Hybrid power flow controller and method

Claim 3

The method of claim 1 , wherein said diverting a current, comprises diverting a current through an adjustable susceptance.

Claim 4

The method of claim 2 , further comprising storing sets of operating points for controlling said first and second voltage sources, choosing one of said sets of operating points to provide said desired active power, and controlling said first and second control voltages to provide said desired amount of active power while maintaining said one of said sets of operating points.

Claim 5

The method of claim 3 , further comprising controlling a value of said adjustable susceptance.

Claim 6

The method of claim 2 , further comprising controlling a voltage at said susceptance, in order to control current diverted through said susceptance.

Claim 7

The method of claim 1 , wherein said first and second controlled voltage sources are coupled to each other by an energy storage device, and further comprising controlling an average energy in said energy storage device to remain constant.

Claim 8

The method of claim 6 , wherein said controlling an average energy comprises controlling current to said input to maintain said average energy stored in said energy storage device, thereby compensating for losses in said providing.

Claim 9

The method of claim 6 , wherein said energy storage device comprises a capacitor, and wherein said controlling average energy in said energy storage device to remain constant comprises controlling said first and second control voltages to maintain a DC voltage across said capacitor.

Claim 10

The method of claim 1 , further comprising controlling said first and second control voltages in magnitude and phase to provide a desired reactive power from an output of said second controlled voltage source.

Claim 11

The method of claim 1 , further comprising controlling said first and second control voltages in magnitude and phase to obtain a desired reactive power from an input of said first controlled voltage source.

Claim 14

The method of claim 11 , wherein said active power from said first power converter is provided to said output by a second power converter coupled to said first power converter.

Claim 15

The method of claim 12 , further comprising controlling said second power converter to couple substantially all of said active power from said first power converter to said output.

Claim 16

The method of claim 11 , further comprises controlling said first and second power converters to divert a first controlled amount of reactive power to said power flow controller.

Claim 17

The method of claim 14 , further comprising controlling said first and second power converter to provide a second controlled reactive power to said output.

Claim 18

An electrical power flow controller comprising: an input and an output; a first power converter and a second power converter connected in series to each other between said input and output; a susceptance connected in shunt to a node between said first power converter and said second power converter; a controller in communication with said first power converter and said second power converter, said controller operable to control said first power converter and said second power converter to provide a controlled quantity of active power to said output, and draw said controlled quantity of active power from said input.

Claim 19

An electrical power flow controller comprising: an input and an output; a first power converter and a second power converter connected in series to each other between said input and output; a susceptance connected in shunt to a node between said first power converter and said second power converter; a controller in communication with said first power converter and said second power converter, said controller operable to control said first power converter and said second power converter to provide a controlled quantity of active power to said output, and draw said controlled quantity of active power from said input.

Claim 20

The electrical power flow converter of claim 16 , wherein said first power converter comprises a transformer coupled voltage-sourced converter.

Claim 21

The electrical power flow converter of claim 17 , wherein said second power converter comprises a transformer coupled second voltage-sourced converter.

Claim 22

The electrical power flow converter of claim 16 , wherein said first power converter is a first electromechanical power converter and said second power converter is a second electromechanical power converter; said second electromechanical power converter coupled to said first electromechanical power converter to exchange active power.

Claim 23

The electrical power flow controller of claim 17 , wherein said controller is operable to control said first power converter and said second power converter to provide a first controlled amount of reactive power at said input terminals.

Claim 24

The electrical power flow controller of claim 17 , wherein said controller is operable to control said first and second power converters to provide a second controlled amount of reactive power at said output terminals.

Claim 25

An electrical power flow controller comprising: an input and output; a reactance connected in series between said input and said output; a first set of terminals connected in shunt with said input and coupling a first power converter; a second set of terminals connected in shunt with said output and coupling a second power converter; said first power converter coupled to provide active power to said second power converter; a controller in communication with said first and second power converters; said controller operable to control said first and second power converters to provide a controlled quantity of active power from said output, and draw said controlled quantity of active power from said input.

Claim 26

An electrical power flow controller comprising: an input and output; a reactance connected in series between said input and said output; a first set of terminals connected in shunt with said input and coupling a first power converter; a second set of terminals connected in shunt with said output and coupling a second power converter; said first power converter coupled to provide active power to said second power converter; a controller in communication with said first and second power converters; said controller operable to control said first and second power converters to provide a controlled quantity of active power from said output, and draw said controlled quantity of active power from said input.

Claim 27

The electric power flow controller of claim 22 , further comprising an energy storage device coupling said first power converter to said second power converter, and wherein said controller is further operable to control current from said input to maintain an energy stored in said energy storage device, thereby compensating for losses in said electrical power flow controller.

Claim 28

A power flow control circuit for diverting electrical power from a first region to provide a controlled amount of active power to a second region, said power flow control circuit comprising a first controllable voltage source providing a first controllable voltage between its input and its output, wherein its input is for interconnection to said first region; a second controllable voltage source providing a second controllable voltage between its input and its output, wherein its output is for connection to said second region; said output of said first controllable voltage source connected to said input of said second controllable voltage source; an impedance connected in shunt to a node between said output of said first power converting circuit; said second controllable voltage source coupled to said first controllable voltage source to obtain active power from said first controllable voltage source; a controller in communication with said first and second controllable voltage sources to control said first and second controllable voltages to provide said active power to said second region from power from said first region, and to couple substantially all active power provided to said first controlled voltage source to said second voltage source.

Claim 29

A power flow control circuit for diverting electrical power from a first region to provide a controlled amount of active power to a second region, said power flow control circuit comprising a first controllable voltage source providing a first controllable voltage between its input and its output, wherein its input is for interconnection to said first region; a second controllable voltage source providing a second controllable voltage between its input and its output, wherein its output is for connection to said second region; said output of said first controllable voltage source connected to said input of said second controllable voltage source; an impedance connected in shunt to a node between said output of said first power converting circuit; said second controllable voltage source coupled to said first controllable voltage source to obtain active power from said first controllable voltage source; a controller in communication with said first and second controllable voltage sources to control said first and second controllable voltages to provide said active power to said second region from power from said first region, and to couple substantially all active power provided to said first controlled voltage source to said second voltage source.