An alternating current (AC) power distribution system may include an independent speed variable frequency (ISVF) generator configured to generate an AC power signal having a frequency that is independent from a frequency of a prime mover. The system may also include at least one AC load configured to receive the AC power signal without performing a full-distribution-power-rated power conversion. In another embodiment, an AC power distribution system includes a generator configured to generate an AC power signal and an AC motor configured to receive the AC power signal without performing a full-distribution-power-rated power conversion, where the AC motor is configured to rotate at a rotational frequency that is independent from a frequency of the AC power signal.

An alternating current (AC) power distribution system may include an independent speed variable frequency (ISVF) generator configured to generate an AC power signal having a frequency that is independent from a frequency of a prime mover. The system may also include at least one AC load configured to receive the AC power signal without performing a full-distribution-power-rated power conversion. In another embodiment, an AC power distribution system includes a generator configured to generate an AC power signal and an AC motor configured to receive the AC power signal without performing a full-distribution-power-rated power conversion, where the AC motor is configured to rotate at a rotational frequency that is independent from a frequency of the AC power signal.

A transfer switch transfers electric power provided to an electrical load from a first power source to a second power source. The transfer switch includes a coil arrangement that controls movement of a member to open or close a contactor of the first or second power source. The coil arrangement may be used with two voltage levels.

A transfer switch transfers electric power provided to an electrical load from a first power source to a second power source. The transfer switch includes a coil arrangement that controls movement of a member to open or close a contactor of the first or second power source. The coil arrangement may be used with two voltage levels.

The present invention relates to a power conditioning system (PCS) efficiency-considered microgrid operation device comprising: a scheduling unit for scheduling outputs of a controllable load, a battery, and an emergency internal combustion generator operated in a microgrid; and an operation control unit for controlling the operation of the battery, the emergency internal combustion generator, and the controllable load according to charging/discharging of the battery, the output of the emergency internal combustion generator, and the output of the controllable load, which have been scheduled, by the scheduling unit, wherein the scheduling unit schedules charging/discharging by considering the efficiency of a PCS such that a state of charge (SOC) of the battery is maintained within a preset range. According to the present invention, the microgrid can be efficiently operated by considering the charging/discharging efficiency of the PCS.

The present invention relates to a power conditioning system (PCS) efficiency-considered microgrid operation device comprising: a scheduling unit for scheduling outputs of a controllable load, a battery, and an emergency internal combustion generator operated in a microgrid; and an operation control unit for controlling the operation of the battery, the emergency internal combustion generator, and the controllable load according to charging/discharging of the battery, the output of the emergency internal combustion generator, and the output of the controllable load, which have been scheduled, by the scheduling unit, wherein the scheduling unit schedules charging/discharging by considering the efficiency of a PCS such that a state of charge (SOC) of the battery is maintained within a preset range. According to the present invention, the microgrid can be efficiently operated by considering the charging/discharging efficiency of the PCS.

A power supply unit (PSU) dynamically limits total recovery current. The PSU includes at least a power input, a power output, a historic maximum power draw memory, an update logic, and a recovery current limiting logic. Some implementations include a latest power measurement register, an hourly max power register, and a rolling max register, and controlling firmware. The update logic monitors a power level. The update logic updates the historic maximum power draw memory to match the monitored level. After a power interruption, the recovery current permitted to flow into the PSU is limited based on the historic usage. The recovery current may be limited in a constant, stepped, or ramped manner. The PSU may also provide power distribution. Multiple PSUs may be treated as a group, allowing an individual PSU to exceed its historic usage while the group's recovery currents are limited to the sum of historic usage levels.

Systems and methods for controlling power flow to and from an energy storage system are provided. One energy storage system includes an energy storage device and a bidirectional inverter configured to control a flow of power into or out of the energy storage device. The energy storage system further includes a controller configured to control the bidirectional inverter based on one or more signals received from the generator set coupled to the inverter via an AC bus. The controller is configured to, based on the one or more signals, control the bidirectional inverter to store power generated by the generator set in the energy storage device and transmit power from the energy storage device to a load driven by the generator set to maintain the generator set within a range of one or more operating conditions.

Electrical systems for providing uninterruptible power to a critical load. One electrical system includes a ring bus, multiple power blocks including one or more generators electrically coupled to the ring bus, and uninterruptible power supplies (UPSs) electrically coupled to the ring bus. In some aspects, the electrical system includes a UPS switchgear electrically coupled between the ring bus and the UPSs. In other aspects, the UPSs are electrically coupled together in parallel. Another electrical system includes a utility switchgear, UPS blocks electrically coupled together in parallel and electrically coupled to the utility switchgear via transformers, low voltage (LV) power blocks electrically coupled to the UPS blocks, and medium voltage (MV) switchgear electrically coupled to the UPS blocks via transformers. Each of the LV power blocks include one or more generators.

Electrical systems for providing uninterruptible power to a critical load. One electrical system includes a ring bus, multiple power blocks including one or more generators electrically coupled to the ring bus, and uninterruptible power supplies (UPSs) electrically coupled to the ring bus. In some aspects, the electrical system includes a UPS switchgear electrically coupled between the ring bus and the UPSs. In other aspects, the UPSs are electrically coupled together in parallel. Another electrical system includes a utility switchgear, UPS blocks electrically coupled together in parallel and electrically coupled to the utility switchgear via transformers, low voltage (LV) power blocks electrically coupled to the UPS blocks, and medium voltage (MV) switchgear electrically coupled to the UPS blocks via transformers. Each of the LV power blocks include one or more generators.