Innovations & Applications
Energy Storage for Microgrids
Combining electrical energy storage, such as a lithium-ion battery system with a solar array, provides the ability to separate from the electrical grid and operate in a completely secure and reliable manner. Batteries also enable matching generation to time of use, peak-shaving, and significantly reduce the fuel and sizing for common backup diesel or biodiesel generators. Even small amounts of storage can have a major impact on reducing fuel costs, maintenance, and emissions. While lead-acid batteries are still the lowest-cost solution for backup power, newer lithium-ion batteries can provide high-efficiency (>90% round-trip), 10 year lifetimes, and deep-cycle capability — making them the most cost-effective solution for many applications. Additionally, they require less than one-third the volume. Our systems can incorporate many types of storage, including hybrid lead-acid (which combines an ultracapacitor with a lead-acid base),flow batteries, flywheels, and other systems.
Energy Storage for Grid Support and Renewables Integration
Many of the issues facing the aging electrical transmission and distribution systems can be mitigated by adding energy storage close to where power is needed, whether at the substation level or behind a customer's meter. Area Frequency Regulation (AFR) and other ancillary services for grid support are lucrative markets in North America, where the benefits of using integrated energy storage systems are becoming more widely known. Princeton Power's Energy Storage System (ESS) combines batteries with grid-tied inverters (GTIB) and a communications system that allows it to interface with the electric grid and provide valuable services, as well as being programmable to run in a variety of grid support modes. Grid support services are critical to enabling further penetration of intermittent resources, such as solar, that can see wide swings in power output during short-term events like cloud coverage. Integrating with storage can be valuable to prove the cost-effectiveness of these generation technologies. The ESS provides a simple solution to demonstrating various types of storage.
Many different types of generators, including large wind turbines, hydroelectric generators, and different types of PV technologies, can be cost-effective as grid-connected generators in various applications. Princeton Power specializes in converters and system design for 3-phase systems between 50-3,000 kW power level. Our products are ideal for control of advanced generators, such as permanent magnet, axial flux and new technologies including low-inductance machines.
AC-link is a unique semi-resonant circuit topology, exclusive to Princeton Power, with distinct advantages in applications that require high-efficiency and premium power quality. The softswitching AC-link circuit is also uniquely able to work with silicon carbide devices in high-voltage applications, where a single silicon carbide (SiC) switch can replace ten or more silicon switches — leading to significantly better reliability and performance.
Silicon Carbide (SiC) Devices
As a wide bandgap material, SiC has the potential to yield switching devices that are significantly higher in efficiency, voltage capability, and temperature range, than today's state-of-the-art silicon devices. In partnership with the leading universities and companies in SiC device fabrication, Princeton Power has developed test beds, testing programs and prototype converters based on advanced and proprietary SiC designs for applications including high-efficiency motor controllers, high-voltage DC transmission and shipboard electric distribution.