This document relates to power supply systems.
An uninterruptible power supply (UPS) system can be implemented to ensure constant power supply to a load even when an input power source fails. To accommodate the power requirement of certain loads, such as loads with high power requirements, a UPS system with a flywheel system can be employed. The flywheel system interfaces with the input power source, or power grid (e.g., a plant wide, citywide, statewide and/or nationwide utilities power transmission grid), and the load. When the power to the load falls below a threshold, for example, when the power grid fails, the flywheel system can discharge the stored energy, which, in turn, can be used to power the load.
As an alternative to the flywheel system, a battery system that includes multiple batteries can be used. The battery system interfaces with the power grid to store energy when the power grid delivers power to the load, and to discharge the energy to the load, for example, when the power grid fails. Each of the flywheel system and the battery system can be configured to deliver back-up power when the power source fails such that the load does not experience a power interruption. In addition, each of the systems can deliver back-up power for a duration sufficient to start back-up generators. In some situations, the flywheel system, the battery system, the power source, and the load can all be components of the same circuit.