Terminal technology development method for collecting real-time vector data of power grid

Abstract

The invention relates to a power grid real-time vector data acquisition technology, in particular to a terminal technology development method for acquiring power grid real-time vector data. As an electric power system transforms to intelligentization and transparency and leaves power flow calculation of the power distribution network, the power flow calculation of the power distribution network can be successfully solved through successful collection of vector data. Most of traditional power monitoring terminals can only collect scalar data of a power grid and cannot realize efficient and accurate power flow calculation of the power distribution network. Although an existing phasor measurement unit (PMU) can collect vector data of a power grid, the existing phasor measurement unit is difficult to be widely applied to vector data collection of the power distribution network due to high cost and large volume. Therefore, how to realize efficient acquisition of the power grid vector data on the premise of low cost and miniaturization becomes a key technical problem in power distribution network load flow calculation. In order to solve the problem, the invention provides a new terminal technology development method, by improving a hardware architecture and a data processing algorithm, high efficiency, accuracy and low cost of power grid vector data acquisition are ensured, and the actual requirements of large-scale deployment and long-term operation are met.

Description

Technical Field

[0001] This invention relates to power grid vector data acquisition technology, and in particular to a method for developing a terminal device for acquiring real-time vector data of the power grid, applicable to power grid data acquisition, power flow calculation of distribution networks, and real-time analysis and scheduling of the power grid. Background Technology

[0002] As traditional power systems transition to new types, real-time calculation of distribution network power flow becomes increasingly important. Existing power monitoring terminals all collect grid scalars, which cannot enable fast, convenient, and low-cost distribution network power flow calculations.

[0003] Currently, some research has attempted to collect power grid vector data, i.e., PMU (phasor measurement unit). PMUs utilize GPS second pulses as a synchronization clock and are used to measure the voltage phasors of various nodes in a power system during transient processes. They are mainly installed in substations and similar locations. However, due to their high cost and large size, they cannot be installed in large quantities on the low-voltage side of distribution transformers. Therefore, the development method proposed in this invention ensures both the accuracy requirements of power flow calculation in the distribution network and meets the requirements of low cost and small size (similar in size to a normal data acquisition terminal), facilitating large-scale installation. Furthermore, it can be integrated with existing data acquisition terminals to form a unified system. Summary of the Invention

[0004] The purpose of this invention is to provide a method for developing a terminal technology for acquiring real-time vector data of the power grid. By improving the hardware architecture and data processing algorithms, it achieves efficient and accurate acquisition of power grid vector data, enabling low-cost and miniaturized production. Specifically, it includes the following steps: S1: Data Acquisition Hardware Design: Powered by single-phase AC, operating normally within the AC 65~265V range. The backup power supply consists of four 10F supercapacitors, which automatically and seamlessly switch on after the main power supply fails, maintaining communication between the terminal and the backend three times. It synchronously acquires three-phase voltage (0~265VAC) and three-phase current (0~6A), with a maximum sampling frequency of 25.6KHz. The CPU uses the NXP LPC1768FBD100K microcontroller, which includes 512 kB of flash memory and 64 kB of data storage. The positioning module uses a GPS / BeiDou dual-mode positioning module, supporting second pulse output, time, and geographic information output.

[0005] S2: Data Acquisition and Conversion Algorithm: The analog signal is sampled at a high sampling rate (typically several thousand times per second). The sampled analog signal is converted into a digital signal. A Fourier transform is performed on the digital signal to extract the fundamental component. The amplitude and phase angle of the voltage and current are calculated to form phasor values, which are the vector values ​​represented in this paper. Assume the acquired voltage signal is...

[0006] Where: V m W is the amplitude, and W is the angular frequency. It is the phase angle.

[0007] The signal is sampled at a sampling interval Δt to obtain a discrete signal. Perform a Fourier transform on the discrete signal to obtain its frequency domain representation V[k]. Find the V[k] corresponding to the fundamental frequency in the frequency domain to obtain its complex representation. The final amplitude is obtained. Phase angle ,Right now .

[0008] S3: High-Precision Time Synchronization Mechanism: To ensure the consistency and accuracy of data from multiple terminal devices in the real-time vector data acquisition system for the power grid, this invention introduces a high-precision time synchronization mechanism. By employing the IEEE 1588 Precision Time Protocol (PTP) or BeiDou signal synchronization technology, time unification is achieved across all terminal devices in the network. In terms of hardware design, each terminal device integrates a high-precision clock synchronization module, capable of receiving synchronization signals and adjusting its local clock to eliminate time deviations and ensure time consistency across all acquisition points. Furthermore, the system attaches a precise timestamp (accurate to the millisecond level) to each piece of acquired data. During data transmission and processing, the system performs real-time correction of the timestamps to avoid inconsistencies or errors in the acquired data due to time differences. In the event of a sudden power outage during data transmission, the system automatically switches to a backup synchronization source to ensure continued data transmission. This time synchronization technology ensures high precision and real-time performance of power grid data, meeting the needs of applications such as distribution network power flow calculation, power dispatching, and fault detection.

[0009] 2. In step S1, a backup power supply consisting of four 10F supercapacitors was proposed for the first time, with a design for automatic seamless switching in the event of power loss. The system is required to maintain communication between the terminal and the backend three times. The specific quantitative design of the supercapacitor capacity (10F × 4) and the number of communication cycles solves the problems of short battery life or switching delays in traditional systems. A dual-mode positioning module (GPS + BeiDou) is used, supporting second pulse output, time, and geographic information output. Applying dual-mode positioning technology to the power grid data acquisition terminal improves time synchronization accuracy and reliability. The high sampling rate of 25.6kHz and the hardware integration of three-phase synchronous acquisition meet the requirements for capturing high-frequency harmonics and transient signals.

[0010] In step S2, for the first time, high-frequency sampling and Fourier transform are combined to optimize the fundamental wave extraction efficiency for the characteristics of power grid signals. The complete process from discrete signal sampling → Fourier transform → fundamental wave extraction → amplitude / phase calculation is clearly defined, forming phasor values ​​(vector values). The optimized fusion of the 25.6kHz sampling rate and fundamental wave extraction, along with the real-time calculation process based on complex number representation, are targeted innovations proposed for the first time.

[0011] Step S3 introduces a dual synchronization mechanism combining network protocols and satellite signals, improving the reliability of time synchronization at power grid terminals. Hardware-level clock synchronization design (not purely software implementation) eliminates time deviations to the microsecond level. Dynamic timestamp correction and redundant synchronization source switching mechanisms ensure data continuity and consistency. This deeply integrates high-precision time synchronization with power grid business needs, addressing the lack of versatility in traditional synchronization technologies.

[0012] The present invention offers the following advantages: it enables vectorization of the distribution network, particularly the vectorization of the data source for distribution network calculations, thereby promoting the "transparency" of the distribution network in a low-cost, safe, and reliable manner, and facilitating power flow calculations. High-frequency sampling and time synchronization capabilities can handle power output fluctuations from photovoltaic and wind power, supporting the grid connection of high proportions of renewable energy. High-precision phasor data can optimize reactive power compensation strategies and reduce line losses (reducing...). (Loss), improve power supply efficiency. Attached Figure Description

[0013] Figure 1 Overview of vector graphics; Figure 2 Terminal structure block diagram; Figure 3 Data acquisition and transformation flowchart; Figure 4 Time synchronization mechanism flowchart; Figure 5 Power failure self-sustaining switching mechanism; Detailed Implementation

[0014] Example 1: like Figures 1-5 The specific steps are as follows: S1 Hardware Design: A high-precision current and voltage sensor is selected, and the analog signal output from the sensor is converted into a digital signal through a signal conditioning circuit. A digital signal processor (DSP) is used for signal processing to ensure that the data acquisition accuracy meets the design requirements. An embedded system is designed as the data processing center, equipped with appropriate storage, processing units, and communication modules.

[0015] S2 Vector Data Calculation and Conversion: Utilizing real-time data processing algorithms in embedded systems, the collected current, voltage, and other data are calculated in real time to obtain the power grid's vector data. The power grid data undergoes standardized formatting to ensure accuracy, and is optimized and compressed to improve transmission efficiency.

[0016] S3 Synchronization Clock Setting: A high-precision clock synchronization module is integrated into the acquisition terminal, supporting IEEE 1588 Precision Time Protocol (PTP) or receiving time synchronization signals via BeiDou signal reception. Terminal devices receive synchronization signals from a central dispatch system or external clock source (such as BeiDou) via network or satellite, periodically calibrating their local clocks to ensure consistency across all terminal devices. A time synchronization algorithm is embedded in the terminal devices to ensure precise calculation and adjustment of local clock deviations. This algorithm automatically adjusts the clock based on the difference between the synchronization signal and the local clock to achieve high-precision synchronization, guaranteeing time consistency across all devices. A timestamp is appended to each piece of acquired data using the local clock. The timestamp accuracy is at the millisecond level, ensuring the accuracy of the time point corresponding to each set of data. If a timestamp deviation is detected, the system automatically corrects the time, ensuring data time consistency and accuracy.

[0017] The above description is only a specific embodiment of the present invention, but the technical features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. A terminal technology development method for collecting real-time vector data of power grid, suitable for power distribution network power flow calculation, characterized in that it comprises the following steps: Step S1: hardware design, including using AC single-phase power supply, using super capacitor as backup power supply, synchronously collecting three-phase voltage and current, using NXPLPC1768FBD100K single-chip microcomputer as central processing unit, and integrating GPS / Beidou dual-mode positioning module to output second pulse and geographic information; Step S2: data acquisition and conversion algorithm, including high-frequency sampling, Fourier transform, fundamental component extraction, and voltage and current amplitude and phase angle calculation, to generate phasor data, i.e. vector data, of power grid; Step S3: high-precision time synchronization mechanism, including using IEEE 1588 Precision Time Protocol (PTP) or Beidou signal synchronization technology for time synchronization, ensuring time consistency of each terminal device, generating accurate time stamp and performing real-time correction, and ensuring consistency and high precision of real-time data of power grid.

2. The method of claim 1, further comprising, in step S1, using four 10F super capacitors to form a backup power supply, ensuring automatic switching when the power supply is lost, and supporting 3 times of maintaining communication with the background.

3. The method of claim 1, further comprising, in step S2, using a high sampling rate of 25.6 kHz to perform high-frequency sampling of power grid signals, optimizing fundamental extraction efficiency, and using complex representation for real-time calculation.

4. The method of claim 1, further comprising, in step S3, hardware-level clock synchronization design, through dynamic time stamp correction and redundant synchronization source switching mechanism, ensuring that data transmission can still be maintained when the device suddenly loses power during data transmission.

5. The method of claim 1, further comprising using dual-mode positioning technology (GPS + Beidou) to improve time synchronization accuracy and reliability.

6. The method of claim 1, the terminal for collecting real-time vector data of power grid can provide high-precision data in power distribution network power flow calculation, and support grid-connected monitoring of renewable energy sources such as photovoltaic and wind power.

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