Utility Peak Shaving and Backup Generator Controllers
Generator controller and synchronizing equipment designed to connect generators to electric utility distribution grid to decrease peak draws from utility and reduce electricity costs for sites of all sizes.
The generator controls pictured were designed, assembled by Power Precision alongside synchronizing equipment to connect two 450 KW diesel generators to the electric utility 12 KV distribution grid. The generators are used for both peak shaving and emergency islanded power purposes. The synchronizing controllers are remotely controlled and monitored by the City's SCADA system and interface with the generators governor and AVR to provide remote load and VAR control. The generators can also be switched to isochronous control for islanded emergency power for the city water supply and be relocated to other critical sites, municipal pump stations, for emergency power.
Public Works Generator Peak Shaving to Grid Upgrade
The Public Works building had an existing 600 V, 800 KW generator designated for backup electricity in the event of loss of electricity from the electrical utility.
A portion of the City's electricity bill every month was due to peak KW demand during winter months. The high peak KW demand set in the winter is applied as a KW demand charge to a year of subsequent monthly bills. There was an opportunity to operate the generator a few times a year during the coldest times in winter months to reduce the peak KW demand and avoid paying a high KW demand charge for many months. The savings on the electricity bills was much more than the cost of some fuel used for a short duration to reduce this peak.
Power Precision designed and built new controls and 600 V switchgear to take the place of the existing transfer switch. The existing transfer switch was removed and the new switchgear was installed and connected to the existing power cables.
A generator and switchgear controller were installed in another enclosure separate from the 600 V components for arc flash safety. The new controller is connected to the generator engine controls and to the SCADA system for remote control and monitoring of new controller and generator information via a data communication network.
With the new switchgear and controls, the same generator will provide electrical power generation for peak-shaving in addition to maintaining its function as a backup generator.
For peak shaving operation, the generator will synchronize and operate in parallel with the electrical utility and supply electrical power onto the electricity grid. In the event of a power failure from the electrical utility, the generator will provide electricity to the Public Works Building islanded from the utility until utility power returns.
Now, with the ability to synchronize, the generator will connect and disconnect without any disruption to the electrical supply for testing and peak shaving operation and to make a ‘bumpless’ transfer of the building loads back to utility power after operation.