Dual stage AC to AC electrical power converters

A dual-stage electrical power converter comprising:

• a first filter comprising:
• N input ports configured to:
• interface with an N-port AC power source, each of the N input ports being associated with a phase of a voltage generated by the AC power source, the first filter configured to:
• filter the inputted voltage phases of the AC power source to reduce distortions within the inputted voltages;
• and
• output the filtered voltages to a corresponding first filter output port,
• a first-stage converter configured to:
• receive, on a first-stage converter input port, corresponding ones of the filtered voltages, wherein each of the first-stage input ports is connected to one of a plurality (N) of bridge legs, each bridge leg comprising:
• at least one switchable active power device, wherein the first-stage converter is configured to:
• convert the inputted filtered voltages into a corresponding intermediate voltage, the intermediate voltage comprising a piecewise representations of the filtered voltages, and
• output the intermediate voltages to a corresponding one of a plurality (N) of output ports,
• a middle filter network configured to:
• receive, on a middle filter input port, a corresponding one of the intermediate voltages,
• filter the inputted intermediate voltage to absorb high-frequency harmonics;
• and
• output the filtered intermediate voltage to corresponding one of a plurality of middle filter output ports,
• a second-stage converter, the second-stage converter configured to:
• receive the output filtered intermediate voltages on corresponding ones of a plurality of second stage input ports, wherein the received intermediate voltages are provided to a second plurality (M) of bridge legs associated with each of the second-stage converter output ports, each of the second plurality of bridge legs comprising:
• at least one switchable active power device, each of the second plurality of bridge legs configured to:
• convert the received intermediate voltages into a pulse width modulated (PWM) voltage;
• and
• output the PWM voltage of each of the second plurality of bridge legs onto a corresponding one of a plurality of second-stage output ports;
• an output filter network configured to:
• receive, on a corresponding one of a plurality of output filter input ports, the PWM voltages;
• filter the received PWM voltages;
• and
• output the filtered PWM voltages onto a corresponding one of a second plurality of output ports;
• and
• a controller configured to:
• sample the voltages and currents of the first-stage converter and the second-stage converter;
• and
• produce one or more gate signals for switching the switchable active power devices in the first-stage converter and the second-stage converter.

A dual-stage electrical power converter comprising:

• a first plurality of first filter input ports configured to:
• interface with an AC power source generating a first plurality of voltages of different phases, wherein the first plurality of voltages are arranged in descending order,
• filter the first plurality of voltages;
• and
• output the filtered a first plurality of voltages on a corresponding output port;
• a first-stage converter configured to:
• interface with the first filter output ports to receive the filtered a first plurality of voltages on a corresponding first-stage converter input port, wherein each of the first-stage converter input ports is associated with a corresponding one of a first plurality of bidirectional bridge legs, each of the first plurality of bridge legs comprising a first plurality of first-stage converter outputs;
• a middle filter network comprising:
• a same number of input ports as the first-stage converter output ports, and
• a same number of output ports as middle filter network input ports,
• a second-stage converter comprising:
• a same number input ports as the middle filter output ports, the second-stage converter having therein bridge legs, each having switchable active power devices;
• and
• an output port associated with the bridge leg outputs;
• an output filter network connected to a corresponding one of the second-stage output ports;
• and
• connecting to an AC load of multiple phases (M), and
• a controller for sampling the voltages and currents of the first-stage converter and the second-stage converter to produce one or more gate signals for switching the bridge legs in the first-stage converter and the second-stage converter, wherein the first-stage converter is operated in a fundamental frequency mode to produce piece-wise signals and the second-stage converter is operated under a high frequency switching mode to chop the piece-wise signals to produce high frequency pulse width modulated (PWM) output voltage and input current waveforms.

A dual-stage electrical power converter comprising:

• an N-port first-stage converter configured to:
• receive a voltage, each first-stage input port connected to a plurality (N) of bridge legs, each bridge leg comprising:
• at least one switchable active power device, wherein the first-stage converter is configured to:
• convert the voltages into an intermediate voltage comprising piecewise representations of the input voltages, and
• output the intermediate voltage to corresponding one of a plurality (N) of output ports;
• a middle filter network configured to:
• receive the intermediate voltage on a corresponding one of a plurality (N) of middle filter input ports;
• filter the inputted intermediate voltage to absorb high-frequency harmonics;
• and
• output the filtered intermediate voltage to a corresponding one of a plurality of middle filter output ports;
• an N-input port second-stage converter, the second-stage converter comprising:
• a second plurality (M) of bridge legs associated with each of the second-stage converter output ports, each of the second plurality of bridge legs comprising:
• at least one switchable active power device, wherein the second-stage converter is configured to:
• convert the inputted voltages from the middle filter network into a desired voltage comprising PWM chopped pieces of the middle filter network voltages;
• and
• output the desired voltages of each of the second plurality of bridge legs onto a corresponding second plurality of outputs, and
• a controller configured to:
• sample the voltages and currents of the first-stage converter and the second-stage converter;
• and
• produce one or more gate signals for switching the switchable active power devices in the first-stage converter and the second-stage converter.