Understanding the Impact of Partial Shading on Solar Panels and How to Mitigate It

Solar power has recently become a popular renewable energy source due to its cleanliness, abundance, and environmental friendliness. However, solar panel installations face a significant challenge due to partial shading. This occurs when some parts of the solar panel receive less sunlight due to obstructions such as trees, buildings, or other objects that cast shadows. This article discusses the effect of partial shading on solar panels.

Partially shaded solar panel (Source: pexels.com)

Partial shading can significantly impact the performance of solar panels. When one or more solar panel cells are shaded, the output of the entire panel decreases, resulting in reduced system efficiency. The effect of partial shading depends on various factors such as panel type, size of the shaded area, and shading pattern.

Shaded cells in a partially shaded solar panel absorb less sunlight, reducing output. However, unshaded cells continue generating power, causing an imbalance in current flow, further reducing output power. Additionally, partial shading can cause the "hotspot effect," where a shaded cell becomes a load on other cells, leading to overheating and possible damage to the cell or entire panel.

There are several methods to mitigate the effect of partial shadings, such as bypass diodes. These diodes parallel each solar cell, enabling current flow around the shaded cell and reducing shading effects. Another approach is using micro-inverters or power optimizers, which convert DC power generated by each cell into AC power and perform maximum power point tracking (MPPT) to ensure each cell operates optimally, even under shading conditions. Proper panel placement and location selection in solar panel installations also help to reduce shading impact.

In conclusion, partial shading can adversely impact the performance of solar panels, leading to reduced output power, hotspots, and possible panel damage. However, using bypass diodes, micro-inverters, or power optimizers and proper panel placement can mitigate the effect of partial shading, enhancing the efficiency and output of solar panel systems.

Accurate Frequency Measurement with Arduino using Proteus Software

If you're interested in building your frequency reader using an Arduino and a PC817 optocoupler, you've come to the right place! In this guide, we'll walk you through the process step-by-step, so you can easily follow along even if you're a beginner.

A PC817 optocoupler is an electronic component that helps isolate the input signal from the output signal. This means it protects the circuit, preventing electrical noise or interference from affecting the input signal. It's a critical component in this project because it helps to ensure accurate frequency measurement.

Frequency reader using Arduino.

Components:

1. Arduino UNO
2. Resistor
3. Capacitor
4. PC817 optocoupler
5. Virtual terminal
6. LCD 1602
7. I2C interface
   
   

Steps

1. Open Proteus 8 software and add ARDUINO UNO R3, CAPACITOR, DIODE, LM016L, PC817, PCF8574, RESISTOR, and VSINE components to the workspace.
   
   

   

   Add components to the workspace

   
   
2. Wiring all the components according to the figure below.
   
   

   

   Wiring the circuit

   
   
3. Download the PROJECT file. Extract the project file and verify.
   
   

   

   Arduino IDE

   
   
4. Copy the Hex file, then paste it to the project file Arduino board.
   
   

   

   Copy and paste the code

   
   
5. Set the AC voltage source to a frequency of 50 Hz and an amplitude of 220-240V and start the simulation.
   
   

   

   Set the AC voltage and frequency at VSINE

   
   

   

   Simulation result 1

   
   The results indicate that the frequency instability is caused by noise at the input side of the PC817. We can neglect this issue because only the error percentage is not small.
   
   
6. Let's try setting the AC voltage source to a frequency of 60 Hz and an amplitude of 120V, as these are the typical settings used in North America for household electrical systems.
   
   

   

   Set the AC voltage and frequency at VSINE
   

   
   

   

   Simulation result 2
   

   
   It's working great, as it can easily detect the 60 Hz frequency.

Video:

We'd love to hear your thoughts on this project! If you have any suggestions or questions, feel free to leave them in the comments section below. We appreciate your time and feedback! Happy building! 👷

Understanding Varistors: Protection Against Voltage Surges and Transient Spikes

Varistors, also known as voltage-dependent resistors (VDRs) or metal-oxide varistors (MOVs), are electronic components that protect devices from voltage surges and transient voltage spikes. They consist of a ceramic material with a high resistance coefficient doped with metal oxides, such as zinc oxide or titanium dioxide. The doping process alters the electrical properties of the ceramic material, allowing it to act as a voltage-dependent resistor. The ceramic material is sandwiched between two metal electrodes of zinc or copper connected to the external circuit.

Varistor Series (Source littelfuse.com)

The working principle of a varistor is based on the nonlinear relationship between the voltage and current in a material with a high coefficient of resistance. When the voltage across the varistor exceeds its breakdown voltage, which is determined by the composition and doping of the ceramic material, the resistance of the varistor drops dramatically, allowing current to flow through it. This behavior provides a low-resistance path for surge current, protecting the device from damage.

Varistors are commonly used in electronic circuits to protect sensitive components from voltage surges and transient voltage spikes. They are essential components in power supplies, AC line protection, and surge protectors for electronic equipment. Additionally, varistors can regulate voltage in certain applications by selecting a varistor with a specific breakdown voltage. This allows designers to develop circuits that regulate the voltage across the varistor and prevent it from exceeding a certain level.

In conclusion, varistors are critical components in modern electronics that protect devices from voltage surges and spikes. Their design and working principle are based on the nonlinear relationship between voltage and current in a high-resistance material, making them essential in power supplies and surge protection devices. With their ability to regulate voltage in certain applications, varistors play an important role in electronic circuit design.