Multi-Circuit PFC Control for Overall Power Factor Stability
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Solution Overview
Problem
Existing electronic circuits, such as LED drivers, face challenges in maintaining optimal power factor and reducing harmonic distortion when operating at varying power levels, leading to suboptimal performance and potential grid disruptions.
Innovation Solution
A device that monitors the power state of multiple electronic circuits and adjusts their power factor correction (PFC) modes to improve the overall power factor by generating control signals that change the PFC operation from high to low power modes, optimizing mains parameters like total harmonic distortion and higher order harmonics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If power factor correction is optimized at full load for each electronic circuit, then power factor and harmonic distortion meet strict standards at high power, but overall system performance degrades at lower power states where requirements are less stringent
Solution Approach 1:
The patent implements dynamic power factor correction by allowing electronic circuits to operate in different PFC modes (first mode at full load, second mode at lower power) based on real-time power state detection. This dynamic adaptation enables the system to optimize PF correction precision when needed while reducing complexity and energy consumption when strict standards are not required, directly resolving the contradiction between manufacturing precision and adaptability.
Solution Approach 2:
The system changes operational parameters by switching between different PFC modes depending on the power state. At full load, circuits operate in the first PFC mode with strict PF and THDi optimization. When power drops below a threshold, the system transitions to the second PFC mode with relaxed parameters, allowing the overall system to maintain compliance while improving adaptability to varying power conditions.
2Reliability
If multiple electronic circuits operate independently with individual power factor correction, then each circuit meets standards at its own optimal point, but the overall system power factor deteriorates when some circuits are at low power
Solution Approach 1:
The patent merges the power factor correction strategies of multiple independent electronic circuits by introducing a coordination mechanism. When one circuit operates at low power with relaxed PFC, another circuit operating at high load can compensate by maintaining strict PFC, thereby maintaining the overall system PF above the required threshold. This combining approach ensures both individual compliance and collective system performance.
Solution Approach 2:
The system implements feedback by continuously monitoring the overall system power factor and total harmonic distortion. When the aggregate PF drops below the threshold due to multiple circuits operating at low power, the system receives feedback and adjusts individual circuit operations (e.g., triggering alarm conditions or adjusting load distribution) to restore compliance, thus maintaining both reliability and overall power factor.
3Reliability
If power factor correction is maintained at strict levels across all power states, then standards are always met, but energy consumption and system complexity increase unnecessarily at low power
Solution Approach 1:
The patent applies partial action by implementing power factor correction at the minimum necessary level for each operating condition. Instead of maintaining full-power PFC settings at all times, the system applies strict PFC only when required by standards (above threshold power), and relaxes PFC when operating below the threshold where standards are less stringent. This partial application of PFC reduces energy consumption and system complexity while maintaining reliability through selective enforcement.
Data Source
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AI summary
The present invention provides a device for controlling an overall PF of two or more electronic circuits that are each configured to perform PFC during operation. The device may be electrically connected between mains and the electronic circuits such that the electronic circuits are electrically supplied from mains with a mains voltage and current via the device and the mains current is divided among the electronic circuits. The device may receive from each electronic circuit information on an electrical input power and/or output power of the respective electronic circuit. The device may generate, in response to determining the electrical input or output power of at least one electronic circuit being smaller than a respective threshold, a control signal causing a change of the PFC of the at least one electronic circuit for increasing the overall PF of the two or more electronic circuits.