KR20080046388A - Multi-function terminal for distributing automation and operating method thereof - Google Patents

Abstract

A multi-function terminal device for distribution automation and an operating method thereof are provided to improve reliability of a fault indication by using a fault current conducting direction scheme, an automation fault detection scheme and a fault point indication scheme. A multi-function terminal device for distribution automation includes a surge protection module(2000), a main module(1900), and a user interface(1800). The surge protection module measures a voltage and a current of a distributing line, and supplies an insulation and an electric power for an input and an output of a switch controller. The main module performs a measuring, a calculation, an event process, a history storage, a communication, a state detection and a control of data measured in the surge protection module. The user interface performs a state indication, a setting and history management and a key input of the main module.

Description

Multi-Function Terminal for Distributing Automation and Operating Method

1A and 1B show an algorithm for detecting a failure in a conventional temporary accident and a momentary accident.

2 is a flowchart illustrating a fixed detection method according to an embodiment of the present invention.

3 and 4 are flowcharts showing each step of FIG. 2 in detail.

5A and 5B illustrate a method of generating and determining automatic FI and manual FI according to an embodiment of the present invention.

6A and 6B illustrate a plunge suppression method according to an embodiment of the present invention.

7 illustrates a method of determining a fault current supply direction according to an embodiment of the present invention.

8A illustrates a case where the power factor is 1 in the fault current supply direction determination method according to an embodiment of the present invention, and FIG. 8B illustrates a process of comparing one phase.

8C illustrates a result of shifting the determination reference voltage phase by 30 degrees in consideration of the reactance component in the fault current conduction direction determination method according to an embodiment of the present invention.

9 is a flowchart illustrating an automatic fault detection algorithm according to an embodiment of the present invention.

10 is a V-T graph according to an embodiment of the present invention.

11 is an O-T graph according to an embodiment of the present invention.

12 is a screen for monitoring an instantaneous voltage drop according to an embodiment of the present invention.

13 is a screen for monitoring an instantaneous voltage increase according to an embodiment of the present invention.

14 is a screen for monitoring a momentary power failure according to an embodiment of the present invention.

15 illustrates an operation algorithm for non-ground fault detection according to an embodiment of the present invention.

16 is a graph when a ground fault occurs in a non-grounded corner according to an embodiment of the present invention.

17 shows the relationship of each voltage due to a ground fault according to an embodiment of the present invention.

18 is a block diagram of a terminal device for power distribution automation according to an embodiment of the present invention.

The present invention relates to a multi-function terminal device for distribution automation and its operation method, in particular, to monitor the condition of the line at all times to facilitate the operation of the line failure detection, protection coordination, quality monitoring, non-ground fault detection, waveform It is about terminal device which can save, file transfer, simulate FI generation test, self-diagnosis segmentation, class assignment, communication port extension and maintenance management and its operation method.

In general, when a fault occurs in the distribution line, it should be able to indicate the fault status for each phase (A, B, C, N), and it should be equipped with a fault indicator which does not malfunction in inrush current.

The fault indicator is divided into automatic and manual, and each should provide independent information. Automatic FI is used to determine temporary failures, and manual FI is used to determine occurrences of instantaneous failures.

Conventionally, the failure occurrence time of each sequence is processed to the point where the failure current is experienced and no voltage (diagonal line) is generated, so that the automatic FI or manual FI information is generated when the final failure detection judgment time is completed.

1A and 1B show an algorithm for detecting a failure in a conventional temporary failure and instantaneous failure.

However, the operation algorithm as described above causes the following problem.

First of all, due to the time difference between the FRTU of the automatic switchgear (GA) and the Fault Indication (FI) event of the recloser (hereinafter referred to as RA), an operator has a delay in determining and troubleshooting the fault.

That is, in case of instantaneous failure, GA's FRTU generates failure detection (FI) information before RA (when 28 seconds of manual FI Setting Time of FRTU is set in current operation), and when RA is temporary FI information is generated before FRTU (20 seconds difference occurs when FRFI's automatic FI Setting Time is set to 20 seconds).

In addition, the RA processes the FI occurrence information without any distinction between manual FI and automatic FI at the time of completion of the sequence (sequence return time or lockout time), and the FRTU is manual FI in case of instantaneous failure or temporary failure. There is a possibility of operating confusion due to automatic FI classification process.

In addition, there are many problems in detecting the environment of the track, and a way to compensate for this is urgent.

The present invention has been made to solve the above problems, and its object is to provide an apparatus and method for detecting a failure more accurately by preventing a delay time caused by the operation of the RA and GA during the failure detection.

Another object of the present invention is to provide an apparatus and a method for detecting and determining a problem in a time line when a problem occurs in a line by monitoring the environment of the line in real time.

This terminal device (FRTU) is configured as shown in Figure 18, the electrical signal is connected to the FRTU via the surge protection module from the control unit of the GA, according to the characteristics of the analog input unit (AI), digital input unit (DI), digital It is divided into an output unit DO and the like. In addition, the power supplied from the control unit of the switch is supplied to each module in the FRTU, the main module performs functions such as the operation / processing of the input signal, the generation of the control output signal, communication with external devices. On the other hand, the user interface module displays the status information by LCD and LED, and performs a function of receiving a button operation signal.

The failure detection method of the present invention requires the following prerequisites.

In the case of GA, it is assumed that the voltage signal of one or more phases operates normally, and the state of contact (opening / opening) is in good condition. (A live state means that the active state is more than the set value (e.g. more than 50% of rated voltage). Is called)

Voltage (live / oblique) information is referred to only at fault determination. In other words, if more than one phase current exceeds the set value in the normal current (below Pickup Current set value), the fault pickup is prepared and the contact state is only a reference condition.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

2 is a flowchart illustrating a fixed detection method according to an exemplary embodiment of the present invention, and FIGS. 3 and 4 are flowcharts showing each step of FIG. 2 in detail.

2 to 4, in the fault detection method of the present invention, the fault detection method is divided into an initial FI information generation step, a failure persistence detection step, a failure type determination step, and a failure detection release step. .

Step 201 is the first FI information generation step. When measuring current / voltage at any time and detecting a current over a set value (PC: Pickup Current) when a line breakdown occurs, the RA responds to the set curve and cuts off the line. FRTU generates Fault Indication (FI) at the time when the voltage becomes below the set value (diagonal level) when the RA shuts off.

At this time, an event occurs, including the fault occurrence phase information, and the fault current of each phase is processed by 1Cycle Window Mask method, and the maximum RMS is stored and an event occurs (Event occurrence information: FI (A, B, C, N) occurrence, fault current) (A, B, C, N) and count).

In addition, the impedance is calculated from the voltage / current measurement point to express the failure point up to the failure point.

Step 202 is a fault-continuous step. RA performs re-closing according to the set sequence, FRTU immediately fails fault-up the phase in which the failure occurred in step 202, and prepares the phase in which the failure does not occur in step 202. If the fault detection condition persists, the fault information is additionally reflected as the fault occurrence phase to generate fault information again.

Step 203 is a failure type determination step.

In case of temporary failure, RA locks out and generates an event.FRTU detects fault current and starts the automatic FI judgment time (automatic FI setting time, eg 20 seconds) from the point of time when the voltage is oblique and maintains for the automatic FI judgment time. It judges it as temporary failure and generates automatic FI information and processes it as an event.

In case of instantaneous failure, RA succeeds in reclosing, generates return information at the set sequence return point, and processes the event. FRTU becomes live before completion of automatic FI judgment time (automatic FI setting time, eg 20 seconds) and current is pickup current. In case of energizing, manual FI setting time (manual FI Setting Time, eg 2 sec) starts counter and judges as momentary failure at the time of completion to generate manual FI information and process event.

Automatic FI Setting Time The clearing condition is cleared before completion of the automatic FI judgment time and when the current exceeds the faulty Pickup Current value, the automatic FI judgment time is cleared or the automatic FI judgment is completed. If the current goes live before the completion of time and the current does not exceed the faulty Pickup Current value, the automatic FI setting time is cleared at the completion of the manual FI setting time.

Manual FI Setting Time Clearing condition is cleared when the FI setting time is in progress.

Step 204 is a step of releasing fault detection (FI generation and failure type).

The FI occurrence and fault type reset condition of the FRTU is cleared when the fault indicator return button is pressed on site or when a FI Reset is received from the remote host. In the case of RA, the lockout information is released and released when the lockout is released, and the FI occurrence and sequence return information are released when the failure indicator return button is pressed at the field or the remote host receives a FI Reset.

Hereinafter, the failure detection method by the automatic and manual FI generation will be described in detail.

5A and 5B illustrate a method of generating and determining automatic FI and passive FI by the FRTU according to an embodiment of the present invention. 5A is an example when a temporary failure occurs in the track, and FIG. 5B is an example when a momentary failure occurs.

Referring to FIG. 5A, after at least an internal setting cycle (eg, 2 cycles) or more has elapsed, the FI information is generated when a current in a line is detected as a pickup current or more and becomes oblique. When the FI information is generated, information on the fault current, fault waveform (I, V), fault direction (+,-) and distance to the fault point are simultaneously generated. In FIG. 5A, it can be seen that a failure occurs for the initial phase A, FI information for phase A is generated, and information about the failure direction and failure waveform for phase A is generated. The information generating method for the fault direction and fault waveform will be described later in detail.

When the FI information for phase A is generated, the automatic FI determination time is counted. If the automatic FI determination time becomes live before the completion of the automatic FI determination time, the automatic FI determination time (Auto FI Setting Time) clearing condition is followed.

In FIG. 5A, although the ship is live before the completion of the automatic FI Setting Time, it can be seen that after the live ship, the line current is live over the Pickup Current. Therefore, the current automatic FI Setting Time is immediately cleared at the live time.

If the automatic FI Setting Time is terminated again after the termination, the same process is repeated. That is, the automatic FI Setting Time is counted again at the same time pointed in diagonally. At this time, if a fault other than the current fault phase is detected again, FI information is generated again for the fault phase. In FIG. 5A, when the secondary road is also oblique, it is detected again until a failure for phase B, FI information for phases A and B is generated, and it can be seen that failure directions and failure waveform information for each phase are generated.

After that, the automatic FI setting time is counted, and when the automatic FI setting time elapses, it is determined that the fault phase is automatic FI due to temporary failure. The automatic FI Setting Time can be variously set by those skilled in the art, and is set to 20 seconds in the present invention.

If the FI generated for the fault condition is determined to be an automatic FI, the automatic FI Setting Time is completed. At the site managing this, the initialization is performed by performing a reset button or a remote reset command (FI Reset).

FIG. 5B is a process of detecting passive FI when a momentary failure occurs in a line. In FIG. 5A, the passive FI is counted again. However, if the current flowing in the fault after the live flow is less than the Pickup Current, the manual FI Setting Time is counted. When the manual FI Setting Time elapses, it is determined as a manual FI, and recognizes a momentary failure. In the case of the manual FI Setting Time counting, if a diagonal line is detected before completion of the counting time, the manual FI Setting Time is cleared and counted again after the live line. The manual FI Setting Time can also be variously set by those skilled in the art, and is set to 2 seconds in the present invention.

If the FI information generated for the fault phase is determined to be the manual FI, the manual FI Setting Time is completed, and at the site managing this, the initialization is performed by performing a field failure indicator return button or a remote reset command (FI Reset).

6A and 6B illustrate a plunge suppression method according to an embodiment of the present invention.

Conventional inrush control method has no failure experience and judges the inrush as the set time when proceeding in the live state from the oblique state, does not proceed to the oblique state after the failure experience, and returns to the normal mode after the manual FI Setting Time when proceeding to the normal state. In this method, the open point is always open (since it is always live), but it does not suppress inrush when the load is switched, and it can cause FI by inrush. If the load current of the healthy phase was kept above the pickup for the supply of, then disappeared, FI could be generated by the operation of the protective device, and the pickup current for the phase was also low.

In the present invention, a new inrush control method is disclosed, and in order to implement such a method, the inrush time is set to 0.0sec to 180.0sec, the multiple to the inrush (X multiples): 2 to 20, and both live lines are not in both live states. Where applicable, and when applied in both live conditions.

In addition, it is judged by Time (0.0sec ~ 180.0sec) and multiple (2 ~ 20) .If inrush current is less than X multiples at the time of applying Inrush, it is determined as inrush. Switch to the fault detection mode.

If you proceed to the normal state without going to the oblique state after the failure experience, return to the normal mode after 1 cycle.

Referring to FIGS. 6A and 6B, the power supply side and the load side represent the simultaneous live timing, and are processed considering the inrush time and the inrush times in the absence of a failure experience.

7 illustrates a method of determining a fault current supply direction according to an embodiment of the present invention.

The basic method of determining the fault current conduction direction is to use a cross-polarizing voltage (line voltage) and shift the applied voltage by a certain angle to maximize the sensitivity of the protective relay element.

Alternatively, apply the Memory Voltage function for the complete loss of voltage, or operate the FI in the case of 30 ^o Leading to 150 ^o Lagging as a protection relay element on A, and do not operate in other direction elements. Use this method to determine the direction of current flow (+90 ^o to -90 ^o based on MTA).

Basic method for determining the fault current conduction direction of the present invention is as follows.

Phase Ia and Vbc phase comparison, Ib phase and Vca phase comparison, Ic phase and Vab phase comparison, and the current phase after fault pickup and the phase of the voltage between lines just before fault pick up. At this time, as an application example, it is preferable to compare the time point of time in consideration of the initial transient state of the fault current and the recloser instantaneous interruption time [within 45 ms / about 3 cycles] at 2 cycles.

In case of a fault in a real system, the L (reactance) component is dominant so that the phase of the current is Lag (ground) rather than the phase of the voltage. Considering this, we change the Cross Polarized Voltage (judgment reference voltage phase) to +30 degrees of the Vbc phase.

If the fault current phase is in the forward area, it is in the forward direction.

8A illustrates a case where the power factor is 1, and FIG. 8B illustrates a process of comparing the phases. At this time, the reference voltage phase is shifted by 30 degrees considering the reactance component. 8c illustrates this process.

9 is a flowchart illustrating an automatic failure detection algorithm of the FRTU according to an embodiment of the present invention.

In the present invention implements the Pickup function through the rate of change of current.

If the auto fault detection mode is added to the set item and the auto fault detection mode is set to Yes, the existing setting Pickup Current is not the absolute level for fault detection and recognizes the fault according to the following conditions.

Pickup Current A current over the set value is recognized as a failure.

Pickup Current Recognizes the fault as a fault determination condition when the current is lower than the set value.

If the auto fault detection mode is set to No, the existing setup pickup current is used as the pickup level for fault detection.

Calculate the current and magnitude change at one time before the sample interval as follows and classify fault and fault.

The automatic fault detection method is as follows.

Calculate the fault current by subtracting the current before 1 cycle from the current (after fault) measurement current using the following formula, and if there is more than 50% current change between cycles, first recognize it as a fault and Ia If one or more of Ib and Ic is above the minimum manually settable phase pickup and △ I increases by more than 50%, it is determined as a failure condition.

ΔIa = Ia-IaL

ΔIb = Ib-IbL

ΔIc = Ic-IcL

Ia = current (after failure) measurement current, IaL = pre-fault load current

After that, the field and shape are determined under the following conditions.

○ A ground fault: | Ia |> 1.5 * | Ib |, | Ia |> 1.5 * | Ic |

○ Phase B ground: | Ib |> 1.5 * | Ia |, | Ib |> 1.5 * | Ia |

○ C ground: | Ic |> 1.5 * | Ia |, | Ic |> 1.5 * | Ib |

○ Accident on AB: | Ia |> 1.5 * | Ic |, | Ib |> 1.5 * | Ic |

○ Accident in BC: | Ib |> 1.5 * | Ia |, | Ic |> 1.5 * | Ia |

○ CA Accident: | Ic |> 1.5 * | Ib |, | Ia |> 1.5 * | Ib |

○ If it is | In |> 0.5 (| Ia | + | Ib | + | Ic |) above two or more accidents, it is considered as a ground fault.

○ Other accidents in ABC

If no voltage is detected within the fault detection time after fault recognition, it is determined as a fault. If no voltage is detected, the fault recognition is canceled and it is judged as a load variation to generate alarm information.

The present invention proposes a method of expressing a fault point distance from a measurement point to a fault point.

The method for displaying the failure point is an algorithm for expressing the distance from the electricity measurement point to the failure point, and inputting and setting the reference impedance (Z: system impedance, transformer impedance, line impedance) of the measurement point, and normal operation ( Measuring before-failure analysis measurement impedance (Z ′), calculating and correcting the difference between the reference impedance (Z) and the normal analysis measurement impedance, measuring the impedance at the time of failure and the impedance at the time of failure The value may be divided into estimating distances from the measurement point to the failure point.

When a line fault occurs at a certain point of a line in a three-phase AC circuit, the symmetrical coordinate method is used to calculate how much the fault current is at that point. In general, faults in the line are mostly unbalanced fault currents except for three-phase short circuits, and it is difficult to calculate unbalanced currents in three-phase circuits without borrowing the symmetric coordinate method. Here, the symmetric coordinate method is an unbalance calculation method of a three-phase circuit. The symmetric coordinate method is decomposed into three currents (image, normal, and inverse phase), and each symmetric component is present. By nesting, you want to know the actual unbalanced value.

In the present invention, the fault current and the voltage measured in the fault detection step are reversed into three-phase symmetrical components (V ₁ , V ₁ , V ₁ , I ₀ , I ₁ , I ₂ ), and then impedance (Z ₀ , Z). ₁ , Z ₂ ) is calculated and compared with the set impedance (system impedance, transformer impedance, line impedance) to the measurement point, and the distance from the measurement point to the failure point is expressed.

It is preferable to use the following equation in order to apply the above-mentioned fault point expression method.

=

-

=

-

=

=

(However, in the above, V ₀ image voltage, V ₁ normal voltage, V ₂ reverse phase voltage, V _a A phase voltage, V _b B phase voltage, V _c C phase voltage, I ₀ image current, I ₁ steady current, I ₂ Reverse Phase Current, I _a A Phase Current, I _b B Phase Current, I _c C Phase Current, Z ₀ Image Impedance, Z ₁ Normal Impedance, Z ₂ Reverse Phase Impedance, Z _t Transformer Impedance, Z _s Grid Impedance, Z _l0 Line Image Impedance, Z _l1 Line normal impedance, Ea is the phase voltage just before failure and a is the Vector operator.)

10 is a view showing a V-T protection cooperation method according to an embodiment of the present invention.

Referring to FIG. 10, the sensor is opened after the Open Delay Time after the no-voltage detection and is input after the Close Time after the live wire detection. When no voltage is detected within the lockout time after closing, it is opened after the open delay time, and the closing state is maintained when the wire is held after the lockout time.

11 is a view showing an O-T protection cooperation method according to an embodiment of the present invention.

Referring to FIG. 11, after the voltage-free detection, it is input after the Open Delay Time, the Restraint Time, and the Close Time, and operates in the V-T mode after the input. After returning to the live state, the lockout state is canceled after the Source Side Reset Time.

The protection coordination algorithm as described above defines the following.

① Open Delay Timer

   0.1-25.5 sec

   -Instantaneous reclosing is ignored

   -At least 1 to 2 seconds shorter than the first delay reclosing of the upper Recloser

② Close Timer

    -1 ~ 255 sec

    -Set 1 ~ 2 seconds longer than (Longest fault detection time of Recloser + Highest fault break time of all types)

③ Lockout Timer

    -1 ~ 255 sec

    -Set equal to or slightly larger than (Relonger's longest fault detection time + interruption time)

   -Never set two lockout timers simultaneously when they exist on the same track

   -Set smaller than Close Timer

④ Tie point closing time ("O-T" Restraint Timer)

   -1 ~ 255 sec

   -Completed sectioning on one side of the loop system circuit and set it to the maximum time expected to be ready to receive power from the other side.

⑤ Section

   -Disable / Enable

   -Disable (Section function disabled), Enable (Section function enabled)

⑥ Auto close

   -Disable / Enable

   -Disable (automatic opening but automatic closing is suppressed), Enable (automatic closing by reclosing function)

⑦ Input direction selection

   Always / Source / Load

   -Always (Unconditional input), Source (Input only to power supply), Load (Load only to load side)

⑧ "V-T", "O-T"

   -V-T / O-T

   -V-T (Section section), O-T (Tie section)

⑨ Open fault selection (not used)

   -Always open / open on failure

   -Always open (always open after Open Delay Time after voltage loss), open on failure (only open when voltage loss due to FI condition is maintained Open Delay Time)

   ※ Open only in case of failure in multi-function terminal device

In general, in the traditional sense, power quality was defined as three factors: frequency maintenance rate, regulation voltage maintenance rate, and power failure.

With the recent development of information / communication / control technology, devices that are sensitive to waveform changes and voltage changes that appear in very short time such as information communication equipment, precision control equipment, office automation equipment, computer equipment, automatic production line, etc. With the use of microprocessor-based control devices such as AC drives and DC drives, interest in power quality of new concepts such as harmonics, voltage imbalance, instantaneous voltage fluctuations, momentary power interruptions and surges, which have not been a problem before, has increased. As a result, customers' desire for power quality is also increasing.

Therefore, in the present invention, the following quality monitoring algorithm is applied.

12 is a screen for monitoring an instantaneous voltage drop according to an embodiment of the present invention.

The causes of the instantaneous voltage drop include lightning, start of a large load, brownout, and the like.

Sag types include Instantaneous (0.5 ~ 30 Cycle (0.1 ~ 0.9 pu)), Momentary ((30Cycle ~ 3 sec (0.1 ~ 0.9 pu)), Temporary (3sec ~ 1 min (0.1 ~ 0.9 pu)) and Long Duration (More than 1 minute (0.8-0.9 pu)) is present.

Detect Level is OFF, 0.50 ~ 0.99pu (Sag is not detected when OFF) and Detect Time is 0.5 ~ 10.0Cycle.

Surveillance information is occurrence / release (BI), Sag duration (AI), phase and total occurrences, and counts by type of Sag.

13 is a screen for monitoring an instantaneous voltage increase according to an embodiment of the present invention.

The causes are sudden load interruptions, accidents on other phases, incorrect transformer settings.

Swell types include Instantaneous (0.5 to 30 Cycle (1.1 to 1.8 pu)), Momentary (30 Cycle to 3 seconds (1.1 to 1.4 pu)), Temporary (3 seconds to 1 minute (1.1 to 1.2 pu)), and Long Duration ( Greater than 1 minute (1.1-1.2 pu)).

Detect Level is OFF, 1.01 ~ 1.50pu (Swell is not detected when set to OFF) and Detect Time: 0.5 ~ 10.0Cycle.

Surveillance information includes occurrence / release (BI), swell duration (AI), phase and total number of occurrences, and count of swell types (count).

14 is a screen for monitoring a momentary power failure according to an embodiment of the present invention.

The causes of momentary power failures include fuse breaks, breaker trips, power line / transformer accidents, and generator accidents.

Interruption types include Momentary (0.5 cycle-3 seconds (less than 0.1 pu)), Temporary (3 seconds-1 minute (less than 0.1 pu)), and Sustained (more than 1 minute (0.0 pu)).

Detect Level is OFF, 0.10 ~ 0.49pu (Do not detect interruption when set to OFF), Detect Time: 0.5 ~ 10.0Cycle.

Monitoring information includes occurrence / release (BI), interruption duration (AI), phase and total number of occurrences, number of occurrences by type of interruption (Count), and accumulated time of interruption (phase) by phase.

In addition, harmonic monitoring due to distortion of the sinusoidal power supply voltage is also performed. Cause of occurrence: non-linear load, converter / inverter, iron resonance, etc. The measurement items are voltage THD (A, B, C) and current THD (A, B). , C, N), the harmonic content (up to the 32nd order) according to the current and voltage order.

Unbalance of current and voltage is caused by unbalance of power amount and power factor of single phase device. The unbalance rate is calculated as

Unbalance Rate = (Video / Normal) × 100

Set Detect Level as 0 ~ 100%, Detect Time: 0.1sec ~ 60.0sec.

The present invention can also monitor the Under Frequency, Detect Level is OFF, 46.00 ~ 59.99Hz, Detect Time: 0.03sec ~ 10.00sec, when OFF, do not monitor the low frequency.

The present invention can identify harmonics flowing into the transformer from the transformer protection side.

K =

The present invention applies the crest factor to the voltage to see the insulation level of the device.

Crest Factor =

The present invention also proposes an ungrounded fixed detection method.

15 is a diagram of an ungrounded fault algorithm according to an embodiment of the present invention.

As shown in FIG. 15, when a ground fault occurs in a non-grounded system as shown in the above figure, the voltages of the healthy phases of all three feeders are doubled.

Referring to FIG. 16, it can be seen that a ground fault has occurred due to the voltage of Vc being 0V, the voltage of Va and Vb being doubled and the generation of an image voltage. However, since this phenomenon appears in all three feeders, it is not possible to distinguish a feeder that has a ground fault. This method has the advantage of not having a CT.

IR1 = IH1, IR2 = IH2, IR3 = IH3

By ground fault

IR3 =-(IH1 + IH2 + IH3-IH3)

IR3 =-(IH1 + IH2)

The feeder with the phase angle of the current measured by the image CT on the upper side (restriction area) is the feeder without a ground fault. The feeder with the phase angle of the current below (operation area) has a ground fault. It can be seen that the feeder has occurred. The above phase angle is a phase angle only considering pure capacitance, and if the resistance or reactance value is taken into consideration, there will be a slight variation in the phase angle of the current.

Since ground current Ia1 is a charging current, it leads 90 degrees of voltage Vaf during ground fault. Since ground current Ib1 is a charging current, it leads 90 degrees of voltage Vbf during ground fault. The above principle can also be used for Petersen Coil Earth.

-SEF PickUp Current: 2 ~ 20A

-SEF PickUp Voltage: 10% ~ 80%

-SEF Max Torque Angle: 0 °, 30 °, 60 °, 90 °, 270 °, 300 °, 330 °

SEF Detection Time: 0.0sec ~ 180.0sec

The present invention enables waveform storage, file transfer, simulation FI test, self-diagnostic subdivision, class assignment, communication port expansion and maintenance.

Conventional terminal equipment stores and stores the number of items and the number of fault waveforms (8), inrush waveform (1) sampling and storage cycles: 24 sampling / Cycle, and 10 cycles. 8), inrush waveform (1), instantaneous waveform (1), and PQM waveforms (6) are added and complemented.

Sampling and storage cycle can be saved selectively according to the operation method. 16 sampling / Cycle save 160 Cycle, 32 sampling / Cycle save 80 Cycle, 64 sampling / Cycle save 40 Cycle, 128 sampling / Cycle 20 cycle Save it.

Existing terminal device transmits only files related to fault and inrush waveform, Config Read / Write, and load current according to time slot, but in the present invention, record segmentation does not exceed application size, fault and inrush waveform, Config Read / Write, Hourly Load Current, Instantaneous Waveform, PQM Waveform, 15 Minute Average Load Current, Terminal Device Information (S / N, Manufacturing Date, Installation Date, Inspection Date, Line Impedance Information, etc.), Remote Firmware Upgrade, Assign Class Read Accuracy Transfer the file.

In addition, the existing terminal device current using a comprehensive tester. Although a simulated FI is generated by applying a voltage to the sequence, the present invention simulates a FI by assuming that the sequence is internally performed by having a FI Test button on the terminal device.

In addition, the existing terminal device can check only the abnormal / normal information in the main device when transmitting the self-diagnosis abnormality / normal information, and did not confirm any abnormality of any item, and operate class 0, 1, 2, 3 fixed setting in class assignment. In addition, there were no RS-232 ports (main communication port, maintenance port) and subordinate device relay ports in communication port.

However, in the present invention, self-diagnosis abnormality / normal information transmission and subdivided items are transmitted, and detailed items include ADC, DSP, RTC, Memory, DO, Analog Power, Inner Power, Switch Control, Setting, Config, Event, Count. Also, the point that can be evented in class assignment is Class Grouping in the form that End-User wants, and 3 RS-232 ports (main communication port, maintenance port, spare port), RS-485 also in communication port One port (spare port) and one Ethernet port (spare port) were included. In addition, the maintenance port is designed to include a wireless Bluetooth module.

In addition, 4 ~ 20mA measurement point is added to control by using sensors such as commercial temperature and humidity. Internal / external temperature and humidity can be measured to remotely transmit on-site weather conditions. It provides alarm for and can check on the LCD whether communication with the master is normal, and processes the information of open / close, lock / unlock, field / remote as one point, and displays the status as IIN. Whether the point is Trouble can not be confirmed from the remote), the point is treated as a Double Point to enable the maintenance management by enabling to check the Trouble state from the remote.

18 is a block diagram of a distribution automation terminal device according to an embodiment of the present invention.

In the above embodiment, the distribution automation terminal device includes a user interface module 1800, a main module 1900, and a surge protection module 2000.

The embodiment schematically illustrates a multifunctional terminal device for implementing the above-described methods for power distribution automation.

Referring to FIG. 18, the user interface module 1800 includes an LCD unit 1801, a keypad unit 1802, a light emitting diode unit 1803, and a console port 1804.

The LCD unit 1801 measures the voltage and current of the distribution line by the power distribution automation terminal of the present invention, or informs the user of a predetermined set value, count, and current state of the current terminal device set by an external user. .

The keypad unit 1802 is used to operate the LCD unit, test a terminal device, or terminate a predetermined state of the terminal device.

The light emitting diode unit 1803 displays a state in which a predetermined failure occurs in the terminal device, a protection coordination, a voltage related state, or a communication state and a diagnosis related state in communication with the outside.

The console port 1804 is connected to an external device to check the status of the current terminal device or download the internal history and provide it to the user. The console port may be a general terminal for allowing an external user to know current information. In the present invention, it is preferable to use a portable computer.

The main module 1900 includes a communication unit 1903, an MMI / IF 1902, a data input unit (DI) 1904, a data output unit (DO) 1905, a central processing unit (CPU) 1901, and a plurality of units. AI 1911, real time clock and logic 1908, multiple memories 1907, 1910 and dual port memory 1906.

The communication unit 1903 preferably includes a predetermined communication driver to enable communication with an external device. Preferably, the communication unit uses a general communication method according to the level to those skilled in the art, but the present invention uses a communication method such as RS232C, RS485, and Ethernet, which are one of serial communication methods. Of course, it will be apparent that the communication method is not limited to the above-listed methods.

The data input unit 1904 inputs the state of the switch control unit, and serves to transmit the state of the switch input from the outside to the central processing unit.

The data output unit 1905 outputs it to the switch control unit via the surge protection module when the control command is received from the main device.

The CPU 1901 stores general communication, status monitoring, control, setting, event processing, and history of the terminal device of the present invention.

The AI 1911 converts an analog signal into a digital signal and converts current, voltage, and the like into a digital signal.

The AI 1911 also includes a high resolution AI 1912. The high resolution AI 1912 is a function for measuring and calculating a large current value such as a fault current higher than the rated current.

The MMF / IF 1902 performs a function of transmitting a signal for interfacing with a user interface module.

The digital signal processor 1909 measures an internal power supply or performs a calculation using the digital values output from the central processing unit and the AI, and transmits the value to the central processing unit.

The central processing unit 1901 and the digital signal processing unit 1909 include respective memories 1907 and 1910 for temporarily storing data during data operation.

A dual port memory 1906 is provided between the central processing unit 1901 and the digital signal processing unit 1909 to temporarily store data transferred between the central processing unit 1901 and the digital signal processing unit 1909. .

The surge protection module 2000 includes an insulator 2001, 2002, a PT / CT 2004, a DC-DC converter and a relay.

The insulators 2001 and 2002 are composed of varistors and capacitors for input / output contacts for surge protection.

The PT / CT 2004 modulates a control unit input voltage / current signal.

The DC-DC converter supplies power of 5V and ± 12V in the terminal device of the present invention, and the relay outputs a control signal to a controller of an external switch when a control signal is output from the main module.

As described above, it has been described with reference to the preferred embodiment of the present invention, but those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

According to the present invention as described above, it is basically installed in the distribution line together with the switchgear for distribution automation to measure the current, voltage, power flowing in the distribution line at all times and to monitor the electrical quality, when the load current fluctuations and failures in the distribution line It can operate as a protective device by detecting the status, and transmit measurement and monitoring operation information to the main device, receive commands from the main device, open the distribution line at the point of failure, and minimize the power outage range. All events occurring on the distribution line It provides information for analyzing the cause of failure by storing the data and transmits the status of the distribution line to the main device using multiple protocols (DNP3.0, IEC60870, Modbus, TCP / IP) to perform status monitoring and control remotely.

In addition, the present invention relates to a method for detecting a preferable failure between the recloser RA and the terminal unit FRTU of the automatic switchgear GA when a failure occurs in the distribution line. By separating and processing fault (FI) occurrence information and failure type judgment, not only can it bring efficiency of operation, but also accurate failure analysis can be provided by providing fault-related events and fault waveforms generated when a track is broken.

In addition, it is possible to improve the reliability of the fault detection method by facilitating inrush suppression, fault current flow direction, automatic fault detection, and fault point expression method, and to perform quick fault recovery by judging the distance from the measurement point to the fault point. can do.

In addition, it is possible to provide a variety of complementary methods in such a detection method to ensure full operation.

Claims (11)

A surge protection module for measuring current and voltage of a distribution line and supplying insulation and power to input and output contacts between switch control units; A main module responsible for measuring, calculating, processing events, storing history, communicating, status monitoring, and controlling data measured by the surge protection module; And Status display, setting and history management and key input of the main module Multifunctional terminal device for distribution automation including an interface. The method of claim 1, The surge protection module An insulator for surge protection for input / output contacts; Instrument transformer (PT) for modifying the voltage for the control unit input voltage signal; An instrument current transformer for modulating a current with respect to a controller input current signal; A DC-DC converter for supplying a true current power supply to the terminal device; And And a relay for outputting a control signal to the controller of the switch when the control signal is output from the main module. The method of claim 1, The main module Communication unit for communicating with an external device; MMI IF to interface signals with the User Interface Module; A data input unit DI into which a state of the switch controller is input; A data output unit (DO) for performing a control output to a control unit of a switch through the surge protection module when a control command is received from a main device; A real time clock (RTC) and logic for time processing; A central processing unit (CPU) connected to the communication unit, real time clock unit and logic unit, MMI I / F, data input unit and data output unit, and storing communication, status monitoring, control, setting, event processing and history; An analog input unit (AI) for converting analog values of current, voltage, and an internal power supply into a digital signal; A digital signal processor configured to measure internal power or perform calculations using the digital value output from the AI; And And a dual-port memory for sharing data of the central processing unit and the digital signal processing unit. The method of claim 1, The user interface module A light emitting diode unit for displaying fault, protection coordination, voltage related, communication, and diagnostic related status; An LCD unit displaying information on measurement, setting, count, history, and status management; A key input unit which performs key input for performing the LCD operation, a test, or a state release; And Console port for connecting to external device for status check and internal history download Multifunctional terminal device for distribution automation comprising a. In the event of a power failure due to a failure in cooperation with a back-up protection device, Operating method of the multi-function terminal equipment for distribution automation, characterized in that the automatic insertion by a predetermined sequence to automatically separate the minimum failure section. The method of claim 5, A method of operating a multi-function terminal device for power distribution automation, characterized in that the voltage is opened after an open delay time after sensing a voltage and is input after a cutoff time after a live wire detection. The method of claim 5, Open after the open delay time when no voltage is detected within the lockout time after the input Or, the operation method of the multi-function terminal device for power distribution automation, characterized in that to maintain the input state when the live line is maintained in the lockout time after the input. The method of claim 5, It is turned on after open delay time, time limit and cutoff time after no voltage detection.It operates in VT mode after input.If no voltage is detected within source side lockout time, it keeps the lockout state. A method of operating a multi-function terminal device for power distribution automation, characterized in that the lockout state is released after a reset time. A method of operating a distribution automation multifunction terminal device, characterized in that quality monitoring is performed using the multifunction terminal device according to claim 1. A method of operating a multi-function terminal device for distribution automation, characterized in that non-grounding fault detection is performed using the multi-function terminal device according to claim 1. By using the multi-function terminal device according to claim 1, it is assumed that after generating current and voltage, a sequence is generated to generate a simulated failure detection or the terminal device is provided with a failure detection test button to proceed internally. A method of operating a multi-function terminal device for power distribution automation, characterized by generating simulated fixed detection.

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