KR102206379B1 - Photovoltaic ground resistance measuring system - Google Patents

Abstract

The present invention relates to a state of grounding of a photovoltaic power facility (e.g., a solar cell array, a relay terminal box (or a junction box), a connection of a ground line in an inverter, and a state of loosening, contamination, damage, corrosion, etc.) ) Is automatically measured to monitor the safety state, and a system and method for measuring the ground resistance of photovoltaic power generation, wherein the ground resistance measurement unit measures the ground resistance using a ground sensor connected to a reference ground; The electric facility measurement unit measures the leakage current of the electric facility by using an electric facility sensor connected to the electric facility; The power facility measurement unit measures the voltage and current of the power facility using the power facility sensor connected to the power facility of the photovoltaic power generation; The data collection processing unit measures the grounding state by collecting the ground resistance measured by the ground resistance measurement unit, the leakage current measured by the electrical facility measurement unit, and the voltage and current measured by the power equipment measurement unit; The data analysis unit schedules and reads the ground state measured by the data collection processing unit, and provides the scheduling meter reading ground state; The monitoring unit visualizes and displays the scheduling meter reading grounding state, stable state, or dangerous state provided by the data analysis unit; The data analysis unit measures the voltage and current of the target facility and calculates the transient impedance by using the information obtained by the transient impedance calculation program.

Description

Photovoltaic ground resistance measuring system and method

The technical field of the present invention relates to a system and method for measuring the ground resistance of photovoltaic power generation, and in particular, the grounding state of power equipment related to photovoltaic power generation (e.g., solar cell array, relay terminal box (or connection box), inverter). The present invention relates to a system and method for measuring the earth resistance of photovoltaic power generation to monitor the safety state by automatically measuring the connection of the ground wire and the condition of loosening, contamination, damage, corrosion of the connection terminal.

Korean Patent Registration No. 10-1117611 (registered on Feb. 10, 2012) discloses a ground current measurement circuit of a photovoltaic power generation system equipped with a photovoltaic generator. Inverters supplying the output of the photovoltaic generator through an AC voltage trunk, respectively, are positive poles. A grounding device that grounds the photovoltaic generator at (+) or minus pole (-), the first shunt resistance through which the first current flows when the photovoltaic generator is grounded at the plus pole (+) and short-circuited, and the photogenerator is at the minus pole (-) When the circuit is grounded and short-circuited, the shunt resistor is inserted into the current mirror circuit, and the shunt resistor is inserted into the current mirror circuit, and the first transistor having the first series resistance is the first of each shunt resistor. A second transistor connected to the terminal and having a second series resistor having the same electrical resistance as the first series resistor is connected to the second terminal of each shunt, and the two current mirror circuits correspond at different evaluation points. When connected and short-circuited, as the two currents flow, the voltage drop generated at each shunt resistor causes an asymmetry in the corresponding current mirror circuit, the magnitude being proportional to the two currents flowing through each shunt resistor, and asymmetry. Is evaluated at the evaluation points of two current mirror circuits that are correspondingly connected at different positions, and the electric potential of the evaluation points is characterized in that when short-circuited, the electric potential at the point where the two currents flow through each shunt resistor. According to the disclosed technology, in a photovoltaic power generation system equipped with a photovoltaic generator, it is used to measure the current through a ground connection element or a ground fault pulse of the grounding device of an inverter that supplies the output of the DC power to the AC voltage trunk line, and the measurement point is evaluated. The ground current can be measured simply and inexpensively even at a potential that is significantly different from that of the point.

Korean Patent Registration No. 10-0306569 (registered on Oct. 10, 2001) is a measurement of the ground resistance of the grounding facility, which is the basis of power facilities and communication facilities, to accurately measure the grounding resistance of the grounding facility even when the power facility or communication facility is in operation. An apparatus and method are disclosed. According to the disclosed technology, in a grounding resistance measuring device for measuring the grounding resistance between current poles by a voltage applied through a voltage pole, power is applied to the current pole to be measured according to a separate frequency preset by the user. A power supply for A current measuring unit that measures the current between the current poles and outputs phase-corrected current information; A potential measurement unit that measures a potential between the potential electrodes through a high input impedance of a predetermined potential or more and outputs phase-corrected potential information; A conversion unit for processing a signal by simultaneously sampling current information and potential information applied from the current measurement unit and the potential measurement unit; A signal generator configured to receive current information and potential information processed by the conversion unit, calculate ground resistance and resistance to earth, and output a preset frequency and current magnitude signal to the conversion unit; It is characterized in that it comprises a display means for displaying the ground resistance and the intrinsic resistance calculated from the signal generating unit, and applying a signal of a predetermined frequency and current magnitude from the user to the signal generating unit.

The grounding system focuses on the prevention of electric shock accidents of the human body as a power environment in which new and renewable energy and smart grids are mixed is recently introduced, as well as the protection of the human body, as well as facility maintenance costs and power generation due to defects in electrical and electronic facilities. It is for the efficient safety of the power generation system by minimizing damage such as loss.

It refers to a phenomenon in which dangerous voltage appears or current flows outside the converter or device because the insulation between the converter and the earth is abnormally deteriorated and is bridged by an arc or conductive material. This is a ground fault and is a kind of accident phenomenon. . And this current is called'ground fault current', and this phenomenon is also called'earth leakage'. When a ground fault occurs in a converter, it often causes electric shock or damage to the power equipment, and the insulation of the converter is deteriorated and damaged. For example, when a ground fault current occurs through a transformer or motor case, these cases If a voltage is generated and a person touches it, it causes an electric shock. Therefore, for a specific device, it is necessary to install a short circuit breaker for preventing electric shock in order to prevent the risk of electric shock when a dangerous voltage is generated in the case due to a ground fault. In order to prevent a disaster caused by a ground fault, it is necessary to maintain the insulation of the converter or equipment in a normal manner, and to protect against a ground fault.

Such a grounding system is buried at the same time during the construction of the structure and is used without replacement or reinforcement for more than several decades. Therefore, it is not possible to check in real time whether abnormal conditions such as loss or disconnection due to corrosion of the grounding system occur. Has a problem. In addition, the inspection standards for grounding work are at the time of completion of the structure and once a year, which are divided into junction box grounding, solar structure grounding, and inverter box grounding depending on the manpower. At this time, there is also a problem of visually determining the connection of the ground wire in the solar cell array, the relay terminal box (or junction box), and the loosening, contamination, damage, and corrosion of the connection terminal in the inverter.

In the conventional grounding system as described above, to check the installation state of the ground wire and whether the ground wire is removed, it is checked whether the ground wire is dropped or corroded, and the grounding resistance value is determined by the electrical equipment technical standards or the grounding resistance specified in the manufacturer's application code. It is checked with a resistance meter, and the grounding resistance check at this time focuses on the prevention of electric shock to the human body, and the grounding status is checked with the naked eye, and the grounding status is checked by measuring the impedance below the standard value through an ohmmeter that depends on manpower Actually. In other words, the conventional photovoltaic power generation ground resistance measurement, as shown in FIG. 1, is a method of directly checking the state of the ground resistance by manpower at a dependent site, and is a method of checking the power equipment related to photovoltaic power generation (for example , There is a problem of visually judging the connection of the ground wire to the relay terminal box (or junction box), the inverter, etc. and loosening, contamination, damage, and corrosion of the connection terminal.

On the other hand, since abnormal voltages such as external surges to major facilities such as power plants and substations sometimes lead to an accident due to an increase in the potential of the ground, it will be said that automatic measurement management for the relevant major facilities is necessary.

Korean Patent Registration No. 10-1117611 Korean Patent Registration No. 10-0306569

The problem to be solved by the present invention is to solve the necessity or problem as described above, and the grounding state of the power equipment related to photovoltaic power generation (eg, solar cell array, relay terminal box (or connection box), inverter It is to provide a solar power generation grounding resistance measurement system and method implemented so that the safety status can be monitored by automatically measuring the connection of the ground wire and the condition of loosening, contamination, damage, corrosion, etc. of the connection terminal.

As a means for solving the above-described problem, according to one feature of the present invention, a ground resistance measuring unit for measuring a ground resistance using a ground sensor connected to a reference ground; An electrical facility measuring unit for measuring a leakage current of an electrical facility using an electrical facility sensor connected to the electrical facility; Power equipment measuring unit for measuring the voltage and current of the power equipment using the power equipment sensor connected to the power equipment of the solar power generation; A data collection processing unit for measuring a grounding state by collecting the ground resistance measured by the ground resistance measurement unit, the leakage current measured by the electrical facility measurement unit, and the voltage and current measured by the power facility measurement unit; A data analysis unit configured to schedule and read a ground state measured by the data collection processing unit to provide a scheduled meter reading ground state; And a monitoring unit for visualizing and displaying a scheduling meter reading ground state, a stable state, or a dangerous state provided by the data analysis unit. The data analysis unit provides a photovoltaic ground resistance measurement system, characterized in that the transient impedance is calculated by a transient impedance calculation program using information obtained by measuring voltage and current of a target facility.

In one embodiment, the reference site is characterized in that a place where the state before energization does not change.

In one embodiment, the ground resistance measuring unit is characterized in that it measures a potential rise of the ground electrode based on an infinite distance.

In one embodiment, the ground resistance measuring unit is characterized in that it measures a potential rise of the ground electrode in the reference ground.

In one embodiment, the ground resistance measurement unit is characterized in that the ground resistance is expressed as R = ρ×f, R is the ground resistance, ρ is the ground resistivity, and f is a function determined as the shape and dimension of the electrode. do.

In one embodiment, the ground resistance measurement unit expresses the ground resistance as R = k×ρ/ι, R is the ground resistance, k is a coefficient determined as a shape, ρ is the earth resistivity, and ι is the electrode. It is characterized in that it is a characteristic dimension indicating the scale.

In an embodiment, the ground resistance measurement unit measures the ground resistance using a ground sensor connected to a ground resistance measurement object buried in the ground.

In one embodiment, the ground resistance measurement unit measures voltage and current using a ground sensor connected to an electrode that is a grounded reference by embedding a plurality of electrodes in a line at a predetermined interval and a predetermined depth in the ground to be measured. It is characterized by calculating the ground resistance.

In one embodiment, the electrical facility measuring unit is characterized in that using an electrical facility sensor connected to the electrical facility to measure voltage and current of the electrical facility and use it as data for measuring ground resistance.

In one embodiment, the power facility measurement unit is characterized in that it measures the voltage and current state of the target facility using a power facility sensor connected to the facility of solar power generation and uses it as data for measuring ground resistance. .

In one embodiment, at least one of the ground resistance measurement unit, the electric facility measurement unit, and the power facility measurement unit is connected using a cable for measuring the grounding state, and contacts the steel structure with a clip terminal at each sensor position. It is characterized in that the ground resistance is measured by measuring voltage and current and measuring impedance by using a phase difference between voltage and current.

In one embodiment, the data analysis unit is characterized in that the grounding state measured by the data collection processing unit is analyzed, processed and transmitted to the monitoring unit so that the monitoring unit can visualize and display a screen.

In one embodiment, the data analysis unit, when processing and analyzing the grounding state measured by the data collection processing unit in real time through an analysis software algorithm, measure the voltage and current of the target facility, It is characterized in that the potential rise measurement and analysis are performed.

In one embodiment, the transient impedance calculation program converts data processing to obtain raw data into voltage and current discrete signals and stores them, and is designed as a software class diagram to derive a final result of the raw data. do.

In one embodiment, the data analysis unit is characterized in that the data is post-processed using an interpolation method through a post-processing algorithm so that the monitoring unit draws cleanly.

In one embodiment, the data analysis unit receives a sine wave of a predetermined frequency output from the ground resistance measurement unit, the electric facility measurement unit, and the power equipment measurement unit through the data collection processing unit and processes the signal in the monitoring unit. It is characterized in that it is displayed as a raw data graph.

In one embodiment, the data analysis unit is characterized in that the impedance is measured by using a phase difference between a voltage and a current, and a frequency and a sampling rate are checked and displayed on a screen through the monitoring unit.

In one embodiment, the data analysis unit is characterized in that by performing a frequency analysis using an FFT analysis algorithm, to determine whether the center frequency and the peak value coincide, and to check and remove errors occurring in other parts. .

In one embodiment, the data analysis unit, the ground resistance measurement unit, the electrical facility measurement unit, when measuring in the power equipment measurement unit, checks which part is the frequency currently being measured, and the value is intended It is characterized in that it checks whether it proceeds without error, and displays the result of the check as an FFT graph through the monitoring unit.

In one embodiment, the data analysis unit considers the rest of the frequency excluding the center frequency as noise by the FFT analysis algorithm, filters the noise to make the previously acquired raw data cleaner than before, and filters the previously acquired raw data to be filtered and then monitors the monitoring with a sine wave graph. It is characterized in that it is displayed through the unit.

In one embodiment, the data analysis unit re-draws the raw data using only the data of a predetermined percentage of the maximum value of the center frequency verified by the FFT, and the size of the peak sine wave is 1.25 [MHz] or a lower region It is characterized in that it checks that an unintended noise signal is introduced into the device.

In an embodiment, the data analysis unit automatically removes signals other than the maximum value found in the FFT analysis algorithm to clean the signal and display it through the monitoring unit.

값을 곱해 주어 임피던스를 구하여 임피던스 결과를 상기 모니터링부를 통해 디스플레이시켜 주도록 하는 것을 특징으로 한다.In one embodiment, the data analysis unit displays the magnitude of the voltage and current for each frequency band through the monitoring unit, and the power factor

It is characterized in that the impedance is obtained by multiplying the value and the impedance result is displayed through the monitoring unit.

값에 의해서 주파수가 증가함에 따라서 임피던스도 증가하는 결과를 상기 모니터링부를 통해 디스플레이시켜 주도록 하는 것을 특징으로 한다.In one embodiment, the data analysis unit,

As the frequency increases according to the value, the result of the impedance increase is displayed through the monitoring unit.

In one embodiment, the data analysis unit calculates a phase difference by detecting a zero proximity point using a calculation method using the magnitude and phase difference of voltage and current, and displays a phase difference graph using the result value through the monitoring unit. , It is characterized in that the relationship between the phase difference and the impedance in the current grounding environment and the relationship between the frequency and the relationship is identified with this result value.

In one embodiment, the data analysis unit calculates a ratio divided by reactance by calculating a pure resistance component to use an impedance graph obtained with a voltage, current, and phase difference as a graph of a ratio of reactance and resistance. It is characterized in that it is displayed through the monitoring unit.

In an embodiment, the data analysis unit is a graph representing a ratio of reactance and resistance, and displays a ratio of a frequency dependent impedance to a resistance independent of frequency through the monitoring unit.

In one embodiment, the monitoring unit provides an initial main screen for ground resistance measurement using an HMI, and the ground resistance measurement screen menu consists of a raw data result, an FFT graph, a filtered sine wave graph, an impedance result, a phase difference graph, and a reactance. It is characterized by providing a graph of the ratio of and resistance.

In one embodiment, the monitoring unit is connected to the HMI through a USB port, detects when the USB port is not connected, and outputs a port error occurrence message.

In an embodiment, the monitoring unit is characterized in that the battery resistance measurement operation is scanned and displayed from 65Hz to 1280MHz, and when the detection operation is completed, a message is output after the measurement is completed.

In one embodiment, the monitoring unit is characterized in that the actual measured raw data is detected and displays a waveform for voltage/current versus frequency application.

In one embodiment, the monitoring unit is characterized in that to display a frequency increase state from 65Hz to 1270MHz for the frequency output.

In an embodiment, the monitoring unit displays data in a state in which noise components have been removed by applying a noise removal algorithm from the discrete signal.

In one embodiment, the monitoring unit is characterized in that the graph displays an impedance value versus frequency as a result of frequency and voltage output.

In an embodiment, the monitoring unit displays a result of calculating a phase difference according to a zero proximity point as a frequency increases.

In one embodiment, the monitoring unit is characterized in that it displays a ratio of frequency-dependent impedance with a graph indicating a ratio of reactance and resistance.

As a means for solving the above-described problem, according to another feature of the present invention, the steps of generating voltage and frequency in each of a ground resistance measurement unit, an electric facility measurement unit, and a power facility measurement unit; Measuring ground resistance using a ground sensor connected to a reference ground in the ground resistance measuring unit; Measuring a leakage current of an electric facility by using an electric facility sensor connected to the electric facility by the electric facility measuring unit; Measuring the voltage and current of the power facility by using the power facility sensor connected to the power facility of the photovoltaic power generation by the power facility measuring unit; Measuring a grounding state by collecting, by a data collection processing unit, a ground resistance measured by the ground resistance measurement unit, a leakage current measured by the electric facility measurement unit, and a voltage and current measured by the power facility measurement unit; Providing a scheduling meter reading grounding state by scheduling a grounding state measured by the data collection processing unit by a data analysis unit and reading the meter; And visualizing and displaying, by a monitoring unit, a grounding state, a stable state, or a dangerous state for scheduling meter reading provided by the data analysis unit. The data analysis unit provides a method for measuring a photovoltaic power generation ground resistance, characterized in that the transient impedance is calculated by a transient impedance calculation program using information obtained by measuring voltage and current of a target facility.

The effects of the present invention include the grounding state of a photovoltaic power facility (e.g., a solar cell array, a relay terminal box (or connection box), a connection of a ground line in an inverter and a loosening of the connection terminal, contamination, damage, By providing a solar power generation grounding resistance measurement system and method implemented to automatically measure conditions such as corrosion) and monitor the safety status, there is no need to check the ground resistance status by personnel directly at the dependent site. It is not necessary to visually judge the connection of the ground wire in the solar cell array, the relay terminal box (or junction box), the inverter, and the loosening, contamination, damage, and corrosion of the connection terminal for related power facilities. It is possible to prevent accidents caused by an increase in the ground potential when an abnormal voltage such as an external surge to the facility is introduced.

1 is a diagram showing a state of measuring a ground resistance in a conventional grounding system.
2 is a diagram illustrating a photovoltaic ground resistance measurement system according to an embodiment of the present invention.
3 is a diagram illustrating a measurement result of raw data through a monitoring unit of FIG. 2 as an example.
4 is a diagram illustrating a sine wave graph before filtering through a monitoring unit in FIG. 2 as an example.
FIG. 5 is a diagram illustrating an example of an FFT graph when noise is introduced through the monitoring unit of FIG. 2.
6 is a diagram illustrating a sinusoidal graph after filtering through a monitoring unit in FIG. 2 as an example.
FIG. 7 is a diagram illustrating an impedance result through a monitoring unit in FIG. 2 as an example.
FIG. 8 is a diagram illustrating a phase difference graph through a monitoring unit in FIG. 2 as an example.
9 is a diagram illustrating a graph of a ratio of reactance and resistance through a monitoring unit in FIG. 2 as an example.
FIG. 10 is a diagram illustrating an initial main screen for measuring ground resistance through the monitoring unit of FIG. 2 as an example.
FIG. 11 is a diagram illustrating a configuration of a screen menu for measuring ground resistance through a monitoring unit in FIG. 2 as an example.
12 is a diagram illustrating a port error occurrence message through a monitoring unit in FIG. 2 as an example.
13 is a diagram illustrating a message after measurement is ended through the monitoring unit of FIG. 2 as an example.
14 is a diagram illustrating a waveform of voltage/current versus frequency application through the monitoring unit in FIG. 2 as an example.
15 is a diagram illustrating an example of a frequency increase state through the monitoring unit in FIG. 2.
16 is a diagram illustrating data in a state in which noise components are removed through a monitoring unit in FIG. 2 as an example.
FIG. 17 is a diagram illustrating an example of an impedance value versus frequency through a monitoring unit in FIG. 2.
18 is a diagram illustrating a result of calculating a phase difference through a monitoring unit in FIG. 2 as an example.
19 is a diagram illustrating an example of a frequency-dependent impedance ratio through the monitoring unit of FIG. 2.
20 is a diagram illustrating a method of measuring a photovoltaic ground resistance according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, since the embodiments can be modified in various ways and have various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical idea. In addition, since the object or effect presented in the present invention does not mean that a specific embodiment should include all of them or only those effects, the scope of the present invention should not be understood as being limited thereto.

The meaning of the terms described in the present invention should be understood as follows.

Terms such as "first" and "second" are used to distinguish one component from other components, and the scope of rights is not limited by these terms. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component. When a component is referred to as being "connected" to another component, it should be understood that although it may be directly connected to the other component, another component may exist in the middle. On the other hand, when it is mentioned that a component is "directly connected" to another component, it should be understood that there is no other component in the middle. On the other hand, other expressions describing the relationship between the constituent elements, that is, "between" and "just between" or "neighboring to" and "directly neighboring to" should be interpreted as well.

Singular expressions are to be understood as including plural expressions unless the context clearly indicates otherwise, and terms such as "comprises" or "have" refer to specified features, numbers, steps, actions, components, parts, or It is to be understood that it is intended to designate that a combination exists and does not preclude the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the field to which the present invention belongs, unless otherwise defined. Terms defined in a commonly used dictionary should be interpreted as having the meaning of the related technology in context, and cannot be interpreted as having an ideal or excessively formal meaning unless explicitly defined in the present invention.

Now, a solar power generation ground resistance measurement system and method according to an embodiment of the present invention will be described in detail with reference to the drawings.

2 is a diagram illustrating a photovoltaic ground resistance measurement system according to an embodiment of the present invention, FIG. 3 is a diagram illustrating a measurement result of raw data through a monitoring unit of FIG. 2 as an example, and FIG. 4 is A diagram illustrating a sine wave graph before filtering through the monitoring unit in as an example, and FIG. 5 is a diagram illustrating an FFT graph when noise is introduced through the monitoring unit in FIG. 2 as an example, and FIG. 6 is a monitoring unit in FIG. A diagram illustrating a sine wave graph after filtering through an example, and FIG. 7 is a diagram illustrating an impedance result through a monitoring unit in FIG. 2 as an example, and FIG. 8 is a diagram illustrating a phase difference graph through a monitoring unit in FIG. 2 as an example, FIG. 9 is a diagram illustrating a graph of a ratio of reactance and resistance through a monitoring unit in FIG. 2 as an example, and FIG. 10 is a diagram illustrating an initial main screen for measuring ground resistance through a monitoring unit in FIG. 2 as an example, and FIG. A diagram illustrating the configuration of a screen menu for measuring ground resistance through a monitoring unit in FIG. 2 as an example, FIG. 12 is a diagram illustrating a port error generation message through the monitoring unit in FIG. 2 as an example, and FIG. 13 is a diagram illustrating the monitoring unit in FIG. A diagram for explaining a message after completion of measurement through an example, and FIG. 14 is a diagram illustrating a waveform for voltage/current versus frequency application through the monitoring unit in FIG. 2 as an example, and FIG. 15 is a frequency increase through the monitoring unit in FIG. A diagram illustrating a state as an example, and FIG. 16 is a diagram illustrating data in a state in which noise components are removed through the monitoring unit in FIG. 2 as an example, and FIG. 17 is a diagram illustrating an impedance value versus frequency through the monitoring unit in FIG. 2 as an example. FIG. 18 is a diagram illustrating a result of calculating a phase difference through a monitoring unit in FIG. 2 as an example, and FIG. 19 is a diagram illustrating a frequency-dependent impedance ratio through a monitoring unit in FIG. 2 as an example.

2 to 19, the photovoltaic ground resistance measurement system (A) performs measurements ranging from a stable state to several MHz for automatic measurement and management of major facilities related to photovoltaic power generation such as power plants and substations. To measure and analyze the increase in potential for high-frequency surges, the ground resistance measurement unit 10, the electric facility measurement unit 20, the power facility measurement unit 30, the data collection processing unit 40, the data analysis unit 50 , And a monitoring unit 60.

The grounding resistance measuring unit 10 has a grounding sensor that is a grounded reference (that is, a grounding sensor connected to the reference ground), measures the grounding resistance using the grounding sensor, and measures the measured grounding resistance. It notifies the data collection processing unit 40. Here, when the ground current (I) flows into the ground electrode, the potential of the ground electrode rises by as much as E[V] compared to before the ground current flows, and E/I[Ω] is called'ground resistance'. . Earthing resistance refers to the sum of the self-resistance of the ground wire and the ground electrode, the contact resistance between the surface of the ground electrode and the soil, and the earth resistance around the electrode, and the main element of the ground resistance is the resistance appearing on the earth surrounding the electrode. In addition, in order to pass a grounding current through the grounding electrode, a separate grounding electrode must be installed on the ground. Power is supplied between the two ground electrodes to flow a ground current. At this time, the second electrode is called a'return electrode'.

In an embodiment, the ground resistance measuring unit 10 may measure a potential rise of the ground electrode based on an infinite distance. That is, the ground resistance measuring unit 10 may measure the increase in the potential of the ground electrode in a place where the state before energization does not change (ie, the reference ground).

In an embodiment, the ground resistance measuring unit 10 may express the ground resistance by Equation 1 below. Where R is the ground resistance, ρ is the earth resistivity, and f is a function determined by the shape and dimensions of the electrode.

(Equation 1)

R = ρ×f

As shown in Equation 1, the ground resistance is proportional to the ground resistivity, that is, in the case of electrodes having the same shape and dimensions, the lower the ground resistivity, the lower the resistance can be obtained. In addition, the function f cannot be determined unless the shape of the electrode is specific, and when the shape of the electrode is constant and the size of the electrode changes to a similar shape, the ground resistance is as Equation 2 below. Here, ι is a characteristic dimension indicating the scale of the electrode, and k is a coefficient determined as a shape.

(Equation 2)

R = k×ρ/ι

As shown in Equation 2, when the earth resistivity is constant, the shape does not change and the earth resistance decreases as the scale increases.

In one embodiment, the ground resistance measurement unit 10 may measure the ground resistance using a ground sensor connected to the ground resistance measurement object buried in the ground, and at this time, a plurality of electrodes are arranged in a row on the ground to be measured. The ground resistance can be calculated by measuring voltage and current using a ground sensor connected to an electrode that is buried at a certain interval and a certain depth and is connected to the grounded reference electrode.

The electrical facility measurement unit 20 includes an electrical facility sensor connected to an electrical facility, which is a structure to check other grounding conditions, and measures the leakage current of the electrical facility using the corresponding electrical facility sensor, and measures the measured leakage. The current is notified to the data collection processing unit 40.

In one embodiment, the electrical facility measurement unit 20 may measure the voltage and current of an electrical facility using an electrical facility sensor connected to the electrical facility, and at this time, as an example of an electrical facility, a transmission tower for installing a high-voltage wire It is possible to measure the voltage and current of target facilities such as, etc., and the measured voltage and current data can be used as data for measuring ground resistance.

The power facility measurement unit 30 is provided with a power facility sensor connected to a photovoltaic power facility (for example, a solar array, a junction box, an inverter, etc.), and uses the power facility sensor. The voltage and current of is measured, and the measured voltage and current is notified to the data collection processing unit 40.

In one embodiment, the power facility measurement unit 30 may measure the voltage and current state of the target facility using a power facility sensor connected to the facility of solar power generation, and at this time, the power facility sensor You can measure the voltage and current status of the target facility by connecting it to the solar cell array, relay terminal box (or junction box), and inverter among the facilities of the facility, and use the measured voltage and current data as data to measure the ground resistance. I can.

In one embodiment, the ground resistance measurement unit 10, the electrical facility measurement unit 20, and the power facility measurement unit 30 may measure the ground resistance at each of the grounding parts. It is connected using a cable (not shown in the drawing for convenience of explanation) and can be contacted with a steel structure with a clip terminal at each sensor position, and the ground resistance is a method of measuring voltage and current and impedance using their phase difference. Can be measured.

The data collection processing unit 40 collects the ground resistance notified from the ground resistance measurement unit 10, the leakage current notified from the electrical facility measurement unit 20, and the voltage and current notified from the power facility measurement unit 30. The grounding state is measured, and the measured grounding state is notified to the data analysis unit 50.

In one embodiment, the data collection processing unit 40 is connected to the ground resistance measurement unit 10, the electrical facility measurement unit 20, and the power equipment measurement unit 30, respectively, the ground resistance measurement unit 10, electricity Data notified from the facility measurement unit 20 and the power facility measurement unit 30 may be collected and processed.

The data analysis unit 50 schedules and reads the measured grounding state notified from the data collection processing unit 40, and provides the scheduled grounding state to the monitoring unit 60.

In one embodiment, the data analysis unit 50 analyzes and processes the measurement grounding state notified from the data collection processing unit 40 to be visualized and displayed on a screen in the monitoring unit 60, I can deliver it.

In one embodiment, the data analysis unit 50 may process and analyze the measurement ground state notified from the data collection processing unit 40 in real time through an analysis S/W algorithm, and at this time, the voltage and current of the target facility Using the information obtained by measuring, it is possible to measure and analyze the potential rise for high-frequency surges.

In an embodiment, the data analysis unit 50 may calculate the transient impedance using information (voltage value and current value) obtained by measuring voltage and current of a target facility through a transient impedance calculation program. In this case, the transient impedance calculation program may convert data processing to obtain raw data into a voltage and current discrete signal and store it, as shown in FIG. 3 in the PC software. It can be designed as a software class diagram to derive the final result of raw data. Here, as shown in FIG. 3, an example of data obtained by randomly generating voltage and current with a transient impedance calculation program can be shown, and in reality, it is expected that it will not be drawn cleanly due to the capacity limits of voltage and current. Through the algorithm, data can be post-processed using interpolation methods, etc., so that it is drawn clearly.

In an embodiment, the data analysis unit 50 receives a sine wave of a predetermined frequency output from the ground resistance measurement unit 10, the electric facility measurement unit 20, and the power facility measurement unit 30 again and processes the signal. Thus, the raw data graph as shown in FIG. 4 can be displayed through the monitoring unit 60, in which case the voltage can be displayed in blue and the current can be displayed in red, and the phase difference between the voltage and the current is used. In addition, the frequency and sampling rate can be checked on the screen through the monitoring unit 60 and displayed as shown in Fig. 4, so that the user can recognize the error situation. have.

In one embodiment, the data analysis unit 50 uses a fast fourier transform (FFT) analysis algorithm to determine whether the center frequency and the peak value coincide, and to identify and remove errors occurring in other parts. Frequency analysis can be performed. At this time, the data analysis unit 50 intuitively determines where the frequency currently being measured is at the time of measurement in the ground resistance measurement unit 10, the electric facility measurement unit 20, and the power facility measurement unit 30. It can be checked as and whether the value proceeds without error as intended, and the result of the confirmation can be displayed through the monitoring unit 60 as an FFT graph as shown in FIG. 5.

In an embodiment, the data analysis unit 50 considers the remaining frequency portions excluding the center frequency as noise by the FFT analysis algorithm, filters the noise, and purifies the previously acquired raw data, and is shown in FIG. 6. After filtering as described above, a sine wave graph may be displayed through the monitoring unit 60. Accordingly, the data analysis unit 50 can re-draw the raw data again by using only the data of a predetermined percentage (eg, several %) of the maximum value of the center frequency verified in the FFT. Accordingly, as shown in FIG. 6, the peak value sine wave has a magnitude of 1.25 [MHz], but it can be confirmed that an unintended noise signal is introduced into a region slightly below it. Accordingly, the data analysis unit 50 automatically removes a signal other than the maximum value found in the FFT analysis algorithm to clean the signal before and after performing the operation, as shown in FIG. 6, the monitoring unit 60 It can be displayed through.

값을 곱해 주어 임피던스를 구하여 도 7에 도시된 바와 같은 임피던스 결과를 모니터링부(60)를 통해 디스플레이시켜 주도록 할 수 있다. 이때, 데이터분석부(50)는, 대부분의 경우 선로의

값에 의해서 주파수가 증가함에 따라서 임피던스도 증가하는 결과를 모니터링부(60)를 통해 디스플레이시켜 주도록 할 수 있다.In one embodiment, the data analysis unit 50 may display the magnitude of the voltage and current for each frequency band through the monitoring unit 60, and the power factor

Impedance is obtained by multiplying a value, and the impedance result as shown in FIG. 7 can be displayed through the monitoring unit 60. At this time, the data analysis unit 50, in most cases,

As the frequency increases according to the value, the result of increasing the impedance may be displayed through the monitoring unit 60.

In an embodiment, the data analysis unit 50 preferably uses a phase difference method using a phase difference between voltage and current (IEEE method), and thus, a calculation method using the magnitude and phase difference of voltage and current may be used. have. Here, in order to use the calculation method using the magnitude and phase difference of the corresponding voltage and current, the phase difference must be calculated by detecting a zero-crossing point, and the resultant value is a phase difference graph as shown in FIG. May be displayed through the monitoring unit 60, and accordingly, the relationship between the phase difference and impedance in the current grounding environment, and the relationship with the frequency may be intuitively grasped with the corresponding result value.

In an embodiment, the data analysis unit 50 calculates a pure resistance component and calculates a ratio divided by reactance in order to use an impedance graph obtained with voltage, current, and phase difference as shown in FIG. The graph of the ratio of reactance and resistance as described above can be displayed through the monitoring unit 60. That is, the data analysis unit 50 is a graph representing a ratio of reactance and resistance, and may display a ratio of frequency-dependent impedance to resistance independent of frequency as shown in FIG. 9. In this case, as shown in FIG. 9, the displayed result may appear very coarse even after filtering. It can be used as a level to grasp whether the overall ratio increases, falls, or has an inflection point.

The monitoring unit 60 displays the grounding state of the scheduling meter reading provided from the data analysis unit 50 through a monitor screen, and visualizes and displays a stable state or a dangerous state.

In an embodiment, the monitoring unit 60 may be connected to the analysis unit 50 to visualize and display the grounding state of each target facility derived from the data analyzed by the analysis unit 50. By displaying the grounding status through the monitor screen and visualizing and expressing the safety status or the danger status, the user can immediately recognize the danger situation.

In an embodiment, the monitoring unit 60 may further include a sound output means (not shown in the drawing for convenience of explanation) such as a speaker to recognize a dangerous situation by voice or sound in addition to a visually displayable monitor. .

In an embodiment, the monitoring unit 60 may provide the initial main screen for measuring the ground resistance as shown in FIG. 10 using a human machine interface (HMI), and the composition of the ground resistance measurement screen menu is shown in FIG. As shown, raw data result (①), FFT graph (②), filtered sinusoidal wave graph (③), impedance result (④), phase difference graph (⑤), and reactance and resistance ratio graph (⑥) are provided. Can give.

In one embodiment, the monitoring unit 60 is connected to the HMI through a USB port, detects when the USB port is not connected, and outputs a Port Error Ocurred message as shown in FIG. 12. To indicate that the USB communication cable is not connected.

In an embodiment, the monitoring unit 60 may allow the battery resistance measurement operation to be scanned and displayed from 65Hz to 1280MHz, and when the detection operation is completed, as shown in FIG. 13, after the measurement is terminated (test terminated) You can print a message.

In an embodiment, the monitoring unit 60 may detect actual measured raw data and display a waveform for voltage/current versus frequency application as illustrated in FIG. 14.

In an embodiment, the monitoring unit 60 may display a frequency increase state starting from 65 Hz for the frequency output to 1270 MHz, as shown in FIG. 15.

In one embodiment, the monitoring unit 60 may display data in a state in which noise components are removed by applying a noise removal algorithm from the discrete signal, as shown in FIG. 16, and noise is removed from the existing raw data. It can display the waveform before and after the operation to clear the signal.

In an embodiment, the monitoring unit 60 may display an impedance versus frequency as a result of frequency and voltage output as a graph as shown in FIG. 17.

In an embodiment, the monitoring unit 60 may display a result of calculating a phase difference according to a zero-crossing point as the frequency increases, as shown in FIG. 18.

In an embodiment, the monitoring unit 60 may display a ratio of frequency-dependent impedance as a graph representing a ratio of reactance and resistance as shown in FIG. 19.

The photovoltaic power generation grounding resistance measurement system 100 having the above-described configuration includes a grounding state of a photovoltaic power facility (e.g., a solar cell array, a relay terminal box (or connection box), and a ground line in the inverter). It is implemented so that the safety status can be monitored by automatically measuring the connection and the condition of the connection terminal, such as loosening, contamination, damage, corrosion, etc., so there is no need to check the ground resistance status by personnel directly at the dependent site. It is not necessary to visually judge the connection of the ground wire in the solar cell array, the relay terminal box (or junction box), the inverter, and the loosening, contamination, damage, and corrosion of the connection terminal for related power facilities. It is possible to prevent accidents caused by an increase in the potential of the ground when an abnormal voltage such as an external surge to the facility is introduced.

The photovoltaic power generation ground resistance measurement system 100 having the configuration as described above, as a distributed power environment in which new renewable energy and smart grid are mixed is recently introduced, as well as protecting the human body (or preventing accidents), The grounding status is automatically checked for the normal operation of the electrical and electronic equipment in operation, and through this, the safety of the grounding status can be visualized. In other words, while the existing focus was only on the prevention of human electric shock accidents, the photovoltaic power generation ground resistance measurement system 100 having the configuration as described above does not lead to power facility failure and accidents when abnormal surges and abnormal voltages are introduced. In order to avoid failure, by measuring, analyzing and monitoring data in real time, failures of primary and secondary facilities can be prevented in advance.

The photovoltaic power generation grounding resistance measurement system 100 having the above-described configuration includes the connection of the solar cell array, the relay terminal box (or connection box), the ground line of the inverter, and the transient grounding from the ground side of the connection terminal to the ground. It is possible to maintain a low impedance state by removing the element causing the potential rise by measuring and analyzing the rising trend of the ground potential by the frequency.

In the photovoltaic power generation grounding resistance measurement system 100 having the configuration as described above, when the impedance increases in a high frequency band, abnormal voltages and currents such as lightning surges and switching surges having a high frequency component are in the current grounding state. In this case, it can be judged that it is not properly playing its role, and for this purpose, a ground can be formed so that the current of high frequency components can quickly escape without affecting other facilities such as electronic devices. Grounding can be achieved using methods including replacement of grounding rods, change of grounding method, and improvement of soil quality.

The photovoltaic power generation grounding resistance measurement system 100 having the configuration as described above may be either a portable method for periodically measuring in the field or a method for remote monitoring from the center, and the frequency varies from 60Hz to several MHz. In the meantime, it is possible to perform measurement and analysis to grasp the trend, identify the main component of the grounding system, and use it as a basis for improving grounding in the high frequency band.

20 is a diagram illustrating a method of measuring a photovoltaic ground resistance according to an embodiment of the present invention.

Referring to FIG. 20, the ground resistance measurement unit 10, the electric facility measurement unit 20, and the power facility measurement unit 30 generate voltage and frequency respectively (S201), and then ground as a grounded reference. In the grounding resistance measuring unit 10 equipped with a sensor (that is, a grounding sensor connected to the reference ground), the grounding resistance is measured using the corresponding grounding sensor, and the measured grounding resistance is measured by the data collection processing unit 40 It is notified to (S202).

In reporting the ground resistance in step S202 described above, the ground resistance measuring unit 10 can measure the increase in potential of the ground electrode based on an infinite distance, that is, a place where the state before energization does not change (i.e., the reference Earth) can measure the potential rise of the ground electrode.

In notifying the ground resistance in step S202 described above, the ground resistance measurement unit 10 may measure the ground resistance using a ground sensor connected to the ground resistance measurement object buried in the ground. The ground resistance can be calculated by measuring voltage and current using a ground sensor connected to the grounded reference electrode by buriing a plurality of electrodes in a line at a predetermined interval and a predetermined depth.

In reporting the ground resistance in step S202 described above, the ground resistance measuring unit 10 may measure the ground resistance at each grounding part, and at this time, a cable for measuring the grounding state (not shown in the drawing for convenience of explanation) It can be connected to the steel structure with a clip terminal at each sensor position, and the ground resistance can be measured by measuring voltage and current and measuring impedance using their phase difference.

In the electric facility measurement unit 20 having an electric facility sensor connected to an electric facility that is a structure to check another grounding state while notifying the ground resistance in the above-described step S202, the electric facility sensor is used. The leakage current of the electric facility is measured, and the measured leakage current is notified to the data collection processing unit 40 (S203).

In reporting the leakage current in step S203 described above, the electric facility measurement unit 20 may measure the voltage and current of the electric facility by using an electric facility sensor connected to the electric facility. In this case, an example of an electric facility It is possible to measure the voltage and current of a target facility such as a transmission tower for installing a high-voltage wire, and the measured voltage and current data can be used as data for measuring ground resistance.

In reporting the leakage current in the above-described step S203, the electrical facility measurement unit 20 may measure the grounding resistance at each grounding part, and at this time, a cable for measuring the grounding state (not shown in the drawing for convenience of explanation) It can be connected to the steel structure with a clip terminal at each sensor position, and the ground resistance can be measured by measuring voltage and current and measuring impedance using their phase difference.

At the same time as notifying the leakage current in the above-described step S203, the power equipment measuring unit having a power equipment sensor connected to the power equipment (for example, solar array, junction box, inverter, etc.) of solar power generation ( In 30), the voltage and current of the power facility is measured using the power facility sensor, and the measured voltage and current is notified to the data collection processing unit 40 (S204).

In notifying the voltage and current in the above-described step S204, the power facility measurement unit 30 may measure the voltage and current state of the target facility by using a power facility sensor connected to the facility of solar power generation. At this time, you can measure the voltage and current status of the target facility by connecting the power facility sensor to the solar cell array, relay terminal box (or junction box), and inverter among the facilities of solar power generation, and the voltage and current data measured here are grounded. It can be used as data for measuring resistance.

In notifying the voltage and current in the above-described step S204, the power facility measurement unit 30 may measure the grounding resistance at each grounding part, and at this time, a cable for measuring the grounding state (shown in the drawing for convenience of explanation) It can be connected to the steel structure with a clip terminal at each sensor position, and the ground resistance can be measured by measuring voltage and current and impedance using their phase difference.

When the voltage and current are notified in the above-described step S204, the data collection processing unit 40, the ground resistance notified from the ground resistance measurement unit 10, the leakage current notified from the electric facility measurement unit 20, and power equipment measurement The voltage and current notified from the unit 30 are collected to measure the grounding state, and the measured grounding state is notified to the data analysis unit 50 (S205).

In reporting the grounding state in the above-described step S205, the data collection processing unit 40 is connected to the ground resistance measurement unit 10, the electrical facility measurement unit 20, and the power equipment measurement unit 30, respectively, and the ground resistance Data notified from the measurement unit 10, electric facility measurement unit 20, and power facility measurement unit 30 can be collected and processed. At this time, if the current value exceeds the preset current value, the above-described step You can make it return to S201.

When the grounding state is notified in the above-described step S205 or the current value in the above-described step S205 does not exceed the preset current value, the data analysis unit 50 informs the data collection processing unit 40. The measured grounding state is scheduled and metered, and the grounding state of the scheduled metering is provided to the monitoring unit 60 (S206).

In providing the scheduling meter reading grounding status in step S206 described above, the data analysis unit 50 analyzes the measurement grounding status notified from the data collection processing unit 40 so that the monitoring unit 60 can visualize and display a screen. , It can be processed and delivered to the monitoring unit 60.

In providing the scheduling meter reading grounding state in the above-described step S206, the data analysis unit 50 may process and analyze the measurement grounding state notified from the data collection processing unit 40 in real time through an analysis S/W algorithm. , At this time, it is possible to measure and analyze the potential rise of the high-frequency surge through the information obtained by measuring the voltage and current of the target facility.

In providing the scheduling meter reading ground state in step S206 described above, the data analysis unit 50 uses the information (voltage value and current value) obtained by measuring the voltage and current of the target facility through the transient impedance calculation program. Transient impedance can be calculated. In this case, the transient impedance calculation program may convert data processing to obtain raw data into a voltage and current discrete signal and store it, as shown in FIG. 3 in the PC software. It can be designed as a software class diagram to derive the final result of raw data. Here, as shown in FIG. 3, an example of data obtained by randomly generating voltage and current with a transient impedance calculation program can be shown, and in reality, it is expected that it will not be drawn cleanly due to the capacity limits of voltage and current. Through the algorithm, the data can be post-processed using interpolation, etc. to make it clean.

In providing the scheduling meter reading ground state in the above-described step S206, the data analysis unit 50 includes a predetermined frequency output from the ground resistance measurement unit 10, the electric facility measurement unit 20, and the power equipment measurement unit 30. The sine wave of is received again, the signal is processed, and a low data graph as shown in FIG. 4 can be displayed through the monitoring unit 60. At this time, the voltage can be displayed in blue and the current can be displayed in red. In addition, impedance can be measured by using the phase difference between voltage and current, and frequency and sampling rate are checked on the screen through the monitoring unit 60 and displayed as shown in FIG. You can make the user aware of the error situation.

In providing the scheduling meter reading ground state in the above-described step S206, the data analysis unit 50 determines whether the center frequency and the peak value coincide, and in order to check and eliminate errors occurring in other parts, the FFT ( Fast fourier transform) analysis algorithm can be used to perform frequency analysis. At this time, the data analysis unit 50 intuitively determines where the frequency currently being measured is at the time of measurement in the ground resistance measurement unit 10, the electric facility measurement unit 20, and the power facility measurement unit 30. It can be checked as and whether the value proceeds without error as intended, and the result of the confirmation can be displayed through the monitoring unit 60 as an FFT graph as shown in FIG. 5.

In providing the scheduling meter reading ground state in the above-described step S206, the data analysis unit 50 considers the rest of the frequency except the center frequency as noise by the FFT analysis algorithm, and filters the noise to obtain previously acquired raw data. After filtering as shown in FIG. 6, the sine wave graph may be displayed through the monitoring unit 60 to be more clean. Accordingly, the data analysis unit 50 can re-draw the raw data again by using only the data of a predetermined percentage (eg, several %) of the maximum value of the center frequency verified in the FFT. Accordingly, as shown in FIG. 6, the peak value sine wave has a magnitude of 1.25 [MHz], but it can be confirmed that an unintended noise signal is introduced into a region slightly below it. Accordingly, the data analysis unit 50 automatically removes a signal other than the maximum value found in the FFT analysis algorithm to clean the signal before and after performing the operation, as shown in FIG. 6, the monitoring unit 60 It can be displayed through.

값을 곱해 주어 임피던스를 구하여 도 7에 도시된 바와 같은 임피던스 결과를 모니터링부(60)를 통해 디스플레이시켜 주도록 할 수 있다. 이때, 데이터분석부(50)는, 대부분의 경우 선로의

값에 의해서 주파수가 증가함에 따라서 임피던스도 증가하는 결과를 모니터링부(60)를 통해 디스플레이시켜 주도록 할 수 있다. In providing the scheduling meter reading ground state in step S206 described above, the data analysis unit 50 may display the magnitude of voltage and current for each frequency band through the monitoring unit 60, and the power factor

Impedance is obtained by multiplying a value, and the impedance result as shown in FIG. 7 can be displayed through the monitoring unit 60. At this time, the data analysis unit 50, in most cases,

As the frequency increases according to the value, the result of increasing the impedance may be displayed through the monitoring unit 60.

In providing the scheduling meter reading ground state in the above-described step S206, in the data analysis unit 50, it is preferable to use a phase difference method using a phase difference between voltage and current (IEEE method). Accordingly, the magnitude and phase difference of voltage and current You can use the calculation method using. Here, in order to use the calculation method using the magnitude and phase difference of the corresponding voltage and current, the phase difference must be calculated by detecting a zero-crossing point, and the resultant value is a phase difference graph as shown in FIG. May be displayed through the monitoring unit 60, and accordingly, the relationship between the phase difference and impedance in the current grounding environment and the relationship with the frequency may be intuitively grasped with the corresponding result value.

In providing the scheduling meter reading ground state in the above-described step S206, the data analysis unit 50 calculates the pure resistance component and divides it by the reactance for auxiliary use with the impedance graph obtained with voltage, current, and phase difference. The ratio may be calculated and displayed through the monitoring unit 60 as a graph of a ratio of reactance and resistance as shown in FIG. 9. That is, the data analysis unit 50 may display a ratio of a frequency-dependent impedance to a resistance independent of frequency as a graph showing a ratio of reactance and resistance as shown in FIG. 9. In this case, as shown in FIG. 9, the displayed result may appear very coarse even after filtering. It can be used as a level to grasp whether the overall ratio increases, falls, or has an inflection point.

When the scheduling meter reading ground state is provided in step S206 described above, the monitoring unit 60 displays the scheduling meter reading ground state provided from the data analysis unit 50 through the monitor screen, and also visualizes a stable state or a dangerous state. Then, it is displayed (S207).

In the above-described step S207, when the scheduling meter reading ground state, stable state, or dangerous state is displayed, the monitoring unit 60 is connected to the analysis unit 50 and derived from the data analyzed by the analysis unit 50. The grounding status of each of the target facilities can be visualized and displayed.At this time, the grounding status is displayed through the monitor screen and the safety status or danger status is visualized and expressed so that the user can immediately recognize the danger situation. .

In the above-described step S207, in displaying the scheduling meter reading ground state, a stable state, or a dangerous state, the monitoring unit 60, in addition to a visually displayable monitor, sound output means such as a speaker (not shown in the drawings for convenience of explanation). Not included), so that the danger situation can be recognized by voice or sound.

In the above-described step S207, in displaying the scheduling meter reading ground state, stable state, or dangerous state, the monitoring unit 60 uses an HMI (Human Machine Interface) to measure the initial main screen of the earth resistance as shown in FIG. As shown in Fig. 11, the composition of the ground resistance measurement screen menu is composed of a raw data result (①), an FFT graph (②), a sine wave graph after filtering (③), an impedance result (④), and a phase difference graph ( ⑤), it can be provided as a ratio graph of reactance and resistance (⑥).

In the above-described step S207, in displaying the scheduling meter reading ground state, stable state, or dangerous state, the monitoring unit 60 is connected to the HMI through the USB port, and detects when the USB port is not connected, and FIG. 12 As shown in FIG. 1, a Port Error Ocurred message can be output to indicate that the USB communication cable is not connected.

In the above-described step S207, in displaying the scheduling meter reading ground state, a stable state, or a dangerous state, the monitoring unit 60 may scan and display the battery resistance measurement operation from 65Hz to 1280MHz, and the detection operation is completed. In this case, as shown in FIG. 13, a message may be output after test terminated.

In the above-described step S207, in displaying the scheduling meter reading ground state, stable state, or dangerous state, the monitoring unit 60 detects the actual measured raw data and shows a waveform for voltage/current versus frequency application in FIG. It can be marked as described.

In the above-described step S207, in displaying the scheduling meter reading ground state, a stable state, or a dangerous state, the monitoring unit 60 sets the frequency increase state from 65 Hz to 1270 MHz for the frequency output as shown in FIG. I can display it.

In the above-described step S207, in displaying the scheduling meter reading ground state, a stable state, or a dangerous state, the monitoring unit 60 displays data in a state in which the noise component is removed by applying a noise removal algorithm from the discrete signal. It can be displayed as shown, and also, it can display the waveform before and after the operation that makes the signal clearer by removing noise than the existing raw data.

In the above-described step S207, in displaying the scheduling meter reading ground state, a stable state, or a dangerous state, the monitoring unit 60 graphs the impedance value versus the frequency as a result of the frequency and voltage output as shown in FIG. I can display it.

In the above-described step S207, in displaying the scheduling meter reading ground state, stable state, or dangerous state, the monitoring unit 60 calculates the result of calculating the phase difference according to the zero-crossing point as the frequency increases. It can be displayed as shown in FIG. 18.

In the above-described step S207, the scheduling meter reading ground state, a stable state, or a dangerous state is displayed. In the monitoring unit 60, the ratio of the frequency-dependent impedance as a graph representing the ratio of reactance and resistance is shown in FIG. You can mark it like this.

As described above, embodiments of the present invention are not implemented only through the above-described apparatus and/or operation method, but through a program for realizing a function corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded, etc. It may be implemented, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs from the description of the above-described embodiment. Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

A: Photovoltaic ground resistance measurement system
10: ground resistance measurement unit
20: electrical facility measurement unit
30: power facility measurement unit
40: data collection processing unit
50: data analysis unit
60: monitoring unit

Claims (5)

A ground resistance measurement unit 10 for measuring ground resistance using a ground sensor connected to the reference ground;
An electrical facility measuring unit 20 for measuring a leakage current of an electrical facility using an electrical facility sensor connected to the electrical facility;
A power facility measuring unit 30 for measuring voltage and current of a power facility by using a power facility sensor connected to the power facility of solar power generation;
A data collection processing unit 40 for measuring a grounding state by collecting the ground resistance measured by the ground resistance measurement unit, the leakage current measured by the electrical facility measurement unit, and the voltage and current measured by the power facility measurement unit;
A data analysis unit 50 configured to schedule and read a ground state measured by the data collection processing unit to provide a scheduled meter reading ground state; And
And a monitoring unit 60 for visualizing and displaying a scheduling meter reading ground state, a stable state, or a dangerous state provided by the data analysis unit;
The data analysis unit 50 calculates the transient impedance by using the information acquired by measuring the voltage and current of the target facility by a transient impedance calculation program,
The transient impedance calculation program,
The data processing to obtain the raw data is converted into a voltage and current discrete signal and stored, and the final result of the raw data is designed as a software class diagram, or
The data analysis unit 50,
Impedance is measured using the phase difference between voltage and current, and frequency and sampling rate are checked and displayed on the screen through the monitoring unit, or
The data analysis unit 50,
A photovoltaic ground resistance measurement system, characterized in that by performing a frequency analysis using an FFT analysis algorithm, determining whether a center frequency and a peak value coincide, and identifying and removing errors occurring in other parts. delete delete delete delete

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