Danfoss TTS350 - Compressor Energy and Signal Flow

Speedmodulationisachievedbytheuseof“Inverter”control.Toaccomplishthis,theincoming3-phaseACsupply
isconvertedtohighvoltageDC,incorporatingsmoothing/storagecapacitors,andthenswitchedbytheInverter,
utilizing3-phaserectifiers,togiveasimulated3-phaseACsupplyofvariablevoltageandfrequencytothe
compressormotor.
2.4 Compressor Energy and Signal Flow
Duringnormaloperation,3-phasepowerisrequiredtobeconnectedtothecompressoratalltimes,evenifitisnot
running.Powerisdistributedthroughthefollowingcomponentstomaintaincompressoroperation:
l
Silicon-ControlledRectifier(SCR)
l
SoftStartBoard
l
DCCapacitorBusBarAssembly
l
Inverter
l
Stator
l
High-Voltage(HV)DC-DCConverter
l
Backplane
l
BearingMotorCompressorController(BMCC)
l
SerialDriver
l
BearingPulseWidthModulation(PWM)Amplifier
l
CompressorI/OBoard
l
IGV
l
Solenoidactuators
Theorderofpowerandsignalflowthroughthecompressorcomponentsisasfollows.RefertoFigure2-6
CompressorEnergyandSignalFlowConnectionsonpage39:
1. A3-phasevoltagesourceisprovidedtothecompressorthroughthevoltageinputterminal.
2. ACvoltageenterstheSCRsandDCvoltagepowerstheDCbus.
3. TheSoftStartBoardlimitsthein-rushcurrentatpower-upbycontrollingtheSCRgates.
4. DCbusvoltagefromtheSCRschargesthecapacitors.
5. DCbusprovidesDCvoltagetoInverter.
6. TheInverterconvertstheDCbusvoltageintoavariablefrequency,3-phasesimulatedACvoltageto
theStator.
7. TheDC-DCConverterusestheDCbusvoltagetoprovide24VDCand250VDCtotheBackplane.
8. TheBackplaneconnectsandsupplieslowDCvoltagetotheservicesidecomponents.


Page 38 of 294 - M-SV-001-EN Rev. H 1/23/2023