Current freezing acquisition system based on synchronous triggering of different sites

Abstract

The invention belongs to the technical field of power line loss detection and monitoring, and particularly relates to a current freezing acquisition system based on synchronous triggering of different sites, which comprises an upper computer and current freezing acquisition units, and is characterized in that each current freezing acquisition unit comprises a low-voltage side assembly and a high-voltage side assembly; the low-voltage side assembly comprises a GPS, a low-voltage photoelectric conversion circuit, a data receiving module, a data processing module, an effective value calculation module and a data uploading module, and the high-voltage side assembly comprises a high-voltage photoelectric conversion circuit, a trigger control circuit, a current sampling assembly and a data sending module. According to the invention, the plurality of current freezing acquisition units synchronously acquire the instantaneous current values of the line at the same time according to the set time, and transverse comparison is carried out, so that the line loss can be analyzed in a synchronous instantaneous current subsection metering mode; the defects that long time needs to be waited for subsection metering through an electricity quantity method, power failure operation needs to be carried out for obtaining line high voltage, and the specific time point of line high loss cannot be determined are overcome.

Description

Technical Field

[0001] The present invention belongs to the technical field of power line loss detection and monitoring, and in particular relates to a current freezing acquisition system based on synchronous triggering of different locations. Background Art

[0002] During the power transmission process, the distribution network will suffer power loss and generate energy loss over a period of time. Power loss includes active power and reactive power; energy loss includes active electric energy and reactive electric energy. In order to further detect the location of line loss and the amount of energy lost, various metering devices are often installed on the line, such as 10kV meters or line fault indicators, to troubleshoot line loss problems by measuring line loss in sections.

[0003] The 10kV meter needs to obtain the line voltage and current and calculate the power consumption. Due to the high voltage level, a power outage is required, making installation extremely inconvenient. The line fault indicator does not need to obtain voltage and can be installed with power on. It can also obtain instantaneous current values ​​as a theoretical basis for line loss investigation. However, the currents of multiple fault indicators are not collected at the same time. In situations where power consumption fluctuates greatly, effective line loss analysis cannot be performed through current. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a current freezing acquisition system based on synchronous triggering at different locations, which is suitable for 10kV power distribution overhead lines, does not obtain line voltage, and can be installed live on multiple branches of the line. Multiple current freezing acquisition units can simultaneously and synchronously obtain line current values ​​according to the set time, and the current values ​​obtained between multiple current freezing acquisition units can be compared horizontally, thereby realizing the analysis of line line loss through current segmented metering, simplifying the disadvantages of waiting for a long time for segmented metering through the electricity method, and obtaining line high voltage requires power outage operations.

[0005] The present invention is implemented in this way. A current freezing collection system based on synchronous triggering of different positions is provided. The system comprises a host computer and at least two current freezing collection units. Each current freezing collection unit comprises a low-voltage side component and a high-voltage side component. The low-voltage side component comprises a GPS, a low-voltage photoelectric conversion circuit, a data receiving module, a data processing module, an effective value calculation module and a data uploading module. The high-voltage side component comprises a high-voltage photoelectric conversion circuit, a trigger control circuit, a current sampling component and a data sending module. The host computer is connected to the GPS of each current freezing collection unit. The timing pulse pin of the GPS is connected to the low-voltage photoelectric conversion circuit. The low-voltage photoelectric conversion circuit is bidirectionally connected to the high-voltage photoelectric conversion circuit. The high-voltage photoelectric conversion circuit is connected to the trigger control circuit. The trigger control circuit is connected to the current sampling component. The current sampling component is connected to the data sending module. The data sending module is connected to the high-voltage photoelectric conversion circuit. The low-voltage photoelectric conversion circuit, the data receiving module, the data processing module, the effective value calculation module and the data uploading module are connected in sequence. The data uploading module is connected to the host computer.

[0006] Preferably, the timing pulse pin of the GPS is a 1PPS pin, and the 1PPS pin outputs a TTL level pulse once every 1s.

[0007] Further preferably, the current sampling component includes a current sampling module and a CT current transformer, the CT current transformer is arranged at the current collection site of the overhead line, the CT current transformer is connected to the current sampling module, the output end of the trigger control circuit is connected to the current sampling module, and the output end of the current sampling module is connected to the data sending module.

[0008] Further preferably, the current sampling module is used to convert the CT analog current signal collected by the CT current transformer into a sampled voltage signal.

[0009] Further preferably, the data sending module is used to perform protocol encoding on the sampled voltage signal converted by the current sampling module, combine it into a single-frame or multi-frame message, and after inserting the corresponding sampling timestamp into the message, transmit it to the high-voltage photoelectric conversion circuit.

[0010] Further preferably, the data receiving module is used to perform protocol decomposition and send the message to the data processing module after receiving the message from the data sending module.

[0011] Further preferably, the data processing module is used to analyze multiple groups of sampling data in combination with the sampling rate and the sampling period, and the effective value calculation module is used to calculate the effective value of the current at the sampling point of the overhead line according to the analysis result of the data processing module.

[0012] The present invention provides a current freezing acquisition system based on synchronous triggering of different positions, which is suitable for detecting line loss in power distribution networks. Compared with the prior art, the advantages are:

[0013] 1. Since this system does not take voltage but only current, it is not affected by voltage fluctuations. It eliminates the disadvantages of traditional metering devices, such as the need to install PT transformers, large size, heavy weight, and inconvenient installation. It also saves voltage components and installation costs, and reduces the complexity of on-site construction.

[0014] 2. The current values ​​frozen synchronously between multiple current freezing acquisition units can be used for horizontal comparison of instantaneous current values ​​at different locations, which can quickly and conveniently troubleshoot and lock line loss fault points; compared with the traditional line loss analysis by electrical quantity, it has faster positioning speed and accuracy.

[0015] 3. Compared with the installation of traditional metering devices, the installation of this system can be supported by live working through insulating pull rods, which is convenient and quick; it reduces the risk of electric shock during on-site installation, and also reduces the risk of power system failure caused by construction work;

[0016] 4. The present invention can be quickly and conveniently applied to temporary detection and monitoring scenarios, and is more suitable for implementing distributed detection and monitoring scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A structural diagram of a host computer and a current freezing acquisition unit of a current freezing acquisition system based on synchronous triggering of different positions provided by the present invention;

[0018] Figure 2 A schematic diagram of line loss analysis using the current freezing acquisition system based on synchronous triggering at different locations provided by the present invention;

[0019] Figure 3 This is a schematic diagram of line loss analysis using daily electricity freezing. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] refer to Figure 1The present invention provides a current freezing acquisition system based on synchronous triggering of different positions, comprising a host computer 1 and at least two current freezing acquisition units, each current freezing acquisition unit comprising a low-voltage side component and a high-voltage side component, the low-voltage side component comprising a GPS2, a low-voltage photoelectric conversion circuit 3, a data receiving module 12, a data processing module 4, an effective value calculation module 5 and a data uploading module 6, the high-voltage side component comprising a high-voltage photoelectric conversion circuit 7, a trigger control circuit 8, a current sampling component and a data sending module 9, the host computer 1 is connected to the GPS2 of each current freezing acquisition unit, the timing pulse pin of the GPS2 is connected to the low-voltage photoelectric conversion circuit 3, the low-voltage photoelectric conversion circuit 3 is bidirectionally connected to the high-voltage photoelectric conversion circuit 7, the high-voltage photoelectric conversion circuit 7 is connected to the trigger control circuit 8, the trigger control circuit 8 is connected to the current sampling component, the current sampling component is connected to the data sending module 9, the data sending module 9 is connected to the high-voltage photoelectric conversion circuit 7, the low-voltage photoelectric conversion circuit 3, the data receiving module 12, the data processing module 4, the effective value calculation module 5 and the data uploading module 6 are connected in sequence, and the data uploading module 6 is connected to the host computer 1.

[0022] The current freezing acquisition system based on synchronous triggering at different locations provided by the present invention is used for analyzing line loss. When in use, different current freezing acquisition units are set at different sampling locations with a relatively long distance, and current sampling components are set on overhead lines at corresponding locations. The sampling time interval is set by the host computer 1, and the GPS 2 sends a pulse signal with a fixed time interval to the low-voltage photoelectric conversion circuit 3 through the timing pulse pin. The low-voltage photoelectric conversion circuit 3 converts the electrical signal into an optical signal, and transmits it to the high-voltage photoelectric conversion circuit 7 through the optical fiber. The high-voltage photoelectric conversion circuit 7 converts the optical signal into an electrical signal, and transmits it to the trigger control circuit 8. The trigger control circuit 8 is configured to generate a pulse signal according to the sampling time interval set by the host computer 1. At a sampling time interval, a sampling signal is regularly sent to the current sampling component, the current sampling component performs sampling and converts the current signal into a voltage signal, the voltage signal is sent to the high-voltage photoelectric conversion circuit 7 through the data sending module 9, the high-voltage photoelectric conversion circuit 7 converts the electrical signal into an optical signal, and transmits it to the low-voltage photoelectric conversion circuit 3 through the optical fiber, the low-voltage photoelectric conversion circuit 3 converts the optical signal into an electrical signal, the electrical signal passes through the data receiving module 12, the data processing module 4, the effective value calculation module 5 and the data uploading module 6 in sequence, the voltage signal is converted into a current signal and finally uploaded to the host computer 1, the host computer 1 calculates the line loss between different locations through the current signals at different locations.

[0023] The low voltage photoelectric conversion circuit 3 and the high voltage photoelectric conversion circuit 7 form a safety guarantee for high and low voltage isolation.

[0024] Specifically, the timing pulse pin of the GPS2 is a 1PPS pin, which outputs a TTL level pulse once every 1 second, and the average error of the same TTL level pulse between different current freezing acquisition units is 30 nS.

[0025] Specifically, the current sampling component includes a current sampling module 10 and a CT current transformer 11. The CT current transformer 11 is arranged at the current collection position of the overhead line. The CT current transformer 11 is connected to the current sampling module 10. The output end of the trigger control circuit 8 is connected to the current sampling module 10. The output end of the current sampling module 10 is connected to the data sending module 9. The current sampling module 10 is used to convert the CT analog current signal collected by the CT current transformer 11 into a sampled voltage signal.

[0026] During the current sampling process, the CT analog current signal is collected by the CT current transformer 11 and transmitted to the current sampling module 10. The current sampling module 10 converts the CT analog current signal collected by the CT current transformer 11 into a sampling voltage signal and transmits it to the high-voltage photoelectric conversion circuit 7.

[0027] Specifically, the data sending module 9 is used to perform protocol encoding on the sampled voltage signal converted by the current sampling module 10, combine it into a single-frame or multi-frame message, and insert the corresponding sampling timestamp into the message before transmitting it to the high-voltage photoelectric conversion circuit 7.

[0028] Specifically, the data receiving module 12 is used to perform protocol decomposition after receiving the message from the data sending module 9 and send it to the data processing module 4.

[0029] Specifically, the data processing module 4 is used to analyze multiple groups of sampling data in combination with the sampling rate and the sampling period, and the effective value calculation module 5 is used to calculate the effective value of the current at the sampling point of the overhead line according to the analysis result of the data processing module 4.

[0030] In order to ensure the temporal consistency of data reception and processing among multiple current freezing acquisition units, all the above data acquisition, reception, conversion, processing and other operations are completed inside the FPGA.

[0031] Example:

[0032] refer to Figure 2 and Figure 3, respectively, are schematic diagrams of line loss analysis using the current freezing collection system based on synchronous triggering of different locations provided by the present invention and line loss analysis using daily electricity freezing. The results show that by comparing the two methods of freezing electricity and freezing instantaneous current, it can be seen that electricity needs to be accumulated for at least 24 hours, which requires a long wait, and it is impossible to distinguish the time point of electricity loss; however, by checking line loss by freezing instantaneous current, it will be very quick to determine whether there is a loss in the transient line loss at that time, and quickly draw a conclusion. By setting the current freezing interval, it can also be determined when the line loss occurred, which is more conducive to on-site analysis.

Claims

1. The current freezing acquisition system based on synchronous triggering at different sites is characterized by: The invention comprises a host computer (1) and at least two current freezing collection units, each current freezing collection unit comprises a low-voltage side component and a high-voltage side component, the low-voltage side component comprises a GPS (2), a low-voltage photoelectric conversion circuit (3), a data receiving module (12), a data processing module (4), an effective value calculation module (5) and a data uploading module (6), and the high-voltage side component comprises a high-voltage photoelectric conversion circuit (7), a trigger control circuit (8), a current sampling component and a data sending module (9), the host computer (1) is connected to the GPS (2) of each current freezing collection unit, and the timing pulse pin of the GPS (2) is connected to the low-voltage side component. The low-voltage photoelectric conversion circuit (3) is connected to the high-voltage photoelectric conversion circuit (7), the low-voltage photoelectric conversion circuit (3) is bidirectionally connected to the high-voltage photoelectric conversion circuit (7), the high-voltage photoelectric conversion circuit (7) is connected to the trigger control circuit (8), the trigger control circuit (8) is connected to the current sampling component, the current sampling component is connected to the data sending module (9), the data sending module (9) is connected to the high-voltage photoelectric conversion circuit (7), the low-voltage photoelectric conversion circuit (3), the data receiving module (12), the data processing module (4), the effective value calculation module (5) and the data uploading module (6) are connected in sequence, and the data uploading module (6) is connected to the host computer (1).

2. The current freezing acquisition system based on synchronous triggering of different sites according to claim 1 is characterized in that: The timing pulse pin of the GPS (2) is a 1PPS pin, and the 1PPS pin outputs a TTL level pulse once every 1 second.

3. The current freezing acquisition system based on synchronous triggering of different sites according to claim 1 is characterized in that: The current sampling component comprises a current sampling module (10) and a CT current transformer (11); the CT current transformer (11) is arranged at a current collection position of an overhead line; the CT current transformer (11) is connected to the current sampling module (10); the output end of the trigger control circuit (8) is connected to the current sampling module (10); and the output end of the current sampling module (10) is connected to the data sending module (9).

4. The current freezing acquisition system based on synchronous triggering of different sites according to claim 3 is characterized in that: The current sampling module (10) is used to convert the CT analog current signal collected by the CT current transformer (11) into a sampled voltage signal.

5. The current freezing acquisition system based on synchronous triggering of different sites according to claim 4 is characterized in that: The data transmission module (9) is used to perform protocol encoding on the sampled voltage signal converted by the current sampling module (10), combine it into a single-frame or multi-frame message, and after inserting the corresponding sampling time stamp into the message, transmit it to the high-voltage photoelectric conversion circuit (7).

6. The current freezing acquisition system based on synchronous triggering of different sites according to claim 5 is characterized in that: The data receiving module (12) is used to perform protocol decomposition after receiving the message from the data sending module (9) and send the message to the data processing module (4).

7. The current freezing acquisition system based on synchronous triggering of different sites according to claim 6 is characterized in that: The data processing module (4) is used to analyze multiple groups of sampling data in combination with sampling rate and sampling period, and the effective value calculation module (5) is used to calculate the effective value of the current at the sampling point of the overhead line according to the analysis result of the data processing module (4).

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