9kW Isolated DC-DCConverter for Hybrid Bus. Alexander Isurin and Alexander CookPCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 1

Components Eliminated with a DC to DC Converter Regulator Alternator Bracket Pulley CastTensioner Bracket Inlet Air Idler Piping Belt ISO 9001:2000 / TS-16949:2002 Registered Company

Introduction 24VLoad up 300-500A Engine Alternator 12V Load up 100ASimplified block diagram of 24V system of the busPCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 3

FIELD CURRENT 1.0xSimplified curve of 0.1xtransient response DC VOLTAGE ~100mS ~100mS of an alternator 2.0x 1.0xPCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 4

Path of Electrical Flow FlowAllison Hybrid Drive Allison DPIM Unit 24 Volts DC Vanner DC-DC Converter ISO 9001:2000 / TS-16949:2002 Registered Company

Main Data 9kW Bi-directional DC-DC converter High voltage side: 500VDC-800VDC Low voltage side: 20VDC-30VDC @300A Operational temperature: -40C to +70C @ full power Efficiency 93-94% excluding reverse polarity protection and pre-charge (92-93% with) Efficiency 82% @ 5% load Consumption @ idle 60W Life time minimum 7 years Cost for customer equivalent to conventional alternator PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 6

Main Battery500-800VDC Option DC-DC Electric 24VDC CONVERTER Equalizer Grid Load Battery Monitor 12VDC Load Charger Vehicle CAN-bus Network Block diagram of the converter integrated into the bus electric system PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 7

DC-DC Convertercurrently inProductionPCIM2011 ISO 9001:2000 / TS-16949:2002 Registered Company 8

New Topology DC-DC Converter in Step-down ModePresented APEC2006 Patent US 6,483,731 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 9

Charge Resonant Tank t0 to t2PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 10

Soft-Switch Commutation t2 to t3 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 11

Discharge Energy of the Inductor t3 to t4 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 12

Discharge Magnetizing Inductor t4 to t5 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 13

Soft-Switch Commutation t5 to t6 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 14

Next half cycle power conversion t6 to t7 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 15

Ch.1- gate signal of S2Ch.2-voltage cross of S2 ZCS and ZVS 1750V/uSCh.3-voltage cross of D6 ZVS 1000V/uSCh.4-current via transformer TR1 Vin=700VDC Pout=9kw PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 16

Discharge Energy of the Inductor t3 to t4 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 17

Phase-shift Topologies Standard topology Improved topologyPCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 18

Comparisons PARAMETERS STANDARD IMPROVED NEWMax. com. freq. 1x 1.2x 2xLoad range Limited UnlimitedCommutation ZVS ZVS ZCS ZVS ZCSRectifier recovery Recovery losses More complex Simple and softParalleling of stages Requires additional control SimpleTransformer Not optimal OptimalControl Standard SpecialEfficiency Approximately the same for all threeIdle losses 1.5% 0.15%Bi-directional Additional constraints ReadilyCOST Basis Basis plus Basis minus >10% PCIM201 ISO 9001:2000 / TS-16949:2002 Registered Company 19

Low voltage side power stage with integrated power transformer Presented without the clamping frame Patent US 7,123,123 PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 20

ComparisonsCost and efficiency of the low-voltage sidepower stage with two types of transformers Power Stage Product System Incorporating: Cost Efficiency Integrated 1 94% transformer Planar transformer 1+20% 92% Commutation frequency 110kHz Low voltage side rating 280APCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 21

Comparisons 650VDC 24V 24V Load DC- Load Engine DC Engine Alternator 12V Load Direct Drive Main Generator 12V LoadThe alternators system efficiency The DC-DC system efficiency65% with 9kW output power 82% with 9kW output power The difference is 17% meaning 2.8 kWSaving average 0.1mpg or 370gal. per year per bus PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 22

Conclusion The DC to DC converter has some notable advantages1. Significant increase in reliability of the 24VDC system2. Cost of maintenance of 24VDC system significantly reduced3. Fuel economy improvement4. Higher performance lower overshoot voltage,5. CAN-bus communication, ease of external control.6. It is easy to connect in parallel.7. Reduction of copper for manufacturing PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 23

Conclusion Finally all the advantages of the DC-DC converter can help to save MONEY and make life betterPCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 24

Thank You for Your Attention.PCIM2012 ISO 9001:2000 / TS-16949:2002 Registered Company 25