Demand Responsive Lighting Control System for Predictable Power Reduction
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Solution Overview
Problem
Existing demand responsive lighting control systems fail to provide predictable reduction in lighting consumption during Automated Demand Response events due to interactions with other control mechanisms, leading to inconsistent and often marginal reductions in power usage.
Innovation Solution
A light control system comprising a light controller and a load controller that receives a power reduction parameter, determines a scaled calibrated setpoint value, and adjusts the output level signal accordingly, ensuring a guaranteed reduction in light output by combining set-point scaling and power scaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If ADR control changes the maximum dim level to limit power consumption, then energy reduction is achieved when prior consumption is high, but no reduction occurs when prior consumption is already low
Solution Approach 1:
The system dynamically changes the setpoint parameter by scaling it with the power reduction parameter (e.g., if 20% reduction is requested, setpoint is scaled to 80%). This ensures predictable reduction by establishing a new target that guarantees the requested power reduction level, resolving the issue where prior consumption levels made reduction unpredictable.
2Illumination intensity
If daylight regulation control loop attempts to maintain target total illumination after dim level scaling, then illumination consistency is maintained, but dim level returns to approximately the same level eliminating reduction
Solution Approach 1:
The system performs preliminary scaling of both the setpoint and the power reduction parameter before the daylight regulation control loop operates. By pre-scaling the power reduction parameter, the system ensures that even though the daylight regulation loop will adjust dim levels to maintain illumination, the overall power consumption is capped at the reduced level, guaranteeing the requested reduction.
3Use of energy by moving object
If ADR control issues a dimming command, then power reduction is intended, but the command may be overridden by other controls or increased by lack of knowledge about other dimming commands
Solution Approach 1:
The system uses a universal scaling approach that applies to all control mechanisms simultaneously. By scaling both the setpoint and the power reduction parameter, the invention creates a multi-functional control strategy that works consistently across occupancy control, daylight regulation, and manual control, preventing any single control from overriding the ADR intent while avoiding conflicts between multiple dimming commands.
Data Source
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AI summary
The invention relates to a light control system (120;121) for controlling a lighting system (100). The light control system (120;121) is arranged to receive a power reduction parameter (alpha). The light control system comprising a light controller (134) arranged to receive a measured light value from a light sensor (127), to determine a light channel level value depending on the measured light value and a calibrated setpoint value if no power reduction parameter has been received, and to determine a light channel level value depending on the measured light value and a scaled calibrated setpoint value if the power reduction parameter has been received, the scaled calibrated setpoint value being equal to the calibrated setpoint value multiplied by the power reduction parameter. A load controller (135) is arranged to receive the light channel level value from the light controller, to determine an output level signal depending on the light channel level value if no power reduction parameter has been received and to determine a scaled output level signal if the power reduction parameter has been received, the scaled output level signal being equal to the output level signal multiplied by the power reduction parameter, and to send the output level signal or the scaled output level signal to drivers of light sources of the lighting system.