PV–Battery Powered BLDC Motor System for Electric Vehicle Application
PV–battery powered BLDC motor drive system developed in MATLAB for electric vehicle (EV) applications. The system intelligently integrates solar PV, battery storage, power converters, and a BLDC motor drive to ensure reliable operation under varying irradiance conditions—including daytime and nighttime operation.
🔧 System Overview
The complete EV drive system consists of:
☀️ Solar PV Array
🔼 DC–DC Boost Converter with Incremental Conductance MPPT
🔋 Battery Energy Storage (48 V, 70 Ah)
🔁 Bidirectional DC–DC Converter
⚙️ BLDC Motor Drive (EV Motor)
🔌 DC Bus (220 V regulated)
This configuration enables:
Maximum power extraction from PV
Stable DC bus voltage
Bidirectional battery charging/discharging
Continuous EV motor operation
☀️ Solar PV Array Specifications
🔹 Single PV panel rating: 250 W
🔹 Voltage at MPP (Vmp): 30.7 V
🔹 Current at MPP (Imp): 8.15 A
🔹 Configuration: 4 panels in series
🔹 Total power at STC: 1000 W (1000 W/m², 25°C)
📈 I–V and P–V Characteristics
1000 W/m² → ~1000 W
800 W/m² → ~800 W
600 W/m² → ~599 W
400 W/m² → ~396 W
The PV array output is connected to the DC bus through a boost converter.
🔼 Boost Converter with Incremental Conductance MPPT
The boost converter performs two key functions:
⚡ Boosts PV voltage from ~120 V to 220 V DC
🎯 Extracts maximum power using Incremental Conductance (IC) MPPT
🧠 Incremental Conductance MPPT Logic
Measures PV voltage & current
Computes:
ΔV, ΔI, ΔP
Decision rules:
If ΔI/ΔV = −I/V → MPP reached
Adjust duty cycle accordingly
Duty cycle limits enforced:
D<sub>min</sub> ≤ D ≤ D<sub>max</sub>
🔁 The algorithm updates the duty cycle every sampling instant and drives the boost converter using a PWM generator.
🔋 Battery Energy Storage System
🔹 Battery rating: 48 V, 70 Ah
🔹 Initial SOC: 50%
🔁 Bidirectional Converter Operation
Why bidirectional?
🌞 Excess PV power → Battery charging
🌙 Low/No PV power → Battery discharging to support EV motor
⚙️ Control Strategy
DC bus voltage (220 V) is measured
Compared with reference voltage
Error processed through PI controller
PWM pulses generated:
Lower switch → Direct pulse
Upper switch → Complementary pulse
✔️ Maintains DC bus voltage✔️ Enables smooth power flow in both directions
⚙️ BLDC Motor Drive (EV Motor)
The BLDC motor acts as the electric vehicle traction motor.
🔌 Drive Components
Voltage Source Inverter (VSI)
BLDC motor model
Hall sensors for rotor position detection
🧭 Commutation Logic
Hall sensor signals → Logic table
Back-EMF derived from logic
Switching pulses generated for:
Q1–Q6 inverter switches
Six-step commutation implemented
🧪 Motor Inputs & Measurements
Load torque:
0 Nm initially
3 Nm applied after 0.1 s
Measured parameters:
Speed (RPM)
Electromagnetic torque
Stator current
Back EMF
🧪 Simulation Scenarios & Results
✅ Case 1: Variable Irradiance (Daytime)
Irradiance:
1000 → 500 → 1000 W/m² (every 0.3 s)
Observations:
DC bus voltage maintained at 220 V
PV power tracks irradiance accurately
Battery:
Slight discharge at low irradiance
Charging during high irradiance
Motor:
Speed ≈ 1300 RPM
Torque ≈ 3 Nm
🌙 Case 2: Zero Irradiance (Nighttime)
Observations:
PV power = 0
Boost converter inactive
Battery fully supplies the BLDC motor
Battery current ≈ 10 A (discharging)
DC bus voltage still regulated at 220 V
Motor speed & torque remain stable
✔️ Demonstrates reliable EV operation even without solar power
⭐ Key Highlights
☀️ Efficient PV energy utilization using IC-MPPT
🔋 Intelligent battery charge/discharge management
⚙️ Stable BLDC motor operation under all conditions
🌙 Seamless transition between PV-powered and battery-powered modes
🚗 Suitable for solar-assisted electric vehicle applications
🎯 Conclusion
This PV–battery powered BLDC motor system successfully demonstrates:
Robust EV drive operation
Renewable energy integration
Advanced power electronics control
Reliability during both daytime and nighttime
📌 A practical and scalable solution for solar-powered electric vehicles.
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