Uninterruptible power source improvements for protection from common grid problems combined with ultra fast switching

Abstract

Improvements are disclosed to a basic offline/standby UPS that keep its high standby efficiency while improving it electrical performance to match a online/double conversion UPS. One such improvement comprises a method for modifying a basic standby power system (SPS) to correct a common grid problem, the method comprising: providing an offline/standby uninterruptible power source (UPS) with a line conditioning inverter which contains a high speed voltage controlled pulse-width modulation (PWM) inverter; detecting and measuring a line voltage using a phase and filter controller having a high speed analog-to-digital converter (ADC); comparing the measured line voltage to an expected line voltage; and detecting any voltage spike or sustained overvoltage deviation from a sinusoidal waveform and sending it to the line conditioning inverter for reducing the load voltage back to nominal.

What is claimed is: 
     
         1 . A method for modifying a basic standby power system (SPS) to correct a common grid problem, the method comprising:
 providing an offline/standby uninterruptible power source (UPS) with a line conditioning inverter which contains a high speed voltage controlled pulse-width modulation (PWM) inverter;   detecting and measuring a line voltage using a phase and filter controller having a high speed analog-to-digital converter (ADC);   comparing the measured line voltage to an expected line voltage; and   detecting any voltage spike or sustained overvoltage deviation from a sinusoidal waveform and sending it to the line conditioning inverter for reducing the load voltage back to nominal.   
     
     
         2 . The method of  claim 1 , wherein reducing the load voltage back to nominal comprises sending a voltage in the opposite direction of the voltage spike or sustained overvoltage. 
     
     
         3 . The method of  claim 2 , wherein the line conditioning inverter functions as a rectifier by charging a battery of the SPS while reducing the load voltage back to nominal. 
     
     
         4 . The method of  claim 1 , wherein reducing the load voltage back to nominal comprises the phase and filter controller and line conditioning inverter acting as a noise filter. 
     
     
         5 . The method of  claim 1 , wherein reducing the load voltage back to nominal comprises removing instability of a mains frequency. 
     
     
         6 . The method of  claim 1 , wherein reducing the load voltage back to nominal comprises correcting voltage deviation from harmonic distortion. 
     
     
         7 . The method of  claim 1 , wherein the line conditioning inverter is at least 5 times smaller in power output than a main inverter of the SPS at the same efficiency. 
     
     
         8 . The method of  claim 1 , wherein the line conditioning inverter operates at only 20% of the power of a main inverter of the SPS at the same efficiency. 
     
     
         9 . A method for modifying a basic standby power system (SPS) to correct a common grid problem, the method comprising:
 providing an offline/standby uninterruptible power source (UPS) with a line conditioning inverter which contains a high speed voltage controlled pulse-width modulation (PWM) inverter;   detecting and measuring a line voltage using a phase and filter controller having a high speed analog-to-digital converter (ADC);   comparing the measured line voltage to an expected line voltage; and   detecting any momentary or sustained undervoltage deviation from a sinusoidal waveform and sending it to the line conditioning inverter for increasing the load voltage back to nominal.   
     
     
         10 . The method of  claim 9 , wherein increasing the load voltage back to nominal comprises sending a voltage in the same direction of the momentary or sustained undervoltage. 
     
     
         11 . The method of  claim 9 , wherein increasing the load voltage back to nominal comprises the phase and filter controller and line conditioning inverter acting as a noise filter. 
     
     
         12 . The method of  claim 9 , wherein increasing the load voltage back to nominal comprises removing instability of a mains frequency. 
     
     
         13 . The method of  claim 9 , wherein reducing the load voltage back to nominal comprises correcting voltage deviation from harmonic distortion. 
     
     
         14 . The method of  claim 9 , wherein the line conditioning inverter is at least 5 times smaller in power output than a main inverter of the SPS at the same efficiency. 
     
     
         15 . The method of  claim 9 , wherein the line conditioning inverter operates at only 20% of the power of a main inverter of the SPS at the same efficiency.