Auto-synchronous isolated inlet power converter

Abstract

An auto-synchronous isolated inlet power converter is disclosed that can be daisy-chained with other power converters and/or an alternating current (AC) power source. The power converter automatically generates output AC power that is in parallel with external input AC power coming into the power converter when the power converter senses the external input AC power so that the power converter operates as a slave in this state. The power converter automatically generates output AC power when the power converter fails to detect the external input AC power coming into the power converter where the power converter operates as a master in this state. The power converter generates the output AC power without any reliance on the external input AC power generated by a utility grid and/or other AC power sources external to the power converter.

What is claimed is: 
     
         1 . An auto-synchronous isolated inlet power converter, comprising:
 a controller configured to automatically generate paralleled output alternating current (AC) power for the auto-synchronous isolated inlet power converter when external input AC power is coupled to the auto-synchronous isolated inlet power converter via an AC inlet receptacle, wherein the paralleled output AC power is a combination of the external input AC power and direct current (DC) power supplied by a DC source that is converted to additional AC power so that the additional AC power is synchronized and combined in parallel to the external input AC power; and   an AC outlet receptacle configured to provide the paralleled output AC power to systems external to the auto-synchronous isolated inlet power converter.   
     
     
         2 . The auto-synchronous isolated inlet power converter of  claim 1 , wherein the controller is further configured to automatically transition the paralleled output AC power generated by the auto-synchronous isolated inlet power converter to output AC power when the external input AC power is no longer coupled to the auto-synchronous isolated inlet power converter, wherein the output AC power is converted from the DC power supplied by the DC source of the auto-synchronous isolated inlet power converter and is not in parallel with the external input AC power. 
     
     
         3 . The auto-synchronous isolated inlet power converter of  claim 2 , wherein the AC outlet receptacle is further configured to provide the output AC power to the systems external to the auto-synchronous isolated inlet power converter when the external input AC power is no longer coupled to the auto-synchronous isolated inlet power converter. 
     
     
         4 . The auto-synchronous isolated inlet power converter of  claim 3 , further comprising:
 a DC to AC converter configuration configured to generate paralleled output AC power to the AC outlet receptacle when the auto-synchronous isolated inlet power converter is operating in a slave mode, wherein the paralleled output AC power is the output AC power generated from the external input AC power and the DC power supplied by the DC source that is converted to additional AC power that is synchronized and in parallel with the external input AC power.   
     
     
         5 . The auto-synchronous isolated inlet power converter of  claim 4 , wherein the DC to AC converter is further configured to generate the output AC power to the AC outlet receptacle when the auto-synchronous isolated inlet power converter is operating in a master mode, wherein the output AC power is generated from the additional AC power from the DC power supplied by the DC source and is not in parallel with the external input AC power. 
     
     
         6 . The auto-synchronous isolated inlet power converter of  claim 5 , further comprising:
 a controller configured to synchronize the additional AC power generated by the DC to AC converter with the external input AC power coupled to an AC inlet receptacle before the additional AC power generated by the DC to AC converter passes through to an AC outlet receptacle during the transition from the master mode to the slave mode.   
     
     
         7 . The auto-synchronous isolated inlet power converter of  claim 6 , further comprising:
 a first relay coupled to the AC inlet receptacle and the AC outlet receptacle and configured to transition to the closed state when the auto-synchronous isolated inlet power converter is transitioning from the master mode to the slave mode so that the external input AC power passes through the first relay to the AC output receptacle; and   a second relay coupled to the DC to AC converter and the AC outlet receptacle and configured to transition to the closed state after the controller has synchronized the additional AC power to the external input AC power to allow AC power generated by the DC to AC converter to pass through to the AC outlet receptacle and generate paralleled output AC power to the AC outlet receptacle so that the auto-synchronous isolated inlet power converter is operating in the slave mode.   
     
     
         8 . A method for generating paralleled output alternating current (AC) power from an auto-synchronous isolated inlet power converter, comprising:
 automatically generating paralleled output AC power, wherein the paralleled output AC power is a combination of the external input AC power and DC power supplied by a DC source that is converted to additional AC power so that the additional AC power is synchronized and combined in parallel to the external input AC power; and   providing the paralleled output AC power to systems external to the auto-synchronous isolated inlet power converter.   
     
     
         9 . The method of  claim 8 , further comprising:
 automatically transitioning the paralleled output AC power to output AC power when the external input AC power is no longer coupled to the auto-synchronous isolated inlet power converter, wherein the output AC power is converted from the DC power supplied by the DC source of the auto-synchronous isolated inlet power converter and is not in parallel with the external input AC power.   
     
     
         10 . The method of  claim 9 , further comprising:
 providing the output AC power to the systems external to the auto-synchronous isolated inlet power converter when the input AC power is no longer coupled to the auto-synchronous isolated inlet power converter.   
     
     
         11 . The method of  claim 10 , further comprising:
 generating paralleled output AC power when the auto-synchronous isolated inlet power converter is operating in a slave mode, wherein the paralleled output AC power is the output AC power generated from the external input AC power and the DC power supplied by the DC source that is converted to additional AC power that is synchronized and in parallel with the external input AC power.   
     
     
         12 . The method of  claim 11 , further comprising:
 generating the output AC power when the auto-synchronous isolated inlet power converter is operating in a master mode, wherein the output AC power is generated from the additional AC power from the DC power supplied by the DC source and is not in parallel with the external input AC power.   
     
     
         13 . The method of  claim 12 , further comprising:
 synchronizing the additional AC power generated by the DC to AC converter with the external input AC power coupled to an AC inlet receptacle before the additional AC power generated by the DC to AC converter passes through to an AC outlet receptacle during transition from the master mode to the slave mode.   
     
     
         14 . The method of  claim 13 , further comprising:
 transitioning a first relay coupled to the AC inlet receptacle and the AC outlet receptacle to the closed state when the auto-synchronous isolated inlet power converter is transitioning from the master mode to the slave mode so that the external input AC power passes through the first relay to the AC output receptacle; and   transitioning a second relay coupled to the DC to AC converter and the AC outlet receptacle to the closed state after the additional AC power is synchronized to the external input AC power to allow AC power generated by the DC to AC converter to pass through to the AC outlet receptacle and generate paralleled output AC power to the AC outlet receptacle so that the auto-synchronous isolated inlet power converter is operating in the slave mode.   
     
     
         15 . An auto-synchronous isolated inlet power converter configuration, comprising:
 a first auto-synchronous isolated inlet power converter included in a plurality of auto-synchronous isolated inlet power converters configured to:
 act as a master auto-synchronous isolated inlet power converter when the first auto-synchronous isolated inlet power converter fails to detect first external input alternating current (AC) power coupled to the first auto-synchronous isolated inlet power converter, wherein the master auto-synchronous isolated inlet power converter automatically provides first output AC power to a slave auto-synchronous isolated inlet power converter included in the plurality of auto-synchronous isolated inlet power converters; and 
   a second auto-synchronous isolated inlet power converter included in the plurality of auto-synchronous isolated inlet power converters configured to:
 automatically transition into generating the paralleled output AC power, wherein the paralleled output AC power is output AC power generated by the second auto-synchronous isolated inlet power converter that is in parallel with the output AC power generated by the first auto-synchronous isolated inlet power converter, and 
 act as a slave auto-synchronous isolated inlet power converter when the second auto-synchronous isolated inlet power converter detects the first output AC power provided by the first auto-synchronous isolated inlet power converter. 
   
     
     
         16 . The auto-synchronous isolated inlet power converter configuration of  claim 15 , wherein the master auto-synchronous isolated inlet power converter is further configured to apply a constant voltage to an AC bus that couples each of the plurality of auto-synchronous isolated power converters to maintain the paralleled output AC power that is generated by the auto-synchronous isolated inlet power configuration at a level. 
     
     
         17 . The auto-synchronous isolated inlet power converter configuration of  claim 16 , wherein the slave auto-synchronous isolated inlet power converter is further configured to monitor a voltage level associated with the AC bus to determine whether the voltage level decreases below a threshold, wherein the threshold of the voltage level is a minimum voltage level that is required to maintain the paralleled output AC power at a level sufficient to satisfy a power requirement of the auto-synchronous isolated inlet power converter configuration. 
     
     
         18 . The auto-synchronous isolated inlet power converter configuration of  claim 17 , wherein the slave auto-synchronous isolated inlet power converter is further configured to generate an increase in current applied to the AC bus to increase the voltage level associated with the AC bus so the voltage level is within the threshold when the voltage level associated with the AC bus decreases below the threshold to maintain the paralleled output AC power at the level sufficient to satisfy the power requirement of the auto-synchronous isolated inlet power configuration. 
     
     
         19 . The auto-synchronous isolated inlet power converter configuration of  claim 18 , wherein the slave auto-synchronous isolated inlet power converter is further configured to generate a decrease in current applied to the AC bus when the voltage level associated with the AC bus is maintained within the threshold by the constant voltage applied to the AC bus by the master auto-synchronous isolated inlet power converter. 
     
     
         20 . The auto-synchronous isolated inlet power converter configuration of  claim 19 , wherein the master auto-synchronous isolated inlet power converter is further configured to:
 monitor the voltage level associated with the AC bus to determine whether the voltage level decreases below the threshold for a period of time, wherein the period of time is indicative that the slave auto-synchronous isolated inlet power converter is not providing sufficient current to the AC bus to maintain the voltage level associated with the AC bus within the threshold; and   generate an increase in current applied to the AC bus to increase the voltage level associated with the AC bus so the voltage level to within the threshold when the voltage level associated with the AC bus decreases below the threshold for the period of time to maintain the paralleled output AC power at the level sufficient to satisfy the power requirement of the auto-synchronous isolated inlet power configuration.