Systems and methods for detecting abrupt voltage changes and supplying reactive power support are provided. In some embodiments, a genset connected to a power grid can identify a maximum voltage value and a minimum voltage value. The maximum voltage value and the minimum voltage value are based on an average of a plurality of mains voltage values. The genset may detect an abrupt voltage change by determining whether an instantaneous mains voltage value is above the maximum voltage value or below the minimum voltage value. The genset can adjust an amount of reactive current either supplied to the power grid or consumed by the genset for a period of time, responsive to detecting the abrupt voltage change.

A system and method are provided for operating a power generating asset. Accordingly, a controller detects a fault condition impacting the power generating asset. The controller then determines whether the fault condition is occurring in the power generating asset or is occurring in the power grid. When the fault condition is occurring in the power generating asset, a first response control scheme is implemented. However, when the fault condition is occurring in the power grid, a second response control scheme is implemented. The response control schemes include a first current threshold and a second current threshold respectively, with first current threshold being less than the second current threshold. Additionally, a control action is implemented in response to an approach of a current to the respective current threshold.

A system and method for automated shutdown, disconnect, or power reduction of solar panels. A system of solar panels includes one or more master management units (MMUs) and one or more local management units (LMUs). The MMUs are in communication with the LMUs with the MMUs and LMUs “handshaking” when the system is in operation. The MMUs are connected to one or more controllers which in turn are connected to emergency detection sensors. Upon a sensor detection of an emergency, the associated MMU is notified which in turn instructs associated LMUs to take appropriate action. In the event that communication with the MMUs has been cut off, the LMUs take the initiative to shut down, disconnect, or reduce the output of associated string(s) of solar panels.

A high voltage direct current (HVDC) transmission system comprises a first terminal comprising a first voltage source converter (VSC) having a first and second VSC terminals and a first line commutated converter (LCC) having first and second LCC terminals; a second terminal comprising a second VSC having third and fourth VSC terminals and a second LCC having third and fourth LCC terminals; and a transmission line pair comprising a positive transmission line that couples the first VSC terminal and the first LCC terminal of the first VSC and the first LCC, respectively, to the third VSC terminal and the third LCC terminal of the second VSC and the second LCC, respectively, and a second positive line that couples the second VSC terminal and the second LCC terminal of the first VSC and the first LCC, respectively, to the fourth VSC terminal and the fourth LCC terminal of the second VSC and the second LCC, respectively.

A photovoltaic system providing both grid-tie and back-up operation comprises an inverter having a first, voltage-controlled output for powering appliances, and a second, current-controlled output for grid back-feed. The second output may have a current-controlled mode when connected to the grid and a voltage-controlled mode otherwise. The first and second outputs comprise independent switching transistors, which however may be driven by the same switching control signals, such that the voltage controlled-output mimics the voltage on the current-controlled output when it is connected to the grid, and therefore tracks the grid voltage. Grid isolation relays disconnect the current-controlled inverter output from the grid if it fails. A connection bypassing the grid isolation relay is monitored by the controller for the presence and stability of the grid supply when it resumes. Both outputs follow the voltage on the voltage-controlled output when the current-controlled output is not connected to the grid.

A fault detection apparatus includes a temperature detection unit, a current detection unit, a controller, and a breaking unit. The temperature detection unit is configured to detect temperatures of the plurality of filter capacitors and output the temperatures to the controller. The current detection unit is coupled to the plurality of filter capacitors and is configured to detect currents of the plurality of filter capacitors and output the currents to the controller. The controller is separately connected to the temperature detection unit, the current detection unit, and the breaking unit, and is configured to: when the received temperature exceeds a first threshold and the received current exceeds a second threshold, control the breaking unit to be disconnected. The breaking unit is connected between the output end of the grid-tied inverter and the plurality of filter capacitors and is configured to be disconnected or connected under control of the controller.

A method includes performing by a processor: determining a phase angle alignment parameter based on a ratio of a phase angle difference and a frequency difference, the phase angle difference comprising a difference between a first phase angle corresponding to a reference synchronized measurement device (SMD) and a second phase angle corresponding to a follower SMD, the frequency difference comprising a difference between a frequency at which the first and second phase angles are measured and a nominal frequency; receiving a first plurality of synchrophasor measurements of a power system signal from the reference SMD; receiving a second plurality of synchrophasor measurements of the power system signal from the follower SMD, the first plurality of synchrophasor measurements and the second plurality of synchrophasor measurements being offset in time relative to each other by a sampling time shift; and aligning phase angles of the second plurality of synchrophasor measurements with phase angles of the first plurality of synchrophasor measurements using the phase angle alignment parameter.

There is provided a method for evaluating a network comprising: providing graphs each indicative of a respective sequential snapshot of a dynamic graph obtained over a historical time interval, the dynamic graph denoting the network, computing sets of meta-parameters, each set of meta-parameters computed according to a respective graph of the graphs, wherein each one of the meta-parameters denotes a network level parameter computed according to a plurality of at least one of edges and nodes of the respective graphs, analyzing sets of meta-parameters according to values computed based on a physics-based analytical model of an evolving physical system, and predicting a likelihood of stabilization of the network during a future time interval according to an indication of convergence of the values according to a convergence requirement, computed based on the physics-based analytical model during the future time interval.

A switching state of a switching arrangement of an electrical distribution arrangement is optimized. In each switching state, an outgoing circuit of the distribution arrangement is connected to a supply by the switching arrangement via a component. Each state differs from others in that the outgoing circuit is connected to the supply via another component. The switching arrangement has enough switching states that each outgoing circuit is connectable to a supply via two different components. An outgoing circuit is presented based on: operating parameters of the components, a switching state, outgoing loads; environmental parameters of the electrical components, forecasted environmental parameters, and forecasted outgoing loads. Forecasted operating parameters are simulated to compare future operating parameters with limit values. Based on likely exceeding limit values in the future, an alternative switching state is suggested such that limit values are not exceeded.

Systems and methods may be used to determine fault types and/or directions even during a loss of potential by receiving, at one or more processors, an indication of a pre-fault power flow direction for a power delivery system. The one or more processors then determine a fault direction during a fault for the power delivery system using current vector angles and the pre-fault power flow direction.