Patent ID: 11867412
Assignee: PREMIER ENERGY HOLDINGS, INC.
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F  H  Y | IPC F  H

Claim 10:
11. A controller comprising:
a first output adapted to provide power to an electric heat pump-based water heater having an alternating current (AC) motor;
a second output adapted for coupling to a resistive water heating element in the electric heat pump-based water heater;
a multiphase variable frequency (VFD) motor drive coupled to provide power to the first output;
an input adapted for connection to a solar photovoltaic power source;
the second output coupled to receive power from a resistive power control apparatus selected from a pulse-width modulator and a DC-DC converter;
a DC/DC power converter configured for connection to a solar photovoltaic system;
wherein the DC/DC power converter is coupled to provide power to the VFD and to the resistive power control apparatus;
wherein the DC/DC power converter, the VFD, and the resistive power control apparatus, are controlled by a microcontroller;
wherein the microcontroller contains firmware configured to:
operate the DC-DC converter to extract maximum power from the input adapted for connection to a solar photovoltaic power source using a maximum-power-point-tracking (MPPT) method,
determine solar power available from the input adapted for connection to a solar photovoltaic power source and
if solar power available is less than a first threshold, operate the resistive power control apparatus to use solar power available in the resistive water heating element;
if solar power available is greater than the first threshold, use the VFD to use the solar power available to power the electric heat pump-based water heater at a frequency and an AC voltage increasing with solar power available, the frequency limited to a maximum frequency and the AC voltage limited to a maximum AC voltage; and
if solar power available is greater than sufficient power to use the VFD to power the electric heat pump-based water heater at the maximum frequency and the maximum AC voltage, to operate the resistive power control apparatus to use that portion of solar power available greater than sufficient power to use the VFD to power the electric heat pump-based water heater at the maximum frequency and the maximum AC voltage to drive the resistive water heating element.