Intelligent LED Road Lighting System：What is a Type 4 street light?
2025-05-20
Type 4 Street Light: Intelligent LED Road Lighting System
Definition & Core Features
A Type 4 Street Lightrefers to an intelligent LED-based illumination system featuring:
- 4th-generation LED Light source
- High luminous efficiency (120-150 lm/W)
- Ultra-low power consumption (50-60% less than conventional lights)
- Directional light output (85-90% light extraction rate)
- Integrated ICT sensors and adaptive controls
Key Technologies
1. Dynamic Dimming System
Utilizes PWM modulation (kHz-level frequency) with microcontroller-based dimming logic:
- 50% brightness = 0.5ms ON / 0.5ms OFF cycle
- No flicker effect at high frequencies
2. Multi-Sensor Network
- Infrared thermal sensors (>35°C trigger)
- Microwave vehicle detectors
- Image recognition systems
- ZigBee + PLC communication
Smart Applications
| Function | Implementation | Energy Saving |
|---|---|---|
| Real-time Fault Reporting | PLC-based status monitoring (Taiwan IIIPC solution) | ↓ 30% maintenance cost |
| Adaptive Brightness | Gradual dimming (1/3-1/2 illumination post-midnight) Toulouse case: 10-sec delay after vehicle detection | ↑ 50% savings |
| Color Temperature Adjustment | Fog/emergency detection → yellow spectrum shift | ↑ Safety |
Energy Impact
Current urban lighting in China:
- Consumes 43.9 billion kWh annually (30% national total)
- Costs ¥28.5 billion/year
- Smart LED systems achieve >40% energy reduction vs traditional "alternate lamp shutdown" methods
Comparative Advantage
LED vs Conventional Lamps:
| Feature | LED (Type 4) | Sodium Lamp | Mercury Lamp | |-----------------|--------------|-------------|--------------| | Lifetime | 50,000+ hrs | 12,000 hrs | 8,000 hrs | | Dimming Capability | Instant | Slow | None | | Light Direction | 180° focused | Omnidirectional | Omnidirectional |