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PD IEC TR 60919 — Performance of High-Voltage Direct Current (HVDC) Systems with Line-Commutated Converters Technical Report Series
Performance of High-Voltage Direct Current (HVDC) Systems with Line-Commutated Converters
⚡ PD IEC TR 60919 is the British Standards Institution (BSI) Published Document implementing the International Electrotechnical Commission (IEC) technical report IEC/TR 60919, addressing the performance of high-voltage direct current (HVDC) transmission systems with line-commutated converters (LCC). Prepared by the UK technical committee PEL/22 “Power electronics” and classified under ICS 29.200 (rectifiers, converters) and 29.240.99 (other transmission and distribution equipment), the series provides technical guidance on steady-state/dynamic performance, faults and switching, and AC-side dynamic voltage control — a key basis for HVDC system design, operation, and performance evaluation.
💡 HVDC transmission offers advantages for large-capacity, long-distance transmission and grid interconnection, but its converters interact with the AC grid in complex ways. These technical reports give designers and operators a unified method for assessing steady-state operation, fault response, and voltage control.
1. Series Structure and Overall Framework 📌
The PD IEC TR 60919 series consists of 3 parts, covering steady-state and dynamic performance, faults and switching, and AC-side dynamic voltage control. Parts 1 and 2 were updated by IEC amendments A1 (2013 and 2015).
| Part | Year | Title | Core Content |
|---|---|---|---|
| PD IEC/TR 60919-1 (+A1) | 2010 (+2013) | Steady-state and dynamic performance | Specifies HVDC system types and steady-state, dynamic performance requirements |
| PD IEC/TR 60919-2 (+A1) | 2008 (+2015) | Faults and switching | Specifies system fault characteristics and performance under switching operations |
| PD IEC/TR 60919-3 | 2009 | AC-side dynamic voltage control | Specifies AC-side dynamic voltage control and interaction with reactive power sources |
⚠️ This series is an IEC/TR technical report of reference nature, not a mandatory standard. Always reference the current BSI version (including amendments) and consider relevant HVDC standards and grid codes.
2. Steady-State and Dynamic Performance: Part 1 Requirements ⚙️
Part 1 specifies the types of HVDC systems and their steady-state and dynamic performance requirements:
- HVDC system types: includes back-to-back systems, point-to-point transmission, and bipolar/monopolar topologies.
- Steady-state performance: specifies converter current, voltage, power, and power-factor characteristics under normal operation.
- Dynamic performance: specifies dynamic response and stability under disturbances and load changes.
- Control characteristics: describes converter control (e.g., constant-current, constant-power, constant-extinction-angle) and its effect on performance.
Part 1 also specifies performance assessment criteria and test-verification methods for system design and acceptance.
3. Faults and Switching: Part 2 Requirements 🚨
Part 2 specifies the performance and response of HVDC systems under faults and switching:
| Item | Description |
|---|---|
| DC-side faults | Current and voltage response and protection action for DC line and converter valve faults |
| AC-side faults | Commutation failure, power fluctuation, and recovery characteristics caused by AC grid faults |
| Switching | Behaviour during converter switching, pole start/stop, and power reversal |
| Protection and recovery | Specifies protection strategy and post-fault recovery requirements |
Part 2 focuses on converter-grid interaction during faults and operations, providing reference for protection setting and operating-mode arrangement.
4. AC-Side Dynamic Voltage Control: Part 3 Requirements 📉
Part 3 specifies the AC-side dynamic voltage control of an HVDC converter station and its interaction with reactive power sources:
| Item | Description |
|---|---|
| Converter as active/reactive power source | Analyses the voltage characteristics of the converter as an active/reactive power source |
| AC network voltage characteristics | Analyses AC network voltage characteristics based on loading at the HVDC substation busbar |
| AC filters, capacitor banks, and shunt reactors | Analyses the effect of filters, capacitor banks, and shunt reactors on voltage/reactive characteristics |
| Dynamic voltage control strategy | Specifies voltage-control and reactive-regulation strategies and coordination |
Part 3 helps designers assess voltage stability and reactive balance after connecting an HVDC converter station to the AC grid, ensuring safe operation.
✅ The three parts form a complete specification for LCC-HVDC system performance: Part 1 on “steady-state and dynamic performance,” Part 2 on “faults and switching,” and Part 3 on “AC-side voltage control,” together supporting DC transmission design and operation assessment.
5. Engineering Practice and Application Notes 🛠️
- 🔍 System design: choose topology and control strategy per Part 1 to meet steady-state and dynamic performance requirements.
- 🔧 Protection setting: analyse fault characteristics per Part 2 to set protection and recovery logic appropriately.
- 📊 Reactive and voltage planning: configure filters, capacitors, and reactors per Part 3 to maintain voltage stability.
- 📋 Comparison with IGBT/VSC technology: this series targets line-commutated converters (LCC); voltage-source-converter (VSC-HVDC) using fully controlled devices has a separate standard system.
6. Frequently Asked Questions ❓
❓ Q: What is line-commutated converter (LCC) HVDC?
A: LCC-HVDC uses thyristor converter valves and relies on AC grid commutation; it is the mainstream technology for large-capacity, long-distance DC transmission, such as back-to-back and point-to-point projects.
A: LCC-HVDC uses thyristor converter valves and relies on AC grid commutation; it is the mainstream technology for large-capacity, long-distance DC transmission, such as back-to-back and point-to-point projects.
❓ Q: Why does HVDC need attention to AC-side voltage control?
A: The converter both absorbs and generates reactive power during operation, interacting with the AC grid, filters, and reactive compensation equipment, affecting voltage stability and requiring coordinated control.
A: The converter both absorbs and generates reactive power during operation, interacting with the AC grid, filters, and reactive compensation equipment, affecting voltage stability and requiring coordinated control.
❓ Q: What is commutation failure?
A: Commutation failure is where an AC-side voltage disturbance prevents converter valves from commutating in sequence, causing a DC current surge and power drop; it is a typical LCC-HVDC fault requiring protection and control measures.
A: Commutation failure is where an AC-side voltage disturbance prevents converter valves from commutating in sequence, causing a DC current surge and power drop; it is a typical LCC-HVDC fault requiring protection and control measures.
🔍 Q: Why is this series published as a Technical Report (TR)?
A: Because it is an IEC technical report providing system-performance evaluation and design guidance rather than mandatory requirements, for reference in DC transmission engineering design and operation.
A: Because it is an IEC technical report providing system-performance evaluation and design guidance rather than mandatory requirements, for reference in DC transmission engineering design and operation.