
Ⅰ. Application Scenario
Kapag ang 12-pulse rectifier units ay gumagana sa mga subway traction substations, ito ay may tendensya na bumuo ng mga characteristic harmonics tulad ng 11th at 13th orders. Ito ay nagdudulot ng sobrang distortion ng contact line voltage waveform (na iminumetro sa 8.5%), na nakakaapekto sa kalidad ng power supply at sa seguridad ng rolling stock equipment.
II. Core Solution
Ilapat ang TKDG-type outdoor epoxy-cast air-core reactors upang makamit ang efficient harmonic absorption at system optimization.
III. Technical Highlights
- Innovative Reactor Design
- Vertical Stacked Winding Structure: Unique spatial layout design reduces footprint while ensuring inductance accuracy, accommodating compact substation space requirements.
- 120°C Continuous Operation Capability: Epoxy resin vacuum casting process provides complete encapsulation insulation, enabling stable long-term operation under natural air cooling at high temperatures. Maintenance-free cycle reaches 20 years.
- System-Level Harmonic Mitigation
- 24-Pulse Rectification Collaborative Mitigation: Reactors and rectifier units form a complete mitigation unit:
▸ 12-pulse rectification → Generates 11th/13th/23rd/25th harmonics.
▸ Upgrade to 24-pulse rectification → Eliminates 23rd/25th harmonics.
▸ TKDG Reactor → Specifically absorbs residual 11th/13th characteristic harmonics.
- Key Performance Parameters
|
Indicator
|
Pre-Mitigation
|
Post-Mitigation
|
Improvement Rate
|
|
Contact Line Voltage THD
|
8.5%
|
2.1%
|
75.3%
|
|
Characteristic Harmonic Content Rate
|
>5%
|
<0.8%
|
>84%
|
|
Continuous Operation Temp. Rise (°C)
|
-
|
≤70 K
|
-
|
IV. Implementation Benefits
- Enhanced Power Supply Safety: Voltage THD meets/complies with the requirement (≤4%) of National Standard GB/T 14549-93 "Power Quality - Harmonics in Public Supply Network", reducing the risk of malfunction in locomotive control systems.
- Energy Efficiency Optimization: Reduced harmonic currents lower line losses. Measured comprehensive energy efficiency of the traction system improved by 3%-5%.
- Space and Cost Advantages:
▸ Vertical structure saves 30% installation area.
▸ Natural cooling design saves 45% in operation and maintenance costs compared to forced-air cooling solutions.
V. Engineering Validation
- 11th harmonic current reduced from 312 A to 58 A.
- 13th harmonic current reduced from 285 A to 62 A.
- Failure rate of capacitor banks and relay protection equipment reduced to zero.
Summary of Solution Advantages: Achieves a leap in 12-pulse system power quality to the level of a 24-pulse system through precise absorption of characteristic harmonics using topology optimization, avoiding the need for capacity expansion retrofits.