KR101171350B1 - A Method and a Relay of DC Voltage Crossover and Ground Fault Detection - Google Patents

Abstract

The present invention provides a switching unit and a voltage meter for detecting and measuring respective voltages by a voltage line cross measurement to detect the mixing and grounding of DC125V, DC48V, DC24V and a plurality of DC voltages, and each analog measured by voltage line cross. Built-in A / D converter for converting voltage to digital coral, memory and microprocessor to determine whether it is mixed or grounded by executing program loaded in memory on microprocessor based on digital signal converted from A / D converter A touch and ground detection method and a relay comprising a touch and ground detection unit and a display unit for indicating touch and ground generation when the touch and ground detection unit determines that the contact and the ground are detected.

Description

A Method and a Relay of DC Voltage Crossover and Ground Fault Detection}

The present invention provides a switching unit and a voltage meter for detecting and measuring respective voltages by a voltage line cross measurement to detect the mixing and the grounding of DC125V, DC48V, DC24V, and two or more DC voltages. An A / D converter for converting an analog voltage into a digital signal, and a memory and a microprocessor for executing a program loaded in the memory on the microprocessor based on the digital signal converted by the A / D converter to determine whether they are mixed or grounded. The present invention relates to a contact and ground detection method and a relay including a built-in contact and ground detection unit and a display unit which displays the contact and ground generation when the contact and ground detection unit determines that the contact and the ground are detected.

Conventional relays related to the present invention include a DC ground detection device of Patent Publication No. 10-0836747 and a digital ground detection relay disclosed in Patent Publication No. 10-0262743, which relates the relationship between DC125V, DC power supply of a substation, and ground. Since there is no detecting device or relay to detect grounding and grounding between DC24V, DC125V and supervisory power supply DC48V which are the control power plants currently required in the substation, it is not easy to know which voltage is mixed or ground occurs in the substation. There is a need for an apparatus or method for efficiently detecting grounding.

In addition, in the existing system, there is a device that detects ground by sending a pulse using a PCT or DCT limited to DC125V, and there is no separate device that detects a touch.

The problem to be solved by the present invention is to have four points of contact at the time of the occurrence of the event of contact and ground to inform the upper system, and to prevent the expansion of the accident in advance by detecting the contact and ground.

The problem to be solved by the present invention is to detect the contact and the ground by the PLCM (power line cross measurement) method, and if it is determined that the ground, by using the DC Direct Virtual Voltage Insulation Throwing (DVIT) method to measure the ground current and the set current value Compared to more accurately determine whether the ground is displayed on the display, and to solve this quickly.

In order to solve the problem of the present invention, a switching unit and a voltage measuring instrument for detecting and measuring respective voltages by a voltage line cross measurement to detect the mixing and grounding of DC125V, DC48V, DC24V and two or more DC voltages, A / D converter for converting each measured analog voltage to digital voltage, and memory that determines whether it is mixed or grounded by executing a program loaded in the memory on the microprocessor based on the digital signal converted by the A / D converter. And a contact and ground detection unit having a microprocessor and a microprocessor, and a display unit for indicating contact and ground generation when the contact and ground detection unit determines that the contact and the ground are detected.

Another solution of the present invention is a PLCM method, which is a precision measurement method that does not detect when a hurried voltage is generated in order to discriminate touch and ground, and interlocks with the switching unit to measure the voltage of each phase in cross contact, ground and normal. If it is judged that it is ground, apply DC5V detection voltage to ground, and the closed circuit is composed of the voltage of each phase to measure the current value of return voltage and compare with the value set in memory. When the measured current is large, it is judged that the ground is generated and implements the contact and ground detection relay which can improve the reliability.

Another object of the present invention is to detect and measure each voltage by a voltage line cross measurement using a switching unit and a voltage meter to detect the contact and ground of DC125V, DC48V, DC24V and two or more DC voltages After converting each analog voltage measured by voltage line cross to digital voltage using A / D converter, it determines whether it is mixed or grounded by executing program in the microprocessor based on the converted digital signal. Through the step of, if it is determined that the contact and the ground to provide a contact and ground detection method consisting of the step of displaying the contact and ground generation in the display unit.

The present invention has four points of contact when an event occurs on the contact and ground can be informed to the upper system, there is an advantageous effect that can prevent the expansion of the accident in advance by detecting the contact and the ground.

Another effect of the present invention is to detect the contact and the ground by the PLCM method, and if it is determined that the ground, by measuring the ground current using the DVIT method to determine whether the ground accurately compared to the set current value to display on the display To solve it quickly.

1 illustrates a PLCM method for detecting contact and ground used in the present invention.
Figure 2 illustrates the DVIT method used in the ground current measurement of the present invention.
3 is a flow chart illustrating a contact and ground detection method according to the present invention.
4 is a block diagram illustrating a mixed contact and ground detection relay according to the present invention.
5 illustrates one of the screens displayed on the display unit of one side of the relay connected to the contact and ground detection apparatus according to the present invention.
<Explanation of symbols for the main parts of the drawings>
11; Switching unit 12; Voltage meter
13; A / D converter 14; Contact and ground detector (PLCM method)
15; Ground determination unit (DVIT method) 16; Memory
17; Display unit 18; I / O part
19; Communication unit 20: overvoltage / overcurrent protection circuit

Hereinafter, the present invention will be described in detail. In the present invention, the mixed and ground detection method detects and measures each voltage by voltage line cross measurement (PLCM) using a switching unit and a voltage meter to detect the mixed and ground of DC125V, DC48V, DC24V and two or more DC voltages. After converting each analog voltage measured by voltage line cross into digital signal using A / D converter, it executes a program in microprocessor based on the converted digital signal, After the step of determining, if it is determined that the contact and grounding is made to display the mixing and ground generation in the display unit.

The touch and ground detection relay according to the present invention includes a switching unit and a voltage meter for detecting and measuring respective voltages by voltage line cross measurement to detect the contact and ground of DC125V, DC48V, DC24V and two or more DC voltages. An A / D converter for converting each analog voltage measured by line cross into a digital signal, and a program loaded in the memory are executed by a microprocessor based on the digital signal converted by the A / D converter to check whether the analog signal is grounded or not. A touch and ground detector including a memory and a microprocessor to be judged, and a display unit which displays the touch and ground when it is determined that the touch and ground are detected by the touch and ground detector. A specific embodiment according to the present invention will be described.

<Examples>

&Lt; Example 1 >

Embodiment 1 of the present invention will be described in detail with reference to the accompanying drawings. Embodiment 1 relates to a mixing and ground detection method according to the present invention. 1 illustrates a PLCM method for detecting contact and ground used in the present invention. Figure 2 illustrates the DVIT method used to detect ground in the present invention. 3 is a flow chart illustrating a contact and ground detection method according to the present invention.

First, the PLCM method and the DVIT method for detecting the contact and ground used in Example 1 according to the present invention will be described in detail.

The contact and ground detection method used in the present invention includes a power line cross measurement (PLCM) method, which is connected to each phase through an internal microprocessor according to the contact and ground conditions of respective voltages. It is a technical configuration that determines whether it is mixed or grounded according to the voltage level by measuring the voltage with a cross between the voltage (DC125P phase, DC125N phase, DC48P phase, DC48N phase, DC24P phase, DC24N phase, ground) with a semiconductor relay. Figure 1 illustrates the determination of the mixing, grounding and normality of DC125V, DC48V, DC24V and other DC voltage by the PLCM method used in the present invention.

The contact and ground detection sequences include P125V and N48V (1), P48V and N125V (2), P125V and N24V (3), P24V and N125V (4), P48V and N24V (5), P24V and N48V (6), and P125V. And voltage (7), P48V and ground (8), P24V and ground (9), N125V and ground (10), N48V and ground (11), N24V and ground (12).

The measurement time for each sequence is 1.6 kW, and it is measured whether the voltage is 200 Hz.

The contact and ground detection sequences and the measurement time for each sequence can be achieved by operating time of the hardware and designing a program change, and a plurality of measurement times can be set to increase accuracy.

As the ground current detection method used in the present invention, after confirming the ground position by the PLCM detection method of FIG. 1, if it is determined that the ground current, DC direct virtual voltage insulation throwing (DVIT) method The ground current is measured more accurately by using a semiconductor relay to insulate the voltage of the other potential and the different phase at the position where the ground occurs, and give the 5V potential only at the measurement site to form a closed circuit. It is to detect current accurately.

Figure 2 illustrates the determination of whether the ground of the DC125V, DC48V, DC24V and other DC voltage by the DVIT method used in the present invention.

In addition, it is preferable to set the current setting value used when determining whether the ground is compared with the measured ground current between 1 kV and 20 kV.

The mixing and ground detection method according to the present invention will be described in detail with reference to FIG. 3.

As shown in FIG. 1, a voltage is measured with a voltage meter while switching DC power corresponding to a detection target to a cross using a switching device composed of semiconductor devices for a measurement target such as DC125V, DC48V, and DC24V. .

Converting the analog voltage signal measured while crossing each measurement object with the voltage meter to a digital signal with an A / D converter.

Based on the converted digital signal, the contact and ground detection unit having an execution program designed and manufactured in accordance with the present invention, mounted in a memory, and configured to be executed by a microprocessor is determined.

In the step of determining whether the mixing, the ground and the normal state, when determining that the mixing occurs by the PLCM when the voltage measured by the voltage meter at the point where the mixing occurs is measured by adding the respective voltages mixed together to be. Specifically, when DC125V and DC48V are mixed, DC125V + DC48V = DC173V, and when DC48V and DC24V are mixed, DC48V + DC24V = DC72V. Judging by.

In the step of determining whether the contact, the ground and the normal state, in the case of judging the occurrence of ground by the PLCM is a state that almost no voltage is measured as the voltage measured by the voltage meter is near or near zero, in this case It is configured to re-examine whether or not grounding occurs correctly by DVIT method.

The normal state corresponds to a case where it is determined that no mixing or grounding occurs in the mixing and ground detection unit.

If the voltage measured by the voltage meter is weak or needs to be amplified, it may be amplified by a signal amplifier, and when it is necessary to remove the noise included in the signal, a noise removing filter may be employed to remove the noise.

If it is determined that grounding occurs in the step of determining whether the contact, ground, and normal, the ground current is detected using the above-described DVIT method.

When the DVIT method is used, the occurrence of grounding can be determined more accurately than the PLCM method, thereby increasing the accuracy and reliability of the contact and ground detection according to the present invention.

More specifically, if the set current value is large compared to the detected ground current and the set current value by comparing the measured ground current with the ground current set in the memory, the normal state detecting the touch and ground is returned to normal touch and ground detection. It is configured to continue.

If the measured ground current is greater than the current value set in the memory, the display unit is configured to display an alarm indicating a ground occurrence to release the ground.

If it is determined through the step of determining the mixing and the ground finally the mixing or ground generation, and displays the mixing and ground in the display unit, and proceeds to the step of eliminating this.

The display unit may be configured as a touch screen, a conventional LCD display unit, or various display screens.

The technical configuration according to the touch and ground detection method of the present invention will be summarized.

A method of detecting a touch and ground, comprising: detecting and measuring respective voltages by a voltage line cross measurement using a switching unit and a voltage meter to detect a touch and ground of DC125V, DC48V, DC24V and two or more DC voltages; Converting each analog voltage measured by the voltage line cross into a digital signal using an A / D converter, and determining whether it is mixed or grounded by executing a program in a microprocessor based on the converted digital signal; If it is determined that the contact and the ground is made to display the contact and ground generation in the display unit.

If it is determined that the ground generation occurs in the step of determining whether the contact and the ground, the ground current is detected by using the DVIT method, and when the detected ground current is smaller than the set current value compared to the current value set in the memory And determining that the state is greater than the set current value, and determining that the ground is generated and displaying the ground on the display unit.

In the step of determining whether or not the contact and the ground may include the step of eliminating the contact and ground generation when it is determined that the contact and ground.

The method for eliminating the contact and ground generation is made up of a technical configuration that generates or eliminates the reset signal after the contact recovery, or reset from the outside.

If the voltage signal measured in the step of detecting and measuring each voltage is weak, amplifying the voltage signal with a signal amplifier and removing noise included in the voltage signal measured in the step of detecting and measuring each voltage. In order to remove the noise may include a noise removing filter.

&Lt; Example 2 >

Embodiment 2 relates to a contact and ground detection relay according to the present invention. 4 is a block diagram of the components of the contact and ground detection relay according to the present invention.

Based on FIG. 4, the touch and ground detection relay according to the present invention includes a voltage meter for measuring DC125V, DC48V, DC24V, and other DC voltages to determine whether the DC125V, DC48V, DC24V, and other DC voltages are mixed or grounded. A switching unit made of a semiconductor device for measuring a corresponding voltage with a voltage meter while alternately switching each DC voltage.

In addition, the PLCM method of FIG. 1 includes an A / D converter for measuring voltage while crossing each point while switching in the switching unit of FIG. 4, and converting each measured analog voltage signal into a digital signal. have.

In addition, a touch and ground detector is provided to determine whether the DC125V, the DC48V, the DC24V and other DC voltages are mixed, grounded, and in a normal state based on the respective signals converted into digital signals.

The contact and ground detection unit for determining whether the contact, the ground and the normal state according to the present invention includes a microprocessor and a memory, and determines the contact and ground as shown in the flowchart shown in FIG. 3, and generates an event (ground or contact). A program capable of performing a series of means, such as displaying an alarm according to the display unit, is mounted in a memory.

In the touch and ground detection unit, when it is determined by the PLCM that the touch is generated, each voltage generated by the touch is added. Since a detailed description thereof has been described in Example 1, the description thereof will be omitted.

In the contact and ground detection unit, when it is determined that the ground is generated by the PLCM, almost no potential is measured, and in this case, it is configured to accurately determine whether the ground is generated by the DVIT method.

When the contact and ground detection unit 14 determines that the ground occurs, the DVIT ground detection unit determines whether or not the ground more accurately. It is configured to judge the steady state when the set current value is large by comparing the ground current set in the memory with the measured ground current, and to determine the occurrence of ground when the measured ground current is larger than the set current value.

When the touch and ground detector 14 determines that the touch and the ground are mixed, the display unit may display a touch or ground.

5 shows a screen displayed on the display unit of the contact and ground detection apparatus according to the present invention.

As shown in FIG. 5, a diagram displaying a DC power configuration diagram through the display unit 17, a ground current setting, a driving relay operation time setting, a reset setting, a reset time setting, and the like. Equipped with AL_Set to do this.

It also has a Time_Set to set the horn stop, manual reset, date and time, and an Event to check the event record.

Includes SETUP function to set detailed functions of touch and ground detection relay, and on the diagram screen, it displays between DC power phases generated by horizontal blue lines when touch occurs. It is configured to.

In the case of ground generation, the current between the DC power supply and the ground generated by the vertical red line is displayed, and it is configured to display which DC power supply and the ground have occurred.

On the other hand, the color displayed on the screen whether the contact and ground occurs is enough that the operator can easily identify the color.

If the voltage measured by the voltage meter is weak or needs to be amplified, it may be amplified by a signal amplifier, and when it is necessary to remove the noise included in the signal, a noise removing filter may be employed to remove the noise.

Hereinafter, the technical configuration according to the touch and ground detection relay of the present invention will be summarized.

In the mixed contact and ground detection relay, a switching unit and a voltage meter for detecting and measuring respective voltages by a voltage line cross measurement to detect the mixed and ground of DC125V, DC48V, DC24V, and a plurality of DC voltages. An A / D converter for converting each measured analog voltage into a digital signal, and a memory that determines whether the microprocessor is grounded by executing a program in the memory based on the digital signal converted by the A / D converter. And a touch and ground detector incorporating a microprocessor, and a display unit which displays the touch and ground when the contact and ground detector are judged to be touch and ground.

If it is determined that the ground occurs in the contact and ground detection unit in which the memory and the microprocessor are built in, a means for detecting a ground current using a DVIT method and a current value set by comparing the detected ground current with a current value set in the memory. Means for determining the normal state when small, and means for indicating the ground occurrence on the display unit by determining that the ground occurs when the current value is larger than the set current value.

And a means for releasing the contact and grounding when the contact and ground detection unit incorporating the memory and the microprocessor determines that the contact and the ground occur.

The contact and ground detector includes a communication unit to communicate with an external mobile communication terminal.

When each voltage signal measured using the switching unit and the voltage meter is weak, a signal amplifier for amplifying the voltage signal, and removing noise included in the voltage signal measured using the switching unit and the voltage meter. It may be provided with a noise removing filter for.

The present invention provides a switching unit and a voltage meter for detecting and measuring respective voltages by a voltage line cross measurement to detect the mixing and grounding of DC125V, DC48V, DC24V and a plurality of DC voltages, and each analog measured by voltage line cross. Built-in A / D converter for converting voltage into digital signal, memory and microprocessor to determine whether it is mixed or grounded by executing program loaded in memory on microprocessor based on digital signal converted from A / D converter By providing a contact and ground detection method and a relay consisting of a touch and ground detection unit and a display unit which displays the touch and ground occurrence when the touch and ground detection unit judges that the contact and ground is to determine the contact and ground accurately and quickly Since this can be eliminated, industrial applicability is very high.

Claims (11)

In the ground detection method,
Detecting and measuring respective voltages by a voltage line cross measurement using a switching unit and a voltage meter to detect grounds of two or more DC voltages;
Converting each analog voltage measured by the voltage line cross into a digital signal using an A / D converter;
Determining whether the microprocessor is grounded based on the converted digital signal; And
If it is determined that the ground is grounding method comprising the step of indicating the occurrence of ground on the display. The method of claim 1,
Detecting a ground current using a DVIT method when it is determined that grounding occurs in the determining of grounding;
Determining a normal state when the detected ground current is smaller than a set current value by comparing with a current value set in a memory; And
If it is greater than the set current value, the ground detection method comprising the step of indicating the ground occurrence in the display unit. The method of claim 1,
The ground detection method further comprises the step of eliminating the ground when the ground is determined in the step of determining whether the ground. The method of claim 1,
Amplifying the voltage signal measured in the detecting and measuring of each voltage by a signal amplifier; And
And removing a noise included in the voltage signal measured in the detecting and measuring of each voltage by a noise removing filter. The method according to any one of claims 1 to 4,
And determining that the ground occurs when the voltage measured by the voltage meter is zero in the determining of the ground. In the ground detection relay,
A switching unit and a voltage meter for detecting and measuring respective voltages by voltage line cross measurement to detect grounding of two or more DC voltages;
An A / D converter for converting each analog voltage measured by voltage line cross into a digital signal;
A ground detector including a memory and a microprocessor configured to determine whether the ground is executed by executing a program mounted in the memory on the microprocessor based on the digital signal converted by the A / D converter; And
A ground detection relay comprising a display unit for indicating the ground occurrence when the ground detection unit is determined to be ground. The method of claim 6,
The ground detection relay detects the ground current by using the DVIT method if it is determined that the ground occurs in the ground detection unit having a memory and a microprocessor,
When it is smaller than the set current value compared with the detected ground current and the current value set in the memory, it is determined as a normal state,
A ground detection relay further comprising means for indicating a ground occurrence in the display unit when the current value is greater than the set current value. The method of claim 6,
And a means for releasing ground when the ground detection unit incorporating the memory and the microprocessor determines grounding. The method of claim 6,
A signal amplifier for amplifying each voltage signal measured using the switching unit and the voltage meter; And
And a noise removing filter for removing noise included in the voltage signal measured using the switching unit and the voltage meter. The method of claim 7, wherein
And the set current value is set between 1 kV and 20 kV. The method according to any one of claims 6 to 10,
And wherein the ground detector detects the ground when the voltage measured by the voltage meter is zero.

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