Motor Controller PFC Switching for Low-Load Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric motors with power factor correction (PFC) circuitry face reduced energy efficiency at lower load points due to the energy consumption of the PFC circuitry outweighing its efficiency advantages, necessitating a more efficient control mechanism.
Innovation Solution
A motor controller with a PFC circuit that activates or deactivates based on commanded motor output thresholds, optimizing power factor control to improve energy efficiency by reducing power consumption when lower outputs are demanded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PFC circuitry is included in electric motors, then power factor is improved, but energy efficiency deteriorates at lower load points
Solution Approach 1:
The patent applies dynamics by making the PFC circuit configurable between active and inactive states based on operating conditions. The controller dynamically switches the PFC circuit on or off depending on the load level, allowing the system to adapt its power factor correction behavior to current operational requirements rather than maintaining a fixed configuration.
Solution Approach 2:
The patent changes the operational parameter of the PFC circuit by allowing it to be configured in different states (active/inactive) based on load conditions. This parameter change enables the system to optimize between power factor improvement and energy consumption by selecting the appropriate PFC circuit state for the current operating point.
2Reliability
If PFC circuit is activated continuously, then power factor control is maintained, but power consumption increases at low loads
Solution Approach 1:
The patent implements periodic action by activating the PFC circuit only during specific periods when the load exceeds a predetermined threshold. Rather than continuous operation, the controller periodically evaluates the load condition and activates the PFC circuit only when necessary, creating an on-demand operation pattern that reduces energy consumption during low-load periods.
Solution Approach 2:
The patent extracts the PFC circuit operation from continuous operation by separating it into conditional activation. The controller extracts the unnecessary PFC circuit activity during low-load conditions, allowing the system to eliminate energy-wasting PFC operation when the load does not require power factor correction.
3Use of energy by moving object
If PFC circuit is deactivated at low loads, then energy savings are achieved, but power factor deteriorates
Solution Approach 1:
The patent applies parameter changes by adjusting the operational state of the PFC circuit based on load parameters. When the load falls below the predetermined threshold, the controller changes the PFC circuit state from active to inactive, accepting a deterioration in power factor as a trade-off for achieving energy savings during low-load operation.
Solution Approach 2:
The patent applies partial action by providing power factor correction only to the extent necessary for meeting load requirements. Rather than maintaining full PFC circuit operation at all times, the system applies partial PFC action only when the load exceeds the threshold, accepting partial deterioration in power factor during low-load periods as an acceptable trade-off for energy conservation.
Data Source
AI summary
An electric motor is provided. The electric motor includes a motor controller configured to convert AC power to a variable frequency variable voltage power for driving the electric motor according to a commanded motor output. The motor controller includes a PFC circuit configured to control a power factor of the electric motor and a microcontroller coupled to the PFC circuit and configured to activate the PFC circuit when the commanded motor output is greater than a threshold motor output, deactivate the PFC circuit when the commanded motor output is less than or equal to the threshold motor output, and generate a control signal based on the commanded motor output. The motor controller further includes an inverter configured to receive the control signal and generate the variable frequency variable voltage power according to the commanded motor output.