This method to use controllable loads (e.g., PEV charging rates) to determine the distribution transformer loading condition is unique. The process to calculate the distribution transformer load condition is described in the following steps: (1) Identify the transformer's full load core loss value (watts); (2) Identify the transformer's base load (e.g., 25kVA) and secondary voltage (e.g. 240VAC); (3) use the following equation representing the classical relationships between power, current and impedance (e.g., Power = Current2 * Impedance) to calculate the full load transformer impedance; Transformer Power = Impedance * [Nameplate Power (W) ]2 / [Nameplate Secondary Voltage (VAC)]2 (4) use the transformer base current and calculated full load impedance to determine the maximum transformer voltage drop before exceeding the transformer power limit; (5) implement a periodic A.C. line voltage measurement and control capability (e.g., 240VAC) that records the line voltage and minimizes the PEV charging rate during relative high A.C. voltage times to determine a second A.C. line voltage value; (6) the two A.C. voltage and power values are then used to calculate a no-load transformer voltage. This no-load A.C. voltage estimate can be used to verify transformer voltage remains above its minimum voltage and determine the transformer's current loading; (7) these controls take into account variations in no-load line voltage and can be as simple as a short-term (e.g., ~one-hour) history of the highest line voltage as most residential loads cycle within that time period.