Project Description

Off grid energy sources are frequently utilized when connecting to a conventional power grid would be prohibitively expensive. However, many off-grid systems experience problems because non-linear electrical devices create harmonic distortion in the system’s power lines. A system with significant harmonics causes increased temperatures in electronics thereby shortening their lifespan while also damaging the power system itself. The purpose of this project was to create and test a shunt active power filter that reduced harmonic distortion in off-grid energy systems. The filter designed and created by the team reduces harmonics injected by a wide array of non-linear electrical devices commonly found in off-grid energy systems thus increasing their efficiency and longevity.

System Diagram

The non-technical system diagram shown in Figures 1, 2, and 3 show how the device created by the Pure Wave team will reduce harmonics in the off-grid system.

Figure 1: In normal operation, off grid inverters supply a pure sine wave to electronic devices.

Figure 2: When non-linear loads are connected to the lines, the sine wave is distorted, resulting in diminished efficiency for other devices.

Figure 3: A shunt active power filter measures the distortion on the line and injects equal and opposite currents. The devices on the line then receive clean, filtered power.

Project Requirements and Specifications

A document detailing all requirements and specifications for this project was written by the Pure wave team and submitted to the client on November 6, 2013. The goal of this document was to ensure that the problem being solved by the team matched the problem the client had in mind. Furthermore, this document provides the client with an idea of all specifications for the final device prior to the submission of the more formal proposal. A brief summary of the requirements and specifications for this project can be found in Tables 1, 2 and 3. To download the requirements and specifications document submitted by the Pure Wave team, click here. Note: The actual document submitted contained a problem description as well as research performed by the team. These sections are not included in the linked document. To see the problem description and research performed by the team check out the problem definition page.