JPS59162713A - Protective relaying device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a protective relay device, particularly a protective relay device that protects a power system using voltage information between each electric station of the power system. This invention relates to a protective relay device that has a function to detect the correctness or failure of a device.

[Technical background of the invention]

The tax protection relay device, which detects fluctuations and out-of-synchronization in the electric power system, is responsible for transmitting and receiving voltage information between each electric station and detecting that the voltage phase difference between the electric stations changes at a predetermined speed. have. That is, its basic configuration is electrical station A, as shown in FIG.

The voltage information *Mu r v is taken into the protective relay devices 2A and 2B through the voltage transformers IA and IB provided at the B terminal, respectively, and is transmitted between both terminals through the transmission devices 3A and 3B. By transmitting and receiving signals to and from each other, changes in the voltage phase between terminals A and B of the electrical station are detected, and a tax adjustment is determined. An example of the basic principle of this determination is shown in FIG. 2. In this figure, step-out is determined when the voltage phase difference θ between A and B exceeds 180°. In this case, if the detection terminal is set to electric station A, the received information VB from electric station B is transmitted to voltage transformer IB.
, or a malfunction occurs in the circuit inside the protective relay device 2B, and the voltage phase of the B electric station is always in the second quadrant (90
°~180°) or 3rd quadrant (180°~270°)
Therefore, even under these normal operating conditions,
When a change occurs in the grid, the voltage phase of electric station B changes to 180°.
There is a possibility that it may be mistakenly detected as a tax adjustment. As an extreme example, the cause may be that the polarity of the voltage transformer 2B of the B terminal is reversed, the polarity of the input circuit in the protection network device is incorrect, or the deterioration of an element such as a filter is the cause.

Here, the voltage phase angle in the case of normal operation will be briefly described below, and an outline thereof is shown in FIG. 3 with the 6A terminal and the B terminal as the power transmission end and the power reception end, respectively. The figure shows a case where the power (PA + "Qh) at the middle input terminal supplies power (Pg + jQm) to the B terminal via the power transmission line reactance jX. In that case, considering the voltage ψ1 of the B terminal as a reference, VA = Vs + jXI
--... (1) 1-Vs = PR+ jQn
From P+-jQm ■=□ ・・・・・・・・・(2) yB *B=Vl=VB (reference) The voltage vA at the sending end A is 0A=f, + "x-! -L Niha ■=vB+ , +
jx-,,---・(3)MV.

The phase relationship of ÷A + vi+ is as shown in FIG. From the same figure, π force δ=□ (4) VA-yB. If this δ is the voltage phase difference between the A and B terminals, and the voltages at both terminals are both 1 pu, then equation (4) will work as long as the transmission line is not extremely long and there is no heavy power flow. , δ are considered to be within about +30°.

Even if the A and B terminals become conductive for transmitting and receiving power, only δ becomes negative and the absolute value does not change.

Therefore, as mentioned above, if an abnormality such as polarity reversal of voltage v1 occurs, the appropriate pressure ÷ B will always be in the second or third quadrant in Figure 29, which is the normal operating state. If there is a power grid operation, etc., the power may cross 180 degrees, erroneously determining that it is a tax adjustment, and erroneously cutting off the power, which may have a very large impact on the power grid.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a protective relay device that monitors the voltage phase during normal operation to detect an abnormality.

[Summary of the invention]

In the present invention, by utilizing the fact that the voltage phase between each electric station is within a predetermined range during normal operation, this is constantly monitored, and an erg alarm is displayed if the voltage phase falls outside the predetermined range. The purpose of this system is to detect polarity reversal in the power system secondary circuit, deterioration of elements in the protective relay, etc., and to ensure normal operation of the protective relay.

[Embodiments of the invention]

Examples will be described below with reference to the drawings. FIG. 5 is a configuration diagram of an embodiment of a protective relay device according to the present invention. In FIG. 5, IA, IB, 2A, and 3A correspond to those in FIG. 1, and the configuration of the B end is omitted because it is the same as the A end. U is means for taking in the voltage information of the own end, which takes in the own end voltage via the voltage transformer IA of the A end, and transmits this to the other end terminal B via the transmission device 3A. W is means for taking in voltage information from the other end, and takes in the other end voltage VB that has been taken in and transmitted by the voltage transformer IB of the other end between the A ends. X is a means for detecting the phase difference between the A and B terminals, which detects the phase difference between the voltages from the U and W, and determines whether this phase difference is within a predetermined range by the phase difference determining means Y. Determine. Reference numeral 2 denotes a display/alarm output means which outputs a display/alarm signal and lights up an auxiliary alarm relay, a display rung, etc. when the phase difference is not within a predetermined value by the phase difference determining means.

FIG. 6 is a block diagram of another embodiment of the protective relay device according to the present invention, in which a microcomputer is used. In FIG. 6, the voltage at each end is taken in through the voltage transformer at each end, which is the same as in the embodiment described above. The voltage taken in here is converted to a low level voltage by the input converter 21, and unnecessary frequency components are removed by the filter 22, and the sample holding circuit 23 (S/
) I ) is input. Then, the output from the sample holding circuit is converted into a digital quantity via the N-converter 24 and taken into the micro combinator 25. Also, φ
The output from the converter 24 is sent to the other end B via the transmission device 3A.
sent to.

On the other hand, from the other end B, a 1F voltage transformer IB, which is not shown,
Opposite end voltage information VB is received via the protective relay device 2B and the transmission device 3B, respectively, and input into the microcomputer 25. Here, the micro combinator 25 is a CPU,
It consists of a ROM, an i'L connector 1, an input/output port, etc., and voltage data of both terminals ■A.

The instantaneous value data of VB is stored in the data memory RAM for a predetermined period of time. And Micro Combiator 25
The defect detection signal from the output port of is sent to the auxiliary relay 27 via the auxiliary relay drive circuit 26 and the display rung drive circuit.
And the display lamp 28 is driven and displayed.

FIG. 7 is a flowchart for explaining the operation. First, in steps 701 and 702, voltage information Vl and VB of both terminals A and H, which have been loaded into the RAM of the microcomputer 25, are loaded. Step 703 is performed so that the phase difference θ between the voltages vA and VB taken in the previous step is within the range shown in area A in FIG.
Calculate the cross product value to detect that it is within ψ. Next, the process moves to step 704, and since the cross product value is negative, it is determined that it is within +ψ, and the process moves to Stella 7'705.

Further, if the cross product value in Stellar f704 is positive, it is determined that the value is outside +ψ, and the process moves to step 708.

In step Shift 05, a cross product value is calculated to detect that the phase difference between voltage ÷ A and voltage S3 is within -ψ in the range shown in area B in FIG. Next, the process moves to step 706, and since the cross product value is positive, it is determined that they are within one ψ, and the process moves to step 707, where it is determined that the voltage phase difference between the A end and the B end is within ±ψ. and move on to the next process. on the other hand,
If the cross product value is negative in step 706, it is determined that it is outside -ψ, and the process moves to step 08. Therefore, Ste.
The GUAR 08 determines that the phase difference of the voltage vAI Vl is outside the predetermined phase difference ±ψ, moves to step 709, outputs a display and alarm signal from the output port of the microcomputer 25, and moves on to the next process.

FIG. 9 is a diagram showing the extraction timing of instantaneous voltage value data of each terminal. Using the instantaneous value data shown here, A
, the basic principle of detecting the voltage phase difference between the B terminals will be explained below. FIG. 9 is an example assuming sampling every 30 degrees with respect to the fundamental frequency of the system. The flowchart shown in FIG. 7 processes whether the following formula is satisfied.

That is, the phase difference between the B' terminal voltage 9 and the A terminal voltage Qm is ±ψ
It detects whether or not it is within the range.

18l・191dn(θ−ψ)ku0 ・・・・・・・・・
...(5) l÷AI・lVi+ l dn (θ+ψ＞
>o ・・・・・・・・・(6) Above (4)
This is the case where the value on the left side of equations , (5) and (6) is Sangurine.

FIG. 10 is a block diagram of another embodiment of the protective relay device according to the present invention.

In this embodiment, the objective is to be achieved using only phase information. The configuration of this embodiment is substantially the same as that shown in FIG. 6, except that a phase detection circuit 20 is provided in place of the sampling and holding circuit 23 and A/D converter 24 shown in FIG.

Figure 11 shows the basic principle of phase detection.
o, tm-1... indicate sampling timing,
The sampling period is set at 30 degrees with respect to the fundamental frequency. Then, the above-mentioned sampling period of every 30' is further divided into 15 equal parts, and the phase is detected by counting the time on the positive side. -An example is as follows.

tm, :is count interval (tm-s to tm-2) t
m-1: 15 counts section (tm-2 to tm-1) t
m: 4 count section (tm-1-tm)
Equivalent 4 counts jm-1-1: o count section (tfn - tm+1) No equine fraction, that is, the above-mentioned count value can be sent and received to both end electric stations as phase information.

FIG. 12 is a flowchart for explaining the operation. First, in steps 121 and 122, the voltage phase information φern+φBm at both ends A and B, which was loaded into the RAM of the microcomputer 25, is loaded. In the stethoscope 123, since the voltage phase information φA171 and rφ1m are both positive waves, the phase difference θ between the electric stations at both ends is θ=(180
°−Φ゛) is detected and the process moves to the stethoscope 124. Step 124 compares the phase difference θ between the electric stations at both ends with a predetermined phase difference value ψ, and if this judgment is small, the process moves to step 125 and it is determined that the phase difference is within the predetermined phase difference ±ψ. Okay, move on to the next process. On the other hand, in step 124, if it is a dog, it moves to step 126, and if it is outside the predetermined phase difference ψ, then it moves to step 127, and displays and outputs an alarm signal from the output port of microcomputer 25. Proceed to the next process. Note that the method for calculating the section in which the voltages v and 1Mn between electrical stations A and B are both positive waves from the counts in FIG. 11 is as shown in equation (8). In other words, the timing at which the voltage at the A terminal changes from a positive wave to a positive wave is used as the reference for the count number at each sampling time of each terminal KL, A, and B, and the timing at which the voltage at the A terminal changes from a positive wave to a negative wave! The sum will be calculated until the ring.

FIG. 13 is a diagram showing the phase angle of the positive wave section of the A and B terminal voltages. Here, the count number is the same as the dimension value of "degrees", so when Φ is detected, the voltages VA, V
, it is clear that the phase difference between them is (180°-Φ0).

Although each of the above-mentioned embodiments has been described as a 2-terminal system, it goes without saying that the present invention is not limited to this and can also be applied to a multi-terminal system of 3 or more terminals. In the case of a multi-terminal system, for example, considering the A terminal standard,
What is necessary is to take the logical sum of the detection between the A terminal and the B terminal and the detection between the A terminal and the C terminal.

Further, in the embodiment described above, the determination is made for each terminal, but the determination may be made for only one arbitrary terminal.

〔Effect of the invention〕

As explained above, according to the present invention, an abnormality in the device is detected by utilizing the fact that the voltage phase between the two electric stations is within a certain range during normal operation. Polarity reversal of the power system secondary voltage circuit and deterioration of elements such as filters in the protective relay device can be detected and malfunctions can be prevented.

[Brief explanation of drawings]

Figure 1 is a system configuration diagram to which the present invention is applied;
The figure is a diagram explaining the basic principle of tax control protection that is the subject of the present invention, and Figure 3 is a diagram illustrating power transmission\Scheme 1.? 1. Fig. 4 is a vector diagram showing the phase angle between the transmitting and receiving ends, Fig. 5 is an embodiment 4/I4 configuration of a protective relay device according to the present invention, Fig. 6 is a configuration diagram of another embodiment, Fig. 71 The figure is a flowchart for explaining the operation, Figure 8 is a diagram showing the relationship between the voltage vector at each end and the operating area and non-operating area, Figure 9 is a diagram showing the extraction timing of instantaneous voltage value data of each terminal, and Figure 10 is a diagram showing the extraction timing of instantaneous voltage value data of each terminal. Figure 11 shows the basic principle for phase detection, Figure 12 shows the 70-chart for explaining the operation, and Figure 13 shows the phase angle of the positive voltage wave at each end. It is a diagram. IA, IB... Voltage transformer 2A, 2B... Protective relay device 3A, 3B... Transmission device 20... Phase detection circuit 21... Input converter 22... Filter 23
... Sampling holding circuit 24 ... Ya Φ converter 25 ... Microcomputer 26 ... Auxiliary relay drive circuit 27 ... Auxiliary relay 28 ... Display lamp drive circuit 29 ... Display lamp patent application Person Tokyo Shibaura Electric Co., Ltd. Agent Patent Attorney Nori Ishii Otoko 3
Figure 7 Figure 8 Figure 9

Claims (2)

[Claims] (1) Voltage information of arbitrary terminals imported from the power system,
In a protective relay device that detects that the phase difference between the voltage information of the other terminal and the voltage information of the other terminal that is taken in from the other terminal and transmitted via the transmission line changes at a predetermined speed, the voltage information of the own electrical station is taken in. a first means, a second means for acquiring voltage information of another electric station, and a third means for detecting a voltage phase difference between the two electric stations from each voltage information acquired by the first and second means.
means, fourth means for determining whether the voltage phase difference detected by the third means is within a predetermined range, and fifth means for issuing an alarm when the voltage phase difference is not within the predetermined range. Protective relay device 0 characterized by (2) The protective relay device according to claim 1, wherein voltage phase information is directly taken in as each end voltage information.