Control Unit and Connectivity Solution for Miniature Wind Turbine

Our customer is a leading German innovator with significant contributions to society in mitigating climate change. Through their innovations in harnessing wind energy; and developing modular wind energy systems, our client has enabled industries to curb carbon emissions while simultaneously cutting down on associated costs.

The primary business challenges that the customer faced were:
 

• Lack of Intellectual Property (IP) Rights: Wind energy is a niche sector. The best way to stand out in the growing field of renewable energy is by owning the intellectual property rights to your innovations. Before approaching us, the customer had relied on off-the-shelf IoT solutions and did not own the IP rights of these solutions.
• They wished to be the sole owners of the game-changing innovation of miniature wind turbines. To fulfill this, they decided to develop a product where they had end-to-end control over the design and software.
• Limited Technical Expertise: The customer did not have in-house technical expertise to develop the miniature wind turbine. Hence, they decided to collaborate with a technology partner with expertise in this field.
• Form Factor: The existing wind harnessing solutions are huge, but our customer wanted to develop a feature-rich wind energy system with a small form factor. This necessitated the custom design and development of a unique solution.

The customer approached us as we have a portfolio of successful endeavours in the renewable energy sector, developing customised full-stack IoT solutions.

Majority of the wind turbines we see today are:
 

• Of gigantic form factor.
• Difficult to transport from the manufacturing unit. Due to the gigantic setup, each component is delivered separately. Doing so will significantly contribute to the growing emissions and carbon footprint.
• Expensive and time-consuming to install.
• Not performing to maximum efficiency.

After having insightful and productive discussions with the customer, Embitel’s IoT engineers decided to develop an end-to-end control unit for a miniature wind turbine.

The control unit we developed comfortably fit into the turbine and boosted its functionality with power-packed features. The highlight of this solution was its form factor, which was achieved by utilizing the brushless DC motor.

The control unit incorporated the following features:

• Digital Signal Processing (DSP): DSP is a primary layer of the power module of our solution. Through this, the analog voltage or current signal is converted to a digital signal. This converted signal is then used by the software.

• Measuring Critical Parameters: The control unit can capture the measurements of AC current, followed by the current once converted to DC. The system also records the input/output Voltage and Current.

• Boost Conversion: This feature is critical to the functionality of the wind turbine as it ensures that the miniature wind turbine produces an output at the required constant value. This feature nullifies the effects of the variable current received by the turbine to give out a constant DC output.

  Boost conversion mainly relies on two processes - AC to DC conversion and its pulse width modulation. As stated above, the current initially generated by the rotating turbine blades is alternating current (AC). With the assistance of the AC/DC converter, current will convert to a more efficient form of current i.e., direct current (DC).

  However, the value of DC recorded by the system will keep changing due to the variable wind speed. To nullify this and produce a constant DC output, separate hardware that carries out the process of Pulse Width Modulation (PWM) is used.

• Emergency Braking: This is a safety feature integrated in the wind turbine to mitigate the harmful effects of unfavorable operating situation. There are 3 situations that could be deemed unfavourable:

  • Scenario 1: When the RPM of the wind turbine blades exceed the safety threshold (300-800 RPM).
  • Scenario 2: When the temperatures of the critical areas are crossing the temperature safety limit.
  • Scenario 3: When there is an over current or voltage in the output.

  Upon facing any of the 3 scenarios, the control unit utilizes the emergency braking feature to bring the RPM under control. Apart from emergency braking, there are 2 other safety features integrated in our solution.

• Temperature Sensing: The control unit is equipped with three temperature sensors to avoid overheating of the setup. Overheating can have adverse effects on the components of the turbine.

• Over-Power Utilization through Chopper Control: The miniature turbine operates optimally between 300-800 RPM. Excessive wind flow could lead to the turbine operating above the safety threshold, leading to excess power generation.

  The extra power generated, must be utilized to safeguard the components of the miniature wind turbine. With the help of Chopper control in the power module area, excessive power is absorbed and dissipated as heat.

• ESD Protection: This is a safety feature integrated into the setup to safeguard it from natural phenomena that cause unwarranted electric discharges in and around the setup of the miniature wind turbine.

• Firmware Updates over RS-485: As many wind turbines can be mounted on a single infrastructure, delivering firmware updates using a wired system was deemed favorable.

We developed a handy, modular, and efficient wind energy harnessing system through miniature wind turbines. The solution we developed resolved the following issues:

• Our customer now had the Intellectual Property rights for the miniature wind turbine controllers.
• Several miniature wind turbines can be installed on a single infrastructure. The setup cost was much less when compared to a conventional wind turbine, making it a cost-effective solution.
• The manufacturing processes for the miniature turbines are small-scale and less complex when compared to conventional wind turbines.
• The efficiency of the miniature wind turbine increased to 90-92%.