摘要:
The present disclosure relates to method for use with a system having first and second uninterruptible power supplies (UPS 1 and UPS 2), and where the two UPSs are connected across a DC+ and a DC− terminal of a common battery, and where a neutral imbalance between neutral lines of the two UPSs has been corrected, giving rise to a current flow from a DC− bus of one of the UPSs to a DC− bus of the other one of the UPSs. The method corrects for a nominal DC reference voltage for one of the UPSs to eliminate the current flow to the DC− bus of the other UPS.
摘要:
A UPS system may be operated selectively in either a high efficiency mode or a low efficiency mode. An inductor is connected in series between the transfer switch and a secondary power source. The transfer switch includes thyristors arranged in a reverse connected configuration. A controller synchronizes gate commands to the thyristors in order to synchronize reserve voltage introduced by the inverter. If the load currents are not in phase with a fundamental voltage of the secondary power source, the controller waits up to a first time period in order to estimate when current through the switches will reach zero. If the out of phase current will reach zero by the end of a second time period, the inverter is switched on at the end of the second time period.
摘要:
A method is provided for communicating data amongst controllers in a power supply system. The method include receiving a present measure of a parameter indicative of an operating state of an uninterruptible power supply (UPS); comparing the present measure to a control window for the parameter, where the control window defines a minimum value for the parameter and a maximum value for the parameter; updating the control window based on the present measure when the present measure falls outside of the control window; and transmitting the present measure via a controller area network to a managing controller when the present measure falls outside of the control window.
摘要:
A static transfer switch is used for switching an output load from a first power source to a second power source. A first switching unit has a first pair of silicon controlled rectifiers (SCR). A second switching unit has a second pair of SCRs arranged in an anti-parallel configuration. The control circuit determines whether at least one of the SCRs is activated in accordance with the voltage between the gate and the cathode of the at least one SCR. If the voltage between the gate in the cathode is at least 150 mV, the control circuit indicates that the at least one of the SCR is activated.