The burn-in test of three-phase UPS by energy feedback method
In the burn-in test of three-phase online uninterruptible power supply (UPS) system, RLC is usually used as a load in the conventional method. For saving energy and decreasing the test cost of UPS, the energy feedback method is proposed to apply the test of the online UPS. In this method, the utility system is used instead of a load. A voltage regulator is used in parallel operation to turn back the energy, which was dissipated in conventional method, to the utility system. The values of real power and reactive power in the output of UPS can be regulated in the proposed method to imitate various loads. From the experimental results, the efficiency of saving energy is more than 85% near half-load and will be higher while the load increases.<<ETX>>
A study on the test of UPS by energy feedback method
In the life test of online uninterruptible power supply (UPS) systems, with heater used as a load, much energy will be wasted in the form of heat. To save energy and decrease the test cost of UPS, an energy feedback method is proposed. Using the utility system instead of the heater as load and the principle of parallel operation of transmission, the energy that will be dissipated is turned back to the utility systems. From the experimental results, the energy savings is approximately 82% in life test.<<ETX>>
Utilizing Emergency and Standby Power for Peak Shaving
The escalating cost of utility electrical power has stimulated the use of emergency and standby power systems for peak shaving. This paper outlines some basic economic considerations and shows how emergency and standby power equipment (automatic transfer switches, engine generator sets, and associated controls) can be coordinated with additional controls to produce optimum results. Special consideration is given to the selection of the additional equipment to assure reliable emergency power and at the same time provide the necessary flexibility, dependability, and long life for daily peak reduction control.