Abstract: A system parallels engine-generators on a common bus and includes circuit breakers and automatic voltage regulators. Each engine-generator includes an output having an alternating current voltage. Each breaker is between the output of a corresponding engine-generator and the bus. Each regulator includes a first mode controlling field excitation for a corresponding engine-generator and a second mode automatically controlling the AC voltage.

Abstract: A system parallels engine-generators on a common bus and includes circuit breakers and automatic voltage regulators. Each engine-generator includes an output having an alternating current voltage. Each breaker is between the output of a corresponding engine-generator and the bus. Each regulator includes a first mode controlling field excitation for a corresponding engine-generator and a second mode automatically controlling the AC voltage.

Abstract: A protective apparatus is for a distributed resource of a utility grid. The protective apparatus includes a processor having an input structured to input frequency of the distributed resource, a first output structured to control speed of the distributed resource, a second output, and a routine structured to actively bias engine-generator speed of the distributed resource through the first output, and detect a predetermined change in the frequency of the distributed resource from the input and responsively indicate the unintentional island condition through the second output. The protective apparatus also includes a circuit interrupter.

Abstract: A loss of a power source for a bus is detected. Responsive to detecting the loss of the power source, a voltage is generated on the bus using an uninterruptible power supply (UPS). A generator is transitioned to a desired output state concurrent with generating the voltage on the bus using the UPS. The generator is coupled to the bus responsive to the generator attaining the desired output state. The UPS may be used to provide power to a load connected to the bus while the generator is in transition. For example, detecting the loss of the power source may be preceded by operating a converter of the UPS coupled to the bus as a rectifier and generating the voltage on the bus using the UPS may include operating the converter of the UPS as an inverter.

Abstract: A power system includes a load bus configured to be connected to a power source, a generator and an uninterruptible power supply (UPS). The generator is operated as an induction generator to provide power to the load bus while providing reactive power to the load bus from the UPS. In some embodiments, prior to operating the generator as an induction generator, the generator is operated as an induction motor while the load bus is receiving power from the power source. Responsive to loss of the power source, the UPS may be used to maintain operation of the generator as an induction motor while the prime mover accelerates up to a speed sufficient to drive the generator as an induction generator.

Abstract: A power system includes a load bus configured to be connected to a power source, a generator and an uninterruptible power supply (UPS). The generator is operated as an induction generator to provide power to the load bus while providing reactive power to the load bus from the UPS. In some embodiments, prior to operating the generator as an induction generator, the generator is operated as an induction motor while the load bus is receiving power from the power source. Responsive to loss of the power source, the UPS may be used to maintain operation of the generator as an induction motor while the prime mover accelerates up to a speed sufficient to drive the generator as an induction generator.

Abstract: A loss of a power source for a bus is detected. Responsive to detecting the loss of the power source, a voltage is generated on the bus using an uninterruptible power supply (UPS). A generator is transitioned to a desired output state concurrent with generating the voltage on the bus using the UPS. The generator is coupled to the bus responsive to the generator attaining the desired output state. The UPS may be used to provide power to a load connected to the bus while the generator is in transition. For example, detecting the loss of the power source may be preceded by operating a converter of the UPS coupled to the bus as a rectifier and generating the voltage on the bus using the UPS may include operating the converter of the UPS as an inverter.