Load testing of uninterrupted power supply systems using regenerative loading by supplying percentage of a test power
AssigneeAT&T Corp.
InventorVeerabhadra R. Kattoju
Life of this patent
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Abstract
To ensure high level of reliability, it is desirable to test an electrical device, such as an uninterruptible power supply (UPS) system, periodically with minimum possible energy usage and without compromising reliability. A regenerative load (RGL) unit is described which makes it possible to conduct a load test of a UPS system and supply a portion of the energy used for the load test from a generator in the RGL unit. An induction motor driven by an adjustable speed drive and coupled to an induction generator is used in the RGL unit to supply the load to the electrical device and supply a portion of the power used by the electrical device under test.
Claims20
A regenerative load (RGL) apparatus for testing an electrical device, the electrical device having an input connected to a primary source of power and an output, the RGL apparatus comprising:
- an input connected to the electrical device output as a load for the electrical device;
- and
- an output connected to the primary source of power, the RGL apparatus supplying A % of test power required to operate the electrical device, whereby the electrical device receives 100% of the test power it requires under load while using only (100-A) % of the test power from the primary source of power.
A method of testing an electrical device comprising:
- connecting the electrical device to a primary source of power;
- connecting an input of a regenerative load (RGL) unit to the electrical device as a load for the electrical device;
- connecting an output of the RGL unit to the primary source of power;
- and
- supplying A % of the power from the RGL unit to operate the electrical device during testing of the electrical device, whereby the electrical device receives 100% of the power it requires under load while using only (100-A) % of the power from the primary source of power.
A method of testing an uninterruptible power supply (UPS) for conserving power, the method comprising:
- connecting an input of the UPS to a primary source of power;
- connecting an input of a regenerative load (RGL) unit to the output of the UPS, the RGL unit containing an induction motor coupled to an induction generator;
- setting up the RGL unit for proper operation;
- connecting an output of the RGL unit to the primary source of power;
- and
- ramping up the speed of the induction motor in the RGL unit to increase the load on the UPS and to supply A % of the power to the UPS.
Dependencies are inferred from the claim text.