An apparatus according to an embodiment includes a control circuit to control operations of an inverter and a switch. The control circuit judges whether or not a power system has a power failure, based on values of the system voltage and a frequency of the power system; and calculates a phase difference between a phase of the output voltage of the inverter and a phase of the system voltage and generate, by means of the phase difference, an output frequency pattern for changing a frequency of the output voltage of the inverter. The control circuit, when it is judged that the power system has recovered from the power failure, controls the inverter to change the frequency of the output voltage of the inverter in line with the output frequency pattern, and closes the switch after the phase difference becomes smaller than or equal to a threshold.

A power system includes an integrated energy storage system (ESS). It further includes a photovoltaic (PV) source. It further includes an integrated inverter having power connections to both the energy storage system and the photovoltaic source. The inverter includes an integrated PV disconnect switch.

The invention relates to a method for controlling power generation from a power plant which comprises a plurality of power generating units. The method involves setting a maximal allowed power production for each power generating unit in a selection of one or more power generating units of second priority to a non-zero value, where the maximal allowed power production is determined dependent on whether a first power production gap is greater or less than zero and dependent on a comparison of the first power production gap with a second available power production capability of the selection of the one or more power generating units of the second priority.

Systems and methods may coordinate and execute bidirectional energy transfer events between electrified vehicles and other devices or structures. Weather related data and/or grid related data may be leveraged for predicting the likelihood of power outage conditions of a grid power source. When power outage conditions are likely, a charging storage limit of a traction battery pack of the electrified vehicle may be automatically increased. The increased charging storage limit temporarily increases the energy storage capacity of the traction battery pack in anticipation of expected power outage conditions, thereby better preparing the traction battery pack for use as a backup power source during the power outage conditions.

An elevator includes an elevator motor, a motor drive for the elevator motor having a frequency converter including a rectifier bridge, an inverter bridge and a DC link in between, which frequency converter is controlled via a controller, the rectifier bridge being connected to AC mains via three feed lines including chokes, and the rectifier bridge being realised via controllable semiconductor switches, an isolation relay being located between the feed lines and AC mains, a backup power supply at least for emergency drive operation, an emergency control for performing an automatic emergency drive, the backup power supply is via a first switch connectable with only a first of the feed lines. A second and/or third of the feed lines is via a second switch connectable as power supply to a car door arrangement, the first switch as well as the second switch are controlled by the emergency control, and the emergency control is connected to a manual drive circuit having a manual drive switch for a manual rescue drive. The elevator includes a first feedback circuit configured to provide to the emergency control first information indicating the switching state of the isolation relay, a second feedback circuit which is configured to provide to the emergency control second information indicating switching state of the first switch. The emergency control is configured to selectively allow or prevent the emergency drive operation on the basis of the first information and the second information.

Methods, systems, and computer readable mediums for protecting and controlling a microgrid with a dynamic boundary are disclosed. One method includes detecting a fault in a microgrid that includes a dynamic point-of-common-coupling (PCC), in response to determining that the microgrid is operating in a grid-connected mode, isolating the fault by tripping a microgrid side smart switch and a grid side smart switch that are located immediately adjacent to the fault, initiating the reclosing of the grid side smart switch, and initiating the reclosing for the microgrid side smart switch via resynchronization if the grid side smart switch is successfully reclosed, and in response to determining that the microgrid is operating in an islanded mode, isolating the fault by tripping a microgrid side smart switch that is located immediately adjacent to the fault, and initiating the reclosing of the microgrid side smart switch.

Systems and methods for controlling and methods for controlling the power factor in a generator system are provided. In some embodiments, the generator system includes one or more generators configured to supply power to a power grid, an automatic voltage regulator configured to regulate a voltage of an output of the generator to a set voltage and regulate a power factor of the output to a set power factor, and a controller. The controller is configured to detect a fault on the output and to adjust the set power factor of the automatic voltage regulator based on the fault. The controller is further configured to ramp the set power factor from the adjusted value to an initial value over a set period of time.

The present disclosure describes systems and techniques that enhance effectiveness and efficiency of a contingency analysis tool that is used for studying the magnitude and likelihood of extreme contingencies and potential cascading events across a power system. The described systems and techniques include deploying the contingency analysis tool in a high-performance computing (HPC) environment and incorporating visual situational awareness approaches to allow power system engineers to quickly and efficiently evaluate multiple power system simulation models. Furthermore, the described systems and techniques include the power system contingency-analysis tool calculating and coordinating protection element settings, as well as assessing controls of the power system using small-signal nomograms, allowing power system engineers to more effectively comprehend, evaluate, and analyze causes and effects of cascading events against a topology of a power system.

An example method comprises receiving historical wind turbine failure data and asset data from SCADA systems, receiving first historical sensor data, determining healthy assets of the renewable energy assets by comparing signals to known healthy operating signals, training at least one machine learning model to indicate assets that may potentially fail and to a second set of assets that are operating within a healthy threshold, receiving first current sensor data of a second time period, applying a machine learning model to the current sensor data to generate a first failure prediction a failure and generate a list of assets that are operating within a healthy threshold, comparing the first failure prediction to a trigger criteria, generating and transmitting a first alert if comparing the first failure prediction to the trigger criteria indicates a failure prediction, and updating a list of assets to perform surveillance if within a healthy threshold.

A method for operating an electric power converter and an electric power converter configured to convert DC power into AC power supplied to a three-phase AC network, conclude, during the converting, that a single-phase tripping has started in the three-phase AC network connected to the three-phase output of the converter, and after the concluding that the single-phase tripping has started in the three-phase AC network, control an active current in the three-phase output of the converter such that a negative sequence voltage in the three-phase output of the converter remains at or below a predetermined level, wherein the converter is configured to perform the controlling until concluding that the single-phase tripping has ended in the three-phase AC network.