Part of the Smart grid glossary:

Susceptance (symbolized B ) is an expression of the ease with which alternating current ( AC ) passes through a capacitance or inductance .

In some respects, susceptance is like an AC counterpart of direct current ( DC ) conductance . But the two phenomena are different in important ways, and they can vary independently of each other. Conductance and susceptance combine to form admittance , which is defined in terms of two-dimensional quantities known as complex number s.

When AC passes through a component that contains a finite, nonzero susceptance, energy is alternately stored in, and released from, a magnetic field or an electric field. In the case of a magnetic field, the susceptance is inductive. In the case of an electric field, the susceptance is capacitive. Inductive susceptance is assigned negative imaginary number values, and capacitive susceptance is assigned positive imaginary number values.

As the inductance of a component increases, its susceptance becomes smaller negatively (that is, it approaches zero from the negative side) in imaginary terms, assuming the frequency is held constant. As the frequency increases for a given value of inductance, the same thing happens. If L is the inductance in henries ( H ) and f is the frequency in hertz ( Hz ), then the susceptance - jB L , in imaginary-number siemens , is given by:

- jB L = - j (6.2832 fL ) -1

where 6.2832 is approximately equal to 2 times pi , a constant representing the number of radian s in a full AC cycle, and j represents the unit imaginary number (the positive square root of -1).

As the capacitance of a component increases, its susceptance becomes larger positively in imaginary terms, assuming the frequency is held constant. As the frequency increases for a given value of capacitance, the same thing happens. If C is the capacitance in farads ( F ) and f is the frequency in Hz, then the susceptance +jB C , in imaginary-number ohms, is given by:

+jX C = + j (6.2832 fC )

Also see admittance , conductance , reactance , resistance , impedance , ohm , siemens , henry , and farad .

This was last updated in March 2010
Posted by: Margaret Rouse

Related Terms

Definitions

  • Advanced Encryption Standard (AES)

    - The Advanced Encryption Standard or AES is a symmetric block cipher used by the U.S. government to protect classified information and is implemented in software and hardware throughout the world to... (SearchSecurity.com)

  • application program interface (API)

    - An application program interface (API) is code that allows two software programs to communicate with each other. Typically, APIs are released for third-party development as part of a software devel... (SearchExchange.com)

  • ampere hour (Ah or amp hour)

    - An ampere hour (abbreviated Ah, or sometimes amp hour) is the amount of energy charge in a battery that will allow one ampere of current to flow for one hour. (WhatIs.com)

Glossaries

  • Smart grid

    - Terms related to smart grids, including definitions about utility electricity delivery systems and words and phrases about smart meters and distributing, monitoring and billing electrical power.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question
  • Could a honeypot machine risk the secure network?

    Honeypots in general always seem to create 2 lines of thought. Are they a good thing or a bad thing? Your intention of using it to see what potential threats are nearby whilst not a bad idea has a ...

  • DX2390 and Networking

    If these are new, then you should be able to get support directly from HP on this issue. I would also apply latest firmware/bios updates and any other updates from the manufacturer that might addre...

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.