📋 Case Study

Australian Limestone Mine Regenerative Braking Energy Recovery

Excessive brake wear, energy waste, and thermal stress on friction brakes during repeated descents

🏗️ Project Overview

Retrofit of 22 electric haul trucks on 12% downhill haul route at Mount Gunson

🎯 Challenge

Excessive brake wear, energy waste, and thermal stress on friction brakes during repeated descents

🔧 Design Approach

Dual-mode regen braking with dynamic resistor bank for excess energy dissipation; onboard supercapacitor buffer for instantaneous power capture; grid feedback inverter for export during daylight hours

📐 Design Diagram

Australian Limestone Mine Regenerative Braking Energy Recovery Excessive brake wear • Energy waste • Thermal stress Truck ↓ descent Regen Braking 2.18 kWh/ton-km Supercap Buffer Resistor Bank 142 kW avg, 18% duty Grid Inverter Daylight export Kinetic → Electrical Instant capture Grid export Challenge Energy recovery Storage Dissipation

AI-generated project design illustration

📐 Key Calculations

Regen Energy Capture Potential

Truck Mass × g × Grade × Distance × Efficiency
Result: 2.18 kWh/ton-km
Represents 64% of descent kinetic energy

Resistor Bank Thermal Duty Cycle

Avg Power × Duty Cycle × Time
Result: 142 kW avg, 18% duty
Determines forced-air cooling spec

📊 Results

Brake pad life extended from 3,200 to 14,500 km; 19% net fleet energy reduction; 2.3 MW peak regen export to site microgrid

💡 Lessons Learned

  • Supercapacitors outperformed Li-ion for burst capture but required thermal derating above 45°C
  • Resistor bank noise required acoustic enclosure to meet WA WorkSafe limits
  • CAN bus latency caused 3% regen inconsistency—resolved with edge-compute gateway

Key Takeaways

  • 1Supercapacitors outperformed Li-ion for burst capture but required thermal derating above 45°C
  • 2Resistor bank noise required acoustic enclosure to meet WA WorkSafe limits
  • 3CAN bus latency caused 3% regen inconsistency—resolved with edge-compute gateway