Common Mode Interference Solutions in Community Microgrid Settings
By Brittany Marshall
Introduction
Continuous Solutions Inc. is a technology company based in Portland, Oregon that specializes in the mitigation and characterization of common mode interference in modern electrical systems. Our unique technologies provide customized solutions to mitigate the negative effects of common mode interference for AC and DC-based power systems. Our technologies have the ability to benefit communities by enabling for the integration of renewable resources in spaces that have traditionally been neglected.
The Issue with Common Mode Interference
Common mode interference in power converter systems is a common problem that can result in system failure or reduced efficiency. It is caused by the interaction of a system's electronic components with the power grid's electric and magnetic fields, leading to interference that is common to all components in the system. This interference is a form of electromagnetic interference (EMI) and radio frequency interference (RFI), and can negatively impact power quality, damage motor bearings, impact communications equipment, and cause incompatibilities between connected equipment.
Access to green technologies, including renewable resources, can be a significant obstacle for low-income and minority communities. Some of the primary obstacles include:
1. Financial barriers: Renewable energy technologies often require significant upfront costs, which can be a barrier for low-income communities that may not have access to financing options or financial resources to invest in renewable energy systems.
2. Lack of information: Many low-income communities may not have access to information about the benefits of renewable energy and the resources available to them to make the transition.
3. Regulatory barriers: Regulations can be a significant barrier for the adoption of renewable energy in some areas. For example, some communities may not have the necessary permits or may face other regulatory hurdles that make it difficult to adopt renewable energy technologies.
Figure 1: Workers Installing Solar on a Roof of a Home. (source: energynews.us)
Mitigating common mode interference can help to remove some of these obstacles by increasing the reliability of power converter systems, which are often an essential component of renewable energy systems. This, in turn, can help to reduce the costs associated with renewable energy technologies and make them more accessible to low-income communities. In a microgrid environment, random assortments of low-cost power converters are often utilized to interconnect various subsystems and pieces of equipment. Common mode interference between converters for items such as solar panels, backup generators, motors, and other equipment can be damaging because one converter may be emitting interference at a signature another device is particularly susceptible to, causing faults and degradation.
For example, if a community wants to install solar panels, they will likely need to use power converters to convert the DC power generated by the panels into usable AC power. Common mode interference can negatively impact the reliability of these power converters, which can increase the overall costs of the system. Especially in communities where cost of entry into renewables and green technologies is a major concern, these reliability issues can be a non-starter. Traditionally, facilities that install multiple power converters utilized a package of technologies sourced from a single manufacturer that had been validated to work well together. In a community environment, where multiple households and businesses may be “tapping-in” to a microgrid with power converters of varying manufacturer and price point, the common mode interactions between these various devices may not only cause an increase in lifetime costs due to equipment failure and upkeep, but it may also actually cause so much interference that the power converters can not function at all.
In addition, by increasing the reliability of power converter systems, mitigating common mode noise can help to reduce the maintenance and repair costs associated with renewable energy systems. This can be particularly beneficial for low-income communities that may not have the financial resources to invest in regular maintenance and repairs.
Figure 2: The Structure of a Microgrid Serving a Community. (source: Edison International)
The Answer: Continuous Solutions Inc.
Continuous Solutions Inc. has developed a complete suite of technologies to solve the issue of common mode interference in power converter systems. Our Common Mode Characterization System (CMCS) allows us to automatically analyze a microgrid system's power equipment to quantify the harmful common mode interactions within the system, allowing us to generate customized mitigation solutions for both the AC and DC sides of the microgrid. Our CMCS determines the common mode interference signature for each piece of equipment, allowing integrators an informed means to correct issues using appropriate interference filters or by removing incompatible equipment. Common Mode Inductors (CMIs) and CM shorting mitigates the ability for those EMI offenders from sharing their noise, and prevents susceptible devices from receiving the noise.
To not only quantify common mode interference issues, but also correct them, Continuous Solutions has developed a suite of common mode interference filters that mitigate faults and degradation of power system equipment. Our mitigation solutions include our CMIs on the DC side and our Common Mode Shorting Networks (CMSNs) on the AC side. Both of these technologies can be customized to fit any system from an electrical standpoint, ensuring maximum efficiency and effectiveness.
Figure 3: The Continuous Solutions Common Mode Interference Solutions Cycle.
Benefits to Communities
By utilizing Continuous Solutions Inc.'s suite of technologies, communities can experience significant cost savings and an increase in capabilities on electrified systems. By moving towards renewable energy, communities can reduce their reliance on non-renewable resources and reduce their carbon footprint. In addition, the implementation of our technologies can lead to long-term cost savings on equipment upkeep, as the mitigation of common mode interference can increase the lifespan of power converter systems.
Microgrids, which are only possible with power conversion systems integrating DC and AC systems, also provide an advantage in their resiliency during natural disasters. In legacy grid systems, massive transmission lines are susceptible to damage or loss during natural disasters, which can effectively “cut off” whole regions from their power generation source. With microgrids, because they are able to self-source through connected, local solar, wind, back-up generators, and batteries, even if the tied-in grid goes down the microgrid can sustain itself, allowing for critical infrastructure such as food refrigeration, water pumping, lighting, medical facilities, etc. to continue to be energized. Considering that a recent study by the Environmental Protection Agency showed that underserved communities will be disproportionately affected by climate change [1], including associated natural disasters such as forest fires and hurricanes, giving these communities the ability to maintain or rapidly restore their electrical infrastructure will be an essential component in protecting such communities.
Furthermore, our technologies can help to bolster the electrification of industrial processes and marine electrical systems, allowing for the integration of renewable resources in spaces that have been traditionally neglected. This can provide communities with a more reliable and cost-effective source of electricity, while also reducing the negative environmental impacts of non-renewable resources.
Overall, by mitigating common mode noise, Continuous Solutions Inc.'s technologies can help to remove some of the obstacles that low-income and underserved communities face in accessing green technologies, including renewable resources. By improving the reliability and inter-connectability of power converter systems, our technologies can help to reduce the costs associated with renewable energy and make it more accessible to these communities.
Continuous Solutions Inc. is dedicated to providing effective and efficient solutions to the issue of common mode interference in power converter systems. Our suite of technologies, including our CMCS, CMIs, and CMSN, allow for a complete solution to common mode interference issues. By utilizing our technologies, communities can experience significant cost savings, increased capabilities on electrified systems, and a reduced reliance on non-renewable resources.
[1] US EPA, “EPA Report Shows Disproportionate Impacts of Climate Change on Socially Vulnerable Populations in the United States,” www.epa.gov, Sep. 02, 2021. https://www.epa.gov/newsreleases/epa-report-shows-disproportionate-impacts-climate-change-socially-vulnerable