way as the above equation. It is omitted here.

地絡故障時の地絡故障起動電圧の実効値Ｖ_Ｓ(t)は、以下の(38)式の手法で計算することもできる。

但し、Ｎは、基準波の１周期を４Ｎ（Ｎは正の整数）等分したサンプリング手法を使用した場合におけるＮである。（リレーの一般的な手法であり、日本の場合、Ｎ＝３、４Ｎ＝１２、３０度サンプリング手法を使用している） The effective value V _S (t) of the ground fault start voltage at the time of the ground fault is calculated by the start voltage calculation means 7 by the following equation (37).

The effective value V _S (t) of the ground fault starting voltage at the time of the ground fault can also be calculated by the following equation (38).

However, N is N in the case of using a sampling method in which one period of the reference wave is equally divided by 4N (N is a positive integer). (This is a general relay method. In Japan, N = 3, 4N = 12, 30 degree sampling method is used.)

但し、I_SETは整定値である。 In step 106, the failure activation determination means 8 determines whether or not there is a failure activation.
That is, it is checked whether a failure has occurred. For example, the current value is compared with the current difference before a predetermined number of samplings, for example, one cycle before. If any one of the following formulas (39) to (41) is satisfied, a failure is started.

However, I _SET is a set value.

When the failure is activated, the process proceeds to step 107.
If no failure is activated, the process proceeds to step 111.

  In step 107, that is, when the failure is started, the pre-failure voltage at the assumed point is latched.

但し、Ｖ_Ｓ(ｔ)は計測された起動電圧、Ｖ_Ｆ(ｔ_０)は故障起動で前記記憶装置１１にラッチした故障前の電圧値である。 Next, at step 108, it is determined by the intra-area fault determination means 9 whether or not there is an intra-area fault (internal fault).
When the following equation (42) is satisfied, the ward failure (internal failure) is determined. If the equation (42) is not satisfied, the out-of-range failure (external failure) is determined.

However, V _S (t) is a measured starting voltage, and V _F (t ₀ ) is a voltage value before failure latched in the storage device 11 upon failure activation.

  In step 109, if it is a ward failure (internal failure), the control execution means 12 issues a trip command to the line breaker CB13.

  In step 110, that is, if it is an out-of-city fault (external fault), no trip command is issued to the line breaker CB13.

  In step 111, if not finished, the process returns to step 101, and thereafter, the processing of each step described above is executed.

  FIGS. 8 to 22 show the results of conducting the operation verification simulation of the distance relay device according to the first embodiment described above using the representative IEEJ EAST10 model system (50 Hz system) shown in FIG.

In FIG. 7, line <11> and line <13> are two parallel transmission lines. The distance relay device is assumed to be installed on the bus (21). The protection range of the distance relay device is 80% of the line length in the protected area from the node 21 to the node 11. A simulation was performed for each of the following five cases A, B, C, D, and E.
Case A: A phase ground fault occurs at 10% of the total line length in branch <11> of installation node 21.
Case B: A phase ground fault occurs at 50% of the total line length of branch <11> of installation node 21.
Case C: A phase ground fault occurs at 70% of the total line length at branch <11> of installation node 21.
Case D: A phase ground fault occurs at 90% of the total line length at branch <11> of installation node 21.
Case E: A phase ground fault occurs at 50% of the total line length at branch <13> of installation node 21.

In each case, the three-phase voltage waveform is shown in FIGS. 8, 11, 14, 17, and 20, and the three-phase current waveform and the zero-phase current waveform are shown in FIGS. 9, 12, 15, 18, and 21. The A-phase starting voltage waveforms are shown in FIGS. 10, 13, 16, 19, and 22. FIG.
In case A, case B, and case C, as shown in FIGS. 10, 13, and 16, the distance relay device operates normally within the operating range, and the operation becomes faster as the position is closer to the failure point (case It was confirmed that the distance relay operation of A was faster than Case C).
Since the operation range in case D, as shown in FIG. 19, A-phase starting voltage waveform Prefailure becomes below the voltage V _F, the distance relay device does not start.
Case E is behind the failure, as shown in FIG. 22, A-phase starting voltage waveform Prefailure becomes below the voltage V _F, the distance relay device does not start. Thus, it was also confirmed that this distance relay device has directionality.
In addition, for example, in detail the relationship between the A phase operating voltage waveform of case A illustrated in FIG. 10 and the operation of the distance relay device,
Before the occurrence of the failure, since the voltage rotation vector change and the current rotation vector change are zero, the starting voltage is zero.
After failure, the value of the starting voltage is greater than the pre-fault voltage V _F, determines that the wards fault (internal fault), issues a trip command to the circuit breaker of the bus (21) side of the transmission lines <11>.
Although the failure continues 25 ms after the occurrence of the failure, the voltage rotation vector change and the current rotation vector change again become zero (difference value of one cycle), and the starting voltage returns to zero.
As described above, the distance relay device according to the first embodiment described above has the following characteristics, that is, is activated only when a failure occurs, and has high speed (outputs an operation output within one cycle).

  As described above, the first embodiment of the present invention is divided into two electric circuits (electric circuit superposition theorem) immediately after a failure occurs, one of which is a steady circuit including a power source, and the other is a rotating circuit. This is a vector variation circuit. In the rotation vector change circuit, it is assumed that a voltage source (steady voltage immediately before the failure) is input at the failure point. The operating voltage is obtained up to the end of the transmission line protection range (for example, up to 80% of the transmission line) using the voltage / current rotation vector change at the distance relay device arrangement point. If the operating voltage is greater than the failure point voltage, it is determined to be within the protection range and operates. If the operating voltage is smaller than the failure point voltage, it is determined that it is outside the protection range and does not operate.

As described above, in the first embodiment of the present invention (see FIG. 1), the target electric circuit (a) is divided into two electric circuits (b) and (c) immediately after the occurrence of the failure. (Electric circuit superposition theorem). (b) is a stationary circuit including a power supply. (c) is a rotation vector change equivalent circuit (also called a fault component equivalent circuit). There are two parallel transmission lines between the buses MN (each ABC 3 phase for a total of 6 phases). G1 and G2 are power supplies, and F is the failure point. v _F is an assumed fault voltage source (its value is a steady voltage just before the fault). In addition, the circuit of Fig. 1 (c) is divided into two types: the short-circuit fault rotation vector change equivalent circuit (applied to short-circuit fault) in Fig. 2 and the ground fault fault rotation vector change equivalent circuit (applicable to ground fault) in Fig. 3. Classify. In the rotation vector variation circuit, it is assumed that a voltage source is inserted at the failure point. It is a high-speed distance relay device that can cope with both ground faults and short-circuit faults using two types of rotation vector change circuit.

  As described above, in the first embodiment of the present invention,

  As described above, in the first embodiment of the present invention (see FIG. 2), in the case of a short-circuit fault (AB phase fault, BC phase fault, AC phase fault, ABC phase fault), the line current rotation vector change and line The starting voltage is calculated using the change in the inter-voltage rotation vector and the impedance up to the assumed point. If the starting voltage is higher than the pre-failure voltage at the assumed point, it is determined that there is a failure in the area, and a trip command is issued to the line breaker.

  As described above, in the first embodiment of the present invention (see FIG. 3), a ground fault (A phase ground fault, B phase ground fault, C phase ground fault, AB phase ground fault, BC phase) In the case of ground fault, AC phase ground fault, ABC phase ground fault), phase current rotation vector variation, phase voltage rotation vector variation, self-zero phase current rotation vector variation, mutual zero phase current rotation vector variation The starting voltage is calculated using the impedance up to the assumed point. If the starting voltage is higher than the pre-failure voltage at the assumed point, it is determined that there is a failure in the area, and a trip command is issued to the line breaker.

  As described above, in Embodiment 1 of the present invention, the distance relay device uses a sampling time corresponding to one cycle time and an electrical angle of 90 degrees when calculating the rotation vector change. Since the sampling frequency uses the measured frequency obtained by the high-precision frequency measurement method described in Japanese Patent Application Laid-Open No. 2004-361124 invented by the present inventor, it is possible to calculate the rotation vector change and the starting voltage with high precision. it can.

  As described above, in the first embodiment of the present invention, the starting voltage calculated by the distance relay device is directional. That is, a large starting voltage is generated only in front of the power transmission line to be protected. It does not start for system faults other than the target.

  As described above, in the first embodiment of the present invention, there is no erroneous start during system oscillation / step-out. If a failure occurs during step-out, it starts at high speed.

  As described above, in the first embodiment of the present invention, when a fault occurs through the ground resistance at the failure point, an accurate start-up voltage is calculated regardless of the value of the ground resistance. Can be realized.

  As described above, the first embodiment of the present invention can operate at high speed (operates within one cycle) and does not erroneously start up due to system out-of-step / sway / heavy load. If a failure occurs in system out-of-step / stabilization / heavy load, the failure can be started at high speed, and there is also a failure determination direction.

  As described above, the first embodiment of the present invention is a voltage time-series instantaneous value sampled from a voltage time-series instantaneous value and a current time-series instantaneous value sampled from the voltage and current detected from the power system, and a voltage time-series instantaneous value. Voltage rotation vector change calculating means for calculating the voltage rotation vector change from the current time series instantaneous value current rotation vector change calculating means for calculating the current rotation vector change from the current time-series instantaneous value, at a predetermined distance from the detection location Starting voltage calculating means for calculating a starting voltage at the time of failure starting of the assumed point using the transmission line impedance up to a certain assumed point, the current rotation vector change of the protection target line and the bus voltage rotation vector change, a protection target line A pre-failure voltage calculating means for calculating a pre-failure voltage at the assumed point using a current, a bus voltage, and a transmission line impedance up to the assumed point; and In the case where the start voltage and the pre-failure voltage are compared to determine a failure in the protected area to determine a failure in the protected area, the determination result in the failure detection means in the area, the start voltage is greater than the pre-failure voltage The distance relay device that outputs a trip output to the circuit breaker of the protection target line.

  As described above, the first embodiment of the present invention is a voltage time-series instantaneous value sampled from a voltage time-series instantaneous value and a current time-series instantaneous value sampled from the voltage and current detected from the power system, and a voltage time-series instantaneous value. Voltage rotation vector change calculating means for calculating the voltage rotation vector change from the current time series instantaneous value current rotation vector change calculating means for calculating the current rotation vector change from the current time-series instantaneous value, at a predetermined distance from the detection location Starting voltage calculating means for calculating a starting voltage at the time of failure starting of the assumed point using the transmission line impedance up to a certain assumed point, the current rotation vector change of the protection target line and the bus voltage rotation vector change, a protection target line A pre-failure voltage calculating means for calculating a pre-failure voltage at the assumed point using a current, a bus voltage, and a transmission line impedance up to the assumed point; and In the case where the start voltage and the pre-failure voltage are compared to determine a failure in the protected area to determine a failure in the protected area, the determination result in the failure detection means in the area, the start voltage is greater than the pre-failure voltage In the distance relay device that outputs the trip output to the circuit breaker of the line to be protected, the starting voltage at the start of the short-circuit fault is calculated based on the equivalent circuit for the short-circuit fault rotation vector change based on the overlap theorem, and the short-circuit fault It responds to. Further, the starting voltage at the time of starting the short-circuit failure is calculated as an effective value by the equation (27) or the equation (28), and the pre-failure voltage is calculated as an effective value by the equation (17).

  As described above, the first embodiment of the present invention is a voltage time-series instantaneous value sampled from a voltage time-series instantaneous value and a current time-series instantaneous value sampled from the voltage and current detected from the power system, and a voltage time-series instantaneous value. Voltage rotation vector change calculating means for calculating the voltage rotation vector change from the current time series instantaneous value current rotation vector change calculating means for calculating the current rotation vector change from the current time-series instantaneous value, at a predetermined distance from the detection location Starting voltage calculating means for calculating a starting voltage at the time of failure starting of the assumed point using the transmission line impedance up to a certain assumed point, the current rotation vector change of the protection target line and the bus voltage rotation vector change, a protection target line A pre-failure voltage calculating means for calculating a pre-failure voltage at the assumed point using a current, a bus voltage, and a transmission line impedance up to the assumed point; and In the case where the start voltage and the pre-failure voltage are compared to determine a failure in the protected area to determine a failure in the protected area, the determination result in the failure detection means in the area, the start voltage is greater than the pre-failure voltage In the distance relay device that outputs the trip output to the circuit breaker of the line to be protected, the starting voltage at the time of starting the ground fault is calculated based on the equivalent circuit for the ground fault rotating vector change based on the superposition theorem, Responds to ground faults. Further, the starting voltage at the time of starting the ground fault is calculated as an effective value by the equation (37) or the equation (38), and the pre-failure voltage is calculated as an effective value by the equation (17).

  As described above, the first embodiment of the present invention is a voltage time-series instantaneous value sampled from a voltage time-series instantaneous value and a current time-series instantaneous value sampled from the voltage and current detected from the power system, and a voltage time-series instantaneous value. Voltage rotation vector change calculating means for calculating the voltage rotation vector change from the current time series instantaneous value current rotation vector change calculating means for calculating the current rotation vector change from the current time-series instantaneous value, at a predetermined distance from the detection location Starting voltage calculating means for calculating a starting voltage at the time of failure starting of the assumed point using the transmission line impedance up to a certain assumed point, the current rotation vector change of the protection target line and the bus voltage rotation vector change, a protection target line A pre-failure voltage calculating means for calculating a pre-failure voltage at the assumed point using a current, a bus voltage, and a transmission line impedance up to the assumed point; and In the case where the start voltage and the pre-failure voltage are compared to determine a failure in the protected area to determine a failure in the protected area, the determination result in the failure detection means in the area, the start voltage is greater than the pre-failure voltage In the distance relay device that outputs the trip output to the circuit breaker of the line to be protected, the starting voltage at the time of short-circuit fault start is calculated based on the equivalent circuit for the short-circuit fault rotation vector change based on the overlap theorem, The start-up voltage at the time of starting the ground fault is calculated based on the equivalent circuit of the ground fault fault rotation vector change based on the superposition theorem, and responds to the short-circuit fault and the ground fault. In addition, the starting voltage at the time of short-circuit failure start-up is calculated as an effective value by the above formula (27) or formula (28), and the start-up voltage at the time of ground fault start-up is effective by the above formula (37) or formula (38). The pre-failure voltage is calculated as an effective value according to the equation (17).

  As described above, the first embodiment of the present invention is a voltage time-series instantaneous value sampled from a voltage time-series instantaneous value and a current time-series instantaneous value sampled from the voltage and current detected from the power system, and a voltage time-series instantaneous value. Voltage rotation vector change calculating means for calculating the voltage rotation vector change from the current time series instantaneous value current rotation vector change calculating means for calculating the current rotation vector change from the current time-series instantaneous value, at a predetermined distance from the detection location Starting voltage calculating means for calculating a starting voltage at the time of failure starting of the assumed point using the transmission line impedance up to a certain assumed point, the current rotation vector change of the protection target line and the bus voltage rotation vector change, a protection target line A pre-failure voltage calculating means for calculating a pre-failure voltage at the assumed point using a current, a bus voltage, and a transmission line impedance up to the assumed point; and In the case where the start voltage and the pre-failure voltage are compared to determine a failure in the protected area to determine a failure in the protected area, the determination result in the failure detection means in the area, the start voltage is greater than the pre-failure voltage In the distance relay device that outputs a trip output to the circuit breaker of the line to be protected, a failure activation determination that calculates a difference between a current value and a current value before a predetermined number of samplings and determines whether or not there is a failure from the difference And the in-zone failure determination unit performs the determination when the determination result by the failure activation determination unit is a failure. Further, the failure activation determining means determines that the failure has been activated when at least one of the equations (39) to (41) is satisfied. Further, the current before the predetermined sampling number is, for example, a current before one cycle. The sampling is performed at a timing of at least one cycle interval and an electrical angle of 90 degrees, for example.

It is a figure which shows Embodiment 1 of this invention, and is a figure of the model system | strain of protection object. It is a figure which shows Embodiment 1 of this invention, and is a connection diagram which shows the rotation vector change part equivalent circuit in a short circuit failure. It is a figure which shows Embodiment 1 of this invention, and is a connection diagram which shows the rotation vector change part equivalent circuit in a ground fault. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the part for the voltage / current rotation vector change of the relay arrangement | positioning point on a complex number plane. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows an example of the functional block diagram of a distance relay. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the processing flow of failure determination with a flowchart. FIG. 5 is a diagram illustrating the first embodiment of the present invention, and is a diagram illustrating a typical IEEJ EAST10 model system adopted when a relay operation verification simulation is performed. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the voltage waveform of a certain case A at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the current waveform of a certain case A at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the A-phase operating voltage waveform of a certain case A at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the voltage waveform of a certain case B at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the current waveform of a certain case B at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the A-phase operating voltage waveform of a certain case B at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the voltage waveform of a certain case C at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the current waveform of a certain case C at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the A phase operating voltage waveform of a certain case C at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the voltage waveform of a certain case D at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the current waveform of a certain case D at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the A-phase operating voltage waveform of a certain case D at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the voltage waveform of a certain case E at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the current waveform of a certain case E at the time of verification simulation implementation. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the A-phase operating voltage waveform of a certain case D at the time of verification simulation implementation.

Explanation of symbols

1 distance relay device,
2 Voltage / current measurement means 3 A / D conversion means,
4 voltage rotation vector change calculation means,
5 current rotation vector change calculation means,
6 Pre-failure voltage VF calculation means at the assumed point,
7 Start-up voltage calculation means for assumed point,
8 failure activation determination means,
9 Defect determination means in the ward,
10 interface,
11 storage means,
12 Control implementation means,
13 Circuit breaker CB,
14 PT,
15 CT.

Claims (8)

Voltage / current measurement means for capturing voltage time series instantaneous values and current time series instantaneous values sampled from voltages and currents detected from the power system,
A voltage rotation vector change calculating means for calculating a voltage rotation vector change from a voltage time series instantaneous value;
Current rotation vector change calculation means for calculating the current rotation vector change from the current time series instantaneous value;
Start-up voltage at the time of failure start-up of the assumed point using the transmission line impedance to the assumed point that is a predetermined distance from the detection location, the current rotation vector change of the protection target line, and the bus voltage rotation vector change A starting voltage calculating means for calculating
A pre-failure voltage calculating means for calculating a pre-failure voltage at the assumed point using a line current to be protected, a bus voltage, and a transmission line impedance up to the assumed point;
And a failure determination means in the area for comparing the start-up voltage and the pre-failure voltage to determine a failure in the protected area,
A distance relay device that outputs a trip output to the circuit breaker of the line to be protected when the start-up voltage is larger than the pre-failure voltage as a result of the determination by the in-zone failure determination means. In distance relay apparatus according to claim 1, it is calculated the activation voltage during short circuit fault activated based on the short-circuit failure rotation vector variation equivalent circuit based on the theorem of overlapping, distance HanareTsugi electrostatic you response to short-circuit failure In the apparatus , the starting voltage at the time of the short-circuit failure starting is calculated as an effective value by the following equation (27) or (28), and the pre-failure voltage is calculated as an effective value by the following equation (17): A distance relay device characterized by that .

However, in Equation (17), Equation (27) and Equation (28), V _Sre (t) is the real part of the starting voltage, V _Sim (t) is the imaginary part of the starting voltage, and V _Mre (t) is the M bus. V _Mim (t) is the imaginary part of the voltage on the M bus side,
Z ₁ is the transmission line impedance up to the assumed point, V _Mre (t) is the real part of the voltage on the M bus side,
V _Mim (t) is the imaginary part of the voltage on the M bus side, i _Mre (t) is the real part of the current on the M bus side, i _Sim (t) is the imaginary part of the current on the M bus side, N is the reference wave N in the case of using a sampling method in which one period is equally divided into 4N (N is a positive integer). In distance relay apparatus according to claim 1, ground fault startup on the basis of the ground fault rotation vector variation equivalent circuit based on the theorem of overlapping activation voltage is calculated, you in response to a ground fault distance In the power disconnecting device , the starting voltage at the time of the ground fault start is calculated as an effective value by the following formula (37) or formula (38), the voltage before the fault is an effective value by the following formula (17) A distance relay device calculated as:

However, in Equation (17), Equation (37) and Equation (38), V _Sre (t) is the real part of the starting voltage, V _Sim (t) is the imaginary part of the starting voltage, and V _Mre (t) is the M bus. V _Mim (t) is the imaginary part of the voltage on the M bus side,
Z ₁ is the transmission line impedance up to the assumed point, V _Mre (t) is the real part of the voltage on the M bus side,
V _Mim (t) is the imaginary part of the voltage on the M bus side, i _Mre (t) is the real part of the current on the M bus side, i _Sim (t) is the imaginary part of the current on the M bus side, N is the reference wave N in the case of using a sampling method in which one period is equally divided into 4N (N is a positive integer). 2. The distance relay device according to claim 1, wherein the start-up voltage at the start of a short-circuit fault is calculated based on a short-circuit fault rotation vector change equivalent circuit based on a superposition theorem, and a ground fault based on the superposition theorem the starting voltage of the ground fault startup based on the rotational vector variation equivalent circuit are calculated, a distance HanareTsugi collector you responding to short-circuit fault and a ground fault, the starting voltage when the short-circuit failure start The following equation (27) or equation (28) is calculated as an effective value, and the start-up voltage at the time of ground fault failure is calculated as an effective value by the following equation (37) or equation (38), and the pre-failure voltage Is calculated as an effective value by the following formula (17) .

However, in Equation (17), Equation (27), Equation (28), Equation (37) and Equation (38), V _Sre (t) is the real part of the starting voltage, and V _Sim (t) is the imaginary number of the starting voltage. , V _Mre (t) is the real part of the voltage on the M bus side, V _Mim (t) is the imaginary part of the voltage on the M bus side, Z ₁ is the transmission line impedance up to the assumed point, and V _Mre (t) is M
The real part of the voltage on the bus side, V _Mim (t) is the imaginary part of the voltage on the M bus side, i _Mre (t) is the real part of the current on the M bus side, and i _Sim (t) is the current part on the M bus side The imaginary part, N, is N in the case of using a sampling method in which one period of the reference wave is equally divided by 4N (N is a positive integer). In the distance relay device according to any one of claims 1 to 4 , fault activation determination means for calculating a difference between a current value and a current value before a predetermined number of samplings and determining whether or not there is a failure from the difference. The distance relay device according to claim 1, wherein when the determination result by the failure activation determination unit is a failure, the intra-city failure determination unit performs the determination. 6. The distance relay device according to claim 5 , wherein the failure activation determination means determines that the failure activation has occurred when at least one of the following formulas (39) to (41) is satisfied. Relay device.

Where i _Are (t) is the current of the A phase, i _Are (t−T) is the current of the A phase before the predetermined sampling number, i _Bre (t) is the current of the B phase, and i _Bre (t -T) is the current before the predetermined sampling number of phase B,
i _Cre (t) is the current of the C phase, i _Cre (t−T) is the current before the predetermined sampling number of the C phase, and I _SET is a set value. The distance relay device according to claim 6 , wherein the current before the predetermined number of samplings is a current before one cycle. 8. The distance relay device according to claim 7 , wherein the sampling is performed at a timing of at least one cycle interval and an electrical angle of 90 degrees.

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