Abstract: A turbine generator system includes a doubly-fed alternating-current (AC) generator having a first poly-phase circuit (e.g., a stator circuit) and a second poly-phase circuit (e.g., a rotor circuit), a poly-phase AC-to-AC converter circuit coupled between the first and second poly-phase circuits, a poly-phase transformer having input windings coupled to the first poly-phase circuit and having output windings, and a uni-directional rectifier circuit coupled to the output windings of the poly-phase transformer and configured to convert poly-phase AC from the transformer output windings to direct current (DC).

Abstract: A hybrid distribution transformer is provided that includes an electromagnetic transformer and a voltage source converter that is operable to reduce fluctuation in the output voltage of the hybrid distribution transformer in the event of an increase or decrease in the input voltage.

Abstract: A power conversion system includes a unipolar bidirectional power converter with DC terminals and a first controller, and a bipolar bidirectional power converter with DC terminals connected in series with the DC terminals of the unipolar bidirectional power converter and a second controller. The first controller is operable to cause only a positive-valued DC voltage across the DC terminals. The second controller is operable to cause a positive-valued or negative-valued DC voltage across the DC terminals of the bipolar bidirectional power converter so that a total voltage of the power conversion system is the sum of the positive-valued or negative-valued DC voltage across the DC terminals of the bipolar bidirectional power converter and the positive-valued DC voltage across the DC terminals of the unipolar bidirectional power converter.

Abstract: A turbine-based energy generation system includes an electric generator and auxiliary load. A power system for the turbine-based energy generation system includes a main converter and an auxiliary converter. The main converter is operable to deliver power generated by the electric generator to a power collection system external to the turbine-based energy generation system when the main converter is coupled to the generator. The main converter is also operable to deliver power provided from the power collection system to the auxiliary converter when the main converter is decoupled from the generator. The auxiliary converter is operable to deliver power generated by the electric generator to the auxiliary load when the auxiliary converter is coupled to the generator. The auxiliary converter is also operable to deliver the power provided by the main converter from the power collection system to the auxiliary load when the auxiliary converter is decoupled from the generator.

Abstract: A DC connection system for renewable power generators includes a first monopole DC collection network, a second monopole DC collection network and a first bipole transmission system. The first monopole DC collection network aggregates positive-valued DC voltage outputs of a first cluster of renewable power generators onto a positive terminal of the first monopole DC collection network. The second monopole DC collection network aggregates negative-valued DC voltage outputs of a second cluster of renewable power generators onto a negative terminal of the second monopole DC collection network. The first bipole transmission system is coupled to the positive and negative terminals of the monopole DC collection networks, for transferring the aggregated power to a power grid substation.

Abstract: Among other things, a distribution transformer and a technique for regulating voltage are provided for herein. The distribution transformer comprises at least three windings and at least two ferromagnetic cores. The distribution transformer may also comprise a power electronic AC-AC converter operable to maintain the input voltage and current of the distribution transformer substantially in phase and/or to reduce fluctuation in the output voltage of the distribution transformer in the event of an increase or decrease in the input voltage, for example.

Abstract: A converter system for coupling to an ac power source includes a rectifier and a bi-directional converter. The rectifier has a first set of terminals inductively coupled to an ac power source and a second set of terminals coupled in series with a series dc bus, and is operable to convert ac power at the first set of terminals to dc power at the second set of terminals. The bi-directional converter has a first set of terminals coupled to the ac power source and a second set of terminals coupled to a parallel bus, and is operable to transfer power from the ac source to the parallel bus in a first operating mode and transfer power from the parallel bus to the series dc bus via the rectifier in a second operating mode. A corresponding power generation network and power transmission method are also provided.

Abstract: A turbine generator system includes a doubly-fed alternating-current (AC) generator having a first poly-phase circuit (e.g., a stator circuit) and a second poly-phase circuit (e.g., a rotor circuit), a poly-phase AC-to-AC converter circuit coupled between the first and second poly-phase circuits, a poly-phase transformer having input windings coupled to the first poly-phase circuit and having output windings, and a uni-directional rectifier circuit coupled to the output windings of the poly-phase transformer and configured to convert poly-phase AC from the transformer output windings to direct current (DC).

Abstract: A turbine-based energy generation system includes an electric generator and auxiliary load. A power system for the turbine-based energy generation system includes a main converter and an auxiliary converter. The main converter is operable to deliver power generated by the electric generator to a power collection system external to the turbine-based energy generation system when the main converter is coupled to the generator. The main converter is also operable to deliver power provided from the power collection system to the auxiliary converter when the main converter is decoupled from the generator. The auxiliary converter is operable to deliver power generated by the electric generator to the auxiliary load when the auxiliary converter is coupled to the generator. The auxiliary converter is also operable to deliver the power provided by the main converter from the power collection system to the auxiliary load when the auxiliary converter is decoupled from the generator.

Abstract: An energy generation system includes a turbine, an electric generator, a step-up transformer, and a converter. The turbine is operable to extract energy from a fluid flow and convert the extracted energy into mechanical energy. The electric generator is operable to convert the mechanical energy from the turbine into AC electrical energy. The step-up transformer is operable to transfer the AC electrical energy at a lower voltage from the electric generator to a higher voltage. The converter is operable to convert the AC electrical energy at the higher voltage to DC electrical energy. The converter includes a converter leg for a phase of the AC electrical energy. The converter leg has an upper arm with a first plurality of sub-modules and a lower arm with a second plurality of sub-modules. Each sub-module is operable to function as a controlled voltage source.

Abstract: A power conversion system includes a unipolar bidirectional power converter with DC terminals and a first controller, and a bipolar bidirectional power converter with DC terminals connected in series with the DC terminals of the unipolar bidirectional power converter and a second controller. The first controller is operable to cause only a positive-valued DC voltage across the DC terminals. The second controller is operable to cause a positive-valued or negative-valued DC voltage across the DC terminals of the bipolar bidirectional power converter so that a total voltage of the power conversion system is the sum of the positive-valued or negative-valued DC voltage across the DC terminals of the bipolar bidirectional power converter and the positive-valued DC voltage across the DC terminals of the unipolar bidirectional power converter.

Abstract: An energy generation system includes a turbine, an electric generator, a step-up transformer, and a converter. The turbine is operable to extract energy from a fluid flow and convert the extracted energy into mechanical energy. The electric generator is operable to convert the mechanical energy from the turbine into AC electrical energy. The step-up transformer is operable to transfer the AC electrical energy at a lower voltage from the electric generator to a higher voltage. The converter is operable to convert the AC electrical energy at the higher voltage to DC electrical energy. The converter includes a converter leg for a phase of the AC electrical energy. The converter leg has an upper arm with a first plurality of sub-modules and a lower arm with a second plurality of sub-modules. Each sub-module is operable to function as a controlled voltage source.

Abstract: A hybrid distribution transformer is provided that includes an electromagnetic transformer and a voltage source converter that is operable to reduce fluctuation in the output voltage of the hybrid distribution transformer in the event of an increase or decrease in the input voltage.

Abstract: A hybrid transformer is provided that includes an electromagnetic transformer and an AC-AC converter with a DC bridge. The AC-AC converter is operable to keep the input voltage and current of the hybrid transformer substantially in phase and to reduce fluctuation in the output voltage of the hybrid transformer in the event of an increase or decrease in the input voltage.