Using VFD technology to create environmentally friendly renewable energy

Problem

In order to create biogas, animal effluent and food waste must be broken down in cogeneration units.

Solution

Utilizing Optidrive E3 VFDs, the process uses pumping and mixing processes to accurately control waste inflow and outflow and mixing speed.

Theodore Amiridis, the Technical Director at Automation Experts, highlighted the integral role of Optidrive E3 variable frequency drives (VFDs) in a biogas production project in Greece. PK Energy, a company specializing in renewable energy, collaborated with Automation Experts and utilized Optidrive VFD technology from Invertek Drives to construct electricity production units using biogas generated through anaerobic digestion.

The project, located in Kefalovrysos, Trikala, involved the breakdown of animal and food waste into microorganisms within two oxygen-free storage units. The waste material was pumped and mixed to create the biogas. The gas was then converted into electricity through two on-site cogeneration units, generating 3MW per hour, which was fed into the mains grid.

Optidrive E3 VFDs were employed for the pump and mixing processes. These VFDs were specifically IP20 enclosures, ranging from 4kW to 37kW in power. The VFDs played a crucial role in accurately controlling the quantity of waste material and the speed of mixing during the biogas production process.

Theodore Amiridis emphasized that the Optidrive E3 VFDs ensured precise control of the pumping and mixing processes, enabling the optimum production of gas. The VFDs were easy to install, commission, and program. Each drive was connected with a PLC through Ethernet/IP protocol, and the VFD PID function was used for pump control. The expertise of Automation Experts, combined with the functionality of the VFDs, facilitated the correct motor and pump speed for optimal gas production.

The Optidrive E3 is part of Invertek Drives' range of user-friendly VFDs. It offers simple commissioning with basic setup parameters, default settings, and additional flexible parameters for customization. The drive features an intuitive keypad and application macros to switch between industrial, pump, and fan modes based on the specific application requirements.