What is Bypass Diode

What is Bypass Diode

• Bypass Diodes are connected in photovoltaic arrangements for the protection of such cells that are completely under the solar light and working properly from such cells that are not working or not in the solar light.
• Soler cells are the cheapest way to produce electricity from the sunlight. We can change the location of the solar panels according to our requirements.
• The solar cells are available in numerous power rating, from some mW to thousands mW.
• A solar cell is a photodiode that transformed the sunlight into the electricity. The photovoltaic panel produces electricity when the photocells are connected in a sequence.

• Usually, it is acknowledged that all the cells in the solar panel are producing equal power.
• But there are some conditions that affect the power production of the cell, like environment temperature, humidity in the air location of the panel.
• The principal fact of the power failure of the solar cell is the shading, that reduced the quantity of the light coming to the light. Shading can be due to some tree, wall of the house, or any other building.
• If the shading remains on some cells of the panel there will be less power generation through this panel, to eradicate the effect of the cells that have shading bypass diodes are used in the solar panel.

  

Features of the Bypass Diode

• These are the main features of the bypass diode.
  • The value of the reverse biasing voltage for this diode is thirty volts.
  • The forward biased functioning current of the diode is fifteen amperes.
  • Minimum forward biased voltage for this diodes is twenty-six milli-volts at eight amperes.
  • The operating temperature for this diode is minus forty to one twenty-five celsius.

Photovoltaic Solar Cell Construction

• In the given diagram, the complete circuit of the solar panel with the bypass diode is constructed, let's discuss it with the detailed.
• The current that we get from the solar panel is the direct current similar to the output power of the battery.
• When the output terminals of the solar cell are open than the voltage at these points will be 0.5 to 0.6 volts.
• The value of the terminals voltage of the solar cells relies on the load attached to the cell.

• For instance, when there is no sunlight due to the clouds the current required by the load will be lighter and the voltage at the ends will be rated value of the cell.
• But if we do increment in load on the terminals of the cells so there is need of the sunlight to maintain the output voltage of the load connected.
• So there is a boundary under that the one solar cell can provide extreme power, it doesn't matter either sunlight is exits or not.
• This amount of the current is recognised as the extreme deliverable current of the cell and denoted as I_MAX.
• The value of the maximum current relies on the area of the cell, angle with the sun, the effectiveness of the cell, and the substances used to assemble the solar cell.
• During the combination of the bypass diode with the photocell,  you should keep in mind the value of the IMAX.

  

Diodes in Photovoltaic Arrays

• A diode is a device that used to transforms alternating current in the direct current.
• Unidirectional working feature of the diode can be used in different circuitries to stop the unnecessary movement of the current.
• When the diodes are used in the solar cells that are known as the blocking diodes.
• In solar panel bypass diodes are joined with the one or more than one cells in parallel combination.
• These diodes help to stop unnecessary current movements towards such diodes that are not working properly, or under shading. In this way, we get the desired output current from the solar panel.
• The connection of the bypass diodes is in parallel with the cell to stop current about it while blocking diode is attached series for the reverse movement of the current towards the cell.
• Both bypass and the blocking diode are different categories of the diodes, as they do different work.

Bypass Diodes in Photovoltaic Arrays

• As we discussed that the diode is a uni-direction component. In the given figure there are 2 coloured diodes are connected with the solar panel array.
• Green colour diodes are the bypass diode that is attached with the solar cell in parallel combination for less resistance path.
• The other 2 red diodes are blocking diodes that are linked with every branch of the circuitry in series.
• Both bypass and blocking diodes are similar in physical structure but according to their use, they are different.
• Blocking diodes also recognized as the isolation diode because they provide blocking for the current to flow toward any cell instead of going towards the output load.
• This series diodes help to avoid other parallel cell's current to flow adjacent cell and it also stops the current of the storing batteries to the cell in case of the night when there is zero production of the current at the cell.

  

Applications of Bypass Diode

• These are the applications of the bypass diode.
  • It used in solar panels.
  • It used in power optimization process and used as a microinverter.