MATLAB Simulation of Fuzzy Logic Control of V2G and G2V in Single Phase Grid
MATLAB Simulation of Fuzzy Logic Control of V2G and G2V in Single Phase Grid
𝐈𝐧𝐭𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧
The MATLAB Simulation of Fuzzy Logic Control of V2G and G2V in Single Phase Grid demonstrates bidirectional energy transfer between an electric vehicle battery and a single-phase utility grid.
The Simulink model supports two operating modes:
Vehicle-to-Grid (V2G): Battery delivers power to the grid.
Grid-to-Vehicle (G2V): Grid supplies power to charge the battery.
A fuzzy logic controller regulates the battery current, while the grid-side converter control maintains the DC-link voltage and controls the grid current.
This model is useful for understanding:
Bidirectional EV charging
V2G and G2V operation
Fuzzy logic current control
DC-link voltage regulation
Single-phase grid synchronization
Unity power factor operation
Battery charging and discharging behavior
𝐒𝐲𝐬𝐭𝐞𝐦 𝐎𝐯𝐞𝐫𝐯𝐢𝐞𝐰
The overall system consists of a single-phase grid, grid-side converter, DC link, bidirectional DC-DC converter, LC filter, lithium-ion battery, fuzzy logic controller, and converter control system.
Main System Components
Component | Description |
Single-Phase Grid | Supplies or receives electrical power |
Source Inductor | Limits and smooths grid current |
Grid-Side Converter | Provides AC-DC and DC-AC bidirectional conversion |
DC-Link Capacitor | Maintains the intermediate DC voltage |
Bidirectional DC-DC Converter | Controls battery charging and discharging |
LC Filter | Reduces current and voltage ripple |
Lithium-Ion Battery | Energy storage source for V2G/G2V operation |
Fuzzy Logic Controller | Controls battery current |
PI Controllers | Regulate DC-link voltage and grid current |
PLL | Extracts grid phase information |
PWM Generator | Generates switching pulses |
𝐒𝐲𝐬𝐭𝐞𝐦 𝐏𝐚𝐫𝐚𝐦𝐞𝐭𝐞𝐫𝐬
The important numerical values used in the model are summarized below.
Parameter | Value |
Grid Peak Voltage | 325 V |
Grid Frequency | 50 Hz |
Source Inductance | 2.3 mH |
DC-Link Reference Voltage | 380 V |
Battery Nominal Voltage | 220 V |
Battery Capacity | 48 Ah |
Initial Battery SOC | 50% |
Battery Type | Lithium-Ion |
V2G Current Reference | +10 A |
G2V Current Reference | -10 A |
Fuzzy Error Membership Functions | 5 |
Fuzzy Change-of-Error Membership Functions | 5 |
Fuzzy Output Membership Functions | 5 |
Total Fuzzy Rules | 25 |
Operating Change Time | 1 s |
𝐕𝟐𝐆 𝐚𝐧𝐝 𝐆𝟐𝐕 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐧𝐠 𝐌𝐨𝐝𝐞𝐬
The operating mode is selected by changing the battery current reference.
Current Reference | Battery Condition | Power Direction | Operating Mode |
Positive | Discharging | Battery → Grid | V2G |
Negative | Charging | Grid → Battery | G2V |
Vehicle-to-Grid Mode
When the reference battery current is set to +10 A:
Battery operates in discharge mode.
Battery current follows approximately +10 A.
Battery SOC gradually decreases.
Power flows from the EV battery toward the grid.
Grid current direction changes according to exported power.
DC-link voltage is maintained near its reference value.
Grid-to-Vehicle Mode
When the current reference is changed to -10 A:
Battery operates in charging mode.
Battery current changes toward -10 A.
Battery SOC begins increasing.
Grid supplies power to the EV battery.
Grid voltage and current operate with the required phase relationship.
DC-link voltage returns to its reference after the transient.
𝐖𝐨𝐫𝐤𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬
The complete power conversion path can be understood as:
Single-Phase Grid → Bidirectional Grid Converter → DC Link → Bidirectional DC-DC Converter → Battery
Power can also flow in the reverse direction:
Battery → Bidirectional DC-DC Converter → DC Link → Grid Converter → Single-Phase Grid
The direction of power flow depends mainly on the selected battery current reference.
Basic Operating Sequence
The single-phase grid is connected to the grid-side converter.
The converter establishes the controlled DC-link voltage.
The battery is connected through the bidirectional DC-DC converter.
The desired battery current reference is selected.
Actual battery current is measured.
Reference and measured currents are compared.
Current error is calculated.
Change in current error is determined.
Both signals are supplied to the fuzzy controller.
Fuzzy logic generates the required duty-cycle command.
PWM pulses operate the bidirectional converter.
Battery charging or discharging takes place according to the reference.
𝐂𝐨𝐧𝐭𝐫𝐨𝐥 𝐒𝐭𝐫𝐚𝐭𝐞𝐠𝐲
The system uses two major control sections:
Fuzzy Logic Battery Current Control
Grid-Side Converter Control
𝐅𝐮𝐳𝐳𝐲 𝐋𝐨𝐠𝐢𝐜 𝐂𝐨𝐧𝐭𝐫𝐨𝐥
The fuzzy logic controller is responsible for controlling the battery current.
Fuzzy Controller Inputs
Two input variables are used:
Current Error
Rate of Change of Current Error
The actual battery current is continuously compared with the selected current reference.
Fuzzy Controller Output
The fuzzy controller generates:
Duty Cycle
The generated duty cycle is sent to the PWM generator, which produces gate pulses for the bidirectional DC-DC converter.
Fuzzy Logic Configuration
Fuzzy Variable | Number of Membership Functions |
Current Error | 5 |
Change of Error | 5 |
Duty Cycle Output | 5 |
Total Rule Base | 25 Rules |
The 25-rule fuzzy rule base determines the appropriate duty-cycle correction depending on battery current error conditions.
𝐁𝐢𝐝𝐢𝐫𝐞𝐜𝐭𝐢𝐨𝐧𝐚𝐥 𝐃𝐂-𝐃𝐂 𝐂𝐨𝐧𝐯𝐞𝐫𝐭𝐞𝐫 𝐂𝐨𝐧𝐭𝐫𝐨𝐥
The battery-side converter contains two IGBT switches and operates bidirectionally.
Its main functions are:
Controlling battery charging current
Controlling battery discharging current
Enabling V2G operation
Enabling G2V operation
Maintaining accurate battery current tracking
Providing controlled power exchange with the DC link
The switching action changes automatically according to the fuzzy controller output.
𝐆𝐫𝐢𝐝-𝐒𝐢𝐝𝐞 𝐂𝐨𝐧𝐯𝐞𝐫𝐭𝐞𝐫 𝐂𝐨𝐧𝐭𝐫𝐨𝐥
The grid-side converter performs both rectifier and inverter operation.
It is designed to:
Maintain the DC-link voltage
Generate sinusoidal grid current
Synchronize grid current with grid voltage
Support bidirectional power transfer
Maintain good power factor
DC-Link Voltage Control
The DC-link voltage is measured and compared with the 380 V reference.
The resulting error is processed by a PI controller.
The controller produces the required grid current magnitude reference.
𝐏𝐋𝐋 𝐚𝐧𝐝 𝐒𝐲𝐧𝐜𝐡𝐫𝐨𝐧𝐢𝐳𝐚𝐭𝐢𝐨𝐧
Grid voltage is measured and supplied to the Phase-Locked Loop (PLL).
The PLL provides the grid phase angle.
This phase information is used to generate a sinusoidal reference waveform synchronized with the grid.
The resulting reference is combined with the grid current magnitude command to obtain the instantaneous source current reference.
𝐂𝐮𝐫𝐫𝐞𝐧𝐭 𝐂𝐨𝐧𝐭𝐫𝐨𝐥 𝐋𝐨𝐨𝐩
The desired source current is compared with the measured source current.
The current error is processed through another PI controller.
The controller produces the modulation signal required by the PWM generator.
The PWM generator then controls the switches of the single-phase grid converter.
This control helps obtain:
Sinusoidal grid current
Controlled current magnitude
Required current phase
Stable DC-link voltage
Bidirectional power transfer
𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐓𝐞𝐬𝐭 𝐂𝐨𝐧𝐝𝐢𝐭𝐢𝐨𝐧
The model is tested using two current-reference levels.
Simulation Interval | Battery Current Reference | Operating Mode |
Initial Period | +10 A | V2G |
After 1 Second | -10 A | G2V |
The model can also be tested in the reverse sequence:
Initial Condition | Second Condition |
-10 A → G2V | +10 A → V2G |
This allows the user to study dynamic transition between both power-flow modes.
𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐑𝐞𝐬𝐮𝐥𝐭𝐬
Several important signals are observed during simulation.
1. Source Voltage
Maintains the required sinusoidal waveform.
Operates at 50 Hz.
Used as the synchronization reference for converter control.
2. Source Current
The source current changes according to power-flow direction.
During V2G
Battery delivers energy to the grid.
Current direction corresponds to power export.
Grid voltage and current show the required phase relationship for reverse power flow.
During G2V
Grid supplies energy to the battery.
Current follows the charging power requirement.
Grid voltage and current operate approximately in phase for grid-to-battery energy transfer.
𝐁𝐚𝐭𝐭𝐞𝐫𝐲 𝐂𝐮𝐫𝐫𝐞𝐧𝐭 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞
The fuzzy controller tracks the selected reference current.
Operating Mode | Reference | Battery Current Response |
V2G | +10 A | Approximately +10 A |
G2V | -10 A | Approximately -10 A |
When the current reference changes, the controller automatically changes the converter operating condition.
𝐁𝐚𝐭𝐭𝐞𝐫𝐲 𝐒𝐎𝐂 𝐁𝐞𝐡𝐚𝐯𝐢𝐨𝐫
Battery SOC provides a clear indication of power-flow direction.
During V2G
Battery discharges.
SOC gradually decreases.
During G2V
Battery charges.
SOC gradually increases.
This behavior confirms correct bidirectional operation.
𝐃𝐂-𝐋𝐢𝐧𝐤 𝐕𝐨𝐥𝐭𝐚𝐠𝐞 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞
The DC-link voltage reference is fixed at 380 V.
During normal operation:
DC-link voltage remains close to 380 V.
A temporary transient appears when the operating mode changes.
The voltage subsequently settles back near the reference.
According to the demonstrated response, the settling occurs approximately 0.2 seconds after the operating-mode transition.
Condition | DC-Link Response |
Steady-State V2G | Maintained near 380 V |
V2G → G2V Transition | Temporary undershoot |
After Transition | Returns near 380 V |
Approximate Settling Time | 0.2 s |
𝐏𝐨𝐰𝐞𝐫 𝐅𝐚𝐜𝐭𝐨𝐫 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐨𝐧
The converter control system is designed to maintain proper grid-current synchronization.
During both operating modes, the control maintains a high-quality sinusoidal current waveform while changing the direction of active power.
This demonstrates effective grid-side control during:
EV battery charging
EV battery discharging
Power-flow reversal
Dynamic mode transition
𝐊𝐞𝐲 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐬
Single-phase V2G and G2V simulation
Fuzzy logic-based battery current control
25-rule fuzzy inference system
Bidirectional power flow
Lithium-ion battery modeling
Bidirectional DC-DC converter
Bidirectional AC-DC converter
380 V DC-link regulation
PLL-based grid synchronization
PI-based voltage and current control
Sinusoidal PWM control
V2G-to-G2V dynamic transition
Battery SOC monitoring
Battery current reference tracking
Grid voltage and current analysis
𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬
This MATLAB/Simulink model can support learning and research in:
Electric vehicle charging systems
Smart grid integration
Vehicle-to-grid technology
Grid-to-vehicle charging
Bidirectional EV chargers
Fuzzy logic control
Battery energy management
Smart charging systems
Renewable energy integrated EV charging
Distributed energy systems
Grid support using EV batteries
Power electronic converter control
𝐖𝐡𝐲 𝐔𝐬𝐞 𝐅𝐮𝐳𝐳𝐲 𝐋𝐨𝐠𝐢𝐜 𝐂𝐨𝐧𝐭𝐫𝐨𝐥?
Fuzzy logic is useful for this type of system because it provides flexible nonlinear control without requiring a highly complicated mathematical model.
In this simulation, fuzzy logic helps:
Track the desired battery current
Control charging and discharging
Respond to reference-current changes
Generate suitable converter duty cycles
Handle bidirectional operating conditions
Improve the understanding of intelligent EV converter control
𝐖𝐡𝐨 𝐂𝐚𝐧 𝐔𝐬𝐞 𝐓𝐡𝐢𝐬 𝐌𝐨𝐝𝐞𝐥?
This simulation is suitable for:
Electrical engineering students
Power electronics learners
MATLAB/Simulink users
EV charging researchers
Smart grid researchers
Control engineering students
Power system engineers
Researchers working on V2G and G2V technologies
𝐂𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐨𝐧
The MATLAB Simulation of Fuzzy Logic Control of V2G and G2V in Single Phase Grid demonstrates effective bidirectional energy transfer between an electric vehicle battery and the utility grid.
The fuzzy logic controller regulates battery current, while the grid-side converter control maintains the 380 V DC link, produces controlled sinusoidal grid current, and manages power-flow reversal.
With a 220 V, 48 Ah lithium-ion battery, a 50 Hz single-phase grid, and selectable +10 A / -10 A battery-current references, the model clearly demonstrates charging, discharging, SOC variation, DC-link transient response, and V2G/G2V mode transition.
It provides a clear MATLAB/Simulink platform for studying fuzzy logic control, bidirectional EV charging, grid-connected power converters, and intelligent energy exchange between electric vehicles and the electrical grid.
Comments