KR102644478B1 - Quality Monitoring Device for Direct current and operating method thereof - Google Patents

Abstract

The present invention includes a first control unit that receives input and output voltage and current values of an A/D converter connected to a power source, and calculates power quality data for the direct current power of the A/D converter based on the received voltage and current values. , a second control unit functionally connected to the first control unit and processing time synchronization for calculating the power quality data, a first memory functionally connected to the first control unit and storing the calculated power quality data, Disclosed is a direct current power quality monitoring device and a method of operating the same, including a communication interface circuit that transmits at least a portion of the calculated power quality data to an external upper server.

Description

Direct current power quality monitoring device used in direct current distribution and operating method thereof {Quality Monitoring Device for Direct current and operating method thereof}

The present invention relates to a DC PQMD (Direct current power quality monitoring device) used in direct current distribution, and more specifically, to a direct current power quality monitoring device that supports maintenance and operation cost reduction and a method of operating the same.

The conventional AC (Alternating Current) distribution network includes a PQM (Power Quality Monitoring) system at all customer entry points of the distribution system in order for power companies to manage electricity quality. These conventional AC distribution networks require expensive equipment with high-performance computing functions and precision in order to acquire data suitable for related standards.

Meanwhile, in recent years, there has been a transition from the existing AC distribution network to a DC distribution network in terms of energy efficiency improvement, but a monitoring system for power quality management has not been properly established in line with this transition. Accordingly, the need for DC PQM for power quality management is increasing.

The present invention is intended to solve the above-described conventional problems. For example, the present invention provides a DC power quality monitoring device used in DC power distribution and a method of operating the same, which can reduce maintenance costs and operating costs for the DC distribution network. there is.

In addition, the present invention is a DC power quality monitoring device capable of measuring the voltage and current of DC distribution in real time (e.g., sampling at 100 kps), analyzing power quality, detecting accidents, and recording waveforms based on the measured voltage and current, and the same. It provides an operation method.

The DC power quality monitoring device according to an embodiment of the present invention receives the input/output voltage and current values of the A/D converter connected to the power source, and adjusts the DC power of the A/D converter based on the received voltage and current values. A first control unit for calculating power quality data, a second control unit functionally connected to the first control unit and processing time synchronization for calculating the power quality data, functionally connected to the first control unit, and the calculated power It is characterized by comprising a first memory that stores quality data, and a communication interface circuit that transmits at least a portion of the calculated power quality data to an external upper server.

Here, the first control unit and the second control unit are integrated into one dual-core digital signal processor, and the dual-core digital signal processor further includes a shared memory for sharing data between the first control unit and the second control unit. It is characterized by including.

Meanwhile, the first control unit is characterized by including a control law accelerator 1 (CLA1) for calculating the power quality and a control law accelerator 2 (CLA2) for updating variables.

In addition, the DC power quality monitoring device further includes a Global Positioning System (GPS) that provides location information related to time synchronization of the second control unit and a Real Time Clock (RTC) that provides a real-time clock. .

The communication interface circuit is characterized in that it transmits at least part of the power quality data to the upper server based on TCP/IP in response to the control of the first control unit.

As an example, the first control unit is characterized in that it determines whether an accident has occurred with respect to the input/output voltage and current values of the A/D converter based on a pre-stored reference value or a reference value stored in the first memory.

Here, the first control unit calculates the power quality data based on the first voltage value and first current value corresponding to the input of the A/D converter and the second voltage value and second current value corresponding to the output. It is characterized by

In addition, the reference value includes a voltage rise and overvoltage detection setting value, a voltage drop and low voltage detection setting value, and an instantaneous power outage and power outage detection setting value.

In relation to a method of operating a DC power quality monitoring device according to an embodiment of the present invention, the DC power quality monitoring device receives input and output voltage and current values of an A/D converter connected to a power source, and the received voltage and current It includes a first control unit that calculates power quality data for the DC power of the A/D converter based on the value, and a second control unit that is functionally connected to the first control unit and processes time synchronization for calculating the power quality data. And the operating method includes the steps of the first control unit driving the second control unit, the second control unit initializing time synchronization and requesting the start of sampling of the A/D converter at a specified period, and the A/D converter Upon completion of sampling, the first control unit receives voltage and current detection values sampled from the A/D converter, the first control unit detecting accident-related values from the received detection values, 1 Characterized in that the control unit includes a step of storing the accident-related values.

The method further includes the step of the first control unit transmitting the accident-related values to a higher level server.

In addition, the step of storing the accident-related values may include storing at least one of the accident level, the channel where the accident occurred, the accident detection time, and the accident type.

According to the DC power quality monitoring device and operating method of the present invention, the present invention supports reducing maintenance and operating costs of the distribution network through power quality measurement and accident type analysis of DC distribution.

1 is a diagram illustrating an example of a DC power distribution system environment including a DC power quality monitoring device according to an embodiment of the present invention.
Figure 2 is a diagram showing one form of a plurality of control units according to an embodiment of the present invention.
Figure 3 is a diagram showing an example of communication between a communication interface circuit and a higher level server according to an embodiment of the present invention.
Figure 4 is a diagram showing an example of operation of the control unit of the DC power quality monitoring device according to an embodiment of the present invention.
Figure 5 is a diagram showing an example of a wiring mode of a direct current distribution system according to an embodiment of the present invention.
Figure 6 is a diagram showing an example of the types of quality data provided by the DC power quality monitoring device according to an embodiment of the present invention.
Figure 7 is a diagram showing an example of a method of operating a DC power quality monitoring device according to an embodiment of the present invention.
Figure 8 is a diagram showing an example of accident data configuration and settings according to an embodiment of the present invention.
Figure 9 is a diagram of Swell and Over Voltage settings related to DC power quality monitoring according to an embodiment of the present invention.
Figure 10 is a diagram related to voltage drop and low voltage settings related to direct current power quality monitoring according to an embodiment of the present invention.
Figure 11 is a diagram of instantaneous power outage and power outage settings related to direct current power quality monitoring according to an embodiment of the present invention.
Figure 12 is an example of a screen including values indicating voltage precision among data test data of a DC power quality monitoring device according to an embodiment of the present invention.
Figure 13 is an example of a screen including values indicating current precision among data test data of a DC power quality monitoring device according to an embodiment of the present invention.
Figure 14 is a diagram showing an example of a peak data value of a DC power quality monitoring device according to an embodiment of the present invention.
Figure 15 is a diagram showing an example of instantaneous power data values of a DC power quality monitoring device according to an embodiment of the present invention.
Figure 16 is a diagram showing an example of accumulated power data values of a DC power quality monitoring device according to an embodiment of the present invention.
Figure 17 is a diagram showing an example of efficiency data values of a DC power quality monitoring device according to an embodiment of the present invention.
Figure 18 is a diagram showing an example of accident record data of a DC power quality monitoring device according to an embodiment of the present invention.

It should be noted that in the following description, only the parts necessary to understand the embodiments of the present invention will be described, and descriptions of other parts will be omitted to the extent that they do not distract from the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as limited to their usual or dictionary meanings, and the inventor should use the concept of terminology appropriately to explain his/her invention in the best way. It must be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined clearly. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, and therefore various equivalents can be substituted for them at the time of filing the present application. It should be understood that there may be variations.

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

FIG. 1 is a diagram showing an example of a DC power distribution system environment including a DC power quality monitoring device according to an embodiment of the present invention, and FIG. 2 is a diagram showing one form of a plurality of control units according to an embodiment of the present invention. . Figure 3 is a diagram showing an example of communication between a communication interface circuit and a higher level server according to an embodiment of the present invention.

Referring to FIG. 1, the DC power distribution system 10 may include a power source 11 and a DC power quality monitoring device 100.

The power source 11 may include a component that provides power to a load. For example, the power source 11 may include a power plant that generates power, a storage that stores the generated power, and a distribution station that supplies the stored electricity. Alternatively, the power source 11 may include an ESS (Energy storage system) that stores power and supplies it to a load (power consumption source 12).

The DC power quality monitoring device 100 can monitor the quality of power supplied from the power source 11 and then converted to DC. The DC power quality monitoring device 100 can perform analysis on the monitored results and store and manage the analysis results. The DC power quality monitoring device 100 may transmit data related to a specific event (eg, an accident) to the upper server 200. In particular, the DC power quality monitoring device 100 of the present invention can support real-time quality measurement and management of direct current power by distinguishing between time management and calculation data management for calculating power quality using two control units. This DC power quality monitoring device 100 includes, for example, a first control unit 150a, a second control unit 150b, a first memory 130, a communication interface circuit 140, a location information collection device 160, and an RTC ( 170) and a second memory 180, and additionally or selectively includes a first voltage detection unit 111a, a second voltage detection unit 111b, a first current detection unit 112a, and a second current detection unit 112b, It may include an A/D converter 120. In the following description, the DC power quality monitoring device 100 of the present invention includes a first voltage detection unit 111a, a second voltage detection unit 111b, a first current detection unit 112a, and a second current detection unit 112b, A/D The description will be made as a configuration that does not include the converter 120.

The first voltage detector 111a is disposed between the power source 11 and the A/D converter 120, measures the voltage of the power delivered from the power source 11 to the A/D converter 120, and , the measured voltage information can be transmitted to the first voltage channel of the DC power quality monitoring device 100 through the A/D converter 120.

The second voltage detection unit 111b is disposed between a power source (e.g., power consumption source 12) and the A/D converter 120, and is connected to the power consumption source 12 from the A/D converter 120. The voltage of the transmitted power may be measured, and the measured voltage information may be transmitted to the second voltage channel of the DC power quality monitoring device 100.

The first current detector 112a is disposed between the power source 11 and the A/D converter 120, and measures the current of power delivered from the power source 11 to the A/D converter 120. , the measured current information can be transmitted to the first current channel of the DC power quality monitoring device 100 through the A/D converter 120.

The second current detection unit 112b is disposed between the power consumption source 12 and the A/D converter 120, and measures the current of the power delivered from the A/D converter 120 to the power consumption source 12. The measurement may be performed, and the measured current information may be transmitted to the second current channel of the DC power quality monitoring device 100.

The A/D converter 120 can convert AC power supplied from the power source 11 into DC power and then supply it to a load (eg, power consumption source 12). The A/D converter 120 may be a component of a power conversion system (PCS). For example, the A/D converter 120 is connected in parallel with the DC power quality monitoring device 100 between the power source 11 and the power consumption source 12, or the DC power quality monitoring device 100 is connected to the DC power quality monitoring device 100. It may be placed at the output terminal of the A/D converter 120.

The first control unit 150a receives power-related information output from the output terminal of the A/D converter 120 (or the first voltage detection unit 111a and the second voltage detection unit 111b, the first current detection unit 112a and the first voltage detection unit 111b). 2 output information of the current detection unit 112b) can be collected, and a determination as to whether an interrupt related to an accident has occurred based on the collected information can be made. In relation to this, the first control unit 150a may store and manage reference information (or reference information) used to determine various situations regarding the output of the A/D converter 120 in the first memory 130. The first control unit 150a supports TCP/IP-based communication with CLA1 (control law accelerator) capable of performing calculations on power quality, CLA2 for variable update, and communication interface circuit 140. It may include SPI2 (serial peripheral interface 2) and EMIF (external memory interface) for reading and writing data in the first memory 130. As shown in FIG. 2, the first control unit 150a can be integrated with the second control unit 150b on one DSP (digital signal processing) board, and is a common memory used with the second control unit 150b. Data access can be performed through (150c). In this regard, the first control unit 150a may include flash memory, RAM memory, and CLA, and similarly, the second control unit 150b may also include flash memory, RAM memory, and CLA.

The second control unit 150b may perform timing management necessary for the monitoring process regarding DC power according to an embodiment of the present invention. In this regard, the second control unit 150b may communicate with the location information collection device 160 (eg, GPS-global positioning system), the RTC 170, and the second memory 180. The second control unit 150b includes a timer for timing management, SPI1 for communication with the second memory 180, a serial communication interface (SCI) for communication with the location information collection device 160, and an RTC (170). ) may include an I2C (inter-integrated circuit) for communication with. The second control unit 150b may be configured with a DSP (TMS320F28377D) prepared for dual core as described in the description of the first control unit 150a. The second control unit 150b is configured to control power quality of the first control unit 150a. While performing the operation, the timer and time synchronization for 100 kHz sampling can be processed. When the second control unit 150b generates an ADC SoC (Start Of Conversion) signal, the A/D converter 120 starts the SoC. When the operation is performed and an EoC (End Of Conversion) signal is generated, the first control unit 150a converts the detected voltage/current value into a digital value, performs data operation, and detects and stores power quality based on the calculated data. It can be done.

The first memory 130 may store a power quality detection value calculated based on voltage/current values detected in response to control by the first controller 150a. In addition, the first memory 130 stores reference values or reference values for determining whether the detected voltage/current value is a value corresponding to the occurrence of a specific event or accident, and upon request from the first control unit 150a, Corresponding reference values can be provided. This first memory 130 may be composed of synchronous dynamic random access memory (SDRAM).

The communication interface circuit 140 may include a component that supports the communication function of the DC power quality monitoring device 100 of the present invention. For example, in the DC power distribution system 10 of the present invention, the DC power quality monitoring device 100 can communicate with the upper server 200 through the communication interface circuit 140, as shown in FIG. 3. The communication interface circuit 140 allocates a plurality of ports (e.g., Port #1, #2, #3) based on TCP/IP, and transmits and receives designated information with the upper server 200 through the corresponding ports. You can. For example, the first port (Port #1) can be used to transmit real-time data and power quality data to the upper server 200. The second port (Port #2) can transmit accident information and accident waveform data to the upper server 200, or receive reference values that serve as a standard for classifying the fault waveform from the higher server. The received reference values may be stored and managed in the first memory 130 or in a memory included in the first control unit 150a. The third port (Port #3) can transmit and receive information about user settings with the upper server 200. The communication interface circuit 140 described above may be operated by Man Machine Interface (MMI) software. Additionally, the second memory 180 may support displaying information related to DC power quality monitoring by operating HMI (HUMAN Machine Interface) software.

The location information collection device 160 may provide location information for time synchronization of the DC power quality monitoring device 100. This location information collection device 160 may be configured, for example, as a Global Positioning System (GPS) module. The location information collection device 160 may provide information for time synchronization to the second control unit 150b through communication with the second control unit 150b.

The RTC 170 (Real Time Clock, RTC) can provide a clock value to maintain the current time. The RTC 170 may be configured to operate even when the DC power quality monitoring device 100 is turned off. The RTC 170 may perform communication with the second control unit 150b and provide real-time clock information to the second control unit 150b at the request of the second control unit 150b.

The second memory 180 may store sensor gain information and provide the corresponding sensor gain information upon request from the second control unit 150b. The sensor gain may include, for example, a gain value of a sensor used in the current detection unit. The second memory 180 may be composed of a ferroelectric random access memory (FRAM), and accordingly, the second memory 180 can preserve data even when the power supply is interrupted.

The DC power quality monitoring device 100 of the present invention described above is a device capable of sampling at 0.5% precision and every 100 kHz, and is structured to send real-time voltage/current data, power quality data, and information to a higher level server. The DC power quality monitoring device 100 uses the first memory 130 (e.g., 128Mbyte SDRAM) to simultaneously store two types of fault waveforms, a transient waveform and a sustained state waveform, and includes data before the accident and data during the accident. , data can be saved after an accident. Here, the DC power quality monitoring device 100 can store fault waveform data of a total of four channels: voltage #1, voltage #2, current #1, and current #2. The transient waveform storage sampling of the DC power quality monitoring device 100 is 100 kHz, 100 msec before the accident, and 900 msec for accident and post-accident data for up to 1 second, and the accident storage memory allocation size can be 400 kbyte. . The continuous state waveform storage of the DC power quality monitoring device 100 stores data through 10 kHz sampling due to data capacity issues, and data can be stored for 1 second before the accident and 3 minutes after the accident and at a maximum of 3 minutes and 1 second. , the accident storage memory allocation size can be 7,240 kbytes. The DC power quality monitoring device 100 can continuously store 10 transient waveforms and 10 continuous waveforms, up to a total of 76.4 Mbytes. Quality data, accident information data, and user settings are communicated with the upper server 200 through TCP/IP communication as described above, and 3 data communications can be performed every 10 msec in the order of Port 1, Port 2, and Port 3.

Figure 4 is a diagram showing an example of operation of the control unit of the DC power quality monitoring device according to an embodiment of the present invention.

Referring to FIG. 4, the second control unit 150b of the DC power quality monitoring device 100 of the present invention starts ADC (Analog-Digital Conversion) sampling according to user settings or predefined settings, and ADC SoC signals can be provided to the A/D converter 120. In this process, the second control unit 150b can receive the current clock value from the RTC (170) to check the Real Time Clock (RTC) value and check GPS data from the location information collection device 160. The second control unit 150b may transmit the start of the sampling process to the first control unit 150a along with the start of sampling for monitoring DC power quality.

When the first control unit 150a receives voltage/current detection values from the A/D converter 120, it can perform analysis on the received samples. In particular, upon receiving the ADC EoC signal along with sample values (e.g., voltage/current detection values) detected from the A/D converter 120, the first control unit 150a may perform ADC sample analysis. Meanwhile, the second control unit 150b may support a real-time monitoring function by performing an external HMI display while the first control unit 150a is performing ADC sample analysis. In this regard, the second control unit 150b may receive the results of the ADC sample analysis from the first control unit 150a. The first control unit 150a can perform transformation on the detected real data, check whether an accident has occurred (Fault Data Check), and save fault waveform data (Fault Data Save). . In parallel, the CLA of the first control unit 150a may perform power quality data conversion.

When the ADC sample analysis is completed, the first control unit 150a selects information to be delivered to the upper server 200 and transmits the selected information through TCP/IP Communication. Additionally, the CLA of the first control unit 150a can update user settings. While the first control unit 150a and the CLA of the first control unit 150a perform operations after the end of the ADC sample, the second control unit 150b maintains an external HMI display, thereby maintaining a real-time monitoring function.

Figure 5 is a diagram showing an example of a wiring mode of a direct current distribution system according to an embodiment of the present invention.

Referring to state 501 in FIG. 5, the DC power quality monitoring device 100 of the present invention is in 1P2W wiring mode, and the power conversion device 300 (PCS) disposed between the power source 11 and the load. can be connected in parallel. At this time, the power source 11 and the power conversion device 300 may be connected by two wires, and in this case, the DC power quality monitoring device 100 is connected to the input wire and output wire of the power conversion device 300. can be connected to The power conversion device 300 may include the A/D converter 120 described above.

Additionally, referring to state 503 in FIG. 5, the DC power quality monitoring device 100 of the present invention is in 1P3W wiring mode and can be connected between the power conversion device 300 and the load. Here, the power conversion device 300 may have a three-phase wiring, and in this case, the DC power quality monitoring device 100 has input and output connected to the remaining two wirings of the power conversion device 300, excluding the ground wire, respectively. You can.

The number of measurement channels of the DC power quality monitoring device 100 according to an embodiment of the present invention is a total of 4 channels, and is operated as 2 voltage channels and 2 current channels, and as described above, the wiring modes are 1P2W and 1P3W. It can be configured as: The mode can be changed depending on user settings.

Figure 6 is a diagram showing an example of the types of quality data provided by the DC power quality monitoring device according to an embodiment of the present invention.

Referring to FIG. 6, as described above, the power quality data measured by the DC power quality monitoring device 100 of the present invention is voltage real-time data (e.g., voltage 1 real-time data collected by the first voltage detector 111a, Voltage 2 real-time data collected by the second voltage detector 111b) and current real-time data (e.g., current 1 real-time data collected by the first current detector 112a, current 2 real-time data collected by the second current detector 112b) data), +peak (maximum) and -peak (minimum) data for Voltage 1, +peak (maximum) and -peak (minimum) data for Voltage 2, +peak (maximum) and -peak (minimum) data for Current 1. , +peak (maximum) and -peak (minimum) data of current 2, ripple frequency of voltage 1, ripple frequency of voltage 2, unbalanced voltage value of voltage 1 and voltage 2, unbalanced voltage ratio of voltage 1 and voltage 2, voltage 1 maintenance rate, voltage 2 maintenance rate, instantaneous power 1, instantaneous power 2, accumulated power amount 1 (+), accumulated power amount 1 (-), accumulated power amount 2 (+), accumulated power amount 2 (-), efficiency #1, efficiency #2 , Swell/Over Voltage, Sag/Under Voltage, momentary power outage/outage, and overcurrent items may be included. In the above-mentioned items, unbalanced voltage values and voltage rates can only be supported in 1p3w wiring mode, and efficiency #1 and efficiency #2 can only be supported in 1p2w wiring mode. The remaining power quality data items can be supported in both 1p2w and 1p3w wiring modes.

Regarding the power quality data described above, the first control unit 150a converts the measured data, voltage and current, into real-time values, and performs power quality calculation in the CLA of the first control unit 150a using the converted data. Thus, the above-described power quality data can be output.

Figure 7 is a diagram showing an example of a method of operating a DC power quality monitoring device according to an embodiment of the present invention.

Referring to FIG. 7, the first control unit 150a of the DC power quality monitoring device 100 may start monitoring DC power quality according to user input or predefined settings, and perform variable and register initialization in step 701. You can. The first control unit 150a may control the operation of the second control unit 150b in step 703. The second control unit 150b may initialize variables and registers in step 705 and drive a Timer Interrupt (100 kHz) in step 707. The second control unit 150b may transmit an SoC signal to start sampling to the A/D converter 120 in step 709. Meanwhile, the second control unit 150b performs GPS time synchronization in step 711 before transmitting the SoC signal to the A/D converter 120, performs RTC write and read operations in step 713, and performs RTC write and read operations for monitoring DC power quality. Can handle time synchronization.

The first control unit 150a may perform CLA 1/2 initialization in step 715 after driving the second control unit 150b. The first control unit 150a may receive a sampling end signal (EoC) from the A/D converter 120 in step 717. The first control unit 150a checks whether an X-int (interrupt related to an accident) is detected in step 719, and if no can be re-performed. The waiting time is, for example, when the second control unit 150b requests the start of sampling of the A/D converter 120 at a cycle of 100 kHz, and the A/D converter 120 performs sampling (e.g., voltage/current detection) according to the corresponding sampling start request. It may be the same as the time to perform value collection) or may include a time longer than that time by a certain length.

If X-int is detected in step 719, the first control unit 150a can detect and collect the X-int value in step 723 and perform ADC detection and derivation of the real value in step 725. In step 727, the first control unit 150a can check the fault level and perform the corresponding fault check in step 729. If the fault confirmation is greater than or equal to a specified value, the first control unit 150a may store the corresponding accident data in step 731 and store fault information (level, channel, detection time, and accident type) in step 733. Next, in step 735, the first control unit 150a may collect the power quality data previously described in FIG. 6. If it is not separate accident data during the fault confirmation process, the first control unit 150a may skip steps 731 and 733. After collecting power quality data, the first control unit 150a may perform upper-level communication in step 737 to deliver the monitoring results to the upper-level server 200 and end processing of X-int occurrences.

Meanwhile, in step 723, the first control unit 150a branches to step 739 and drives CLA2, and in step 741, CLA2 of the first control unit 150a performs variable update (incident level, ripple time, current time), In step 743, CLA2 operation may be terminated under the control of the first control unit 150a. Additionally, in step 725, the first control unit 150a branches to step 745 and drives CLA1, and in step 747, CLA1 of the first control unit 150a can derive power quality through the Real value. Afterwards, in step 743, the first control unit 150a may end driving CLA1.

The above-described DC power quality monitoring device 100 defines accident data of the DC distribution network as Swell / Over Voltage, Sag / Under Voltage, momentary power outage / power outage, and overcurrent, and stores information and waveforms about the accident. It may be configured to transmit the data to the upper server 200. Here, accident data must be able to store both pre-accident and post-accident data, and can be stored for up to 3 minutes. Accident determination can be set arbitrarily by the user, and the accident type can be detected through accident level and time. Support.

Figure 8 is a diagram showing an example of accident data configuration and settings according to an embodiment of the present invention.

Referring to FIG. 8, the accident data configuration can be divided into an accident time determination setting range (horizontal axis) and an accident level determination setting range (vertical axis), as shown. The accident time determination setting range can be defined as a value from 0.01 s (sec) to 60 s or more, and the accident level determination setting range can be from a minimum of 10% of the standard value to 120% of the standard value or more. Here, the accident time determination setting range values and the accident level determination setting range values may be changed according to user settings.

As an example, a time between 0.01s and 0.5s may be set as a momentary power outage, and a time exceeding 0.5s may be defined as a power outage. If the fault level determination setting range is 80% to 90% of the default value, it is defined as Voltage Sag, 110% to 120% is defined as Voltage Swell, and over 120% is defined as transient or overvoltage. It can be defined as (Over Voltage). Between 90% and 110% is defined as the operating regulation voltage range, and the voltage ripple regulation range may be defined within the operating regulation voltage range (e.g., 97.5% to 102.5%). Less than 80% can be defined as Under Voltage.

As an example, considering the determination of accident information data, based on the rated voltage of 750V (100%), the Swell / Over Voltage range is 120%, and the accident maintenance time is set to 60 seconds, if the distribution network rises by 910V while maintaining the rated voltage of 750V. Since the DC power quality monitoring device 100 has confirmed that Swell / Over Voltage is above the set range, it can be detected as Swell / Over Voltage. The DC power quality monitoring device 100 can process accident determination and data storage with Swell if the voltage rise maintenance time is 60 seconds or less when the voltage returns to 750V to the normal state. The DC power quality monitoring device 100 can determine an accident as Over Voltage and store data if the voltage rise maintenance time exceeds 60 seconds when the voltage returns to the normal state of 750V.

Figure 9 is a diagram of Swell and Over Voltage settings related to DC power quality monitoring according to an embodiment of the present invention.

Referring to FIG. 9, when the voltage value (Rated Voltage) is detected as shown, that is, when the voltage value (Rated Voltage) exceeds the preset Swell/Over Voltage detection level value, the power quality is detected as Swell. , if the power increase is maintained for a certain period of time, the power quality may be detected as over voltage. The period during which power quality is detected as Swell can be adjusted depending on the power quality type setting.

Figure 10 is a diagram related to voltage drop and low voltage settings related to direct current power quality monitoring according to an embodiment of the present invention.

Referring to FIG. 10, when the voltage value (Rated Voltage) is detected as shown, that is, when the voltage value (Rated Voltage) falls below the preset Sag/Under Voltage detection level value, the power quality is a voltage drop. (Sag), and if the voltage drop is maintained for a certain period of time, the power quality can be detected as Under Voltage. The period during which power quality is detected as Sag can be adjusted depending on the power quality type setting.

Figure 11 is a diagram of instantaneous power outage and power outage settings related to direct current power quality monitoring according to an embodiment of the present invention.

Referring to FIG. 11, when the voltage value (Rated Voltage) is detected as shown, that is, the voltage value (Rated Voltage) continues to fall below the preset Sag/Under Voltage detection level value and then is detected for momentary power failure detection. If it falls below the set interruption detection level, the power quality is detected as a momentary power outage, and if the momentary power outage is maintained for a certain period of time, the power quality can be detected as a power outage. The period during which power quality is detected as an instantaneous power outage can be adjusted according to the power quality type setting. Here, the priority of Interruption Detection related to power outage can be set higher than Sag/Under Voltage Detection.

Figure 12 shows values showing voltage precision among data test data of a DC power quality monitoring device according to an embodiment of the present invention, and Figure 13 shows current precision among data test data of a DC power quality monitoring device according to an embodiment of the present invention. These are the values shown. FIG. 14 is a diagram showing an example of a peak data value of a DC power quality monitoring device according to an embodiment of the present invention, and FIG. 15 is an example of an instantaneous power data value of a DC power quality monitoring device according to an embodiment of the present invention. This is a drawing showing . FIG. 16 is a diagram showing an example of accumulated power data values of a DC power quality monitoring device according to an embodiment of the present invention, and FIG. 17 is an example of efficiency data values of a DC power quality monitoring device according to an embodiment of the present invention. 18 is a diagram showing an example of accident record data of a DC power quality monitoring device according to an embodiment of the present invention.

The values illustrated in FIGS. 12 to 18 above show an example of a screen provided by the DC power quality monitoring device of the present invention through HMI, and are power quality data calculated based on the detected voltage/current values. You can. By checking the above-mentioned values, the user can easily monitor the DC power distribution network, monitor the occurrence of accidents, and easily determine the time and type of accident when the accident occurred.

Meanwhile, the embodiments disclosed in the specification and drawings are merely provided as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is obvious to those skilled in the art that in addition to the embodiments disclosed herein, other modifications based on the technical idea of the present invention can be implemented.

10: Direct current distribution system
11: power source
100: DC power quality monitoring device
111a, 111b, 112a, 112b: detection unit
120: A/D converter
130: first memory
140: Communication interface circuit
150a, 150b: Control unit
160: Location information collection device
170:RTC
180: second memory

Claims (11)

A first control unit that receives input/output voltage and current values of an A/D converter connected to a power source and calculates power quality data for direct current power of the A/D converter based on the received voltage and current values;
a second control unit functionally connected to the first control unit and processing time synchronization for calculating the power quality data;
a first memory functionally connected to the first control unit and storing the calculated power quality data;
A communication interface circuit that transmits at least a portion of the calculated power quality data to an external upper server;
The first control unit
CLA1 (control law accelerator 1) for the power quality calculation; and
Includes CLA2 (control law accelerator 2) for variable update,
A DC power quality monitoring device characterized in that the second control unit maintains an external HMI display while the CLA1 and CLA2 perform operations after the ADC sample ends to maintain a real-time monitoring function. delete According to paragraph 1,
GPS (Global Positioning System) that provides location information related to time synchronization of the second control unit; and
A direct current power quality monitoring device further comprising a Real Time Clock (RTC) that provides a real-time clock. According to paragraph 1,
The communication interface circuit is
A DC power quality monitoring device, characterized in that, in response to the first control unit control, transmitting at least part of the power quality data to the upper server based on TCP/IP. According to paragraph 1,
The first control unit
A DC power quality monitoring device characterized in that it determines whether an accident has occurred with respect to the input/output voltage and current values of the A/D converter based on a pre-stored reference value or a reference value stored in the first memory. According to clause 5,
The first control unit
DC power quality, characterized in that the power quality data is calculated based on a first voltage value and a first current value corresponding to the input of the A/D converter and a second voltage value and a second current value corresponding to the output. Monitoring device. According to clause 5,
The above reference value is
Voltage rise and overvoltage detection settings;
Voltage drop and undervoltage detection setpoints;
A direct current power quality monitoring device comprising an instantaneous power outage and a power outage detection set value. According to paragraph 1,
The first control unit and the second control unit are integrated into one dual-core digital signal processor, and the dual-core digital signal processor further includes a shared memory for sharing data of the first control unit and the second control unit. A direct current power quality monitoring device, characterized in that. A first control unit that receives input/output voltage and current values of an A/D converter connected to a power source and calculates power quality data for the direct current power of the A/D converter based on the received voltage and current values, and 1. A method of operating a direct current power quality monitoring device including a second control unit functionally connected to the control unit and processing time synchronization for calculating the power quality data,
The first control unit driving the second control unit;
The second control unit initializing time synchronization and requesting the start of sampling of the A/D converter at a designated period;
Upon completion of sampling by the A/D converter, the first control unit receives voltage and current detection values sampled from the A/D converter;
detecting, by the first control unit, accident-related values from the received detection values;
Including, wherein the first control unit stores the accident-related values,
The first control unit
CLA1 (control law accelerator 1) for the power quality calculation; and
Includes CLA2 (control law accelerator 2) for variable update,
A method of operating a direct current power quality monitoring device, characterized in that the second control unit maintains an external HMI display while the CLA1 and CLA2 perform operations after the end of the ADC sample, thereby maintaining a real-time monitoring function. According to clause 9,
A method of operating a DC power quality monitoring device further comprising: the first control unit transmitting the accident-related values to a higher level server. According to clause 9,
The step of storing the accident-related values is
A method of operating a direct current power quality monitoring device, comprising: storing at least one of the accident level, the channel where the accident occurred, the accident detection time, and the accident type.