Abstract: A method of delivering an optimized power level from a backup energy system to a load connected to a primary energy supply via a DC link and an inverter is provided. The method has the steps of: sensing a voltage of the DC link connected to the load; connecting a converter between the backup energy supply and the DC link; evaluating a rate of change of the voltage of the DC link; determining an estimate of the average load current using the rate of change of the DC link voltage; and controlling the converter using the average load current to switch the optimized power output from the backup energy supply to the load. In an embodiment, the step of determining an estimate of the average load current using the rate of change of the DC link voltage is performed in accordance with a formula I.sub.load =C.sub.DC link (dV.sub.DC link /dt).

Abstract: A superconducting voltage stabilizer is set forth which utilizes a superconducting coil for storing and releasing electrical energy. A first semiconductor switch is disposed to conduct current from the superconducting coil therethrough when the superconducting coil is to be charged or is to store energy and to inhibit current flow therethrough when the superconducting coil is to release energy. A crowbar circuit including a second semiconductor switch and a dump load are also employed. A third semiconductor switch is connected in parallel with the dump load and is disposed in series between the superconducting coil and the crowbar circuit. Quench detection and control circuits are employed for detecting a quench condition of the superconducting coil.

Abstract: A shunt connected energy stabilizing system with isolation switching for providing stored energy to loads or to a utility or industrial electrical distribution system or source of electrical power. An energy backup and recovery system stores energy in a superconducting magnet and releases the energy to a real power/reactive power (VARs) generator which in turn delivers energy to either the loads or to both the loads and the source of electrical power. During periods of voltage sag or power outage, an isolation switch provide a means for isolating the loads from the source of power so that energy can be supplied to the loads only to provide "ride-thru". In effect, the isolation of the load sheds this load from the power system, thereby boosting the rest of the electrical distribution to a level so that other loads on the power system are not disturbed by the voltage sags. By supplying energy to the loads only, small superconducting magnets can be used thereby providing economic and size advantages.

Abstract: A shunt connected energy stabilizing system with isolation switching for providing stored energy to loads or to a utility or industrial electrical distribution system or source of electrical power. An energy backup and recovery system stores energy in a superconducting magnet and releases the energy to a real power/reactive power (VARs) generator which in turn delivers energy to either the loads or to both the loads and the source of electrical power. During periods of voltage sag or power outage, an isolation switch provides a way for isolating the loads from the source of power so that energy can be supplied to the loads only to provide "ride-thru". In effect, the isolation of the load sheds this load from the power system, thereby boosting the rest of the electrical distribution to a level so that other loads on the power system are not disturbed by the voltage sags. By supplying energy to the loads only, small superconducting magnets can be used thereby providing economic and size advantages.

Abstract: A superconductive voltage stabilizer employs an improved current switch. The improved current switch controls the release of current stored in an energy storage device or superconducting inductive energy storage coil for selective delivery of the current to a load or an electric utility system. A transformer employed in the current switch provides isolation of the energy storage components from the load, thereby making a local ground possible. The amount of energy which can be recovered from the energy storage device is also increased.

Abstract: A superconducting energy stabilizer having multiple load connections employs DC-DC conversion. A discharging DC-DC converter removes stored energy from a superconducting inductive energy storage device or superconducting magnet and delivers the energy to an energy storage cell for use by a load or a utility or industrial electrical distribution system. Regenerated energy can also be retrieved from regenerative type devices and stored in the superconducting magnet for later use. A charging DC-DC converter provides this function. The charging DC-DC converter and the discharging DC-DC converter as well as an off-the-line power supply which provides energy for storage in the superconducting magnet can operate simultaneously under the control of a control system.

Abstract: A superconductive voltage stabilizer comprises an AC/DC converter, a voltage regulator, an energy storage cell and a superconducting energy storage coil. Alternating current is converted to direct current and stored in a superconducting coil. The stored direct current is selectively delivered to an energy storage cell to satisfy the energy requirements of a load. A voltage regulator senses the energy drawn from the energy storage cell and when appropriate releases stored energy from the superconducting coil to maintain a constant supply of energy to the load.