Memmedzade R.C., Mufidzade N.A.
THE IMPACT OF COMPENSATION DEVICES ON THE TRANSFER CAPABILITY OF HIGH-VOLTAGE TRANSMISSION LINES *
Аннотация:
ensuring stable and efficient operation of high-voltage transmission networks is becoming increasingly vital due to rising energy demand and grid complexity. One key aspect influencing transmission performance is the management of reactive power, which directly impacts voltage regulation and power flow capability. In this context, reactive power compensation devices—particularly flexible AC transmission system (FACTS) technologies such as STATCOM and SVC—have gained significant importance. This study presents a comparative technical evaluation of these compensators, focusing on their operational principles, performance characteristics, and their effectiveness in enhancing system stability, reducing losses, and maximizing power transfer across long-distance lines.
Ключевые слова:
reactive power compensation, FACTS devices, STATCOM, SVC, voltage regulation, power transfer enhancement, high-voltage grid stability, dynamic load control
Classification of Compensation Devices in Power Transmission.Reactive power compensation plays a critical role in maintaining voltage stability and improving the power transfer capability of transmission lines. Based on their configuration and operational mechanism, compensation devices used in electrical power systems are broadly categorized into two groups: series and shunt compensators. Furthermore, they can be divided into active (controlled electronically, capable of injecting or absorbing power dynamically) and passive (consisting of fixed inductive or capacitive elements) types.Series compensators, such as series capacitors, are connected directly into the transmission line and are effective in reducing impedance and voltage drops over long distances. Shunt compensators, including SVCs and STATCOMs, are installed parallel to the line and primarily support voltage regulation through reactive power exchange. Active compensators like STATCOMs offer faster response and higher control precision, while passive devices such as SVCs are more economical for steady-state support.The table below outlines a comparative analysis of commonly used compensation devices in terms of structure, speed, efficiency, and application area.Table 1.5. Structural Overview of Key Reactive Power Compensators. Modern power systems rely heavily on advanced static devices for voltage control and dynamic reactive power support. Among these, SVC and STATCOM stand out due to their structural efficiency and widespread use in high-voltage networks.5.1 Static Var Compensator (SVC).An SVC is a shunt-connected device designed to provide variable reactive power support through a combination of controlled and fixed components. Its architecture typically integrates:• Thyristor-Controlled Reactors (TCRs): Allow fine control of inductive reactive power via phase-angle modulation.• Thyristor-Switched Capacitors (TSCs): Provide stepwise capacitive compensation with rapid switching capability.• Fixed banks: Include both capacitors and reactors that support base-level reactive needs.• Harmonic filtering systems: Eliminate distortions introduced by thyristor operations.• Measurement and control units: Monitor system voltage and issue control signals to the thyristors accordingly.5.2 Static Synchronous Compensator (STATCOM).STATCOM is an advanced power electronic device employing voltage source inverter (VSI) technology. Its modular structure consists of:• Voltage Source Inverter (VSI): Generates a controllable AC voltage using DC energy stored in a capacitor.• DC-link capacitor: Maintains a constant DC voltage for the VSI and enables bidirectional reactive power flow.• Filtering units: Suppress switching harmonics and maintain waveform quality.• Step-up transformer: Matches STATCOM output to the transmission voltage level.• Real-time control system: Enables ultra-fast voltage regulation through digital signal processing techniques.These structural elements make STATCOM particularly suited for environments requiring rapid voltage response and stability reinforcement, while SVC remains a reliable option for steady-state applications.6. Operating Principles of Reactive Power Compensators.Reactive power compensators function by dynamically adjusting their interaction with the grid to maintain voltage levels within acceptable limits. While both SVC and STATCOM serve this purpose, their operational mechanisms differ fundamentally in terms of control strategy and power conversion method.6.1 SVC: Thyristor-Based Reactive Adjustment.The SVC operates through coordinated control of two key thyristor-based components:• Thyristor-Controlled Reactors (TCR): Gradually absorb reactive power by varying the conduction angle of the thyristor, allowing smooth inductive control.• Thyristor-Switched Capacitors (TSC): Provide capacitive compensation in discrete steps by switching capacitor banks on or off.When the grid voltage decreases, SVC increases capacitive support by activating TSCs. Conversely, when voltage rises, inductive absorption through TCRs helps reduce it. This process enables voltage stabilization under slowly varying or moderately dynamic load conditions.6.2 STATCOM: Inverter-Based Voltage Injection.Unlike SVC, STATCOM uses a voltage source inverter (VSI) to synthesize an AC voltage from a controlled DC source. It regulates reactive power flow based on the voltage difference between the inverter output and the grid:• If the inverter voltage exceeds grid voltage, the device injects reactive power (capacitive mode).• If the inverter voltage is lower, it absorbs reactive power (inductive mode).Thanks to its fully electronic nature, STATCOM delivers extremely fast dynamic response and maintains stable operation even during low voltage conditions—making it ideal for grids with frequent disturbances or rapid load changes.7. Comparative Evaluation of SVC and STATCOM.While both SVC and STATCOM aim to support reactive power regulation and voltage stability, their technological foundations lead to distinct advantages and limitations in practical applications.Table 2.Interpretation: SVC remains a cost-effective solution for steady-state voltage support in traditionally configured grids. In contrast, STATCOM offers superior technical performance, especially in systems with high variability, low fault-level scenarios, or renewable integration—justifying its higher cost in critical infrastructure.8. Future Outlook for Reactive Power Compensation Technologies.The ongoing evolution of power systems—driven by growing demand, increasing integration of renewable sources, and heightened grid complexity—necessitates a new generation of compensation technologies. Future developments are expected to address not only traditional voltage regulation tasks but also adapt to emerging challenges such as real-time variability, decentralization, and power quality.Key directions for innovation include:• Next-Generation STATCOM Architectures: The adoption of modular multilevel converters (MMCs) and embedded energy storage is expected to transform STATCOMs into multifunctional units capable of supporting both reactive and active power demands with greater efficiency and reduced harmonic impact.• AI-Driven Adaptive Control: Integration of machine learning algorithms will enable compensators to autonomously analyze grid conditions and adjust operating modes in real time, improving responsiveness and minimizing human intervention.• Context-Aware Compensation: Future systems will feature dynamic control logic that responds not only to voltage deviations but also to forecasted load behavior, weather-dependent generation patterns, and fault likelihood.• Expansion Beyond Transmission Systems: As distribution networks and microgrids become more complex and critical, compensation technologies will be scaled and adapted for lower-voltage environments, enabling local stability and power quality enhancement.• Multifunctional Role in Energy Quality: Reactive power devices will evolve from being single-purpose regulators into holistic power quality assets—capable of managing harmonics, flicker, voltage unbalance, and transient suppression.These advancements collectively aim to make the electrical grid more resilient, flexible, and intelligent—aligning with the global transition toward smarter, greener energy infrastructures.CONCLUSION.This study provides a comprehensive evaluation of reactive power compensation devices and their role in enhancing the operational capacity and voltage stability of high-voltage transmission networks. Through technical and comparative analysis, it has been demonstrated that while both SVC and STATCOM contribute meaningfully to system performance, their effectiveness varies depending on the dynamic requirements of the grid.STATCOM, with its inverter-based control and fast response characteristics, emerges as a key enabler for future-oriented power systems, particularly in environments with frequent load variation or renewable energy integration. On the other hand, SVC continues to offer a cost-efficient solution for steady-state reactive power control in conventional grid segments.An essential insight from this analysis is the importance of proper planning, device placement, and capacity sizing—factors that directly influence the technical efficiency and financial viability of compensation strategies. As power systems evolve toward more decentralized and intelligent infrastructures, the strategic deployment of reactive power compensators will remain a critical element of sustainable and stable energy transmission.
Номер журнала Вестник науки №5 (86) том 2
Ссылка для цитирования:
Memmedzade R.C., Mufidzade N.A. THE IMPACT OF COMPENSATION DEVICES ON THE TRANSFER CAPABILITY OF HIGH-VOLTAGE TRANSMISSION LINES // Вестник науки №5 (86) том 2. С. 1184 - 1191. 2025 г. ISSN 2712-8849 // Электронный ресурс: https://www.вестник-науки.рф/article/22974 (дата обращения: 20.07.2025 г.)
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