Solutions-GoLead Intelligent

Background and Challenges

As a critical hub connecting the generation side to the power grid, power plant step-up substations face challenges such as multi-unit grid connection, main transformer switching, and complex electromagnetic interference. The main challenges include:

Stringent Grid-Connection Accuracy Requirements

Multiple generating units must be synchronized precisely when connected to the step-up busbar; any synchronization deviation may trigger grid resonance or electrical impact.
High Risk of Main Transformer Switching Impact

No-load energization of step-up main transformers can easily generate high-magnitude magnetizing inrush currents, causing stress on power equipment and unintended protection operations.
Complex Electromagnetic Environment

High-power equipment and frequent switching operations create strong sources of electromagnetic interference within the substation, placing high demands on the anti-interference capability of protection devices.

Overview

Based on extensive expertise in synchronization control and smart circuit breaker technologies, and tailored to step-up substation application scenarios, GoLead Intelligent delivers an integrated solution featuring full-scenario adaptive synchronization control, main transformer inrush current suppression, and fast smart switching.

The solution covers key processes including generator grid connection, main transformer switching, and rapid step-up line transfer, ensuring stable, safe, and efficient operation of power plant step-up substations.

Key Technologies

High-Precision Automatic Synchronization System

The solution adopts a high-precision automatic synchronization device with phase angle control accuracy of ≤0.5°, supporting simultaneous grid connection of multiple generating units. By embedding smart fuzzy control algorithms, the system accurately determines the optimal synchronization moment, achieving a first-closing success rate above 99.9%. In addition, built-in real-time waveform recording and analysis functions enable full-process traceability of synchronization operations, providing strong support for commissioning optimization and long-term performance evaluation.
Main Transformer Switching Inrush Suppression

To address the inrush current challenges during main transformer energization, the solution integrates intelligent phase-controlled circuit breakers that execute closing operations at voltage zero-crossing points, effectively limiting inrush current to within twice the rated current. During opening operations, current zero-crossing control is applied to significantly reduce arc re-ignition probability and suppress operating overvoltage to below 1.7 times the rated voltage, thereby enhancing equipment safety and prolonging service life.
Fast Line Transfer and Fault Isolation

The fast transfer system is designed for rapid fault response and disturbance-free recovery. Fault detection is completed within 5 ms, triggering transfer logic immediately, while coordination with fast vacuum circuit breakers enables line disconnection and switching to be completed within 10 ms. This ensures swift fault isolation and power restoration for the step-up system, minimizing voltage disturbances and maintaining overall grid stability.
Environmental Adaptability and System Integration

Engineered for harsh outdoor step-up substation conditions, the solution supports wide-temperature operation from –20 °C to +55 °C and maintains reliable performance under high humidity and strong electromagnetic interference. It supports mainstream communication protocols such as IEC 61850 and Modbus, enabling seamless integration with power plant automation systems and dispatch platforms. Meanwhile, comprehensive functions including real-time telemetry, abnormal alarm reporting, and full lifecycle data management significantly enhance operation and maintenance efficiency.

Application Results and Cases

The solution has been successfully deployed in the step-up substations of multiple large-scale thermal, hydropower, and wind power plants, delivering significant performance improvements.

Grid-connection accuracy for multi-unit synchronization has increased by over 30%, greatly enhancing coordinated equipment operation efficiency. Main transformer switching inrush currents have been reduced by more than 60%, effectively minimizing protection misoperations and equipment faults. In addition, fast fault transfer has shortened power restoration time by over 90%, substantially improving grid stability and system responsiveness.

Together, these results provide a solid foundation for building a clean, efficient, and reliable power transmission system.

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