Abstract: This invention relates to a hybrid passive agent system impedance monitoring station and method. The method of monitoring impedance of an electrical system includes the steps of providing an impedance monitoring station adapted to test and monitor system impedance, solving for system impedance in a time domain, solving for system impedance in a frequency domain, and determining a time domain driving point impedance and a frequency domain driving point impedance to identify the impedance of the system.

Abstract: A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.

Abstract: This invention relates to a hybrid passive agent system impedance monitoring station and method. The method of monitoring impedance of an electrical system includes the steps of providing an impedance monitoring station adapted to test and monitor system impedance, solving for system impedance in a time domain, solving for system impedance in a frequency domain, and determining a time domain driving point impedance and a frequency domain driving point impedance to identify the impedance of the system.

Abstract: A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.

Abstract: A method and apparatus for automatically monitoring and controlling various parameters of individual ultracapacitor cells in a series string of such cells. These parameters are monitored, and a replacement charge current is delivered to any cell which has lost charge due to discharge either external or internal to the cell. Also, the application of this method and apparatus to energy storage systems for an electrical power transmission grid.

Abstract: A method and apparatus for automatically monitoring and controlling various parameters of individual ultracapacitor cells in a series string of such cells. These parameters are monitored, and a replacement charge current is delivered to any cell which has lost charge due to discharge either external or internal to the cell. Also, the application of this method and apparatus to energy storage systems for an electrical power transmission grid.

Abstract: A multilevel converter-based, intelligent, universal transformer includes back-to-back, interconnected, multi-level converters coupled to a switched inverter circuit via a high-frequency transformer. The input of the universal transformer can be coupled to a high-voltage distribution system and the output of the universal transformer can be coupled to low-voltage applications. The universal transformer is smaller in size than conventional copper-and-iron based transformers, yet provides enhanced power quality performance and increased functionality.

Abstract: A multilevel converter-based, intelligent, universal transformer includes back-to-back, interconnected, multi-level converters coupled to a switched inverter circuit via a high-frequency transformer. The input of the universal transformer can be coupled to a high-voltage distribution system and the output of the universal transformer can be coupled to low-voltage applications. The universal transformer is smaller in size than conventional copper-and-iron based transformers, yet provides enhanced power quality performance and increased functionality.

Abstract: A multifunction hybrid intelligent universal transformer includes a conventional transformer coupled with power electronics on the secondary side to enhance the functionality of power conversion. The universal transformer includes features for overcoming the deficiencies associated with conventional transformers, including voltage sag compensation, instantaneous voltage regulation, outage compensation, capacitor switching protection, harmonic compensation, single-phasing protection, DC output, and variable frequency output.

Abstract: A multifunction hybrid intelligent universal transformer includes a conventional transformer coupled with power electronics on the secondary side to enhance the functionality of power conversion. The universal transformer includes features for overcoming the deficiencies associated with conventional transformers, including voltage sag compensation, instantaneous voltage regulation, outage compensation, capacitor switching protection, harmonic compensation, single-phasing protection, DC output, and variable frequency output.

Abstract: A multilevel converter-based, intelligent, universal transformer includes back-to-back, interconnected, multi-level converters coupled to a switched inverter circuit via a high-frequency transformer. The input of the universal transformer can be coupled to a high-voltage distribution system and the output of the universal transformer can be coupled to low-voltage applications. The universal transformer is smaller in size than conventional copper-and-iron based transformers, yet provides enhanced power quality performance and increased functionality.

Abstract: A multifunction hybrid intelligent universal transformer includes a conventional transformer coupled with power electronics on the secondary side to enhance the functionality of power conversion. The universal transformer includes features for overcoming the deficiencies associated with conventional transformers, including voltage sag compensation, instantaneous voltage regulation, outage compensation, capacitor switching protection, harmonic compensation, single-phasing protection, DC output, and variable frequency output.