Microgrid Operation in Grid-Connected and Islanded Mode

Microgrid Operation in Grid-Connected and Islanded Mode

𝐈𝐧𝐭𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧

Microgrids are becoming increasingly important for integrating renewable energy, battery storage, local loads, and utility grids into a flexible electrical power system.

Microgrid Operation in Grid-Connected and Islanded Mode

Grid connected and Islanded mode operation of Microgrid

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This MATLAB/Simulink model demonstrates the operation of a single-phase microgrid in both grid-connected and islanded modes. The system combines:

• Wind energy generation

• Solar photovoltaic generation

• Battery energy storage

• Bidirectional DC–DC conversion

• DC load

• Single-phase inverter

• AC loads

• LCL filter

• Utility grid

• Grid synchronization and inverter control

• Automatic switching between operating modes

The main objective is to maintain reliable power delivery while managing variations in renewable generation, load demand, and grid availability.

𝐒𝐲𝐬𝐭𝐞𝐦 𝐎𝐯𝐞𝐫𝐯𝐢𝐞𝐰

The simulated microgrid uses a common 400 V DC bus to integrate renewable sources, storage, and loads.

Component	Main Specification	Function
Wind Energy System	≈ 2.8 kW	Renewable power generation
Wind Generator	PMSG	Converts mechanical to electrical power
Wind MPPT	P&O	Extracts maximum available wind power
Solar PV System	2 kW	Solar power generation
PV MPPT	Incremental Conductance	Maximum PV power extraction
DC Bus	400 V	Common DC-link voltage
DC Load	1000 W	Direct DC-side demand
Battery	48 Ah, 50% initial SOC	Energy storage and power balancing
Battery Converter	Bidirectional DC–DC	Charging/discharging control
Inverter	Single-phase full bridge	DC-to-AC conversion
AC Load 1	1000 W	Initial AC demand
AC Load 2	1400 W	Additional AC demand
Total AC Load	2400 W	Maximum AC-side demand
Grid	230 V RMS, 50 Hz	Grid support and power exchange
Output Filter	LCL	Reduces inverter switching harmonics

𝐌𝐢𝐜𝐫𝐨𝐠𝐫𝐢𝐝 𝐀𝐫𝐜𝐡𝐢𝐭𝐞𝐜𝐭𝐮𝐫𝐞

The overall energy flow can be understood as:

Wind Energy → PMSG → Rectifier → Boost Converter → DC Bus

Solar PV → Boost Converter → DC Bus

Battery ↔ Bidirectional DC–DC Converter ↔ DC Bus

DC Bus → DC Load

DC Bus → Single-Phase Inverter → LCL Filter → AC Load / Utility Grid

This structure allows different energy sources to operate together while maintaining the required DC and AC voltages.

𝐖𝐢𝐧𝐝 𝐄𝐧𝐞𝐫𝐠𝐲 𝐒𝐲𝐬𝐭𝐞𝐦

The wind generation section consists of:

• Wind turbine

• Permanent Magnet Synchronous Generator

• Rectifier

• Boost converter

• P&O MPPT controller

The PMSG produces variable electrical power depending on wind speed.

Wind System Operating Conditions

Parameter	Value
Wind System Rating	≈ 2.8 kW
Initial Wind Speed	12 m/s
Wind Power at Rated Condition	≈ 2.77 kW
Changed Wind Speed	10.8 m/s
Wind-Speed Change Time	2 s
Power after Wind-Speed Reduction	≈ 1.5 kW
MPPT Technique	Perturb & Observe

At 12 m/s, the wind system generates approximately 2.7–2.77 kW.

After 2 seconds, the wind speed decreases to 10.8 m/s, resulting in a significant reduction in generated wind power.

𝐏&𝐎 𝐌𝐏𝐏𝐓 𝐟𝐨𝐫 𝐖𝐢𝐧𝐝 𝐄𝐧𝐞𝐫𝐠𝐲

The wind boost converter is controlled through a Perturb and Observe MPPT algorithm.

The controller continuously adjusts the converter operating point so that the wind generation system can extract high power under changing wind conditions.

Main purpose of the wind MPPT:

• Track the maximum available wind power

• Control the boost converter duty cycle

• Adapt to wind-speed variations

• Improve renewable energy utilization

• Deliver the extracted power to the 400 V DC bus

𝐒𝐨𝐥𝐚𝐫 𝐏𝐕 𝐒𝐲𝐬𝐭𝐞𝐦

The second renewable source is a 2 kW solar photovoltaic system.

The PV array is connected to the common DC bus through a boost converter.

PV System Parameters

Parameter	Value
PV Rated Power	≈ 2 kW
Maximum Power	≈ 2002 W
Voltage at Maximum Power	245.6 V
DC Bus Voltage	400 V
MPPT Method	Incremental Conductance
Controlled Converter	Boost Converter

At standard operating conditions, the PV system produces approximately 2002 W.

𝐈𝐧𝐜𝐫𝐞𝐦𝐞𝐧𝐭𝐚𝐥 𝐂𝐨𝐧𝐝𝐮𝐜𝐭𝐚𝐧𝐜𝐞 𝐌𝐏𝐏𝐓

The PV voltage and current are continuously measured.

These signals are processed using an Incremental Conductance MPPT controller.

The MPPT controller provides the required command for PWM generation, which controls the semiconductor switch of the PV boost converter.

The controller performs the following tasks:

• Measures PV voltage

• Measures PV current

• Tracks the maximum-power operating point

• Generates the converter control command

• Adjusts the PWM duty cycle

• Maintains effective PV power extraction under irradiance changes

This allows the PV system to respond dynamically to solar irradiance variations.

𝐏𝐕 𝐈𝐫𝐫𝐚𝐝𝐢𝐚𝐧𝐜𝐞 𝐕𝐚𝐫𝐢𝐚𝐭𝐢𝐨𝐧

To evaluate MPPT performance, the solar irradiance is varied during simulation.

Operating Stage	Irradiance
Stage 1	1000 W/m²
Stage 2	500 W/m²
Stage 3	100 W/m²
Stage 4	500 W/m²
Stage 5	1000 W/m²
Change Interval	0.3 s

As irradiance decreases, PV current and generated power decrease.

When irradiance returns to 1000 W/m², the PV system again approaches its rated maximum output.

𝐃𝐂 𝐁𝐮𝐬 𝐚𝐧𝐝 𝐃𝐂 𝐋𝐨𝐚𝐝

The PV, wind, battery, DC load, and inverter are integrated through a common 400 V DC bus.

Parameter	Value
DC Bus Reference	400 V
DC Load	1000 W
Main Regulation Device	Battery bidirectional converter

Maintaining a stable DC bus is essential because variations occur continuously due to:

• Renewable generation changes

• AC load switching

• DC load demand

• Grid connection/disconnection

• Battery charging

• Battery discharging

The bidirectional battery converter plays an important role in compensating for these power variations.

𝐁𝐚𝐭𝐭𝐞𝐫𝐲 𝐄𝐧𝐞𝐫𝐠𝐲 𝐒𝐭𝐨𝐫𝐚𝐠𝐞

The battery is connected to the common DC bus using a bidirectional DC–DC converter.

Battery Parameters

Parameter	Value
Battery Capacity	48 Ah
Initial SOC	50%
Battery Voltage	12–22 V, as considered in the model
Converter	Bidirectional DC–DC
DC Bus Reference	400 V
Primary Function	DC-link voltage regulation

The battery can operate in two basic conditions:

• Charging: excess renewable power is available.

• Discharging: generation is insufficient to meet demand.

𝐁𝐚𝐭𝐭𝐞𝐫𝐲 𝐕𝐨𝐥𝐭𝐚𝐠𝐞 𝐂𝐨𝐧𝐭𝐫𝐨𝐥

The measured DC bus voltage is compared with the 400 V reference.

The resulting voltage error is processed by a PI controller.

The controller then generates the required command for the bidirectional converter PWM system.

Control sequence

1. Measure DC bus voltage.

2. Compare it with 400 V.

3. Determine the DC-link voltage error.

4. Process the error through the PI controller.

5. Generate the required PWM duty command.

6. Control the converter IGBTs.

7. Charge or discharge the battery accordingly.

8. Restore the DC bus close to 400 V.

This control mechanism helps stabilize the DC-link voltage during variations in generation and load.

𝐀𝐂 𝐋𝐨𝐚𝐝 𝐒𝐲𝐬𝐭𝐞𝐦

Two AC loads are considered in the simulation.

Load	Power	Operating Condition
AC Load 1	1000 W	Connected initially
AC Load 2	1400 W	Connected after 2 s
Total AC Load	2400 W	After 2 s

Initially, the AC-side demand is 1000 W.

At 2 seconds, an additional 1400 W load is connected.

The total AC load therefore increases to 2400 W.

This step change is useful for evaluating the transient response of the microgrid controller.

𝐒𝐢𝐧𝐠𝐥𝐞-𝐏𝐡𝐚𝐬𝐞 𝐈𝐧𝐯𝐞𝐫𝐭𝐞𝐫

The DC bus is connected to the AC system through a single-phase full-bridge inverter.

An LCL filter is placed between the inverter and AC system to improve output power quality.

Main inverter functions

• Convert DC power into AC power

• Maintain AC load voltage during islanded operation

• Exchange power with the utility grid

• Synchronize inverter operation with grid voltage

• Respond to load variations

• Support transitions between operating modes

𝐆𝐫𝐢𝐝 𝐏𝐚𝐫𝐚𝐦𝐞𝐭𝐞𝐫𝐬

Parameter	Value
Grid Voltage	230 V RMS
Peak Voltage	≈ 325 V
Grid Frequency	50 Hz
Interface	Single-phase inverter + LCL filter
Grid Connection	Controlled breaker

The breaker determines the operating condition of the microgrid.

• Breaker closed → Grid-connected mode

• Breaker open → Islanded mode

𝐆𝐫𝐢𝐝-𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝 𝐚𝐧𝐝 𝐈𝐬𝐥𝐚𝐧𝐝𝐞𝐝 𝐌𝐨𝐝𝐞𝐬

Feature	Grid-Connected Mode	Islanded Mode
Utility Grid	Connected	Disconnected
Grid Voltage Available	Yes	No
Grid Current	Depends on power balance	Zero
Inverter Main Role	Power exchange/current control	AC voltage regulation
Synchronization	Grid PLL	Local reference
Power Deficit	Grid/battery support	Battery support
Excess Renewable Power	Can be exported	Managed locally
AC Voltage	Grid supported	Inverter maintained

𝐂𝐨𝐧𝐭𝐫𝐨𝐥 𝐒𝐭𝐫𝐚𝐭𝐞𝐠𝐲

A key feature of the model is that different inverter control methods are used depending on whether the utility grid is available.

The switching logic selects between:

• Grid-connected inverter control

• Islanded inverter control

This enables the same inverter to perform different control objectives under different operating conditions.

𝐈𝐬𝐥𝐚𝐧𝐝𝐞𝐝 𝐌𝐨𝐝𝐞 𝐂𝐨𝐧𝐭𝐫𝐨𝐥

When the utility grid is disconnected, the inverter becomes responsible for supporting the local AC system.

Reference sine and cosine signals are generated for inverter control.

The load voltage and current are measured and processed using dq-based control.

Islanded control process

• Generate local reference signals.

• Measure AC load voltage.

• Measure AC load current.

• Transform measured signals into the control reference frame.

• Compare the measured load voltage with the voltage reference.

• Process voltage and current errors using PI controllers.

• Generate inverter modulation references.

• Convert the control signals back into the required inverter waveform.

• Generate PWM switching pulses.

• Maintain stable AC power for the local loads.

The main objective is voltage and frequency support for the isolated microgrid.

𝐆𝐫𝐢𝐝-𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝 𝐌𝐨𝐝𝐞 𝐂𝐨𝐧𝐭𝐫𝐨𝐥

When connected to the utility network, the inverter operates as a grid-interfacing converter.

Its primary role changes from local voltage formation to controlled power exchange with the grid.

The control strategy considers:

• PV generation

• Battery SOC

• Microgrid demand

• Grid voltage

• Inverter current

• Power availability

𝐏𝐨𝐰𝐞𝐫 𝐄𝐱𝐜𝐡𝐚𝐧𝐠𝐞 𝐋𝐨𝐠𝐢𝐜

The implemented logic considers PV current and battery state of charge.

Condition	Microgrid Operation
PV Current < 0.5 A and SOC < 10%	Import power from grid
PV Current > 0.5 A and SOC > 10%	Export available power to grid
Renewable Power > Demand	Grid export / battery charging
Renewable Power < Demand	Grid import / battery discharge

Representative grid power values observed in the simulation include:

Grid Power Condition	Approximate Value
Exported Power	≈ 326 W
Maximum Reported Imported Power	≈ 1.63 kW
Grid Support during a Higher-Demand Condition	≈ 2.1 kW

𝐏𝐋𝐋 𝐟𝐨𝐫 𝐆𝐫𝐢𝐝 𝐒𝐲𝐧𝐜𝐡𝐫𝐨𝐧𝐢𝐳𝐚𝐭𝐢𝐨𝐧

A Phase-Locked Loop (PLL) is used during grid-connected operation.

Its purpose is to synchronize the inverter with the utility grid.

The PLL provides the required phase information for:

• Grid synchronization

• Reference-frame transformations

• Current control

• PWM signal generation

Accurate synchronization is important for safe and stable grid power exchange.

𝐆𝐫𝐢𝐝 𝐂𝐮𝐫𝐫𝐞𝐧𝐭 𝐂𝐨𝐧𝐭𝐫𝐨𝐥

During grid-connected operation, reference currents are generated based on the desired operating condition.

The controller then:

1. Measures the inverter/grid current.

2. Generates synchronized reference signals.

3. Converts signals into the control frame.

4. Compares actual and reference currents.

5. Processes current errors through PI controllers.

6. Generates modulation commands.

7. Produces PWM pulses for the inverter.

This enables controlled power flow between the microgrid and utility network.

𝐌𝐨𝐝𝐞 𝐒𝐰𝐢𝐭𝐜𝐡𝐢𝐧𝐠 𝐋𝐨𝐠𝐢𝐜

A switch-case based control structure is used to select the required inverter controller.

When grid-connected:

The PWM generator receives commands from the grid-connected controller.

When islanded:

The PWM generator receives commands from the islanded-mode controller.

This allows the converter control strategy to change automatically according to the breaker condition.

𝐖𝐨𝐫𝐤𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬

The overall microgrid operation can be summarized as follows:

1. Renewable Power Generation

Wind and PV systems generate electrical power according to environmental conditions.

2. MPPT Operation

P&O MPPT is used for the wind system, while Incremental Conductance MPPT is used for the PV system.

3. DC Bus Integration

Both renewable systems deliver their power to the 400 V DC bus.

4. DC Load Supply

A 1000 W DC load receives power directly from the DC bus.

5. Battery Energy Management

The bidirectional converter charges or discharges the battery according to the DC bus power balance.

6. AC Power Generation

The full-bridge inverter converts DC bus power into AC power.

7. Grid-Connected Operation

The grid can supply a deficit or receive available excess power.

8. Islanded Operation

When the breaker opens, the utility grid is removed and the inverter maintains the local AC system.

𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐒𝐜𝐞𝐧𝐚𝐫𝐢𝐨

Several disturbances are introduced to evaluate system performance.

Disturbance	Simulation Condition
PV Irradiance Change	1000 → 500 → 100 → 500 → 1000 W/m²
Irradiance Interval	0.3 s
Initial Wind Speed	12 m/s
Changed Wind Speed	10.8 m/s
Wind-Speed Change	2 s
Initial AC Load	1000 W
Additional AC Load	1400 W
Total AC Load after Switching	2400 W
DC Load	1000 W
Grid Condition	Connected / disconnected

These disturbances allow the model to demonstrate the dynamic response of the renewable sources, battery, inverter, and grid interface.

𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐑𝐞𝐬𝐮𝐥𝐭𝐬

The simulation provides several important observations.

𝐏𝐕 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞

• PV voltage changes according to MPPT operation.

• PV current responds strongly to irradiance changes.

• PV power reduces when irradiance falls.

• Power returns close to 2 kW when irradiance returns to 1000 W/m².

• Short transients appear during sudden environmental changes.

𝐖𝐢𝐧𝐝 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞

At the initial wind speed:

• Wind speed = 12 m/s

• Wind power ≈ 2.7–2.77 kW

After the wind-speed reduction:

• Wind speed = 10.8 m/s

• Wind power reduces to approximately 1.5 kW

The P&O MPPT-controlled converter continuously adapts to the changing operating point.

𝐁𝐚𝐭𝐭𝐞𝐫𝐲 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞

The battery current changes according to the microgrid power balance.

• Negative or positive current represents charging/discharging according to the model's sign convention.

• Battery power responds to PV variations.

• Battery support changes when the wind speed decreases.

• Battery operation changes when the AC load increases.

• SOC varies gradually because the simulated time interval is relatively short.

The battery therefore acts as the main balancing element of the DC microgrid.

𝐃𝐂 𝐁𝐮𝐬 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞

The DC-link voltage remains close to the 400 V reference.

Transient deviations occur during:

• Startup

• PV irradiance variation

• Wind-speed change

• AC load switching

• Grid disconnection

• Mode transition

The bidirectional converter controller then acts to restore the voltage toward its reference.

𝐀𝐂 𝐋𝐨𝐚𝐝 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞

Initially:

AC load demand ≈ 1000 W

After 2 seconds:

AC load demand ≈ 2400 W

The inverter responds by increasing its output current while maintaining the required load voltage.

𝐆𝐫𝐢𝐝-𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝 𝐑𝐞𝐬𝐮𝐥𝐭𝐬

During grid-connected operation:

• Renewable systems supply available power.

• The battery participates in DC bus regulation.

• The utility grid balances the remaining power difference.

• Power can flow from the grid to the microgrid.

• Excess renewable energy can also be transferred toward the grid.

• Grid voltage remains approximately 230 V RMS at 50 Hz.

• Inverter current varies according to the power exchange requirement.

This mode provides additional flexibility because the utility grid acts as an external source or sink.

𝐈𝐬𝐥𝐚𝐧𝐝𝐞𝐝 𝐌𝐨𝐝𝐞 𝐑𝐞𝐬𝐮𝐥𝐭𝐬

When the grid breaker is opened:

• Grid voltage at the microgrid connection becomes zero.

• Grid current becomes zero.

• The microgrid continues supplying local loads.

• The inverter changes to islanded control.

• Renewable sources continue operating.

• The battery compensates for the remaining power mismatch.

A representative islanded operating condition is:

Quantity	Approximate Value
Wind Power	1.5 kW
PV Power	2 kW
AC Load	2.4 kW
DC Load	1 kW
Total Local Load	3.4 kW
Grid Power	0 W
Grid Current	0 A

The battery provides or absorbs the remaining difference depending on instantaneous renewable output and converter losses.

𝐌𝐨𝐝𝐞 𝐓𝐫𝐚𝐧𝐬𝐢𝐭𝐢𝐨𝐧 𝐏𝐞𝐫𝐟𝐨𝐫𝐦𝐚𝐧𝐜𝐞

One of the most important tests is the transition from grid-connected mode to islanded mode.

During switching:

• Grid power becomes zero.

• Grid current falls to zero.

• The islanded inverter controller becomes active.

• A temporary disturbance occurs in the DC-link voltage and power signals.

• The battery rapidly changes its power contribution.

• AC load supply continues through the local inverter.

The observed switching transient settles in approximately 0.3 seconds.

This demonstrates the ability of the control system to maintain microgrid operation following grid disconnection.

𝐊𝐞𝐲 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐬

This MATLAB/Simulink microgrid model demonstrates:

• 𝐆𝐫𝐢𝐝-𝐜𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝 operation

• 𝐈𝐬𝐥𝐚𝐧𝐝𝐞𝐝 operation

• Solar PV integration

• Wind energy integration

• Battery energy storage

• 400 V DC bus regulation

• P&O wind MPPT

• Incremental Conductance PV MPPT

• Bidirectional battery converter

• Single-phase full-bridge inverter

• LCL output filtering

• PLL-based grid synchronization

• dq-based inverter control

• PI voltage control

• PI current control

• Grid import operation

• Grid export operation

• Variable solar irradiance

• Variable wind speed

• Dynamic AC load switching

• Automatic controller selection

• Renewable power sharing

• Battery charge/discharge operation

• Dynamic grid disconnection response

𝐖𝐡𝐲 𝐆𝐫𝐢𝐝-𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐞𝐝 𝐚𝐧𝐝 𝐈𝐬𝐥𝐚𝐧𝐝𝐞𝐝 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐨𝐧 𝐌𝐚𝐭𝐭𝐞𝐫𝐬

A modern microgrid should be capable of operating under different grid conditions.

Grid-connected operation provides:

• Utility power support

• Renewable power export

• Better management of generation deficits

• Reduced stress on battery storage

• Flexible power exchange

Islanded operation provides:

• Continued local power supply during grid disconnection

• Improved energy resilience

• Better use of distributed renewable generation

• Local voltage and frequency support

• Independent operation of critical loads

Combining both modes produces a much more flexible energy-management platform.

𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬

This type of microgrid configuration is useful for studying and developing:

• Renewable-energy-based microgrids

• Smart grids

• Residential microgrids

• Commercial energy systems

• Industrial microgrids

• Remote power systems

• Campus energy systems

• Renewable power integration

• Battery energy storage

• Distributed generation

• Grid-forming and grid-following inverter concepts

• Power management systems

• Hybrid renewable energy systems

• Utility-interactive power converters

• Backup and resilient energy systems

𝐁𝐞𝐧𝐞𝐟𝐢𝐭𝐬 𝐟𝐨𝐫 𝐒𝐭𝐮𝐝𝐞𝐧𝐭𝐬, 𝐑𝐞𝐬𝐞𝐚𝐫𝐜𝐡𝐞𝐫𝐬, 𝐚𝐧𝐝 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐬

The simulation provides a useful platform for understanding the interaction between renewable generation, storage, converters, and the utility grid.

It can help users study:

• MPPT controller behavior

• Renewable power fluctuations

• DC bus voltage regulation

• Battery charging and discharging

• Bidirectional converter operation

• Inverter current control

• Inverter voltage control

• Grid synchronization

• Load-step response

• Renewable power sharing

• Grid import/export behavior

• Mode switching

• Islanded microgrid operation

• Dynamic system response

𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐒𝐮𝐦𝐦𝐚𝐫𝐲

Parameter	Value / Method
Simulation Platform	MATLAB/Simulink
Microgrid Type	PV–Wind–Battery Hybrid Microgrid
Operating Modes	Grid-Connected and Islanded
DC Bus Voltage	400 V
PV Rating	2 kW
PV Maximum Power	≈ 2002 W
PV MPP Voltage	245.6 V
PV MPPT	Incremental Conductance
Wind Rating	≈ 2.8 kW
Wind MPPT	P&O
Initial Wind Speed	12 m/s
Reduced Wind Speed	10.8 m/s
Battery Capacity	48 Ah
Initial Battery SOC	50%
DC Load	1 kW
Initial AC Load	1 kW
Maximum AC Load	2.4 kW
Grid Voltage	230 V RMS
Grid Peak Voltage	≈ 325 V
Grid Frequency	50 Hz
Inverter	Single-Phase Full Bridge
Filter	LCL
Grid Synchronization	PLL
Main Controllers	PI Controllers
Approx. Mode-Switch Settling	0.3 s

𝐂𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐨𝐧

The Microgrid Operation in Grid-Connected and Islanded Mode simulation demonstrates how solar PV, wind energy, battery storage, DC loads, AC loads, an inverter, and the utility grid can be coordinated within a common energy system.

The PV system uses Incremental Conductance MPPT, while the wind energy system uses P&O MPPT for maximum renewable power extraction. A bidirectional battery converter maintains the DC bus around 400 V and helps balance generation and demand.

During grid-connected operation, the utility network can either supply the microgrid or receive available excess power. When the grid is disconnected, the inverter changes its control strategy and continues supporting the local AC loads using renewable generation and battery storage.

The model clearly demonstrates renewable integration, energy storage operation, grid synchronization, load variations, power sharing, and dynamic transition between grid-connected and islanded operating modes, making it a useful MATLAB/Simulink reference for students, researchers, and power-system engineers.