Dynamic Means for Correcting for Load Imbalance and Harmonic Distortion

Abstract

A method and apparatus are directed to a dynamic means for correcting imbalance and harmonic distortion in an electrical system. In one embodiment, the device includes an imbalance and harmonics measurement module configured to measure power parameters for determining imbalance and harmonics within the electrical three-phase system. Within this system a series of capacitors are configured to respond to measured demands reported and designated to correct for imbalance and harmonics distortion. The device is networked among various source load controllers are responsible for designating master and slave relationships within the closed system.

1 . An apparatus comprising: a switching power means that delivers a rectified alternating current (AC) input voltage to a switching means during operation of the switching power means, the switching power means comprising: an voltage/current sensing means; a switch, coupled to the voltage/current sensing means, to control current to an output means (capacitor) of the switching power means; a processor to analyze and calculate and controller to receive and respond to a control signal to provide load imbalance correction so that an input, inductor current of the switching power means tracks the AC input voltage; wherein during operation of the switching power means current flows through the only when the switch is nonconductive. 
     
     
         2 . The apparatus of  claim 1  wherein during operation of the switching power means (1) the switching power means is coupled to a voltage source that provides an input voltage and (2) a point along the waveform of the current in the current sensing means is linearly related to a point along the waveform of the voltage. 
     
     
         3 . The apparatus of  claim 1  wherein during operation of the switching power converter (1) the switching power means is coupled to a voltage source that provides an input voltage and (2) for a output power of the switching power means current in the current sensing resistor is between 90 degrees and 180 degrees of the waveform. 
     
     
         4 . The apparatus of  claim 1  further comprising a controller to operate the switching power means in continuous conduction mode. 
     
     
         5 . The apparatus of  claim 1  further comprising: an inductor coupled to an input node of the switching power means and coupled to a the switch; and a diode coupled between the switch and the switching power means wherein the current sensing means is coupled between the switch and the switching power means. 
     
     
         6 . The apparatus of  claim 1  further comprising a load coupled to the switching power means. 
     
     
         7 . The apparatus of  claim 8  wherein the load comprises one or more light emitting diodes. 
     
     
         8 . An apparatus comprising: means to provide a rectified, alternating current (AC) input voltage to a switching power means to a higher output voltage of the switching power means to operate a switch to control current to an a switching power converter and to provide load imbalance correction so that a processor can track an input current from an inductive load, the processor can analyze the inductor current of the AC input voltage; and the controller response to signal a response to the output means during operation of the switching power converter current flows through the current sensing means only when the switch is nonconductive. 
     
     
         9 . An integrated circuit to control a switching power means, the integrated circuit comprising: a load imbalance correction controller having at least one input to receive a sense signal representative of a current of the switching power means, wherein the switching power means includes a switch and: (i) the sense signal represents current in the switching power means only when the switch is nonconductive; and (ii) the load imbalance correction controller (processor) is configured to generate a control signal to control conductivity of the switch and control conductivity of the switch controls load imbalance correction of the switching power means so that an input, inductor current of the switching power means tracks the AC input voltage. 
     
     
         10 . The integrated circuit of  claim 9  wherein during operation of the switching power means (1) the switching power means is coupled to a voltage source that provides an input voltage and (2) a point along the AC waveform between 90 degrees and 180 degrees is determined of the current in the current sensing means is linearly related to the AC waveform of the input voltage. 
     
     
         11 . The integrated circuit of  claim 9  wherein during operation of the switching power means (1) the switching power means is coupled to a voltage source that provides an input voltage and (2) for a constant output power of the switching power means current in the current sensing means is approximately constant. 
     
     
         12 . The integrated circuit of  claim 9  wherein the load imbalance correction controller is configured to operate the switching power means in continuous conduction mode. 
     
     
         13 . The integrated circuit of  claim 10  wherein the load imbalance correction controller is further configured to: generating a value of the received control signal, wherein the switch conducts during operation of the switching power means; and determining an amount of current for a control signal, wherein the switch is nonconductive during a value of the control signal, wherein determining the amount of current is determined from measuring and comparing load inputs from inductive loads, wherein each inductive load generates a voltage waveform and a current waveform. 
     
     
         14 . A method of controlling a switching power means, the integrated circuit comprising: receiving a sense signal representative of a current of the switching power means, wherein the switching power means includes a switch and the sensing means that emits a signal represents current in the switching power means only when the switch is nonconductive; and generating a signal to the controller to address and control conductivity of the switch, wherein controlling conductivity of the switch controls load imbalance correction of the switching power means so that an input, inductor current of the switching power means tracks a rectified, alternating current (AC) input voltage to the switching power means. 
     
     
         15 . The method of  claim 14  wherein during operation of the switching power means (1) the switching power means is coupled to a voltage source that provides an input voltage and (2) a point along the waveform of the current in the current sensing means is linearly related to a point along the waveform of the voltage. 
     
     
         16 . The method of  claim 14  wherein during operation of the switching power means (1) the switching power means is coupled to a voltage source that provides an input voltage and (2) for a output power of the switching power means current in the current sensing means is between 90 degrees and 180 degrees of the waveform. 
     
     
         17 . The method of  claim 14  further comprising a controller to operate the switching power means in continuous conduction mode. 
     
     
         18 . The method of  claim 14  further comprising: a controller generating a value of the received control signal, wherein the switch conducts during operation of the switching power means; and determining an amount of current for a control signal, wherein the switch is nonconductive during a value of the control signal, wherein determining the amount of current is determined from measuring and comparing load inputs from inductive loads, wherein each inductive load generates a voltage waveform and a current waveform. 
     
     
         19 . The method of  claim 1  wherein the switching power means further comprises: a diode; and a capacitor coupled to the diode and the switch; wherein the current sensing means is coupled to the switch and the capacitor. 
     
     
         20 . The method of  claim 1  wherein during operation the switching power means current flowing through the current sensing means represents the input of inductor current. 
     
     
         21 . The apparatus of  claim 8  wherein during operation of the switching power means current flows through the current sensing means only when the switch is nonconductive. 
     
     
         22 . The method of  claim 13  wherein the rectified, alternating current (AC) input voltage to the switching power means further comprises: providing current from an inductor to the switching power means through a diode to a capacitor at an output of the switching power means when the switch is nonconductive, wherein the current sensing means is coupled to the switch and the capacitor. 
     
     
         23 . The method of  claim 13  wherein during operation the switching power means current flowing through the current sensing means represents the input of the inductor current. 
     
     
         24 . The integrated circuit of  claim 9  wherein to control conductivity of the switch further controls provision of current from an inductor to the switching power means through a diode to a capacitor at an output of the switching power means when the switch is nonconductive, wherein the current sensing means is coupled to the switch and the capacitor. 
     
     
         25 . The integrated circuit of  claim 9  wherein during operation the switching power means current flowing through the current sensing means represents the input, of the inductor current. 
     
     
         26 . The method of  claim 14  wherein generating the control signal to control conductivity of the switch to the controller further comprises: providing current from an inductor of the switching power means through a diode to a capacitor at an output of the switching power means when the switch is nonconductive, wherein the current sensing means is coupled to the switch and the capacitor. 
     
     
         27 . The method of  claim 14  wherein during operation the switching power means current flowing through the current sensing means represents the input of the inductor current.