If you want to integrate a substantial percentage of renewable energy onto the grid, you need to be able to precisely control the injection of power into the grid to maintain power network stability. Solar and wind power are intermittent with rapid changes in generation. But with advanced weather forecasting, reserve power and a fast power-control system you can ensure that the grid remains stable even when conditions change, such as when a cloud moves over a solar array and generation levels decline or when EV charging systems suddenly disturb the grid.
Active Control Technology
PXiSE’s fast advanced control technology (ACT) power-control system works much like the autopilot in every commercial aircraft providing a smooth ride and guidance to the destination. Our latest patented technology is, essentially, the autopilot for the grid.
As utilities, renewable power generators and property owners install more renewables and build new microgrids, conventional methods for operating large numbers of disparate and intermittent resources are too slow to effectively manage voltage and frequency — which are critical to the smooth operation of the grid — as well as optimize a site’s renewable generation.
PXiSE Energy Solutions, offers the ACT software platform that smoothly connects renewables and enables microgrids to operate more efficiently, while managing performance, reliability and communication with the grid. The ACT software platform saves on costs, because it doesn’t require expensive equipment and can help reduce energy costs. In addition, the ACT platform helps renewable power operators boost revenues by maximizing their generation and reducing curtailment.
Three patent pieces of technology
ACT focuses on three patented pieces of technology to allow energy resources to reliably synchronize to the grid while also bringing more cost savings.
- The first is an application for monitoring a power grid using existing sensors to measure time-stamped voltage and current data at multiple locations on the grid. The PXiSE ACT synchronizes the data at multiple sites and smooths the angle data so it can be used in control systems. This is called “unwrapping” the angle data. The voltage and angles are the primary control forces in the power grid and should be used for control of the power grid.
- The second technology is multivariable feedback control of the power grid. This is often know as 2×2 decoupling control. This is required because the power system voltage and frequency both change when real and reactive power are injected into the grid. For the past 125 years this law of physics has been ignored by controlling frequency with spinning generators providing inertial stability and controlling voltage with very slow capacitor bank switching. But high renewable power generation grids have little or no inertia that limits renewable penetration to less than about 25 percent. Hence a new control technology is required for power grids with high renewables.
- Our third and latest patent builds on these two pieces of technology by introducing feedback control of multiple distributed energy sources including batteries. This component allows for feedback control of multiple renewable devices on the network that may have different characteristics, such as varying time responses and speeds. For the first time, our patented software creates a control system that can handle a wide variety of renewable power device systems at once and the system automatically controls the network power quality. With our solution, users can manage batteries, solar panels, wind turbines and any variety of generation resources – all through a single platform, which works in real time to ensure a smooth and grid-friendly process.
We believe feedback control can be used across the power network. For instance, the Western Interconnect — the power grid west of the Rockies — has fluctuating frequency and voltage. Many oscillations, which can be as high as 14 Hertz, are coming from turbines on wind farms, solar farms and electric vehicle charging systems as well as unmeasured solar rooftops. These are on-going concerns for utilities. Our control system can assist the grid by modulating wind and solar farm output to stabilize the main power grids and using vehicle to grid and local utility scale battery systems, such as mandated by the California PUC.
Application to all phases of electric systems
The ACT software platform, and the patented algorithms involved, including the multi-variable controllers, can be applied to all phases of the any electric system – solar, wind and microgrids as well as large power grid applications.
Adding increasing amounts of renewable generation to the grid is an important goal for many governments, companies and individuals. Meeting that goal will require a better way of managing numerous different devices with one system. The PXiSE ACT software platform was built as a cost effective solution to this problem.