Methods and apparatus of controllers for power converter with parallel power channels having independent DC buses

A computer readable media storing computer executable instructions wherein said instructions when executed are adapted to control operation of a parallel converter system including a plurality of parallel converters, each being coupleable to a corresponding controller, with a method comprising:

• generating, via each of the controllers, a channel reference signal, wherein the generated channel reference signal is responsive to a participation factor of the parallel converter, and a net converter output reference current;
• transmitting each of the generated channel reference signals to a corresponding one of the parallel converters;
• and
• adjusting an output current of each of the parallel converters responsive to the corresponding channel reference signals received, the adjusting controlling a combined output current of the parallel converter system;
• wherein the controller is a power sharing controller comprising:
• an average voltage waveform generator configured to generate an average voltage signal in response to the input voltages received from each of the individual controllers;
• a common mode waveform generator configured to generate a common mode waveform signal in responses to the average voltage signal generated;
• and
• a signal combiner configured to combine the input voltage from the individual controller and the common mode waveform signal to generate the channel reference signal;
• wherein each of the power sharing controller receives a channel participation factor PK of the channel K, where K=1, 2, . . . , and N, and a reference current Iref,dq, wherein the reference current Iref,dq represents the net converter output reference current along the d and q axis representing the reactive and active components of the output current, respectively, and the channel participation factor PK of the channel K represents the channel K's proportion of the overall power output of the parallel converter system;
• and
• wherein each of the plurality of parallel converters comprises:
• an active front end (AFE) converter power module configured to convert AC inputs to DC outputs;
• an inverter power module configured to convert the DC outputs from the AFE converter power module to AC outputs;
• a modulator configured to receive the channel reference signal and control the AFE converter power module and the inverter power module in response to the channel reference signal received;
• wherein the parallel converter system further comprises a plurality of individual controllers, each being coupleable to a corresponding power sharing controller to receive input voltages from each of the individual controllers.

A parallel converter system comprising:

• a plurality of parallel converters;
• and
• a plurality of controllers, each being coupleable to a corresponding parallel converter;
• wherein each of the controllers provides a channel reference signal to its corresponding parallel converter to adjust the output current independently such that a combined output current of the parallel converter system is controlled, wherein the channel reference signal is responsive to a participation factor of the parallel converter, and a net converter output reference current
• wherein the controller is a power sharing controller comprising:
• an average voltage waveform generator configured to generate an average voltage signal in response to the input voltages received from each of the individual controllers;
• a common mode waveform generator configured to generate a common mode waveform signal in responses to the average voltage signal generated;
• and
• a signal combiner configured to combine the input voltage from the individual controller and the common mode waveform signal to generate the channel reference signal;
• wherein each of the power sharing controller receives a channel participation factor PK of the channel K, where K=1, 2, . . . , and N, and a reference current Iref,dq, wherein the reference current Iref,dq represents the net converter output reference current along the d and q axis representing the reactive and active components of the output current, respectively, and the channel participation factor PK of the channel K represents the channel K's proportion of the overall power output of the parallel converter system;
• and
• wherein each of the plurality of parallel converters comprises:
• an active front end (AFE) converter power module configured to convert AC inputs to DC outputs;
• an inverter power module configured to convert the DC outputs from the AFE converter power module to AC outputs;
• a modulator configured to receive the channel reference signal and control the AFE converter power module and the inverter power module in response to the channel reference signal received;
• wherein the parallel converter system further comprises a plurality of individual controllers, each being coupleable to a corresponding power sharing controller to receive input voltages from each of the individual controllers.