System and method of controlling power to a non-motor load
AssigneeEaton Corporation
InventorsKevin Lee, Jyrki K. Ahlgren, Ian T. Wallace, Thomas M. Doring
Life of this patent
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Abstract
A motor drive for conditioning power to be delivered to a non-motor load includes a voltage feedback circuit that monitors a DC bus voltage and, based on changes in the DC bus voltage, adjusts a power conditioning scheme such that near steady-state load conditions are maintained in response to a transient load condition. The voltage feedback circuit has a voltage sensor that provides voltage feedback to a controller that determines what changes in power conditioning are needed in response to a transient load condition that manifests itself in a change in DC bus voltage.
Claims26
A motor drive comprising:
- a power input;
- a DC bus connected to the power input;
- at least one switch connected to the DC bus;
- a power output connectable to a load;
- and
- a controller connected to the DC bus and configured to control switching of the at least one switch to maintain near steady-state at the load in response to changes in voltage at the DC bus.
A power conditioner to supply conditioned power to a non-motor load, the power conditioner comprising:
- a rectifier bridge to convert an AC power input to DC power and provide a DC bus voltage;
- an inverter connected to receive the DC bus voltage;
- a filter connected to the inverter to feed an output of the inverter to the non-motor load;
- and
- a PID controller that receives feedback of the DC bus voltage and regulates the inverter to maintain near steady-state at the non-motor load in response to transient load conditions.
A method of regulating power to a load comprising the steps of:
- detecting a change in voltage across a DC bus of a motor drive;
- and
- dynamically controlling switching of a switch array of the motor drive in response to a detected change in voltage across the DC bus such that load voltage regulation is ±1% in steady-state with less than 3% total harmonic distortion.
A power conditioner comprising:
- an adjustable speed drive (ASD) having an inverter configured to receive a DC bus voltage and deliver an output voltage;
- a transformer configured to receive the output voltage of the inverter and provide a load voltage to a non-motor load;
- a voltage sensor connected to sense the DC bus voltage and provide feedback thereof;
- and
- a controller connected to control at least one switch of the inverter, the controller programmed to:
- input the DC bus voltage feedback from the voltage sensor;
- process the DC bus voltage feedback to provide a derivative term;
- forecast changing load conditions from the derivative term;
- and
- control the at least one switch of the inverter to maintain a near stead-state load condition.
Dependencies are inferred from the claim text.