Requirements to passive components in drivesNiels Gade, Danfoss Drives A/S

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Passive components in intermediate circuits

• DC-Inductor:

• Reduce line side harmonics

• Reduce voltage ripple

• Accept peak current without saturation

• DC-field bias with PM to shrink size

• DC-capacitor:

• Provide energy storage

• Deliver ripple current to inverter

• Lifetime:

• Losses (ESR and ripple current)

• Temperature

• Humidity

• Future requirements: • Voltage (electrolytic)

• ESR/ripple current (electrolytic)

• Energy density (film)

• Humidity (film)

DC-link filter

ESL ESRC

Capacitor equivalent circuit

Normal and DC-biased core Electrolytic capacitor

“slim” DC-link

Film capacitor

Variable speed drive

DC-biased core

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Motor integrated Solutions

• Low loss / high power density

• Harsh environment

• Temperature

• Vibration

• Humidity

• Limited space:

• Odd shape solutions

• Inductors

• Integration with stator laminations

• SMCs or sintered powder cores

• Capacitors

• Energy density and robustness

• Loss dissipation (thermal mgt.)

• Alternative topologies:• CSI vs VSI

Soft Magnetic Composite cores (arbitrary shape)

Integration of motor and drive

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Ultra compact sinusoidal drives

• Ultra compact solution:

• High power density Low loss

• Small filters high frequency switching

• Low loss and high frequency:

• WBG active components

• Cores: High frequency, low loss, high permeability

• Powders / SMCs / ferrites

• Windings: Low loss, low cost

• Al versus Cu

• Capacitors: Integration in power modules

• Designs: Careful control of parasitic elements in layouts

L2L1

C1

L f

C f