Interleaved parallel inverters with integrated filter inductor and interphase transformer

Abstract

A power electronics system, comprising a first inverter configured to receive DC power from a power source and a second inverter configured to receive DC power from the power source is provided. The system includes a first output inductor connected in series to an output of the first inverter, a second output inductor connected in series to an output of the second inverter, a coupling inductor configured to receive current from the first output inductor and the second output inductor, and an AC power output.

What is claimed is: 
     
         1 . A power electronics system, comprising:
 a first inverter configured to receive direct current (DC) power from a power source;   a second inverter configured to receive DC power from the power source;   a first output inductor connected in series to an alternating current (AC) output of the first inverter;   a second output inductor connected in series to an AC output of the second inverter;   a coupling inductor configured to receive current from the first output inductor and the second output inductor; and   an AC power output to provide current from the coupling inductor.   
     
     
         2 . The power electronics system of  claim 1  further comprising a control system configured to provide a control signal associated with a disturbance frequency, determine an amplitude of oscillation in an output power of the AC power output, wherein the oscillation is caused by the disturbance frequency, detect an islanding condition, if the amplitude of oscillation is below a threshold, and disconnect the grid from the AC power output if the islanding condition is detected. 
     
     
         3 . The power electronics system of  claim 1  wherein the coupling inductor includes a coil winding around a coupled core and a self-inductance core. 
     
     
         4 . The power electronic system of  claim 3  wherein the coil winding includes a series of elongated turns. 
     
     
         5 . A power electronics system, comprising:
 a first multi-phase inverter configured to receive direct current (DC) power from a power source;   a second multi-phase inverter configured to receive DC power from the power source;   a first plurality of output inductors, each of the first plurality of output inductors connected in series to an output phase of the first multi-phase inverter;   a second plurality of output inductors, each of the second plurality of output inductors connected in series to an output phase of the second multi-phase inverter;   a plurality of coupling inductors, each of the plurality of coupling inductors configured to receive current from a respective output inductor of the first plurality of output inductors and a respective output inductor of the second plurality of output inductors; and   a multi-phase alternating current (AC) power output to provide current from the plurality of coupling inductors.   
     
     
         6 . The power electronics system of  claim 5  further comprising a control system configured to provide a control signal associated with a disturbance frequency, determine an amplitude of oscillation in an output power of the AC power output, wherein the oscillation is caused by the disturbance frequency, detect an islanding condition, if the amplitude of oscillation is below a threshold, and disconnect the grid from the AC power output if the islanding condition is detected. 
     
     
         7 . The power electronics system of  claim 5  wherein each of the plurality of coupling inductors includes a coil winding around a coupled core and a self-inductance core. 
     
     
         8 . The power electronic system of  claim 7  wherein the coil winding includes a series of elongated turns. 
     
     
         9 . An inductor coil winding comprising:
 a first terminal;   a series of concentric turns in a first plane, the series of concentric turns leading in from the first terminal and having a diameter allowing for an opening within the series of concentric turns;   a series of elongated turns in a second plane, the series of elongated turns leading in from the series of concentric turns and having a length greater than the diameter of the series of concentric turns, and allowing for an opening within the series of elongated turns; and   a second terminal, the second terminal leading out form the series of elongated turns.   
     
     
         10 . The inductor coil winding of  claim 9  wherein the series of concentric turns provides main inductance. 
     
     
         11 . The inductor coil winding of  claim 10  wherein the series of elongated turns provides coupled inductance. 
     
     
         12 . The inductor coil winding of  claim 11  wherein the first terminal is an input terminal electrically connected to an output of an inverter to receive current from the inverter. 
     
     
         13 . The inductor coil winding of  claim 9  further comprising a self-inductance core in the opening within the series of concentric turns and a coupled core in the opening within the series of elongated turns, the coupled core configured to provide a magnetic coupling to another inductor coil winding. 
     
     
         14 . A filter assembly comprising:
 a first self-inductance core;   a second self-inductance core;   a coupler core;   a first plurality of inductor coil windings, each of the first plurality of inductor coil windings having a series of first turns around the first self-inductance core, and a series of second turns around the first self-inductance core and the coupler core; and   a second plurality of inductor coil windings, each of the second plurality of inductor coil windings having a series of first turns around the second self-inductance core, and a series of second turns around the second self-inductance core and the coupler core.   
     
     
         15 . The filter assembly of  claim 14  wherein the first self-inductance core, the second self-inductance core, and the coupler core each include three limbs, one limb for each of three phases. 
     
     
         16 . The filter assembly of  claim 14  wherein the first turns of each of the first plurality of inductor coil windings are concentric turns and the first turns of each of the second plurality of inductor coil windings are concentric turns. 
     
     
         17 . The filter assembly of  claim 16  wherein the second turns of each of the first plurality of inductor coil windings are elongated turns and the second turns of each of the second plurality of inductor coil windings are elongated turns. 
     
     
         18 . The filter assembly of  claim 14  wherein the first plurality of inductor coil windings is configured to electrically connect to a first inverter at a first terminal to receive an alternating current output from the first inverter and the second plurality of inductor coil windings is configured to electrically connect to a second inverter at a second terminal to receive an alternating current output from the second inverter. 
     
     
         19 . The filter assembly of  claim 18  wherein the first plurality of inductor coil windings is electrically connected to the second plurality of inductor coil windings at a third terminal configured to provide a combined alternating current from the first and second inverter. 
     
     
         20 . The filter assembly of  claim 14  further comprising a plurality of thermal plates interspersed among the first and second plurality of inductor coil windings and configured to remove thermal energy from the first and second plurality of inductor coil windings.