Self-testing power supply apparatus, methods and computer program products

Abstract

A power supply apparatus, such as an on-line UPS, includes an AC/DC converter circuit having an input configured to be coupled to an AC source, a DC/AC converter circuit having an input coupled to an output of the AC/DC converter circuit by a DC link, and a bypass circuit operative to couple and decouple the output of the DC/AC converter circuit to and from the input of the AC/DC converter circuit. Power is transferred from the output of DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus, such as a factory or field load test. For example, power may be circulated around a loop including the AC/DC converter circuit, the DC/AC converter circuit and the bypass circuit to conduct the test in order to test these components under load. A status of such components may be determined responsive to the test. In further embodiments, such components may be calibrated responsive to the test.

1 . A method of operating a power supply apparatus including an AC/DC converter circuit having an input configured to be coupled to an AC source, a DC/AC converter circuit having an input coupled to an output of the AC/DC converter circuit by a DC link, and a bypass circuit operative to couple and decouple the output of the DC/AC converter circuit to and from the input of the AC/DC converter circuit, the method comprising: 
 transferring power from the output of DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus.    
   
   
       2 . A method according to  claim 1 , further comprising circulating power around a loop including the AC/DC converter circuit, the DC/AC converter circuit and the bypass circuit to conduct the test.  
   
   
       3 . A method according to  claim 1 , wherein transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises: 
 controlling the DC/AC converter circuit and/or the AC/DC converter circuit responsive to a power command for the test.    
   
   
       4 . A method according to  claim 3 , wherein the power command represents a desired real power and/or reactive power transfer.  
   
   
       5 . A method according to  claim 3 , wherein the DC/AC converter circuit and/or the AC/DC converter circuit comprise a bridge circuit, and wherein controlling the DC/AC converter circuit and/or the AC/DC converter circuit responsive to a power command comprises varying a magnitude and/or phase of an AC voltage at a node of the bridge circuit responsive to the power command.  
   
   
       6 . A method according to  claim 3 , further comprising transferring power from the output of the DC/AC converter circuit to the input of the AC/DC converter circuit while concurrently operating the AC/DC converter circuit to regulate a DC voltage on the DC link for the test.  
   
   
       7 . A method according to  claim 1 , further comprising causing the DC/AC converter circuit and/or the AC/DC converter circuit to produce a predetermined current for the test.  
   
   
       8 . A method according to  claim 7 , wherein the predetermined current comprises a predetermined harmonic current.  
   
   
       9 . A method according to  claim 1 , wherein transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises transferring power from the output of the DC/AC converter circuit to the input of the AC/DC converter circuit via the bypass circuit while the input of the AC/DC converter circuit is coupled to the AC power source.  
   
   
       10 . A method according to  claim 1 , wherein transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises transferring power from the output of the DC/AC converter circuit to the input of the AC/DC converter circuit via the bypass circuit while the input of the AC/DC converter circuit is decoupled from the AC power source.  
   
   
       11 . A method according to  claim 1 , wherein transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises transferring power from the output of the DC/AC converter circuit via the bypass circuit while providing power to a load coupled to the output of the DC/AC converter circuit.  
   
   
       12 . A method according to  claim 1 , wherein transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises transferring power from the output of the DC/AC converter circuit via the bypass circuit to test the AC/DC converter circuit, the bypass circuit and/or the DC/AC converter circuit.  
   
   
       13 . A method according to  claim 1 , further comprising determining a status of a component of the apparatus responsive to the test.  
   
   
       14 . A method according to  claim 1 , further comprising calibrating a component of the apparatus responsive to the test.  
   
   
       15 . A method according to  claim 1 , wherein transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a factory test and/or a field test.  
   
   
       16 . A method according to  claim 1 , wherein the apparatus further comprises a DC power source coupled to the DC link, and wherein transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises transferring power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the DC power source.  
   
   
       17 . A method according to  claim 1 , wherein the power supply apparatus is an uninterruptible power supply (UPS).  
   
   
       18 . A power supply apparatus comprising: 
 an AC/DC converter circuit having an input configured to be coupled to an AC source;    a DC/AC converter circuit having an input coupled to an output of the AC/DC converter circuit by a DC link;    a bypass circuit operative to couple and decouple the output of the DC/AC converter circuit to and from the input of the AC/DC converter circuit; and    a test control circuit operatively associated with the bypass circuit and at least one of the AC/DC converter circuit and the DC/AC converter circuit and configured to cause power transfer from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus.    
   
   
       19 . A apparatus according to  claim 18 , wherein the test control circuit is operative to circulate power around a loop including the AC/DC converter circuit, the DC/AC converter circuit and the bypass circuit to conduct the test.  
   
   
       20 . An apparatus according to  claim 18 , wherein the test control circuit is operative to control the DC/AC converter circuit and/or the AC/DC converter circuit responsive to a power command for the test.  
   
   
       21 . An apparatus according to  claim 20 , wherein the power command represents a desired real power and/or reactive power transfer.  
   
   
       22 . An apparatus according to  claim 20 , wherein the DC/AC converter circuit and/or the AC/DC converter circuit comprises a bridge circuit, and wherein the test control circuit is operative to vary a magnitude and/or phase of an AC voltage at a node of the bridge circuit responsive to the power command.  
   
   
       23 . An apparatus according to  claim 20 , wherein the AC/DC converter circuit is operative to regulate a DC voltage on the DC link for the test.  
   
   
       24 . An apparatus according to  claim 18 , wherein the test control circuit is operative to cause the DC/AC converter circuit and/or the AC/DC converter circuit to produce a predetermined current for the test.  
   
   
       25 . An apparatus according to  claim 24 , wherein the predetermined current comprises a predetermined harmonic current.  
   
   
       26 . An apparatus according to  claim 18 , wherein the test control circuit is operative to cause power transfer from the output of the DC/AC converter circuit via the bypass circuit to test the AC/DC converter circuit, the bypass circuit and/or the DC/AC converter circuit.  
   
   
       27 . An apparatus according to  claim 18 , wherein the test control circuit is further operative to determine a status of a component of the apparatus responsive to the test.  
   
   
       28 . An apparatus according to  claim 18 , wherein the test control circuit is operative to cause power transfer from the output of the DC/AC converter circuit via the bypass circuit to conduct a factory test and/or a field test.  
   
   
       29 . An apparatus according to  claim 18 , further comprising a DC power source coupled to the DC link, and wherein the test control circuit is operative to transfer power from the output of the DC/AC converter circuit via the bypass circuit to conduct a test of the DC power source.  
   
   
       30 . An uninterruptible power supply (UPS) comprising: 
 an rectifier circuit having an input configured to be coupled to an AC source;    an inverter circuit having an output configured to be coupled to a load;    a DC link coupled between an output of the rectifier circuit and an input of the inverter circuit;    a DC power source coupled to the DC link;    a bypass circuit operative to couple and decouple the output of the inverter circuit to and from the input of the rectifier circuit; and    a test control circuit operatively associated with the bypass circuit and the rectifier circuit and/or the inverter circuit and configured to cause power transfer from the output of inverter circuit via the bypass circuit to conduct a test of the apparatus.    
   
   
       31 . A UPS according to  claim 30 , wherein the test control circuit is operative to circulate power around a loop including the rectifier circuit, the inverter circuit and the bypass circuit to conduct the test.  
   
   
       32 . A UPS according to  claim 30 , wherein the test control circuit is operative to control the inverter circuit and/or the rectifier circuit responsive to a power command for the test.  
   
   
       33 . A UPS according to  claim 32 , wherein the power command represents a desired real power and/or reactive power transfer.  
   
   
       34 . A UPS according to  claim 30 , wherein the test control circuit is operative to cause the inverter circuit and/or the rectifier circuit to produce a predetermined current for the test.  
   
   
       35 . A UPS according to  claim 34 , wherein the predetermined current comprises a predetermined harmonic current.  
   
   
       36 . A UPS according to  claim 30 , wherein the test control circuit is further operative to determine a status of a component of the UPS responsive to the test.  
   
   
       37 . A UPS according to  claim 30 , wherein the test control circuit is operative to cause power transfer from the output of the inverter circuit via the bypass circuit to conduct a factory test and/or a field test.  
   
   
       38 . A UPS according to  claim 30 , wherein the test control circuit is operative to transfer power from the output of the inverter circuit via the bypass circuit to conduct a test of the DC power source.  
   
   
       39 . A computer program product for controlling a power supply apparatus including an AC/DC converter circuit having an input configured to be coupled to an AC source, a DC/AC converter circuit having an input coupled to an output of the AC/DC converter circuit by a DC link, and a bypass circuit operative to couple and decouple the output of the DC/AC converter circuit to and from the input of the AC/DC converter circuit, the computer program product comprising a computer readable storage medium having computer readable program code embodied therein, the computer readable program code comprising: 
 program code configured to cause power transfer from the output of DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus.    
   
   
       40 . A computer program product according to  claim 39 , wherein the computer readable program code comprises program code configured to cause power to circulate around a loop including the AC/DC converter circuit, the DC/AC converter circuit and the bypass circuit to conduct the test.  
   
   
       41 . A computer program product according to  claim 39 , wherein the program code configured to cause power transfer from the output of DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises program code configured to control the DC/AC converter circuit and/or the AC/DC converter circuit responsive to a power command for the test.  
   
   
       42 . A computer program product according to  claim 39 , wherein the power command represents a desired real power and/or reactive power transfer.  
   
   
       43 . A computer program product according to  claim 39 , wherein the program code configured to cause power transfer from the output of DC/AC converter circuit via the bypass circuit to conduct a test of the apparatus comprises program code configured to cause the DC/AC converter circuit and/or the AC/DC converter circuit to produce a predetermined current for the test.  
   
   
       44 . A computer program product according to  claim 43 , wherein the predetermined current comprises a predetermined harmonic current.