System and method for Var injection at a distributed power generation source

摘要

A method to add locally generated real and reactive power to a power distribution grid including: generating or storing direct current (DC) power by distributed power source; converting the DC power to an alternating current (AC) power; calculating or measuring a power factor of the AC power provided from the distribution grid; determining a power factor for the conversion of DC power to AC power based on the power factor for the AC from the distribution grid, and the conversion of the DC power to the AC power sets the power factor for the AC power to conform to the determined power factor.

主权项

1. A method to add locally generated real or reactive power to a power distribution grid comprising:
distributing, through the power distribution grid, alternating current (AC) power generated by a power generation plant to local sites connected to the power distribution grid; generating or storing direct current (DC) power by a distributed power source at one of the local sites, wherein the distributed power source is connected to the power distribution grid; converting the DC power to AC power by executing pulse width modulation (PWM) of an inverter local to the distributed power source, wherein the inverter comprises insulated gate bipolar transistor (IGBT) switches configured to set a power factor, a frequency, and a phase of a voltage for the AC power converted by the inverter; sampling the AC power distributed by the power distribution grid at the local site of the distributed power source; calculating a power factor, a frequency, and a phase of a voltage for the AC power distributed by the power distribution grid based on sampling the AC power distributed by the power distribution grid at the local site of the distributed power source; comparing the power factor, the frequency, and the phase of the voltage for the AC power distributed by the power distribution grid to a desired power factor, a desired frequency, and a desired phase of a voltage for the AC power distributed by the power distribution grid at the local site of the distributed power source, wherein the desired power factor, the desired frequency, and the desired phase of a voltage for the AC power distributed by the power distribution grid are stored in a controller of the inverter; determining the power factor, the frequency, and the phase of the voltage for the conversion of DC power to AC power based on the power factor, the frequency, and the phase of the voltage for the AC power distributed by the power distribution grid; combining the AC power generated by the conversion with the AC power distributed by the power distribution grid; and wherein the conversion of the DC power to the AC power sets the power factor, the frequency, and the phase of the voltage for the AC power generated by the conversion to conform to the determined power factor, the determined frequency, and the determined phase of the voltage of the power distribution grid.