Across the Grid: A Guide to Electrical Distribution Systems

Ubiquitous electricity is no longer a novelty for most of us. We don’t gasp when we flick on the light switch, and we don’t (usually) cheer when the AC kicks on. However, just because we expect reliable, ongoing power supply doesn’t mean the process of receiving that power is simple or old hat. 

On the contrary, electrical distribution systems are increasingly complex. As we see the rise of electric vehicles, cleaner energy initiatives, multi-directional power flow, and more, delivering power safely and efficiently is growing more complicated and more crucial. 

Electrical Distribution Heirarchy and Breakdown 

Electrical distribution is the final stage in delivering electricity from transmission systems to homes and businesses. Electrical distribution systems are the method by which energy actually reaches customers using distribution and utility poles. 

Here is a quick, oversimplified breakdown:

A power plant generates electricity, and transmission lines carry high-voltage power over long distances to substations. Primary distribution focuses on carrying high-voltage electricity across transmission lines and over long distances to supply electricity to large consumers like industrial plants or continuing on to substations.  At substations, voltage is reduced, and secondary distribution begins. In this second phase, electricity is distributed to suburbs and neighborhoods using distribution poles. Transformers step down voltage before energy enters homes or step up voltage to keep spreading it across distances and reach more customers. This is the stage we commonly see around our homes, offices, and schools. 

Electrical distribution systems focus on power distribution after transmission, once power is being distributed at medium or low voltages.

Different Types of Electrical Distribution Systems

How electricity is delivered to customers can vary. The type of distribution system depends on services required, location, cost analysis, geographical characteristics, and more. There are two main ways to characterize distribution systems and ways in which they differ. 

By Networks

In general, there are three types of networks: 

• Radial networks use one power source to supply energy to an entire group. There's only one path for energy to be distributed. Any service outages or disruptions along the feeder will affect the entire group of customers. 

  

  Radial systems spread energy to multiple locations with only one path.

  
  

• Loop systems send electricity in loops throughout an area and return to the original plant. This network can minimize outage impacts or interruptions using switches and reclosers. If one section of the feeder experiences difficulties, a switch can be thrown to supply power from another direction.

  

  Loop systems include switches to control flow and minimize outages.

  
  

• Network systems are more expensive but are also considered the most reliable for continuous electrical services. Every customer is connected to at least two different power supplies, so if one supply fails, another one can take its place, and the customer never experiences an interruption.  

  

  In network systems, every end-user is connected to at least two power supplies.

By Location

• Urban areas tend to require higher loads because there are more businesses and customers. The higher demand for power necessitates heavier-duty equipment and more frequent substations. Typically, systems will move underground in cities since pole failures can cause a lot of damage in highly populated areas.

• Semi-urban and suburban areas demand less power than cities, but the amount of homes and traffic still sends many networks underground. Equipment is usually a little smaller than in cities, and substations are less frequent. 

• In rural areas with smaller populations, you’ll see smaller equipment, and stations will be spaced farther apart. Equipment doesn’t need to handle the high demands of urban or suburban neighborhoods. (There are added challenges in rural areas, however, with geographic obstacles making reliability and maintenance difficult.)

Designing Electrical Distribution Systems 

The influx and increasing frequency of solar panels, wind farms, distributed energy resources, and electric vehicles have taken a toll on the electrical grid. Distribution planning has to respond accordingly to make sure energy can be provided safely and efficiently. Robust systems provide data flow for better decision-making, improve the customer experience, ensure reliability even in the midst of storms or peaks, reduce risks, and maintain regulatory compliance. 

When designing electrical distribution systems, engineers focus on issues like: 

• Load balancing 

• Redundancy planning 

• Smart tech integration 

• Regulatory compliance 

• And more. 

But designing electrical systems is just step one. Keeping them running and directing power to the end-user demands constant work. 

Maintenance and Operations in Electrical Distribution Systems 

Electrical systems do not fall under the set-it-and-forget-it category. This is just a snippet of some of the day-to-day operations that keep our grid functioning. 

Power Flow Mechanics 

As mentioned above, systems can be classified by how electricity flows between the system, creating loop, radial, and network systems. Voltage gradually decreases using transformers as electricity moves farther from generation and closer to homes and businesses.

Current flow and phase balancing are crucial to provide us with the safe and stable supply of electricity that we rely on. Unequal currents across phases create extra stress on the grid and can create failures. With distribution energy resources integrating with the grid, power flow mechanics must also account for bidirectional flow. 

Maintaining and Monitoring Electrical Systems

Advanced monitoring is a critical piece of maintaining electrical distribution systems. Supervisory Control and Data Acquisition (SCADA) platforms provide electrical engineers and operators with visibility into their entire grid, with voltages, currents, switch positions, transformer temps, and much more. By being able to spot problems quickly and respond faster, engineers can adjust flow and voltages or even leverage automatic devices to make decisions throughout the network. 

For example, automated reclosers can detect temporary faults, like a tree branch touching a line, and briefly disconnect power. Then, when the fault clears, the recloser can reconnect power. 

The modern electric distribution system provides enormous amounts of data every minute. Advanced systems can collect measurements across thousands of points within the network for health indicators. Grid telemetry and more are incredibly important as things change and the grid becomes more and more complex. (Just as important as data flow is understanding where the data is coming from—when we don’t know where smart meters are located, they’re not very smart.)

Routine Operations

Think about how much our electric grid had to adapt to keep up with all the folks who started working from home a few years ago. Remote work is just one example of why a grid demands constant supervision. Teams have to monitor loads to address shifting demands and needs. When maintenance work is being done, flow switching redirects power to keep the lights on. When seasons change, the system must be adjusted for different loads. 

As mentioned previously, smart tech and SCADA software is automating some of these routine changes, redirecting power, and adjusting loads based on incoming data. But there are lots of operations that we can’t automate. Substation and asset inspections are conducted regularly to keep equipment up-to-date. Veg management prevents foreign objects like branches from touching lines and highlights areas where issues may potentially occur. Preventative maintenance work follows scheduled cycles to keep things running smoothly. 

Electrical Systems Challenges and Solutions

With so much affecting the grid and so many variables, challenges are inevitable. These are a few of the major issues we’ve identified, but we’d love to hear about the issues your team’s identified as you maintain electrical systems.

Different Networks and Varying Degrees of Reliability

We touched on this a little earlier, but the type of distribution network greatly affects the reliability of that network. 

A single point of failure in a radial system will affect all downstream customers, and there are limited rerouting options during outages. This also means radial systems are more vulnerable to equipment failure because there’s only one route to push electricity through. Smart sectionalizing can help minimize the effects of outages, and preventative maintenance is hugely important for these networks. 

Loop networks can result in backfeeding, which can severely damage equipment and cause cascading issues. As a result, loop networks need more complex protective measures and coordination with switching operations. It’s expensive to build, but for automated tech to work they need to be more advanced. 

With so much redundancy included, multiple supply paths to coordinate, and higher voltage to distribute, network systems are expensive to install and maintain. The greater flow of electricity requires more robust equipment and sophisticated monitoring systems. 

Maintenance Concerns for Different Geographies 

Asset Management for Suburban Areas

Suburbs have their own challenges, as overhead lines often move underground within busy suburban areas. Teams need to manage both overhead and underground assets that are in close proximity. 

Asset management systems make it easier to track both underground and overhead equipment. While it’s still a pain and complicated to manage assets clustered in one area, GIS tools help keep track of equipment with verified location data. 

Improving Maintenance to Rural Communities

Maintaining rural networks becomes a battle against the elements and landscape. Crews may have to drive an hour or more to check on one faulty line, or equipment upgrades may be miles apart. Sometimes, the weather can make entire areas inaccessible. 

Remote monitoring systems can help reduce unnecessary trips to check up on feeders, so storm response teams can focus their attention on the areas that truly need help. Plus, the more data and intel we get from reporting systems, the faster we can predict and prevent outages. 

Evolving Electrical Distribution Systems 

Legacy systems don’t provide the depth of detail or visibility required for smart tech integration. Outdated systems increase response time and outages, and they’re not prepared to handle behind-the-meter integrations with DERs. 

Similarly, analog and pen-and-paper recordkeeping doesn’t cut it in our digital age. There’s too much information and too many data points, all of which need to be tied to true locations to make sense and make decisions. 

Transitioning to new management systems can start with smarter meters, grid upgrades, and more rigorous maintenance that focuses on intelligent and advanced tech. 

As smart technology increases the amount of data coming back from the grid, physical files and even spreadsheets can be exchanged for flexible software. Storing and managing data and assets within a database makes it far easier to gather valuable intel on electrical systems without having to sort through loads of paperwork.

Moving from One-Way to Two-Lane Traffic 

Traditional systems only ever had to send power out to end-users and customers, but distributed energy resources are changing the flow of energy. When a customer has generated more energy than they can use, DERs may push electricity back through the grid. 

It’s a totally different ball game and requires advanced flow modeling tools and edge-of-grid quality management systems to maintain proper voltage even with DERs adding to the system.. 

Leveraging Katapult Pro for Electrical Distribution

Whether you’re gathering data on a plant for upgrades, designing new poles, managing storm responses, or coordinating new projects, Katapult Pro provides software tools for streamlining the distribution design and maintenance process. 

Collect valuable, detailed data on your grid, assets, and equipment. Use that data to engineer and design new feeders based on your specific regional standards. Track and manage projects and work across your footprint and coordinate with subs and construction crews. 

Build and maintain intelligent, robust networks with flexible tools and software tailored to your project needs.

Learn More