Capstone Turbine Corporation
Model C65 Hybrid UPS User’s Manual
Page
18 of 66
400027 Rev A (July 2010)
Capstone reserves the right to change or modify, without notice, the design, specifications, and/or contents of this document without
incurring any obligation either with respect to equipment previously sold or in the process of construction.
Grid LCM (GLCM)
The GLCM connects to the normal utility grid power, and converts AC power for
connection to the internal 760V DC bus. The GLCM is bi-directional, and power can flow
either to or from the utility grid. The GLCM has its own protective relay functions that
monitor the stability of the utility bus voltage, and it will automatically disconnect power
from an unstable grid. When it has disconnected power from the grid, the GLCM continues
to monitor the grid voltage. If the engine has not been commanded to start, the GLCM will
reconnect power without delay when the grid returns to a stable condition. If the engine is
running or is in a start sequence, the GLCM will reconnect power when the grid has
remained stable for a user-defined reconnection delay period.
Load LCM (LLCM)
The LLCM takes power from the internal 760 VDC bus to the customer’s critical load. The
LLCM is unidirectional, and power will only flow from the internal DC bus to the critical
load. It will maintain the frequency and phase angle of its output to match the utility grid
voltage sensed by the GLCM whenever the utility voltage is stable, and will revert to a
preset frequency when the utility voltage is unavailable. The LLCM will provide a preset
voltage output to power the critical loads. Protective relay functions are also integrated into
the LLCM to protect against disturbances on the load output.
Battery Control Module (BCM)
The BCM converts the battery string voltage to the internal 760 VDC. It is able to import
full power to the Hybrid UPS system from an external energy storage system (typically a
battery string), and can also export power to an individual energy storage system
connected to only one microturbine for recharging.
Battery String
The battery string can be a battery bank or other energy storage system, either supplied by
Capstone or the customer. It will typically be sized for at least 15 minutes of full power capability
so that it can provide power to the protected load while a non-operating turbine generator is
started.
The Hybrid UPS MicroTurbine must be connected to an external battery or other storage
system which provides energy for MT startup when disconnected from the electric utility
grid, and which provides temporary power when utility power suddenly becomes
unavailable.
For external battery systems sold as an accessory by Capstone, management of the
battery and its state of charge is automatic between the Hybrid UPS microturbine and the
external battery pack. An awareness of these battery management functions will promote
an understanding of why the system may appear to behave autonomously. For example,
the MicroTurbine will always attempt to recharge the battery after a user commanded shut
down and before the MicroTurbine enters the cool down state.
For battery storage systems provided by others, a separate battery management and
charging system must be provided. The Hybrid UPS system will not provide any battery
management, condition monitoring, or charging. An indication of battery state of charge
must be provided through the UPS Controller. Contact Capstone for application guidance.
