Multimode power processor

An AC power processor, for use with a DC voltage source, for delivering power to a load, in parallel and in coordination with an AC voltage source, the processor comprising means for controlling the flow of electrical energy into and out of said DC voltage source, including:

• a plurality of switching elements connected to the DC voltage source, wherein the switching elements are capable of converting an AC current from the AC voltage source to DC current and directing the DC current to the DC voltage source, and wherein the switching elements are capable of converting a DC current from the DC voltage source into an AC current and directing the AC current to the load;
• at least one inductive element interposed between said switching elements and said AC voltage source;
• means for determining a plurality of switch configurations on a subcyclic basis with respect to the AC power source and based on a desired optimization strategy;
• and
• means for switching the switching elements;
• wherein the processor is capable of operating in at least three modes including:
• an inverter mode wherein AC current is supplied to the load only by said power processor;
• a charge-supply mode wherein the AC power source supplies current to the load and said power processor;
• and
• a parallel supply mode wherein both the AC power source and the power processor supply current to the load in parallel.

A multi-modal power supply system for delivering power to a load in coordination with an AC power source and a DC voltage source, the system comprising:

• at least one bridge including a plurality of switching elements capable of AC-DC and DC-AC conversions, wherein each switching element is capable of being positioned in an on state or an off state;
• at least one means for connecting said bridge to the DC voltage source;
• at least one means for interconnecting said bridge, the AC power source and the load, including:
• a bridge-AC connection means for connecting said bridge to the AC voltage source;
• a parallel connection means for connecting the load to said bridge-AC connection means at parallel points;
• and
• an inductive means disposed between said bridge and the parallel points;
• at least one means for sensing the voltage and current of the DC voltage source;
• at least one means for sensing the voltage and current of the AC power source;
• at least one means for sensing the voltage and current between said bridge and said inductive means;
• and
• at least one control means for changing the positions of said plurality of switching elements on a subcyclic basis based on the sensed voltages and currents;
• wherein said plurality of switching elements is capable of converting the AC current from the AC voltage source to DC current, and directing the DC current to the DC voltage source;
• wherein said plurality of switching elements is capable of converting the DC current from the DC voltage source into AC current and directing the AC current to the load;
• wherein said plurality of switching elements are capable of being positioned into at least four configurations for each phase, including:
• a first configuration wherein the DC voltage source supplies a positive polarity voltage to the load across said inductive means,
• a second configuration wherein the DC voltage source supplies a negative polarity voltage to the load across said inductive means,
• a third configuration wherein said inductive means supplies a positive polarity voltage to the load, and
• a fourth configuration wherein said inductive means supplies a negative polarity voltage to the load;
• and
• wherein said system is capable of operating in at least three modes including:
• an inverter mode wherein AC current is supplied to the load by either the DC voltage source or said inductive means, or both;
• a charge-supply mode wherein the AC power source supplies power to the load, said inductive means, or said DC voltage source, or a combination thereof;
• and
• a parallel supply mode wherein the AC power source and at least one of said inductive means or the DC voltage source, or both, supply power to the load in parallel.

An uninterruptible power supply system for delivering power to a load comprising:

• input lines for receiving an AC power input having a waveform with positive and negative half cycles;
• output lines for providing an AC power output to the load;
• a battery capable of providing a DC output voltage;
• a power transformer having a primary coupled to a secondary, the secondary being connected across the output lines;
• an inverter connected to the primary of the power transformer and to the battery, including switching devices connected in a bridge configuration which are controllable to convert DC voltage power from the battery to AC voltage power at the primary of the power transformer and to supply the battery with power from the primary, the switching devices being responsive to control signals to switch between on and off states;
• and
• control means, connected to the switching devices in the inverter, for controlling the power into and out of the inverter on a subcyclic basis relative to the AC power input, including:
• means for sensing the battery voltage;
• means for determining the polarity of the AC input;
• means for determining a desired AC power output current;
• means for generating a sinusoidal reference signal having an amplitude substantially equal to the desired output current;
• means for comparing the sinusoidal reference signal with the output current to yield a current error signal;
• and
• means for generating a pulse width proportional to the amplitude of the current error signal for modulating the inverter switching devices;
• wherein the switching devices are capable of assuming at least four pairs of configurations based upon the polarity of the error signal and the polarity of the AC input voltage, wherein the switches are pulsed on into a first configuration of each pair for the duration of each pulse width and pulsed off into a second configuration of each pair;
• wherein said system is capable of operating in one of a plurality of states, including:
• a first power supply state in which the battery is capable of supplying power to the load through the inverter, said state corresponding to the first configuration when the polarities of the error signal and the AC input voltage coincide;
• a second power supply state in which an effective inductance, which includes the effective leakage inductances of the primary and secondary of the transformer, is capable of supplying power to the load, said state corresponding to the second configuration when the polarities of the error signal and the AC input voltage coincide;
• a first power consumption state in which the AC power input is capable of charging the battery through the inverter, said state corresponding to the first configuration when the polarities of the error signal and the AC input voltage differ;
• and
• a second power consumption state in which the AC power input is capable of supplying power to the effective inductance, said state corresponding to the second configuration when the polarities of the error signal and the AC input voltage differ;
• wherein the system is capable of supplying power to the load from the battery and the AC power input simultaneously.

An uninterruptible power supply system for delivering power to a load comprising:

• input lines for receiving an AC power input having a waveform with positive and negative half cycles;
• output lines for providing an AC power output to the load;
• a battery capable of providing a DC output voltage;
• a power transformer having a primary coupled to a secondary, the secondary being connected across the output lines;
• an inverter connected to the primary of the power transformer and to the battery, including switching devices connected in a bridge configuration which are controllable to convert DC voltage power from the battery to AC voltage power at the primary of the power transformer and to supply the battery with power from the primary, the switching devices being responsive to control signals to switch between on and off states on a subcyclic basis;
• and
• control means, connected to the switching devices in the inverter, for controlling the power into and out of the inverter on a subcyclic basis relative to the AC power input, including:
• means for sensing the battery voltage;
• means for determining the polarity of the AC input;
• means for determining a desired AC power output current;
• means for generating a sinusoidal reference signal having an amplitude substantially equal to the desired output current;
• means for comparing the sinusoidal reference signal with the output current to yield a current error signal;
• and
• means for generating a pulse having a width proportional to the amplitude of the current error signal for modulating the inverter switching devices;
• wherein the switching devices are capable of assuming at least three configurations, including:
• a first battery-connect configuration which enables current to flow between the battery and the primary when the AC input voltage is positive;
• a second battery-connect configuration which enables current to flow between the battery and the primary when the AC input voltage is negative;
• and
• a battery-isolation configuration which enables current to flow between the switching devices and an effective inductance which includes the effective leakage inductance of the primary and the secondary of the transformer, while substantially preventing current flow between the battery and the switching devices;
• wherein said control means is capable of configuring said switching devices between said first battery-connect configuration, said second battery-connect configuration and said battery-isolation configuration based upon the polarity of the AC input voltage and the error signal;
• wherein said switches are modulated into one of said battery-connect configurations for a duration based on the pulse width, and otherwise configured into the battery-isolation configuration;
• wherein the battery is capable of supplying power to the load through said inverter when the polarities of the AC input voltage and the error signal coincide;
• wherein the effective inductance is capable of supplying power to the load through said inverter when the polarities of the AC input voltage and the error signal coincide;
• wherein the AC power input is capable of charging the battery through the inverter means when the polarities of the AC input voltage and the error signal differ;
• wherein the AC power input is capable of supplying power to the effective inductance by building up a current therein when the polarities of the AC input voltage and the error signal differ;
• wherein said system is capable of supplying power to the load from the battery and the AC power input simultaneously;
• and
• wherein said system is capable of supplying power to the load in the absence of AC input power;
• whereby the inverter is capable of operating in at least three modes, including:
• a battery charging mode in which the AC input power is rectified and supplied to the battery;
• an inverter mode in which the battery supplies AC power to the load;
• and
• a parallel mode in which the AC input power and the battery simultaneously supply AC power to the load.