Power Ripple Absorption Circuit for Battery Charging
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Solution Overview
Problem
Existing power factor correctors produce sinusoidal components that can prematurely wear batteries during charging, and the use of high-capacity chemical capacitors to mitigate voltage ripple is inefficient due to their short lifetimes.
Innovation Solution
A step-down power ripple absorption circuit connected in parallel with the power factor correction circuit, comprising a capacitor in series with an inductor and a switch, controlled by a module that measures currents and voltages to attenuate power ripple and maintain voltage within a predefined interval, allowing for the use of lower capacitance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-capacity chemical capacitors are used to reduce voltage ripple and support rms current, then voltage ripple is sufficiently reduced, but the capacitor lifetime becomes short
Solution Approach 1:
The power factor correction system is segmented into two functional parts: a first power factor correction circuit for basic power factor improvement, and a second power factor correction circuit specifically dedicated to ripple current compensation. This segmentation allows each circuit to be optimized for its specific function, enabling the use of smaller capacitors while maintaining overall system performance.
Solution Approach 2:
A coupling inductor is introduced as an intermediary element between the first and second power factor correction circuits. This inductor serves as a mediator that transfers and transforms the ripple current components, allowing the second circuit to compensate for ripple currents without requiring the first circuit's capacitor to handle the full ripple current burden, thus reducing the required capacitance value.
2Stability of the object's composition
If large capacitors are used to smooth voltage variations at the output of the power factor corrector, then voltage ripple is reduced, but the device complexity and cost increase
Solution Approach 1:
The voltage stabilization function is segmented between two circuits: the first power factor correction circuit provides basic voltage support, while the second power factor correction circuit specifically targets ripple current compensation. This segmentation enables effective voltage stabilization with smaller individual capacitor values, reducing overall device complexity.
Solution Approach 2:
The system changes the operating parameters of the two circuits differently: the first circuit operates at a higher switching frequency optimized for power factor correction, while the second circuit operates at a lower switching frequency optimized for ripple current compensation. This parameter differentiation allows each circuit to use smaller components while achieving the desired voltage stability.
3Object-generated harmful factors
If a single power factor correction circuit is used, then the device structure is simple, but it cannot effectively eliminate sinusoidal components in the output power
Solution Approach 1:
The power factor correction functionality is segmented into two specialized circuits: the first circuit handles basic power factor correction, while the second circuit is specifically dedicated to eliminating sinusoidal ripple components. This functional segmentation enables effective elimination of harmful sinusoidal components in the output power, while each circuit remains relatively simple in structure.
Solution Approach 2:
The coupling inductor acts as an intermediary that enables the second power factor correction circuit to selectively target and compensate for sinusoidal ripple current components without interfering with the primary power factor correction function of the first circuit. This intermediary element allows the system to eliminate harmful sinusoidal components while maintaining manageable circuit complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables continuous power delivery to batteries without the need for large capacitors, extending their lifespan and improving charging efficiency by filtering out sinusoidal components and regulating voltage effectively.
Implementation Method 1
a capacitor connected in series with an inductor and a switch
Implementation Method 2
a capacitor connected in series with an inductor and a switch, controlled by a module that measures currents and voltages to attenuate power ripple and maintain voltage within a predefined interval
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention concerns an absorption circuit (9) for absorbing a power ripple intended to be connected in parallel to a piece of electrical equipment powered by a power factor correction circuit (1), said absorption circuit (9) being a step down voltage circuit comprising: -a capacitor (19) mounted in series with an inductor (17) and at least one switch (15, 23), -a control module (25), -means (27) for measuring a first current (I3) intended to power said electrical equipment, the switch (15, 23) being controlled by the control module (25) to vary the charging of the capacitor on the basis of the ripple of the first current (I3) in order to attenuate the power ripple, and said circuit further comprising means (28) for measuring the voltage (Vc) at the terminals of the capacitor (19), and the control module (25) being configured to control a second current (Ic) flowing through the capacitor (19) in such a way that the voltage (Vc) at the terminals of the capacitor (19) remains within a predefined interval.