MATLAB Simulation of Solar PV–EV Charging Station with Grid
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MATLAB Simulation of Solar PV–EV Charging Station with Grid
𝐈𝐧𝐭𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧
The MATLAB Simulation of Solar PV–EV Charging Station with Grid demonstrates an intelligent charging architecture that combines a solar photovoltaic source, EV battery, stationary battery, DC load, bidirectional DC–DC converter, and single-phase utility grid.
The main objective is to maximize the utilization of solar energy while reducing unnecessary power drawn from the grid. The system automatically changes its power-flow strategy depending on:
Solar PV generation
EV connection status
DC load demand
Battery operating condition
Availability of grid support
The complete system is implemented in MATLAB/Simulink, making it suitable for studying renewable-energy-based EV charging, converter control, MPPT operation, battery power management, and grid interaction.
𝐒𝐲𝐬𝐭𝐞𝐦 𝐎𝐯𝐞𝐫𝐯𝐢𝐞𝐰
The simulated charging station contains the following major sections:
4 kW solar PV array
Interleaved buck converter
Incremental Conductance MPPT
400 V common DC bus
DC load
EV battery
Stationary battery
Bidirectional DC–DC converter
Single-phase grid
Grid-connected inverter
Current-control system
Battery-selection logic
Voltage regulation
Power and SOC measurement
The solar PV system acts as the primary energy source. The battery and grid provide energy support depending on PV generation and EV availability.
𝐒𝐲𝐬𝐭𝐞𝐦 𝐒𝐩𝐞𝐜𝐢𝐟𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬
Parameter | Value |
Single PV module power | 250 W |
PV modules connected in series | 16 |
Total PV rated power | 4 kW |
PV module voltage at MPP | 30.7 V |
PV module current at MPP | 8.15 A |
PV string voltage at MPP | 491.2 V |
Regulated DC-bus voltage | 400 V |
Utility grid voltage | 230 V AC |
Typical DC load power | 1 kW |
Battery operating voltage observed | Around 250 V |
EV initial SOC in the demonstrated case | Around 9% |
Storage battery SOC in the demonstrated case | Around 50% |
Simulation duration shown | 3 s |
At rated solar irradiation, the 16-series-module PV string produces approximately 491.2 V at its maximum power point. Therefore, a step-down power converter is required to interface the PV source with the 400 V DC bus.
𝐒𝐨𝐥𝐚𝐫 𝐏𝐕 𝐀𝐫𝐫𝐚𝐲
The PV array is designed using 16 series-connected 250 W modules.
At approximately 1000 W/m² solar irradiation:
PV output power reaches nearly 4000 W
PV operating voltage is close to 500 V
Maximum-power-point current is approximately 8.15 A
The PV voltage must be reduced before supplying the 400 V DC link
Solar irradiation is intentionally varied during simulation to test the dynamic response of the charging station.
Irradiation Test Conditions
Irradiation | Approximate PV Power |
1000 W/m² | 4000 W |
500 W/m² | 2000 W |
0 W/m² | Approximately 0 W |
These changing conditions demonstrate how the charging system manages energy when solar generation increases, decreases, or becomes unavailable.
𝐈𝐧𝐭𝐞𝐫𝐥𝐞𝐚𝐯𝐞𝐝 𝐁𝐮𝐜𝐤 𝐂𝐨𝐧𝐯𝐞𝐫𝐭𝐞𝐫
An interleaved buck converter interfaces the PV array with the common DC bus.
Its main purposes are:
Step down the PV voltage from approximately 491 V to 400 V
Transfer solar energy to the DC link
Reduce input-current ripple
Reduce output-current ripple
Improve current sharing
Provide smoother power transfer compared with a conventional single-phase buck converter
Operate according to the MPPT-generated duty cycle
Using interleaved converter stages is particularly useful when handling relatively high current because the current is distributed between converter branches.
𝐈𝐧𝐜𝐫𝐞𝐦𝐞𝐧𝐭𝐚𝐥 𝐂𝐨𝐧𝐝𝐮𝐜𝐭𝐚𝐧𝐜𝐞 𝐌𝐏𝐏𝐓
The PV converter is controlled through an Incremental Conductance Maximum Power Point Tracking algorithm.
The MPPT receives:
PV voltage
PV current
It continuously evaluates variations in these quantities and adjusts the converter duty cycle.
The controller includes parameters such as:
Initial duty cycle
Maximum duty-cycle limit
Minimum duty-cycle limit
PV voltage variation
PV current variation
Based on changing solar conditions, the MPPT increases or decreases the duty cycle until the PV array operates close to its maximum available power point.
Benefits of MPPT
Maximum utilization of available solar energy
Improved performance under changing irradiation
Automatic converter duty-cycle adjustment
Better renewable-energy utilization
Reduced dependence on grid power
𝐂𝐨𝐦𝐦𝐨𝐧 𝐃𝐂 𝐁𝐮𝐬
A 400 V DC bus acts as the central energy-transfer point of the complete system.
It connects:
Solar PV converter
DC load
Battery converter
Grid-connected inverter
EV battery or stationary battery
Maintaining this DC-link voltage close to 400 V is important for stable operation of all connected converter stages.
𝐁𝐢𝐝𝐢𝐫𝐞𝐜𝐭𝐢𝐨𝐧𝐚𝐥 𝐃𝐂–𝐃𝐂 𝐂𝐨𝐧𝐯𝐞𝐫𝐭𝐞𝐫
The battery is connected to the common DC bus using a bidirectional DC–DC converter.
Unlike a conventional unidirectional converter, this converter can transfer energy in both directions.
Charging Operation
Power flows:
DC bus → converter → battery
This mode is used when excess PV or grid power is available for battery charging.
Discharging Operation
Power flows:
Battery → converter → DC bus
This mode is mainly used by the stationary battery when PV generation becomes insufficient.
𝐃𝐂-𝐁𝐮𝐬 𝐕𝐨𝐥𝐭𝐚𝐠𝐞 𝐂𝐨𝐧𝐭𝐫𝐨𝐥
The bidirectional converter uses a voltage-control loop to regulate the DC bus.
The controller:
Measures actual DC-bus voltage
Compares it with the 400 V reference
Processes the voltage error using a PI controller
Generates the required duty-cycle command
Sends switching pulses through the PWM generator
This allows the converter to compensate for changes in:
PV generation
Battery power
EV charging demand
DC load power
As observed in the simulation, the DC-link voltage remains close to its reference during operating-condition changes.
𝐄𝐕 𝐁𝐚𝐭𝐭𝐞𝐫𝐲 𝐚𝐧𝐝 𝐒𝐭𝐚𝐭𝐢𝐨𝐧𝐚𝐫𝐲 𝐁𝐚𝐭𝐭𝐞𝐫𝐲
An important feature of this charging architecture is the automatic selection between the EV battery and the stationary battery.
Battery Selection Logic
Control Input | EV Battery | Stationary Battery |
1 | Connected | Disconnected |
0 | Disconnected | Connected |
This arrangement prevents both batteries from operating through the same branch simultaneously in the demonstrated configuration.
𝐌𝐨𝐝𝐞 𝟏 – 𝐄𝐕 𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝
When the control input is set to 1:
EV battery is connected
Stationary battery is disconnected
Solar PV becomes the preferred charging source
Grid power is used only when required
EV battery SOC increases during charging
When sufficient PV power is available:
PV supplies the DC load
Remaining PV power charges the EV battery
Grid power is maintained close to zero
When PV generation falls to almost zero:
Grid becomes active
Grid supplies the required DC-side demand
EV charging can continue
Stationary battery remains disconnected
𝐌𝐨𝐝𝐞 𝟐 – 𝐄𝐕 𝐍𝐨𝐭 𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝
When the control input is set to 0:
EV battery is disconnected
Stationary battery is connected
PV supplies the DC load first
Excess PV charges the stationary battery
Stationary battery supports the load during low PV generation
Grid contribution remains approximately zero in the demonstrated operating case
This allows locally stored renewable energy to support the DC load without unnecessarily importing power from the grid.
𝐆𝐫𝐢𝐝 𝐈𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐢𝐨𝐧
The system uses a 230 V single-phase utility grid connected to the common DC link through a controlled inverter.
The grid is not continuously used as the primary power source.
Instead, it acts mainly as a support source when:
EV is connected
Solar generation becomes insufficient
Charging demand cannot be satisfied by available PV power
This strategy helps minimize purchased grid energy.
𝐆𝐫𝐢𝐝 𝐂𝐨𝐧𝐯𝐞𝐫𝐭𝐞𝐫 𝐂𝐨𝐧𝐭𝐫𝐨𝐥
The inverter is operated using a current-control strategy.
The control system includes:
Reference-current generation
Measured inverter current
Coordinate transformations
PI current controllers
Voltage reference generation
PWM pulse generation
Converter switching control
The current reference depends mainly on:
PV availability
EV connection status
Required charging operation
When adequate PV generation is available, the grid-current reference can be reduced to approximately zero.
When solar power is unavailable and the EV requires charging, a grid-current reference is generated to obtain the required power from the utility.
𝐏𝐕 𝐀𝐯𝐚𝐢𝐥𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐋𝐨𝐠𝐢𝐜
The demonstrated control checks the PV current to determine whether meaningful solar generation is available.
A PV-current threshold of approximately 0.5 A is used in the described control logic.
Typical Decision Process
PV Condition | EV Status | Grid Action |
PV available | EV connected | Grid power minimized |
PV unavailable | EV connected | Grid supplies required power |
PV available | EV disconnected | PV supplies load/storage battery |
PV unavailable | EV disconnected | Storage battery supplies local load |
This operating strategy reduces unnecessary grid usage.
𝐖𝐨𝐫𝐤𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬
The complete operating sequence can be understood in a few simple steps:
Solar irradiation is applied to the PV array.
PV voltage and current are measured.
Incremental Conductance MPPT determines the converter operating duty cycle.
The interleaved buck converter transfers maximum available PV power to the 400 V DC bus.
The DC load receives the required power.
The control system checks whether an EV is connected.
If the EV is connected, the EV battery becomes active.
If the EV is absent, the stationary battery becomes active.
Excess solar power charges the active battery.
If PV generation is inadequate, either the grid or stationary battery supports the system according to the operating mode.
The bidirectional converter maintains DC-bus stability.
Voltage, current, power, grid response, and battery SOC are monitored continuously.
𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐑𝐞𝐬𝐮𝐥𝐭𝐬
The simulation evaluates the system under changing solar irradiation and different battery-selection conditions.
PV Response
The solar PV system successfully follows changes in irradiation.
Operating Condition | PV Power | DC Load | Remaining Power |
1000 W/m² | ≈ 4000 W | ≈ 1000 W | ≈ 3000 W |
500 W/m² | ≈ 2000 W | ≈ 1000 W | ≈ 1000 W |
0 W/m² | ≈ 0 W | ≈ 1000 W | Backup source required |
At high irradiation, substantial excess PV energy is available for battery charging.
𝐄𝐕-𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝 𝐑𝐞𝐬𝐮𝐥𝐭𝐬
With the EV connected:
EV battery voltage remains approximately 250 V
EV charging current becomes positive
EV SOC gradually increases
Stationary battery current remains approximately zero
At high PV generation, solar energy supplies both load and EV charging
At approximately 4 kW PV generation, around 1 kW supplies the load and the remaining power is available for charging
At approximately 2 kW PV generation, around 1 kW supplies the load and approximately 1 kW remains available for EV charging
When PV generation reaches zero, the grid supplies the required charging and load power
When PV generation returns, grid power reduces toward zero
This demonstrates effective source coordination.
𝐒𝐭𝐚𝐭𝐢𝐨𝐧𝐚𝐫𝐲-𝐁𝐚𝐭𝐭𝐞𝐫𝐲 𝐑𝐞𝐬𝐮𝐥𝐭𝐬
When the EV is disconnected:
EV battery current becomes zero
Stationary battery becomes active
High PV generation charges the stationary battery
At approximately 4 kW PV power, the load consumes about 1 kW and nearly 3 kW is available for battery charging
At approximately 2 kW PV power, around 1 kW supplies the load and the remaining 1 kW charges the battery
When PV output falls to zero, stationary-battery power reverses direction
Negative battery power indicates that the battery is supplying energy to the DC bus
Grid power remains close to zero during this demonstrated mode
The result confirms the bidirectional nature of the battery converter.
𝐒𝐎𝐂 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞
Battery SOC provides another indication of system power flow.
EV Connected
EV SOC starts at approximately 9%
SOC gradually increases during charging
Stationary-battery SOC remains almost unchanged because it is disconnected
EV Disconnected
EV SOC remains nearly unchanged
Stationary-battery SOC changes according to charging and discharging operation
Because the simulation duration is only a few seconds, SOC variation is naturally small.
𝐏𝐨𝐰𝐞𝐫 𝐅𝐥𝐨𝐰 𝐒𝐮𝐦𝐚𝐫𝐲
Operating Situation | Main Power Flow |
High PV + EV connected | PV → DC Load + EV |
Medium PV + EV connected | PV → DC Load + EV |
No PV + EV connected | Grid → DC Load + EV |
High PV + EV absent | PV → DC Load + Storage Battery |
Medium PV + EV absent | PV → DC Load + Storage Battery |
No PV + EV absent | Storage Battery → DC Load |
This simple operating table summarizes the complete energy-management strategy.
𝐊𝐞𝐲 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐬
4 kW solar PV generation
Incremental Conductance MPPT
Interleaved buck converter
400 V regulated DC bus
EV charging capability
Stationary energy-storage support
Bidirectional battery power flow
Automatic EV/storage-battery selection
Single-phase grid integration
Grid current control
PI-based converter regulation
PWM switching control
Variable irradiation testing
Dynamic source selection
Battery SOC monitoring
Real-time voltage and current measurement
PV, battery, load, and grid power monitoring
Reduced dependency on grid energy
𝐀𝐝𝐯𝐚𝐧𝐭𝐚𝐠𝐞𝐬 𝐨𝐟 𝐭𝐡𝐞 𝐏𝐫𝐨𝐩𝐨𝐬𝐞𝐝 𝐒𝐲𝐬𝐭𝐞𝐦
Higher Solar-Energy Utilization
MPPT operation helps extract the maximum available power from the PV array.
Reduced Grid Dependency
The grid is mainly used when solar energy cannot meet EV charging demand.
Better Power Quality at the DC Side
The interleaved converter helps reduce current ripple compared with a conventional single-channel buck converter.
Energy Storage Support
The stationary battery supplies the local load when PV generation becomes insufficient.
Flexible EV Charging
EV charging automatically adapts according to solar-power availability.
Stable DC-Link Operation
The bidirectional converter control keeps the common DC bus near 400 V.
𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬
This MATLAB/Simulink model can be useful for studying:
Solar-powered EV charging stations
Smart charging infrastructure
Grid-assisted EV chargers
Renewable-energy integration
Battery energy-storage systems
Residential EV charging
Commercial charging stations
Smart-grid energy management
DC microgrids
Bidirectional power converters
MPPT control techniques
Power-electronic converter control
Renewable-energy-based transportation systems
Grid power minimization strategies
It is suitable for students, researchers, engineers, educators, and professionals working in renewable energy, electric mobility, power electronics, and smart-grid control.
𝐖𝐡𝐚𝐭 𝐂𝐚𝐧 𝐁𝐞 𝐎𝐛𝐬𝐞𝐫𝐯𝐞𝐝 𝐢𝐧 𝐭𝐡𝐞 𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧?
The model provides several useful measurements for understanding system behavior:
PV voltage
PV current
PV power
DC-bus voltage
DC-load current
DC-load power
EV battery voltage
EV battery current
EV battery power
Stationary-battery voltage
Stationary-battery current
Stationary-battery power
EV SOC
Stationary-battery SOC
Inverter voltage
Inverter current
Grid current
Grid power
These waveforms make it easier to analyze how the complete charging station responds to changing PV generation and battery operating modes.
𝐖𝐡𝐲 𝐓𝐡𝐢𝐬 𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐢𝐬 𝐔𝐬𝐞𝐟𝐮𝐥
The model combines several important concepts within a single MATLAB/Simulink environment:
Solar PV modeling
MPPT
DC–DC conversion
Interleaved converter topology
Battery charging
Battery discharging
EV integration
Grid-connected inverter control
Current control
DC-bus voltage regulation
Automatic energy management
Instead of studying these elements individually, users can observe how they interact within a complete renewable-energy EV charging station.
𝐂𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐨𝐧
The MATLAB Simulation of Solar PV–EV Charging Station with Grid presents an effective renewable-energy-based charging architecture integrating a 4 kW solar PV array, interleaved buck converter, Incremental Conductance MPPT, 400 V DC bus, EV battery, stationary battery, bidirectional converter, DC load, and 230 V utility grid.
Simulation results demonstrate that the system intelligently manages power according to solar availability and EV connection status. During high PV generation, solar energy supplies the local load while excess energy charges the connected battery. When solar power decreases, charging power is automatically reduced according to available generation.
When the EV is connected and solar power becomes unavailable, the grid provides the required charging and load power. When the EV is disconnected, the stationary battery supports the DC load during insufficient solar generation.
Overall, the model demonstrates solar-energy maximization, controlled battery charging, bidirectional energy transfer, DC-bus regulation, automatic source selection, and reduced grid dependence in a single MATLAB/Simulink platform.
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