I. Core Requirements for Time and Frequency Synchronization in the Power Industry

The safe and stable operation of the power industry—including power generation, transmission, transformation, distribution, and consumption—depends on… Accurate Time synchronization: Core business applications (power grid dispatch, fault recording, relay protection, and electric energy metering) require time‑frequency synchronization. Accuracy, reliability, and anti-interference performance The requirements are stringent; the specific needs are as follows:

1. Microsecond- to nanosecond-level precision : Grid dispatch and relay protection scenarios require synchronization accuracy. ≤1μs , Fault recording scenario requirements ≤10μs , Requirements for Electric Energy Metering Scenarios ≤1ms , ensuring fault tolerance Accurate Coordination between protection and fault location.
2. Strong anti-interference capability : Substations and power plants are subject to harsh environments such as strong electromagnetic interference and lightning strikes; therefore, time‑frequency equipment must be capable of resisting electromagnetic interference ( EMC Level ≥Level 4 ), lightning protection ( IEC 61000-4-5 ) Ability.
3. High-reliability redundancy : Power grid 7×24 For continuous operation over extended periods, the time‑frequency synchronization system must support dual‑node hot standby, multi‑source timing redundancy, and link redundancy, enabling seamless switchover in the event of a failure. MTBF≥150000 Hour.
4. Industry-standard compatible : Must comply with IEC 61588 (Power-specific PTP Agreement), DL/T 1100.1 (Power System Time Synchronization System), GB/T 26866 (National standards and industry specifications, such as the power system synchronization clock.)
5. Localization and XinChuang Compatibility Key power infrastructure must achieve domestic production and independent, controllable time‑frequency equipment, be compatible with the indigenous innovation (XinChuang) ecosystem, and mitigate risks associated with reliance on foreign technologies.

II. Time and Frequency Synchronization Technology Architecture in the Power Industry

Adopt “ Master Clock - From the clock - Terminal device ” Three-tier architecture, combined with “ Satellite time synchronization + Network Time Synchronization + Dedicated line time synchronization ” Multi-source redundancy mode ensures unified time synchronization across the entire network.

(1) Primary Master Clock (Dispatch Center)

• Deployment Location: State Grid / China Southern Power Grid Headquarters and provincial-level dispatch centers.
• Core configuration: domestically developed XinChuang time server (Zhongxin Chuang) DNTS-9HG ), supports single-constellation BeiDou / Beidou + GPS Dual-mode time synchronization, with a built-in rubidium atomic clock, achieving timing accuracy of 2.8ns ; Configure a forward‑type satellite security isolation device ( DNSIS-611A ), filtering electromagnetic interference signals.
• Core functionality: Serving as the network-wide time reference source, by… PTP/IEC 61588 The protocol distributes standard time to secondary slave clocks; it supports dual‑unit hot standby and automatic switchover, ensuring the reliability of the reference source.

(2) Secondary Timing Clock (Substation) / Power plant)

• Deployment Location: 220kV Substations of 110 kV and above, as well as large power plants.
• Core specifications: PTP Boundary clock ( BC ) or a transparent clock ( TC ), supports receiving the master clock signal, with synchronization accuracy of ≤1μs ; Built-in temperature-compensated crystal oscillator, timing accuracy 1 μs/h ; support B Code ( IRIG-B ), PPS Signal output.
• Core functions: Distribute time signals to in‑station terminal devices (relay protection devices, fault recorders, and smart meters); achieve inter‑subnet synchronization to mitigate accuracy degradation in the complex network environment of substations.

(3) Terminal Device Synchronization (Field Level)

• Synchronization method:
  • High-precision equipment (relay protection, fault recorders): via B Code‑dedicated line time synchronization, synchronization accuracy ≤1μs ；
  • General-purpose devices (smart meters, monitoring terminals): via NTP/PTP Network time synchronization, synchronization accuracy ≤10μs ；
  • Distributed devices (distribution terminals): Achieve independent synchronization via a Beidou dual-mode timing module, with accuracy of… ≤10ns。
• Core requirement: Terminal devices must be compatible. IEC 61588 、 IRIG-B It supports protocols that enable timestamped logging, thereby meeting the requirements for fault tracing.

(4) Monitoring and Management Platform

• Deploy a nationwide unified power time‑frequency synchronization monitoring platform, based on… B/S Architecture: real-time monitoring of the synchronization status, signal quality, and operational conditions of the master clock, slave clocks, and terminal devices.
• Core features: time‑offset alerts (with configurable thresholds), device fault localization, historical data analytics, compliance report generation, and support for remote configuration and operations & maintenance.

III. Core Technology Adaptation and Standards Compliance

(1) Key Technology Adaptation

1. Electromagnetic Interference Resistance Technology : The time server features a metal-shielded enclosure and a filtered circuit design, and through IEC 61000-4-3 (Radiation immunity), IEC 61000-4-6 Conducted immunity certification, suitable for the strong electromagnetic environment of substations.
2. Wide-temperature and lightning-proof design : Equipment operating temperature range - 40℃~70℃ , supports lightning protection ( 8/20 μs Waveform, surge current ≥20kA ), suitable for outdoor and harsh environments.
3. For power use only PTP Agreement : Support IEC 61588-2009 (Electricity Profile ), optimizing the network latency compensation algorithm to address accuracy degradation caused by the complex network topology and lengthy links in substations.
4. Domestic substitution and XinChuang compatibility : The master clock uses Haiguang. / Feiteng domestic chips, Kylin domestic operating system, and a standalone Beidou timing module have all passed certification by the Information Technology Innovation Committee, meeting the requirements for IT‑innovation‑driven substitution in the power sector.

(II) Compliance with Core Standards

• International Standard ： IEC 61588 (Precision Time Protocol), IEC 60870-5-103 (Remote Terminal Equipment and System Communication Protocol).
• National Standard ： GB/T 26866-2011 “Synchronous Clock for Power Systems,” GB/T 33602-2017 Technical Requirements for Time Synchronization Systems and Equipment in Smart Substations.
• Industry standard ： DL/T 1100.1-2019 “Time Synchronization System for Power Systems Part 1 Section: Technical Specifications, DL/T 860.92-2016 Technical Specifications for the Network Packet Recording and Analysis Device of Intelligent Substations.

IV. Typical Application Scenarios and Outcomes

(1) 220kV Time-Frequency Synchronization Project for Smart Substations

• Deployment Plan: 1 Taiwan DNTS-9HG Master Clock (Single BeiDou) + 2 Taiwan PTP Boundary Clock + Relay protection device B Code timing + Smart meter NTP Timekeeping + Monitoring platform.
• Application Effectiveness: Time Synchronization Accuracy Across All Station Devices ≤500ns , the fault recording data timestamps are consistent, and the fault location error is ≤10 Meter; the equipment meets electromagnetic interference resistance standards and operates stably without failures.

(II) Provincial Power Grid Dispatch Center Time基准 Project

• Deployment Plan: 2 Taiwan DNTS-9HG Dual-machine hot standby primary clock + DNSIS-611A Satellite isolation device + Cross-regional PTP Transmission network + Network-wide monitoring system.
• Application Effectiveness: Network-wide Time Deviation ≤1μs , meeting the coordinated requirements of grid dispatch and relay protection; domestically produced equipment has passed the power‑industry information‑technology innovation acceptance, enhancing its level of independent controllability.

V. Key Considerations for Implementation and Operations & Maintenance

1. Installation Environment Requirements : The master clock and slave clocks must be installed in shielded rooms or metal cabinets, away from high-voltage equipment, variable-frequency drives, and other strong sources of electromagnetic interference; the antenna should be mounted in an open, unobstructed area, with lightning protection and grounding resistance. ≤4Ω 。
2. Link Deployment Specifications ： B The dedicated line uses shielded twisted pair, with a transmission distance of… ≤100 Rice; PTP The network employs fiber optics or industrial Ethernet to prevent co‑location with other service networks and minimize interference.
3. Regular Calibration and Testing : The master clock is calibrated twice annually by the National Institute of Metrology, China, and its synchronization accuracy and anti‑interference performance are tested each year to ensure compliance with relevant standards.
4. Fault Emergency Response : Develop contingency plans for primary clock failures, satellite signal interruptions, link outages, and other emergencies; equip with backup clock modules; and ensure a specified fault‑response time. ≤30 Minute.
5. Compliance Management : Regularly generate operational reports for the synchronization system and cooperate with inspections by the electricity regulatory authority to ensure that equipment complies with industry standards and indigenous innovation requirements.