Manuals / Texas Instruments / Computer Equipment / Network Router

Texas Instruments 28xxx manual Controlling Zero Voltage Switched Full Bridge ZVSFB Converter

Models: 28xxx TMS320x28xx

1 119

Download 119 pages 2.85 Kb

Page 89

3.9Controlling Zero Voltage Switched Full Bridge (ZVSFB) Converter

www.ti.com

Controlling Zero Voltage Switched Full Bridge (ZVSFB) Converter

3.9Controlling Zero Voltage Switched Full Bridge (ZVSFB) Converter

The example given in Figure 3-15assumes a static or constant phase relationship between legs (modules). In such a case, control is achieved by modulating the duty cycle. It is also possible to dynamically change the phase value on a cycle-by-cycle basis. This feature lends itself to controlling a class of power topologies known as phase-shifted full bridge, or zero voltage switched full bridge. Here the controlled parameter is not duty cycle (this is kept constant at approximately 50 percent); instead it is the phase relationship between legs. Such a system can be implemented by allocating the resources of two PWM modules to control a single power stage, which in turn requires control of four switching elements. Figure 3-16shows a master/slave module combination synchronized together to control a full H-bridge. In this case, both master and slave modules are required to switch at the same PWM frequency. The phase is controlled by using the slave's phase register (TBPHS). The master's phase register is not used and therefore can be initialized to zero.

Figure 3-15. Controlling a Full-H Bridge Stage (FPWM2 = FPWM1)

	Ext SyncIn
	(optional)
Master
Phase reg	SyncIn
	SyncIn
En
Φ=0°	EPWM1A
CTR=zero	EPWM1B
CTR=zero
CTR=CMPB
X	SyncOut
	SyncOut
Slave
Phase reg	SyncIn
	SyncIn
En	EPWM2A
Φ=Var°	EPWM2A
CTR=zero	EPWM2B
CTR=CMPB
X	SyncOut
	SyncOut

VDC_bus

Vout

EPWM1A

EPWM2A

EPWM1B

EPWM2B

Var = Variable

SPRU791D–November 2004–Revised October 2007

Applications to Power Topologies

89

Submit Documentation Feedback

Image 89

Texas Instruments 28xxx, TMS320x28xx manual Controlling Zero Voltage Switched Full Bridge ZVSFB Converter

Contents

TMS320x28xx, 28xxx Enhanced Pulse Width Modulator ePWM Module Reference GuideSubmit Documentation Feedback SPRU791D-November 2004-Revised OctoberContents Controlling Multiple Half H-Bridge HHB Converters List of Figures List of FiguresEvent-Trigger SOCB Pulse Generator List of Tables Submit Documentation Feedback SPRU791D-November 2004-Revised OctoberPreface Read This FirstRelated Documentation From Texas Instruments Data ManualsRelated Documentation From Texas Instruments Tools GuidesApplication Reports TMS320C28x, C28x are trademarks of Texas Instruments TrademarksSubmit Documentation Feedback SPRU791D-November 2004-Revised OctoberChapter IntroductionIntroduction Submodule Overview1.2 Submodule Overview 1.1 IntroductionSubmodule Overview Figure 1-1. Multiple ePWM Modules∙ PWM output signals EPWMxA and EPWMxB Figure 1-2. Submodules and Signal Connections for an ePWM Module∙ Trip-zone signals TZ1 to TZ6 ∙ ADC start-of-conversion signals EPWMxSOCA and EPWMxSOCBRegister Mapping 1.3 Register MappingSubmit Documentation Feedback Register MappingOffset Overview ePWM SubmodulesTime-Base TB Submodule Counter-Compare CC Submodule2.1 Overview Table 2-1. Submodule Configuration ParametersOverview Submit Documentation FeedbackExample 2-1. Constant Definitions Used in the Code Examples Table 2-1. Submodule Configuration Parameters continuedOverview Submit Documentation FeedbackSubmit Documentation Feedback Example 2-1. Constant Definitions Used in the Code Examples continuedOverview 2.2.1 Purpose of the Time-Base Submodule Figure 2-1. Time-Base Submodule Block Diagram2.2 Time-Base TB Submodule Table 2-2. Time-Base Submodule Registers Figure 2-2. Time-Base Submodule Signals and Registers2.2.2 Controlling and Monitoring the Time-base Submodule 2.2.3 Calculating PWM Period and Frequency Table 2-3. Key Time-Base Signals∙ Up-Down-Count Mode ∙ Up-Count Mode2.2.3.1 Time-Base Period Shadow Register Figure 2-3. Time-Base Frequency and Period∙ Active Register ∙ Shadow RegisterFigure 2-4. Time-Base Counter Synchronization Scheme 2.2.3.2 Time-Base Counter SynchronizationFigure 2-5. Time-Base Counter Synchronization Scheme ∙ Software Forced Synchronization Pulse Figure 2-6. Time-Base Counter Synchronization Scheme∙ EPWMxSYNCI Synchronization Input Pulse Figure 2-7. Time-Base Up-Count Mode Waveforms 2.2.4 Phase Locking the Time-Base Clocks of Multiple ePWM Modules2.2.5 Time-base Counter Modes and Timing Waveforms Time-Base TB Submodule Figure 2-8. Time-Base Down-Count Mode WaveformsEvent Event 2.3 Counter-Compare CC SubmoduleFigure 2-11 illustrates the counter-compare submodule within the ePWM Figure 2-11. Counter-Compare Submodule2.3.2 Controlling and Monitoring the Counter-Compare Submodule 2.3.1 Purpose of the Counter-Compare SubmoduleTable 2-4. Counter-Compare Submodule Registers Figure 2-12. Detailed View of the Counter-Compare Submodule2.3.3 Operational Highlights for the Counter-Compare Submodule Table 2-5. Counter-Compare Submodule Key Signals2.3.4 Count Mode Timing Waveforms ∙ Shadow ModeFigure 2-13. Counter-Compare Event Waveforms in Up-Count Mode ∙ Up-down-count mode used to generate a symmetrical PWM waveformFigure 2-14. Counter-Compare Events in Down-Count Mode Counter-Compare CC SubmoduleSynchronization Event Synchronization Event2.4.1 Purpose of the Action-Qualifier Submodule 2.4 Action-Qualifier AQ SubmoduleFigure 2-17. Action-Qualifier Submodule Table 2-6. Action-Qualifier Submodule RegistersTable 2-7. Action-Qualifier Submodule Possible Input Events Figure 2-18. Action-Qualifier Submodule Inputs and Outputs∙ Set High ∙ Clear LowPage Table 2-8. Action-Qualifier Event Priority for Up-Down-Count Mode 2.4.3 Action-Qualifier Event PriorityTable 2-9. Action-Qualifier Event Priority for Up-Count Mode Table 2-10. Action-Qualifier Event Priority for Down-Count ModeWhen using up-count mode to generate an asymmetric PWM 2.4.4 Waveforms for Common ConfigurationsSee the Using Enhanced Pulse Width Modulator ePWM Module for 0-100% Table 2-11. Behavior if CMPA/CMPB is Greater than the PeriodFigure 2-20. Up-Down-Count Mode Symmetrical Waveform Action-Qualifier AQ Submodule EPWMxB-Active HighExample 2-2. Code Sample for Figure Action-Qualifier AQ Submodule EPWMxB-Active LowEPWMxA Example 2-3. Code Sample for FigureAction-Qualifier AQ Submodule Submit Documentation FeedbackSubmit Documentation Feedback Example 2-4. Code Sample for FigureAction-Qualifier AQ Submodule Action-Qualifier AQ Submodule EPWMxA and EPWMxB - Active LowExample 2-5. Code Sample for Figure Action-Qualifier AQ Submodule EPWMxA and EPWMxB - ComplementaryExample 2-6. Code Sample for Figure Example 2-7. Code Sample for Figure EPWMxA-Active LowAction-Qualifier AQ Submodule Submit Documentation Feedback2.5.1 Purpose of the Dead-Band Submodule 2.5 Dead-Band Generator DB Submodule2.5.2 Controlling and Monitoring the Dead-Band Submodule Figure 2-27. DeadBand Submodule∙ Mode 2-5 Classical Dead-Band Polarity Settings Figure 2-28. Configuration Options for the Dead-Band Submodule2.5.3 Operational Highlights for the Dead-Band Submodule ∙ Input Source SelectionTable 2-13. Classical Dead-Band Operating Modes action-qualifier submodule to generate the signal as shown for EPWMxADead-Band Generator DB Submodule Submit Documentation FeedbackFigure 2-29. Dead-Band Waveforms for Typical Cases 0% Duty 100% Figure 2-29 shows waveforms for typical cases where 0% duty 100%Dead-Band Generator DB Submodule Submit Documentation FeedbackFED = DBFED × TTBCLK RED = DBRED × TTBCLK 2.6.1 Purpose of the PWM-Chopper Submodule 2.6 PWM-Chopper PC Submodule2.6.2 Controlling the PWM-Chopper Submodule 2.6.3 Operational Highlights for the PWM-Chopper SubmodulePWM-Chopper PC Submodule 2.6.4 WaveformsFigure 2-31. PWM-Chopper Submodule Operational Details Pulses 2.6.4.1 One-Shot PulseTable 2-16. Possible Pulse Width Values for SYSCLKOUT = 100 MHz Start OSHT pulse EPWMxA in PSCLK Prog. pulse width OSHTWTH OSHTSustaining Pulses 2.6.4.2 Duty Cycle Control87.5% PSCLK PeriodFigure 2-35. Trip-Zone Submodule 2.7 Trip-Zone TZ Submodule2.7.1 Purpose of the Trip-Zone Submodule 2.7.3 Operational Highlights for the Trip-Zone Submodule 2.7.2 Controlling and Monitoring the Trip-Zone SubmoduleTable 2-17. Trip-Zone Submodule Registers ∙ Cycle-by-Cycle CBCTable 2-18. Possible Actions On a Trip Event Example 2-8. Trip-Zone ConfigurationsScenario A Scenario BTrip-Zone TZ Submodule 2.7.4 Generating Trip Event InterruptsFigure 2-36. Trip-Zone Submodule Mode Control Logic Figure 2-38. Event-Trigger Submodule 2.8 Event-Trigger ET SubmoduleFigure 2-37. Trip-Zone Submodule Interrupt Logic 2.8.1 Operational Overview of the Event-Trigger Submodule SignalsTable 2-19. Event-Trigger Submodule Registers input = Figure 2-41. Event-Trigger Interrupt GeneratorFigure 2-43. Event-Trigger SOCB Pulse Generator Figure 2-42. Event-Trigger SOCA Pulse GeneratorEvent-Trigger ET Submodule Submit Documentation FeedbackSubmit Documentation Feedback SPRU791D-November 2004-Revised OctoberKey Configuration Capabilities Applications to Power TopologiesOverview of Multiple Modules FrequenciesFigure 3-1. Simplified ePWM Module 3.2 Key Configuration Capabilities3.1 Overview of Multiple Modules Controlling Multiple Buck Converters With Independent Frequencies 3.3 Controlling Multiple Buck Converters With Independent FrequenciesSubmit Documentation Feedback Controlling Multiple Buck Converters With Independent FrequenciesIndicates this event triggers an ADC start Controlling Multiple Buck Converters With Independent FrequenciesSubmit Documentation Feedback Example 3-1. Configuration for Example in FigureControlling Multiple Buck Converters With Independent Frequencies Figure 3-5. Control of Four Buck Stages. Note FPWM2 = N x FPWM1 3.4 Controlling Multiple Buck Converters With Same FrequenciesControlling Multiple Buck Converters With Same Frequencies Figure 3-6. Buck Waveforms for Figure 3-5 Note FPWM2 = FPWM1Submit Documentation Feedback Example 3-2. Code Snippet for Configuration in FigureControlling Multiple Buck Converters With Same Frequencies Figure 3-7. Control of Two Half-H Bridge Stages FPWM2 = N x FPWM1 3.5 Controlling Multiple Half H-Bridge HHB ConvertersControlling Multiple Half H-Bridge HHB Converters Example 3-3. Code Snippet for Configuration in Figure 3.6 Controlling Dual 3-Phase Inverters for Motors ACI and PMSMSubmit Documentation Feedback Controlling Dual 3-Phase Inverters for Motors ACI and PMSMControlling Dual 3-Phase Inverters for Motors ACI and PMSM Submit Documentation Feedback Example 3-4. Code Snippet for Configuration in FigureControlling Dual 3-Phase Inverters for Motors ACI and PMSM Figure 3-11. Configuring Two PWM Modules for Phase Control 3.7 Practical Applications Using Phase Control Between PWM Modules3.8 Controlling a 3-Phase Interleaved DC/DC Converter =240 Figure 3-13. Control of a 3-Phase Interleaved DC/DC ConverterControlling a 3-Phase Interleaved DC/DC Converter Controlling a 3-Phase Interleaved DC/DC Converter Figure 3-14. 3-Phase Interleaved DC/DC Converter Waveforms for FigureSubmit Documentation Feedback Example 3-5. Code Snippet for Configuration in FigureControlling a 3-Phase Interleaved DC/DC Converter Figure 3-15. Controlling a Full-H Bridge Stage FPWM2 = FPWM1 3.9 Controlling Zero Voltage Switched Full Bridge ZVSFB ConverterFigure 3-16. ZVS Full-H Bridge Waveforms Controlling Zero Voltage Switched Full Bridge ZVSFB ConverterSubmit Documentation Feedback Example 3-6. Code Snippet for Configuration in FigureControlling Zero Voltage Switched Full Bridge ZVSFB Converter Submit Documentation Feedback SPRU791D-November 2004-Revised OctoberTime-Base Submodule Registers RegistersCounter-Compare Submodule Registers Action-Qualifier Submodule RegistersTable 4-2. Time-Base Phase Register TBPHS Field Descriptions Figure 4-2. Time-Base Phase Register TBPHS4.1 Time-Base Submodule Registers Figure 4-1. Time-Base Period Register TBPRDTable 4-4. Time-Base Control Register TBCTL Field Descriptions Figure 4-4. Time-Base Control Register TBCTLTime-Base Submodule Registers Submit Documentation FeedbackSubmit Documentation Feedback Time-Base Submodule RegistersFigure 4-5. Time-Base Status Register TBSTS 4.2 Counter-Compare Submodule RegistersTable 4-5. Time-Base Status Register TBSTS Field Descriptions Figure 4-6. Counter-Compare A Register CMPAFigure 4-7. Counter-Compare B Register CMPB Table 4-6. Counter-Compare A Register CMPA Field DescriptionsTable 4-7. Counter-Compare B Register CMPB Field Descriptions Counter-Compare Submodule RegistersFigure 4-8. Counter-Compare Control Register CMPCTL 4.3 Action-Qualifier Submodule RegistersTable 4-8. Counter-Compare Control Register CMPCTL Field Descriptions Action-Qualifier Submodule RegistersSubmit Documentation Feedback Figure 4-9. Action-Qualifier Output A Control Register AQCTLAAction-Qualifier Submodule Registers Submit Documentation Feedback Figure 4-10. Action-Qualifier Output B Control Register AQCTLBAction-Qualifier Submodule Registers Figure 4-11. Action-Qualifier Software Force Register AQSFRC Figure 4-13. Dead-Band Generator Control Register DBCTL 4.4 Dead-Band Submodule RegistersDead-Band Submodule Registers Submit Documentation FeedbackSubmit Documentation Feedback Dead-Band Submodule RegistersFigure 4-14. Dead-Band Generator Rising Edge Delay Register DBRED 4.5 PWM-Chopper Submodule Control RegisterFigure 4-15. Dead-Band Generator Falling Edge Delay Register DBFED Figure 4-16. PWM-Chopper Control Register PCCTLPWM-Chopper Control Register PCCTL Bit Descriptions continued 4.6 Trip-Zone Submodule Control and Status RegistersTrip-Zone Submodule Control and Status Registers Submit Documentation FeedbackSubmit Documentation Feedback Figure 4-17. Trip-Zone Select Register TZSELTrip-Zone Submodule Control and Status Registers Figure 4-18. Trip-Zone Control Register TZCTL Figure 4-19. Trip-Zone Enable Interrupt Register TZEINTTable 4-18. Trip-Zone Control Register TZCTL Field Descriptions Trip-Zone Submodule Control and Status RegistersTable 4-20. Trip-Zone Flag Register TZFLG Field Descriptions Figure 4-20. Trip-Zone Flag Register TZFLGTrip-Zone Submodule Control and Status Registers Submit Documentation FeedbackFigure 4-21. Trip-Zone Clear Register TZCLR 4.7 Event-Trigger Submodule RegistersTable 4-21. Trip-Zone Clear Register TZCLR Field Descriptions Figure 4-22. Trip-Zone Force Register TZFRCTable 4-23. Event-Trigger Selection Register ETSEL Field Descriptions Figure 4-23. Event-Trigger Selection Register ETSELBits NameTable 4-24. Event-Trigger Prescale Register ETPS Field Descriptions Figure 4-24. Event-Trigger Prescale Register ETPSEvent-Trigger Submodule Registers Submit Documentation FeedbackName Figure 4-25. Event-Trigger Flag Register ETFLGDescription Submit Documentation FeedbackFigure 4-26. Event-Trigger Clear Register ETCLR Table 4-25. Event-Trigger Flag Register ETFLG Field DescriptionsTable 4-26. Event-Trigger Clear Register ETCLR Field Descriptions Event-Trigger Submodule RegistersProper Interrupt Initialization Procedure 4.8 Proper Interrupt Initialization ProcedureFigure 4-27. Event-Trigger Force Register ETFRC Table 4-27. Event-Trigger Force Register ETFRC Field DescriptionsSubmit Documentation Feedback SPRU791D-November 2004-Revised OctoberAppendix A Revision HistoryTable A-1. Changes for Revision D SPRU791D-November 2004-Revised OctoberAppendix A Table A-1. Changes for Revision D continuedSection Submit Documentation FeedbackIMPORTANT NOTICE power.ti.comProducts Applications