KR101336045B1 - An active insulation resistance measurement for non-interrupting electric power of a distribution board and a switchboard - Google Patents

Abstract

The present invention relates to an uninterruptible insulation resistance measurement device of a distribution board and a switchboard which measures a ground insulation resistance current flowing in the insulation resistance based on a measurement value obtained by sampling a leakage current flowing in a load wire in the uninterruptible live wire state. The uninterruptible insulation resistance measurement device according to the present invention comprises; a signal detection part which detects the leakage current flowing in the load wire in the live wire state; a signal processing part which samples the leakage current detected by the signal detection part; an insulation detection part which separates and extracts a valid content current flowing in the insulation resistance from the leakage current sampled by the signal processing part and calculates the insulation resistance using the extracted valid content current; and an automatic correction part which measures a correction signal through the signal detection part by generating the correction signal and performs a correction action by checking whether a measuring value is in a permissible error range or not. [Reference numerals] (AA) Distribution board / Switchboard;(BB) Load

Description

Uninterruptible insulation resistance measuring device for distribution panel and switchboard {AN ACTIVE INSULATION RESISTANCE MEASUREMENT FOR NON-INTERRUPTING ELECTRIC POWER OF A DISTRIBUTION BOARD AND A SWITCHBOARD}

The present invention measures the earth insulation resistance current flowing through the insulation resistance based on the measured value obtained by sampling the leakage current flowing through the load line in the uninterrupted live state, and performs a calibration automatically to improve the reliability of the measurement And an apparatus for measuring uninterrupted insulation resistance of a switchboard.

More than half of the increasing number of fires and disasters related to electricity have been caused by electrical leakage. This is a major cause of insulation resistance, which can greatly reduce the social and economic losses caused by fire if the cause can be prevented in advance.

The most common troubles in private electrical equipment are accidents caused by a short circuit in the low-voltage circuit. These problems develop due to electrical fires, electric shocks, and the extension of the power outage range. Therefore, it is important to shut down the circuits in advance through early short-circuit detection and alarm. Do.

Uninterruptible insulation device has the advantage that can grasp the tendency of insulation deterioration for electrical facilities such as houses, factories, buildings, etc., as well as secure the reliability of the electricity supply and greatly reduce the cost of the occasional inspection.

However, the measurement of insulation resistance requires a power outage, which makes it impossible to measure the insulation of the entire electrical system. In addition, the increase of computers and electronic devices may cause a high level of equipment damage.

In addition, power failure may not be possible due to computer-based system or information management, and insulation resistance measurement may not be possible. In addition, power outages can be costly due to disruption and complexity of the surrounding community due to system downtime or loss of critical information.

The most important part of the security maintenance management method of electrical equipment is the measurement of insulation resistance. In order to measure the insulation resistance, the measurement method of the insulation resistance meter by the DC leakage image current and the leakage ground relay are almost mainstream. However, in the current leakage accident, the current of the capacitive component due to the ground capacitance occupies most, and it is impossible to measure only the current of the resistive component due to the earth insulation resistance directly connected to the accident in the live state.

Insulation resistance measuring method for measuring DC leakage current is a method of measuring insulation resistance of converter through power failure, and it has the disadvantages such as low precision and reliability and troublesome inspection.

Leakage ground relay is a device that measures the leakage current of fault line and compares it with the set value, determines the abnormality and generates alarm output. It is installed in the distribution system and has the function of tripping the breaker.

Such a conventional technology is not only accurate measurement of the leakage current by the insulation resistance by measuring the image current of the earth resistance component and the ground capacitance component, but also has the disadvantage of measuring only very low insulation resistance value.

As described above, the conventional measurement of insulation resistance causes power failure, and not only the measurement of the entire electrical control system is impossible, but also the loss of important information of the power failure system due to damage of electronic equipment.

The present invention has been made to solve the above problems, the uninterruptible insulation of the distribution panel and switchboard for measuring the earth insulation resistance current flowing through the insulation resistance based on the measured value obtained by sampling the leakage current flowing through the load line in the uninterrupted live state It is to provide a resistance measuring device.

In addition, the present invention is to provide an apparatus for measuring uninterrupted insulation resistance of the switchgear and switchgear that can automatically perform the calibration through a self-diagnosis at regular intervals to improve the reliability of the measuring device.

In order to solve the above problems, the uninterruptible insulation resistance measuring apparatus of the distribution panel and the distribution panel according to the present invention is a signal detecting unit for detecting the leakage current flowing in the load line in the live state, and sampling the leakage current detected by the signal detection unit A signal processor, an active component current flowing through the insulation resistance from the leakage current sampled by the signal processor, and an insulation detector for calculating insulation resistance using the extracted active component current, and generating a calibration signal. And an automatic calibration unit measuring the calibration signal through the signal detection unit and checking whether the measured value is within a tolerance range to perform a calibration operation.

The signal detector may measure a leakage current using an image current transformer.

The signal detector removes a specific frequency component from the detected leakage current using a low pass active filter.

The signal processor may set the sampling period to at least two times the cutoff frequency of the low pass active filter.

The insulation detection unit includes: an active component detection circuit for separating and extracting the effective component current by a reference voltage applied between the ground line and the ground received from the grounding line of the overlapping transformer and the ground with respect to the detected leakage current; And an output current conversion circuit for converting the effective component current extracted by the circuit into a current value or insulation resistance value converted into a ground voltage of the target converter.

The uninterruptible insulation resistance measuring apparatus further includes a communication port for communication with an embedded web server for remote monitoring.

The present invention can measure the earth insulation resistance current Igr flowing through the insulation resistance based on the measured value obtained by sampling the leakage current flowing through the load line.

In addition, the present invention can improve the reliability of the measuring device by performing a calibration automatically through a self-diagnosis at regular intervals.

In addition, the present invention enables the web-based remote monitoring and control to measure the insulation resistance in the live state.

In addition, the present invention adopts the Igr method, which overcomes the limitations of capacitance, noise, loss error and non-operation factors due to the scalar amount detection, which is the magnitude of the leakage current, which is a drawback of the conventional Io method. As a result, the reliability and safety of the insulation resistance measurement can be improved.

1 is a block diagram illustrating an uninterruptible insulation resistance measuring system of a distribution panel and a distribution panel according to the present invention.
2 is a circuit diagram illustrating a lowpass filter associated with the present invention.
3 is a block diagram of a reference voltage generator according to the present invention.
4 is a flowchart illustrating a ground leakage current measurement process according to the present invention.
5 is a flowchart illustrating a control process of an apparatus for measuring uninterruptible insulation resistance according to the present invention.
6 is a flowchart illustrating an alarm processing procedure of the apparatus for measuring uninterruptible insulation resistance according to the present invention.
7 is a flowchart illustrating a process of setting an uninterruptible insulation resistance measuring apparatus according to the present invention.
8 is a flowchart illustrating a calibration process of an apparatus for measuring uninterruptible insulation resistance according to the present invention.
9 is a flowchart illustrating a display process of an apparatus for measuring uninterruptible insulation resistance according to the present invention.
Figure 10 shows the front and rear parts of the uninterruptible insulation resistance measuring apparatus related to the present invention.
11 is a front view showing a reference voltage generator according to the present invention.
Fig. 12 shows an overlapping transformer according to the present invention.
13 is an example showing the installation of the overlapping transformer according to the present invention.
14 is a block diagram illustrating a processor of an embedded server according to the present invention.
15 shows a process procedure of an embedded server related to the present invention.
16 is a flowchart illustrating the operation sequence of the embedded server according to the present invention.
17 is a flowchart illustrating a measurement data analysis procedure of the embedded server according to the present invention.
18 is a flowchart illustrating a measurement data request procedure of the embedded server according to the present invention.
19 illustrates a transmission structure of a communication protocol related to the present invention.
20 is a flowchart illustrating a process of initializing a communication processor according to the present invention.
21 is a flowchart illustrating a data request event sequence according to the present invention.
22 is a flowchart illustrating a data reception event processing process related to the present invention.
23 is a flowchart illustrating a process of analyzing received data related to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating an uninterruptible insulation resistance measuring system of a distribution panel and a distribution panel according to the present invention.

As shown in FIG. 1, the uninterruptible insulation resistance measuring system includes an overlapping transformer 100, an uninterruptible insulation resistance measuring apparatus 200, and a reference voltage generator 300. Here, since the uninterruptible insulation resistance measuring apparatus 200 has eight channels, it is possible to remotely monitor up to eight measurement points.

The overlapping transformer 100 is for supplying a measurement voltage to a ground wire of a one-point grounding method. The superposition transformer 100 has a transformer type ground wire of an insulated supervisory circuit wound several times by winding the excitation coil on the primary side and penetrating the window, and a low frequency voltage is induced in the ground wire. do. The electric circuit for insulation monitoring which consists of a ground wire as a power supply (for insulation detection), and load to earth insulation insulation of a converter is comprised here. Since the winding impedance of the overlapping transformer 100 is smaller than the insulation impedance to detect, the simulation was ignored.

The uninterruptible insulation resistance measuring apparatus 200 includes a signal detector, a signal processor, an interface, an insulation detector, a display, an automatic calibration, and the like.

The signal detector includes a clamp type current transformer 210 as a current sensor. Here, the current sensor is a zero current transformer (ZCT) is used.

In measuring leakage current, a converter for converting current and voltage signals including harmonic components is essential. These transducers can be parallel to the operation of the equipment in an environment where there is no direct connection for current or voltage measurements in the power system. The error of the current sensors used for signal detection does not exceed 5% in relation to the measured value in magnitude and 5 ° at the phase angle.

Before sampling the continuous signal, the signal detector removes a high frequency component in advance with the low pass active filter shown in FIG. 2, and sets the sampling frequency to at least two times the low pass filter cutoff frequency.

는 [수학식 1]과 같이 정의된다.Cutoff Frequency of the Third-Order Lowpass Active Filter of FIG.

Is defined as shown in [Equation 1].

가 되도록 저항값을 결정하면 콘덴서

의 값은 [수학식 2] 내지 [수학식 4]에 의해서 각각 결정된다.here,

When the resistance value is determined so that

The value of is determined by [Equation 2] to [Equation 4], respectively.

In consideration of the high signal source impedance of the input signal input to the low pass active filter, a buffer of high input impedance is inserted at the front of the filter for conversion. The impedance frequency characteristics are -9 dB and 5 harmonics about -13 dB for the fundamental commercial frequency to suppress the power harmonics.

The signal processor consists of an analog / digital (A / D) converter, a microprocessor, and a digital filter.

The A / D converter converts the signal voltage and reference voltage of the front end into digital and inputs them to the microprocessor.

The A / D converter, which converts analog signals to digital, is an important part of the leakage current measurement system. The A / D converter used to perform such A / D conversion consists of three stages: sampling, quantization, and coding.

에 샘플링 함수

를 곱함으로써 이루어지고 그 결과인 ZCT 입력 누설전류 이산신호

는 [수학식 5]와 같이 정의된다.In using digital signal processing to receive and analyze the leakage current detected by the ZCT, the voltage and current waveforms are represented by digital sampling magnitudes taken discretely in time. This sampling process results in a continuous leakage current signal of the input waveform.

Sampling function

ZCT input leakage current discrete signal

Is defined as shown in [Equation 5].

Here, T means a sampling period.

When there is a frequency component in the continuous signal that is higher than 1/2 of the sampling frequency, an aliasing phenomenon appears in the discrete signal produced by sampling the frequency, and in this case, the third-order lowpass active filter is applied. Pass it through to completely restore the original signal.

The sampled analog signal is quantized in many discrete sizes, represented by a finite length, and quantization essentially generates quantization noise during A / D conversion. In the N-bit A / D converter, the signal-to-quantization noise ratio (SNR) can be expressed as Equation 6 in the fully sinusoidal input.

A/D 변환기를 이용하여 주변회로와 인터페이스를 구현하였다.The SNR of a 12-bit A / D converter is 86.04 Hz, which generates noise in areas where aliasing is neglected. Therefore, in the present invention, 12 bits of high resolution A / D conversion processing is performed so that aliasing does not occur during A / D conversion.

A / D converter was used to implement the peripheral circuit and interface.

A command signal (0 or 1) is generated every predetermined time to control the bias current polarity of the bias supply circuit. The microprocessor controls the function and operation of each component or performs operations such as A / D conversion, leakage current (Igr) measurement processing, and output display of the calculation result.

The interface unit is an interface circuit of a channel for monitoring and controlling the insulation state at each of 8 insulation measurement points, and includes an opto-coupler, an operational amplifier, an active low pass filter, and a buffer amplifier. (Buffer Amplifier).

The interface unit not only provides an interface for a ZCT input for each channel, but also has a function for improving the accuracy of leakage insulation data by removing external noise of a ZCT input signal of 60 Hz.

The insulation detector detects an effective part by the voltage of the insulation detection frequency received from the ground wire (or neutral wire) of the transformer and the earth with respect to the current of the insulation detection frequency component flowing through the load insulation impedance detected by the image current transformer (ZCT). Separately extract the resistive current from which the effective part is calculated.

In the output current conversion circuit, the extracted resistive current is converted into a current value (pass standard) or an insulation resistance value converted into the ground voltage of the target converter and supplied to the display unit. In this method, the insulation on the ground potential (neutral wire), which is not possible with the conventional Io method for measuring the vector sum current, can be detected under the same condition as the phase with other earth currents. If this is removed, the same condition as that of the insulation resistance measured from the grounding type 2 wire is measured by the DC insulation resistance meter, so that reliable insulation management is possible.

The automatic calibration unit generates a calibration signal at a predetermined cycle, measures the calibration signal, and compares the measured value with a reference value to determine whether the uninterruptible insulation resistance measuring apparatus 200 needs to be calibrated. Here, the reference value means an error tolerance range.

The automatic calibration unit enters a calibration mode if the measured value does not match the reference value. After entering the calibration mode, the automatic calibration unit calculates a calibration value based on the measured value, and calibrates the uninterruptible insulation resistance measuring apparatus 200 using the calculated calibration value. Then, the automatic calibration unit re-measures the calibration signal after calibration and checks whether the re-measurement value matches the reference value.

If the recalibration value and the reference value match, the automatic calibration unit recognizes that the calibration is completed, and enters the measurement mode.

On the other hand, the automatic calibration unit immediately enters the measurement mode when the measured value and the reference value match.

As described above, the uninterruptible insulation resistance measuring apparatus 200 according to the present invention uses a self-diagnosis of the insulation resistance measuring apparatus 200 at regular intervals so that the measured value does not deviate from an allowable error range (eg, within ± 5%). 200) can improve the reliability.

As shown in FIG. 3, the reference voltage generator 300 is a circuit for generating a reference voltage of 1 V and 10 Hz from an overlapping transformer 100 in a live state of 60 Hz and 220 V, and includes an overvoltage detector 310 and a waveform converter. A schmidt trigger 320, an active filter 330, a counter 340, a reference voltage pulse generator 350, and a power amplifier 360 may be divided.

The superposition transformer 100 is a transformer in which several coils are wound on the primary side, and the ground wire is the secondary conductor of one turn. The ground wire is the power supply side for insulation detection, and the insulation impedance between the converter and the ground is applied to the load. It consists of an insulation monitoring circuit.

The overlapping transformer 100 receives a sinusoidal wave signal of 220V and 60Hz and converts it into 1V and 10Hz.

The waveform converter 320 converts the 1V, 10Hz sine wave signal converted by the superposition transformer 100 into a square wave signal. Since the square wave signal passes through the low pass filter (LPF) 330 and the fault detection circuit, the square wave signal removes noise generated around the measurement and detects a circuit abnormality. The square wave signal via the low pass filter 330 and the fault detection circuit is sent to the counter 340 for digital signal processing operation. The power amplifier 360 amplifies the current gain of the square wave signal output from the counter 340 and transmits it to the uninterruptible insulation resistance measuring apparatus 200.

Igr algorithm

Regarding the leakage current of the insulation detection frequency component flowing through the load impedance detected by the clamp type CT, the resistive effective value current Igr is determined by the reference voltage of the insulation detection frequency component applied between the transformer ground wire and the earth and the earth. Separately extract and find the insulation resistance value.

When vector operation of the input signal, a reference signal for the reference voltage and the reference phase is required.

The reference signal (Ref) accurately adjusts the voltage and phase from the commercial power supply. Since the commercial power source usually contains 1 ~ 2 [%] of low-order harmonics, the DFT process is performed by the DSP and the component of the basic commercial frequency is used. Yields only.

In the present invention, the DFT implements an algorithm for processing fundamental wave components targeting commercial frequencies.

Since the commercial power frequency 60 [Hz] generally maintains an accurate value, only a specific commercial frequency component can be selectively calculated by making the number of samplings satisfy the following Equation 7 during the DFT operation.

here,

N: sampling count

Δt: sampling time

n: integer

T: period of the measured wave (commercial frequency)

to be.

The spectral value of the fundamental commercial frequency is shown in [Equation 8].

here,

N: sampling count

n: integer

: 기본 상용주파수의 스펙트럼

: Spectrum of basic commercial frequency

: 샘플링 k번째의 순시 값

: K-th instantaneous value of sampling

to be.

으로부터 90° 앞선 스펙트럼

는 [수학식 9]와 같이 나타낸다.remind

90 ° ahead of the spectrum

Is expressed as shown in [Equation 9].

Equation 9 may be converted to Equation 10 below.

To convert from the effective component DFT spectrum to the same spectrum of the invalid component, the algorithm is implemented by substituting the cos and sin terms in [Equation 9] into the? Sin and cos terms as shown in [Equation 10].

및

로 나타낸다. 이것에 의해 대지 누설전류의 유효분 Igr, 무효분 Ix는 [수학식 11], [수학식 12]로 표현할 수 있다.The fundamental wave spectrum and the 90 ° advanced spectrum of the reference signal Ref can be calculated by Equations 9 and 10 directly. this

And

Respectively. As a result, the effective portion Igr and the invalid portion Ix of the ground leakage current can be expressed by the following equations (11) and (12).

4 is a flowchart illustrating a calculation process of the ground leakage current Igr according to the present invention.

The firmware control algorithm of the uninterruptible insulation resistance measuring apparatus 200 is largely divided into a setting mode, an alarm processing mode, and a display mode as shown in FIG. 5.

The main processes include setting mode (setting key input), calibration mode (calibration key input), alarm processing, and display (leakage current, insulation resistance).

As shown in FIG. 6, when the Igr measurement becomes larger than the set value by comparing the alarm set value and the Igr measurement value as shown in FIG. 6, the alarm processing process stores an event occurrence time in a memory and generates an alarm output. When the Igr measurement value is smaller than the set value, the uninterruptible insulation resistance measuring apparatus 200 is in the auto mode and initializes all data inputs, and then releases the alarm.

In the setting mode process, as shown in FIG. 7, Igr setting, Rg setting, channel number setting, Rg alarm value setting, Igr alarm value setting, and sensitivity setting are performed.

In the calibration mode, when the calibration switch is input as shown in FIG. 8, the calibration lamp flashes at a zero-second period in the zero adjustment mode. Confirmation of calibration indicates that the calibration is completed by causing the lamp to flash in a 0.2 second cycle when the calibration switch is pressed.

In the display process, the cord is connected to the ground and the ground of the circuit to check whether the LED of the monitoring power source is turned on. The clamp type CT is clamped to the ground line, and the control is as shown in FIG. 9 so that the leakage current Igr and the insulation resistance Rg measurement value are displayed after 5 seconds by pressing the measurement start switch.

Specifications and functions of the uninterruptible insulation resistance measuring apparatus 200 are as shown in [Table 1], the appearance is as shown in FIG.

Item Specification Control power AC100-240V Rated frequency 50/60 Hz Power Consumption 20VA or less Insulation Resistance 10MΩ or more (But between power supply input and ground) Withstand voltage CUTOFF current 10mA for 1 minute AC2000V (between power supply input and ground) Temperature range 0 ℃-+ 50 ℃ weight 5 Kg or less Suitable Image Current Transformer Through type current transformer (TZ), separate type current transformer (SZ) Application monitoring Low voltage converter with Class B grounding (but less than 5 kV of designated capacity)
Insulation monitoring voltage: 10 Hz 0.5V Circuits 8 circuits Scanning time 15 sec / CH All CH scanning time = 15 sec (8-free CH) Measurement mode Measure all channels and display them sequentially
1 CH selective measurement possible Effective measuring range AC85-265 V Measurement target Single phase 2-wire, Single phase 3-wire, 3-phase 3-wire, 3-phase 4-wire Frequency range of measurement AC 45-65 Hz Input resistance measurement range 2㏀-500㏀ Composite leakage current input Rated Range: 0mA-1000mA
Effective measuring range: 5%-120% Earth resistance component value current Valid range of display: 0 -120mA (OR display when exceeding 120mA)
Display resolution: 1 mA Earth insulation resistance Display effective range: 1㏀-1000㏀ MAX
(OR) display above 500㏀ (UR) display below 1 표시
Display resolution: 1㏀
* Resistance value according to input voltage and earth resistance component current
Earth insulation resistance according to input voltage value
The display range of the value changes.
Input voltage: AC100V-265V 1㏀-500㏀ Alarm output contact 1a AC250V 5A 30VDC 5A Break output contact 8a AC250V 5A 30VDC 5A Communication port RS-485 MODBUS

Specifications of the reference voltage generator are shown in [Table 2], and the appearance thereof is shown in FIG.

Item Specification Control power supply voltage AC 85-265 V Rated frequency 60 Hz Power Consumption 15VA Insulation Resistance 10㏁ or more (between power terminal and ground terminal) Withstand voltage AC2000V for 1 minute (between power terminal and ground terminal) Temperature range -10 ℃-+ 60 ℃ 90% RH or less (no condensation) weight 5Kg Monitoring signal overlapping method Nested transformer method Insulation Monitoring Frequency 10 Hz Output voltage 0.25 V Abnormal output Alarm display when insulation monitoring voltage is below 0.2V Dimensions 210 × 150 × 300 mm

The specification of the overlapping transformer is shown in [Table 3], and the appearance thereof is as shown in FIG.

Item Specification Insulation Resistance 10㏁ or more (between nested power output terminals and case) Withstand voltage 2000 VAC for 1 minute (between superimposed power output terminals and case) Use place inside Temperature range -10 ℃-+ 60 ℃ Below 85RH (without dew condensation) Dimensions 148 × 147 × 130mm weight 15kg

Next, the process of measuring the uninterrupted insulation resistance will be described.

When the transformer 100 for overlapping the reference voltage generator 300 is clamped as in the related art, an accurate measurement can be performed because the current flowing in the reference signal code of the uninterruptible insulation resistance measuring device 200 is measured (about 200 mA). none. Therefore, in the present invention, the load side is clamped.

[How to measure]

First, the overlapping transformer 100 is installed as shown in FIG. 13. After installing the overlapping transformer 100 to the ground wire to be sure to lock the locking device for fixing. Then, the reference voltage generator 300 and the overlapping transformer 100 are connected to the connector. The power switch of the reference voltage generator 300 is turned on and then the output switch is turned on.

To measure the insulation resistance, connect the clamp CT and the reference cord to the branch and turn on the power. As shown in Fig. 1, the reference code is connected to the ground, and LK (red clip) is connected to the ground side of the circuit. At this time, check that the green lamp of the monitoring power supply is blinking.

Clamp the CTs in a Class B ground wire or voltage branch circuit. When the measurement start switch is pressed, the measurement is started, and after 5 seconds, the measured value during measurement blinks and is displayed. If the measured value is 10 ms or less, the measurement is terminated after 30 seconds or 50 seconds or more, but the measured value is displayed as a hold.

[Calibration method]

Take out the uninterruptible insulation resistance measuring device 200 from the carrying cover (Carrying Cover), the clamp CT is connected to the measuring device 200 to prepare for calibration. At this time, the uninterruptible insulation resistance measuring device 200 is placed in a place where there is no vibration in the clamp.

After the calibration preparation, if phase adjustment is necessary, power is supplied to the measuring apparatus 200 by pressing a calibration switch of the uninterruptible insulation resistance measuring apparatus 200. The measuring device 200 turns on a calibration lamp and enters a phase adjusting mode. The phase adjustment volume of the measuring device 200 is manipulated to adjust the display value to 0 ± 1.

In the case of zero adjustment, when the calibration switch of the measuring device 200 is input, the measuring device 200 blinks the calibration lamp at a period of 0.5 seconds and enters a zero adjustment mode. The zero adjustment volume of the measuring device 200 is manipulated to adjust the display value to 0 ± 1.

When the calibration switch of the measuring device 200 is pressed to confirm the calibration, the measuring device 200 blinks the calibration lamp at 0.2 second intervals and starts the checking operation. The measuring device 200 is a buzzer for about 1 to 50 seconds from the start and displays the internal resistance measurement. If the displayed value is between 95KΩ ~ 105KΩ, the calibration is completed.

Hereinafter, the configuration of an embedded web server will be described.

As shown in FIG. 14, when an event of the embedded web server for remote monitoring occurs, the process configuration is largely divided into a communication processor, a measurement processor, an operation processor, and a start processor.

15 is a block diagram illustrating a process procedure of an embedded web server.

In order to proceed with the process, it initializes various built-in buffer structures and transmits data to KEN server by analyzing and calculating measurement data according to the transmission cycle of queue through RS-485 communication.

1) Startup process

Initial execution of the embedded server consists of creating a data buffer, starting up the computational processor, starting up the communications and instrumentation processors, and starting up the UDP processor.

2) metrology process

Receiving an on-site call signal, the measurement processor generates the sensor's quantity, buffers of measurement cycles, and generates a cue signal from RS-485. It transmits data to the queue according to this measurement cycle.

3) arithmetic processor

The computational processor transmits the received data to the KEN server and interlocks with each processor according to the received data, and transmits it to the UDP processor according to TimeSend buffer creation and transmission time.

4) communication processor

It transmits the data entered in the queue to RS-485, and the data entered in RS-485 is transmitted to the operation processor.

[Operation Sequence of Embedded Server]

As shown in FIG. 16, after verifying the set information, a schedule is created and processed, and a communication state of each measuring device is checked. The condition is abnormal, write the full text and save it in the message queue (MESG-Q). Subsequently, the complete data request for each measuring instrument is stored in the MESG-Q to process the set information periodically.

According to FIG. 17, the measuring instrument data of MESG-Q is temporarily stored.

To do this, first analyze the data of the measuring device, then verify the failure status, change the full text when it occurs, and process it first, and change the full text by verifying the transmission time of the regular data.

Then, the changed full text is saved in a log file, and the full text is stored in the MESG-Q.

Referring to FIG. 18, the full text of the MESG-Q is read, and the data is requested when the processing device is required, and the data is verified when the stored data is requested. The full text is saved in a log file, and the full text is stored in the MESG-Q.

19 illustrates a data structure transmitted via a communication protocol related to the present invention.

Data transmitted by the entire protocol consists of a protocol header and a Ken protocol (a).

The data transmitted by the setting protocol and time protocol, and the real time protocol is composed of a protocol header and a kind buffer, and a Ken protocol. The data type is classified according to the value input to the type buffer (b, c, d).

When the setting value is changed (save comparison for each Ken in the buffer) According to the setting protocol, it is saved in the setting value request buffer every 50 minutes every hour and then the data is sent every hour or the Ken setting value is sent immediately after real-time data transmission.

If the time is on time, send data according to the real-time protocol (setting according to Ken <time>).

The data transmitted when an alarm occurs consists of protocol header and type buffer, fault information buffer, and Ken protocol (e).

[Table 4] and [Table 5] below show the values that are input to the protocol type buffer and the fault information buffer and their values.

Value Description 10 Periodic Information Notification 11 Ken setting response 12 Ken Unanswered Response 13 Ken Current Information Response 14 Notification of Disability Information Change (Cancel / Occurrence) 15 Disability Information Release 20 Data transmission setting response

Value Description A Set when BUFF [42] is 14, 15

[Processor List]

Middle class Small classification Description TCP / IP RECV Material Request
Full Setpoint Request
Schedule Change (Basic Buffer)
Schedule (Basic Buffer) Request
System Reboot Request
Full text change of server SEND Data request response
Full Setpoint Request Response
Schedule (basic buffer) change complete
Schedule (Basic Buffer) Request Response
Complete system reboot
Server Content Change Response Message RECV Analysis of KEN, Igr, OR, IR, PT data
Check sum
Received data set value (lower limit, upper limit) Comparison Alarm status transmission SEND Control professional transmission
Request for data by schedule LED Module RUN LED blinks

According to FIG. 20, in order to initialize the communication processor, the communication processor is generated, and after reading the DB, the measurement equipment buffer and the object for each communication port are generated, the schedule buffer for each port is generated, and the timer is stopped.

Referring to FIG. 21, when a data request event occurs, a request message is generated according to an order by comparing schedules, and the generated request message is transmitted.

As shown in FIG. 22, when a data reception event occurs, the size of the received data is checked and stored in the reception buffer.

The received data is analyzed by the procedure as shown in FIG.

As described above, the present invention monitors the insulation state on-line at all times to identify the tendency of insulation deterioration to secure the reliability of power supply, and to regularly analyze the monitoring data and to save energy as well as to drastically reduce the cost. It becomes possible to combine with.

By incorporating the technology proposed in the present invention, it is expected that the reduction of labor and the drastic reduction of inspection cost and automation will greatly contribute to stimulating the economy of the electric equipment security related market as well as the ripple effect of reducing the economic loss.

In addition, the present invention can seek to quantify the power-related database through information sharing and digitization of data, which is expected to have a significant ripple effect not only in power but also in related industries.

Insulation resistance measuring apparatus according to the present invention not only prevents the disaster caused by poor insulation of electrical equipment in advance, but also to monitor the real-time insulation resistance on the web-based internet 24 hours in the uninterrupted live state for cost reduction, and analyze this data By detecting minute insulation deterioration through DB early, it is possible to prevent electrical fires, property loss, and casualties caused by ground faults.

Claims (7)

A signal detector for detecting a leakage current flowing in the load line in the live state;
A signal processor for sampling the leakage current detected by the signal detector;
An insulation detection unit for separating and extracting the active ingredient current flowing through the insulation resistance from the leakage current sampled by the signal processing unit, and calculating the insulation resistance using the extracted active ingredient current;
Uninterruptible insulation resistance of the distribution panel and switchboard, characterized in that it comprises an automatic calibration unit for generating a calibration signal to measure the calibration signal through the signal detection unit and check whether the measured value is within the tolerance range. Measuring device. The method of claim 1,
The signal detection unit is an uninterruptible insulation resistance measuring device of the distribution panel and switchgear, characterized in that for measuring the leakage current using an image current transformer. The method of claim 1,
The signal detection unit,
An apparatus for measuring uninterrupted insulation resistance of a distribution panel and a distribution panel using a low pass active filter to remove a specific frequency component from the detected leakage current. The method of claim 3,
The signal processing unit,
An apparatus for measuring uninterrupted insulation resistance of a distribution panel and a distribution panel, wherein a sampling period is set to at least two times the cutoff frequency of the low pass active filter. The method of claim 1,
The insulation detection unit,
An active component detection circuit for extracting and extracting the effective component current by a reference voltage applied between the ground line and the ground received from the ground line of the overlapping transformer and the ground with respect to the detected leakage current;
And an output current conversion circuit for converting the active ingredient current extracted by the active ingredient detection circuit into a current value or an insulation resistance value converted into a ground voltage of a target converter. The method of claim 1,
Uninterruptible insulation resistance measuring device of the distribution panel and switchgear further comprising a communication port for communication with the embedded web server for remote monitoring. The method of claim 1,
The automatic correction unit,
When the measured value is out of the tolerance range, the calibration value is calculated based on the measured value and the uninterruptible insulation resistance measuring apparatus of the switchgear and switchboard, characterized in that for performing the calibration operation.

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