Passive Components Blog
No Result
View All Result
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    Rubycon Extends Capacitance of Polymer Hybrid Aluminum Capacitors

    VINATech Partner with ONiO to Develop Batteryless IoT Power Architecture

    Knowles Releases Inductors for Mission-Critical RF Applications

    Bourns Unveils Smallest Automotive Grade Thick Film Resistors

    Wk 28 Electronics Supply Chain Digest

    Bourns Increases Maximum Inductance Values of Semi-Shielded Power Inductors

    YAGEO Unveils Next Gen BMS Isolation Transformers

    Littelfuse Compact Tactile Switch Offers Low-Noise Switching and Dust Protection

    Murata Announces Mass Manufacturing of World’s First 0402 47µF MLCC

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Accelerating Full Bridge LLC Resonant Converter Design with Frenetic AI

    Understanding Switched Capacitor Converters

    Coupled Inductors Circuit Model and Examples of its Applications

    Inductor Resonances and its Impact to EMI

    Highly Reliable Flex Rigid PCBs, Würth Elektronik Webinar

    Causes of Oscillations in Flyback Converters

    How to design a 60W Flyback Transformer

    Modeling and Simulation of Leakage Inductance

    Power Inductor Considerations for AI High Power Computing – Vishay Video

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    Rubycon Extends Capacitance of Polymer Hybrid Aluminum Capacitors

    VINATech Partner with ONiO to Develop Batteryless IoT Power Architecture

    Knowles Releases Inductors for Mission-Critical RF Applications

    Bourns Unveils Smallest Automotive Grade Thick Film Resistors

    Wk 28 Electronics Supply Chain Digest

    Bourns Increases Maximum Inductance Values of Semi-Shielded Power Inductors

    YAGEO Unveils Next Gen BMS Isolation Transformers

    Littelfuse Compact Tactile Switch Offers Low-Noise Switching and Dust Protection

    Murata Announces Mass Manufacturing of World’s First 0402 47µF MLCC

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Accelerating Full Bridge LLC Resonant Converter Design with Frenetic AI

    Understanding Switched Capacitor Converters

    Coupled Inductors Circuit Model and Examples of its Applications

    Inductor Resonances and its Impact to EMI

    Highly Reliable Flex Rigid PCBs, Würth Elektronik Webinar

    Causes of Oscillations in Flyback Converters

    How to design a 60W Flyback Transformer

    Modeling and Simulation of Leakage Inductance

    Power Inductor Considerations for AI High Power Computing – Vishay Video

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
No Result
View All Result
Passive Components Blog
No Result
View All Result

Aluminium Capacitors Series Connection Balancing

30.10.2023
Reading Time: 3 mins read
A A

In the design of a capacitor bank, it is important to balance the capacitors for both DC and transient signal. This paper written by Vishay explains the balancing methods that applies to aluminum electrolytic capacitors.

If two capacitors are placed in series to a DC voltage source U, the midpoint-voltage is not automatically 0.5 x U. The voltage distribution is dominated by the leakage current, which varies by capacitor and is voltage-dependent. The capacitor that has the larger leakage current at 0.5 x U will have a somewhat smaller voltage drop than the other capacitor, leading to an equalized leakage current through both capacitors.

RelatedPosts

Vishay NTC Immersion Thermistor Delivers Fast Response in Liquid Cooled Automotive Systems

Vishay Expands Automotive High Frequency Thin Film Chip Resistors

Vishay Extends Axial Wirewound Resistors with WSZ Lead Form

Depending on the difference in leakage current, this could lead to voltage drops larger than the rated voltage, which could result in decreased lifetime or even early failure. Balancing the DC voltage is therefore necessary. This can be done in a passive way as shown in Drawing 1: two resistors in parallel to the capacitors, with values typically calculated as Rmax = (2 x Umax. – U)/Ileak– 5min x Umax. would be the maximum allowable voltage drop across one capacitor (typically Urated). U is the applied DC voltage. Ileak-5min is the DC leakage current as measured after five minutes of applied rated voltage.

The disadvantage of this way of passive balancing is a relatively high efficiency loss, typically from 1 % to 5 %. This is unacceptable in applications like solar inverters, where the need for maximum efficiency dominates the market. Here designers work with active balancing.

Practical advice: if one of the capacitors in a series connection fails, replace both capacitors with two fresh ones from the same batch, to ensure that the leakage currents of both devices in one branch are roughly equal.

Two capacitors in series connected to a power source will react differently to transient signals. For the change in voltage drop over a capacitor, C1 holds ∆ V1 = 1/C1 ∫ I1(t)dt. With a fixed current (I=I1 =I2) running through C1 and C2, we get C1 ∆ V1 = C2*∆ V2, or ∆ V1/∆ V2 = C2/C1. So the change in midpoint voltage is determined by the ratio of the capacitances. This leads to simple requirements from designers: C1 = C2. This is correct from a theoretical point of view, but manufacturers of electrolytic capacitors work with a typical production variation of ± 20 % in capacitance in their specifications. This tolerance is set on all produced capacitors; within one batch, variation is less. Typically, the variation within one batch is ± 6 % (total spread from a minimum to maximum capacitance of 12 %).

Practical advice: use capacitors from the same production batch per individual branch. When switching to another production batch, one should measure the 100 Hz capacitance value of all capacitors in that specific branch to exclude unbalanced branches. The same holds for the replacement of capacitors at failure. Remove all capacitors from the branch and replace with fresh ones from the same batch.

Related

Source: Vishay

Recent Posts

Rubycon Extends Capacitance of Polymer Hybrid Aluminum Capacitors

16.7.2025
56

VINATech Partner with ONiO to Develop Batteryless IoT Power Architecture

16.7.2025
18

Murata Announces Mass Manufacturing of World’s First 0402 47µF MLCC

10.7.2025
46

VINATech Supercapacitors Enhance Automotive Safety with Reliable E-Latch Emergency Power

7.7.2025
50

Exxelia Unveils Advanced Components for the Medical Device Industry

9.7.2025
50

YAGEO Releases First to Market 750V Aluminum Capacitors

30.6.2025
58

Smolteks CNF-MIM Capacitors Meet Thermal and Voltage Stability Industry Requirements

30.6.2025
32

Learn How Supercapacitors Enhance Power System in Knowles eBook

30.6.2025
25

TDK Releases Industry First 1uF 100V X7R MLCCs in 1608 Case

27.6.2025
27

YAGEO Extends Lifetime of its Aluminum SMD Chip Capacitors to 5500hrs at 125C/Ur

27.6.2025
63

Upcoming Events

Jul 23
13:00 - 14:00 CEST

PCB design for a Smartwatch

Jul 29
16:00 - 17:00 CEST

Impact of Elevated Voltage and Temperature on Molded Power Inductors in DC/DC converters

View Calendar

Popular Posts

  • Buck Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Boost Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Flyback Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • LLC Resonant Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • What is a Dielectric Constant and DF of Plastic Materials?

    4 shares
    Share 4 Tweet 0
  • Ripple Current and its Effects on the Performance of Capacitors

    3 shares
    Share 3 Tweet 0
  • Dual Active Bridge (DAB) Topology Explained

    0 shares
    Share 0 Tweet 0
  • How to Design an Inductor

    0 shares
    Share 0 Tweet 0
  • MLCC Case Sizes Standards Explained

    0 shares
    Share 0 Tweet 0
  • MLCC and Ceramic Capacitors

    0 shares
    Share 0 Tweet 0

Newsletter Subscription

 

Passive Components Blog

© EPCI - Leading Passive Components Educational and Information Site

  • Home
  • Privacy Policy
  • EPCI Membership & Advertisement
  • About

No Result
View All Result
  • Home
  • Knowledge Blog
  • Premium Suppliers

© EPCI - Leading Passive Components Educational and Information Site

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.
Go to mobile version