Abstract: In a first embodiment, a system for controlling a microgrid includes a processor-based control system. The control system is configured to receive information via a communications pathway from at least one microgrid asset within a microgrid system and identify one or more errors associated with an operation of the microgrid system. In addition, the control system is configured to respond to the one or more identified errors with one or more actions. Each identified error from the one or more identified errors is associated with at least one action from the one or more actions. Further, control system is configured to generate an optimal dispatch schedule having one or more control signals configured to control the microgrid operation to reduce cost and to improve an operational efficiency of the microgrid. The optimal dispatch schedule is based at least in part on the response to the one or more identified errors.

Abstract: In a first embodiment, a system for controlling a microgrid includes a processor-based control system. The control system is configured to receive information via a communications pathway from at least one microgrid asset within a microgrid system and identify one or more errors associated with an operation of the microgrid system. In addition, the control system is configured to respond to the one or more identified errors with one or more actions. Each identified error from the one or more identified errors is associated with at least one action from the one or more actions. Further, control system is configured to generate an optimal dispatch schedule having one or more control signals configured to control the microgrid operation to reduce cost and to improve an operational efficiency of the microgrid. The optimal dispatch schedule is based at least in part on the response to the one or more identified errors.

Abstract: The present invention relates to methods for providing impedance protection differentiating between in-zone and out-of-zone faults based on instantaneous, digitally derived operating and polarizing distance comparator signals. The method uses a pair of fast orthogonal filters to derive D and Q components of the input voltages and currents. Two sets of operating and polarizing signals are derived for better speed of response under varying fault moment with respect to the peaks and zero crossings of power signals. Three stages of comparison between the operating and polarizing impedance terms are used. These comparator stages use half a cycle averaging windows, and three-quarters-of-a-cycle windows. The first stage of comparison is based on energy comparator responding to both magnitude and phase information in the signals. Stages 2 and 3 are of phase comparison type, responding mostly at the phase information and neglecting the magnitude information for better immunity to noise and signal distortions.

Abstract: A method of digitally correcting the raw output voltage from a Capacitive Voltage Transformer (CVT) with the intent to remove transient components impacting on transient accuracy of protection function. A typical CVT is represented using three parameters in the linear CVT model. A digital filter designed based on the three parameters and incorporating a dedicated mechanism to ensure numerical stability of the former. A method of self-adjusting the said filter based on system events and performed after the method has been deployed in the field and supplied from a specific CVT.

Abstract: A method of digitally correcting the raw output voltage from a Capacitive Voltage Transformer (CVT) with the intent to remove transient components impacting on transient accuracy of protection function. A typical CVT is represented using three parameters in the linear CVT model. A digital filter designed based on the three parameters and incorporating a dedicated mechanism to ensure numerical stability of the former. A method of self-adjusting the said filter based on system events and performed after the method has been deployed in the field and supplied from a specific CVT.

Abstract: The present invention relates to methods for providing impedance protection differentiating between in-zone and out-of-zone faults based on instantaneous, digitally derived operating and polarizing, distance comparator signals. The method uses a pair of fast orthogonal filters to derive D and Q components of the input voltages and currents. Two sets of operating and polarizing signals are derived for better speed of response under varying fault moment with respect to the peaks and zero crossings of power signals. Three stages of comparison between the operating and polarizing impedance terms are used. These comparator stages use half a cycle averaging windows, and three-quarters-of-a-cycle windows. The first stage of comparison is based on energy comparator responding to both magnitude and phase information in the signals. Stages 2 and 3 are of phase comparison type, responding mostly at the phase information and neglecting the magnitude information for better immunity to noise and signal distortions.