Electromagnetic immunity

Illustrated explanation

Waveform shape, unwanted components and circuit response

4Electromagnetic immunity
Waveform shape, unwanted components and circuit responseCallout 1: Harmonics. Callout 2: Signal integrity. Callout 3: Switching drive. Callout 4: Immunity response. Switching drives and non-sinusoidal signals can contain several frequency components. Signal integrity concerns the intended waveform, while immunity concerns response to an applied disturbance. Current term: Electromagnetic immunity, callout 4. 1Fundamental + harmonicsHarmonics 2Signal integrity 3MDrive + motor cableSwitching drive 4CircuitObserve operationImmunity response
  1. Harmonics

    Components occur at integer multiples of a fundamental frequency. Their presence and amplitude depend on the actual source waveform.

  2. Signal integrity

    Compare the received waveform with the intended signal. Reflections, timing and distortion depend on the full transmission path.

  3. Variable frequency drive (VFD)

    The drive controls motor supply through its output stage. Cable screening and bonding must suit the drive and installation instructions.

  4. Electromagnetic immunityThis term

    A defined disturbance is applied while equipment operation is assessed. Immunity depends on the method, level and performance criteria.

Switching drives and non-sinusoidal signals can contain several frequency components. Signal integrity concerns the intended waveform, while immunity concerns response to an applied disturbance.

Illustrative traces without frequency, amplitude or acceptance limits. They are examples of waveform concepts rather than measured performance.