PV Grid | Harmonic Mitigation in Grid connected PV using Shunt Active Filter | Shunt Active Filter

Summary

This educational video discusses the simulation model for harmonic mitigation in grid-connected photovoltaic (PV) systems using a synchronous power filter. It covers the PV array, inverter, and LCL filter setup, with a focus on the control mechanisms like MPPT, field-oriented control, and PQ theory. The video demonstrates the impact of adding a non-linear load and the effectiveness of the synchronous power filter in reducing Total Harmonic Distortion (THD) in the grid current, ensuring it meets standards.

Takeaways

• 🌞 The video discusses a simulation model for harmonic mitigation in a grid-connected photovoltaic (PV) system using a synchronous power filter.
• 🔌 The model includes a PV array, a boost converter, an inverter, an LCL filter, and a synchronous power filter to connect to the grid.
• 🔋 The PV array has a rating of 100.2 kilowatts, with 47 power strings, each consisting of 10 series-connected modules, with a maximum power point voltage of 29 volts.
• 🚀 The boost converter is controlled by a maximum power point tracking (MPPT) algorithm, which takes PV voltage and current as inputs and outputs a reference voltage.
• 🔄 The three-phase inverter is controlled using a voltage and current controller, with field-oriented control (FOC) and decoupling techniques employed.
• 🔗 The PLL (Phase-Locked Loop) generates the frequency and phase reference, converting grid voltage and inverter current into a DQ0 format for control.
• 🔵 The DC link voltage is maintained at 700 volts, which is the decoupling voltage of the inverter, ensuring stable operation.
• 🌐 The grid has a voltage of 400 volts and a frequency of 50 Hz, with a non-linear load represented by a diode rectifier with an RL load.
• 🛠️ The synchronous power filter uses a three-phase inverter, an inductor, and a voltage controller, with compensating current calculated using PQ control theory.
• 📊 The video demonstrates the simulation process, starting without a non-linear load, then including it, and finally adding the synchronous power filter to mitigate harmonics, with the Total Harmonic Distortion (THD) of the grid current being a key metric of performance.

Q & A

What is the main topic of the video?

The main topic of the video is about harmonic mitigation in a grid-connected photovoltaic (PV) system using a synchronous power filter.

What components are included in the simulation model discussed in the video?

The simulation model includes a PV array, a boost converter, an inverter, an LCL filter, a grid, a synchronous power filter, and a non-linear load.

What is the rating of the PV array in the simulation?

The PV array rating in the simulation is 100.2 kilowatts.

How is the boost converter controlled in the simulation?

The boost converter is controlled by means of a Perturb and Observe (P&O) MPPT (Maximum Power Point Tracking) algorithm.

What is the role of the inverter in the system?

The inverter converts the DC power from the PV array to AC power suitable for the grid, and it is controlled by voltage and current controllers using a field-oriented control concept.

What is the purpose of the synchronous power filter in the system?

The synchronous power filter is used to mitigate harmonics in the grid current, ensuring that the current waveform is sinusoidal and meeting grid standards.

How is the non-linear load represented in the simulation?

The non-linear load is represented by a diode rectifier with an RL load in the simulation.

What is the Total Harmonic Distortion (THD) of the grid current before the addition of the synchronous power filter?

Before the addition of the synchronous power filter, the THD of the grid current is around 3.63%, which is less than 5% and thus follows the grid standards.

What happens to the THD of the grid current after adding the non-linear load?

After adding the non-linear load, the THD of the grid current increases to around 7.23%, which is more than the 5% standard and indicates current distortion.

How effective is the synchronous power filter in reducing the THD of the grid current?

The synchronous power filter effectively reduces the THD of the grid current to 4.85%, which is less than 5% and meets the grid standards.

What is the significance of the THD value being less than 5% in the context of the grid?

A THD value less than 5% signifies that the current waveform is close to sinusoidal, which is essential for maintaining the stability and quality of the electrical grid.