Electric motor controller and methods of determining input power line energization

A method of determining an energized power line of a plurality of input power lines of a motor drive controller configured to be coupled to a power source and to an electric motor, the power source providing an AC input voltage having a frequency, said method comprising:

• receiving, by a computing device of the motor drive controller, an isolated signal output by an energized line detection device, the isolated signal corresponding to which of the plurality of input power lines has been energized, wherein the energized line detection device includes a first heat generation device coupled to a first input power line of the plurality of input power lines and a second heat generation device coupled to a second input power line of the plurality of input power lines;
• periodically receiving temperature measurement signals from a first temperature sensor positioned adjacent to the first heat generation device and a second temperature sensor positioned adjacent to the second heat generation device;
• determining whether one of the first heat generation device and the second heat generation device has changed in temperature by comparing a present temperature measurement signal to a prior temperature measurement signal;
• and
• determining, by the computing device, which input power line of the plurality of input power lines has been energized based on the compared temperature measurement signals.

A heating, ventilation, and air conditioning (HVAC) motor control system comprising:

• an HVAC system controller configured to determine an operating mode of said HVAC motor control system;
• an electric motor;
• and
• an electric motor drive controller coupled to said electric motor, said motor drive controller comprising:
• a plurality of power input lines, each power input line of said plurality of power input lines configured to receive an alternating current (AC) input voltage from an AC power source;
• an energized line detection device configured to sense that a power input line of said plurality of power input lines has been energized by the AC power source, and configured to output an isolated signal, said energized line detection device comprising a current transformer having a primary winding and a secondary winding, said each input power line coupled to a respective turn of said primary winding;
• and
• a computing device coupled downstream from said energized line detection device and configured to:
• receive the isolated signal output by said current transformer, the isolated signal representing a conditioned voltage signal Vc;
• receive a measured motor operation condition of said electric fan motor;
• calculate an energized line value given by
• x
• =
• k
• ×
• Vc
• ⁢
• /
• ⁢
• P
• out
• η
• +
• V
• DC
• ,
• wherein k represents a predetermined scaling factor, Pout represents an output power of the electric motor, VDC represents a measured DC link voltage, and η represents motor efficiency;
• and
• determine which input power line of said plurality of input power lines has been energized based on the calculated energized line value and the measured motor operation condition.

An electric motor drive controller configured to be coupled to an electric motor, said electric motor drive controller comprising:

• a plurality of power input lines, each power input line of said plurality of input power lines configured to receive an alternating current (AC) input voltage from an AC power source;
• an energized line detection device configured to sense that a power input line of said plurality of power input lines has been energized by the AC power source, and configured to output an isolated signal, said energized line detection device comprising a current transformer having a primary winding and a secondary winding, said each input power line coupled to a respective turn of said primary winding;
• and
• a computing device coupled downstream from said energized line detection device and configured to:
• receive the isolated signal output from said secondary winding of said current transformer;
• calculate an energized line value given by
• x
• =
• k
• ×
• Vc
• ⁢
• /
• ⁢
• P
• out
• η
• +
• V
• DC
• ,
• wherein k represents a predetermined scaling factor, Vc represents a conditioned voltage signal output by said current transformer, Pout represents an output power of the electric motor, VDC represents a measured DC link voltage, and η represents motor efficiency;
• and
• determine which input power line of said plurality of input power lines has been energized based on the calculated energized line value.