Self-Commutating Converters for High Power Applications -- Contents -- Preface -- 1 Introduction -- 1.1 Early developments -- 1.2 State of the large power semiconductor technology -- 1.2.1 Power ratings -- 1.2.2 Losses -- 1.2.3 Suitability for large power conversion -- 1.2.4 Future developments -- 1.3 Voltage and current source conversion -- 1.4 The pulse and level number concepts -- 1.5 Line-commutated conversion (LCC) -- 1.6 Self-commutating conversion (SCC) -- 1.6.1 Pulse width modulation (PWM) -- 1.6.2 Multilevel voltage source conversion -- 1.6.3 High-current self-commutating conversion -- 1.7 Concluding statement -- References -- 2 Principles of Self-Commutating Conversion -- 2.1 Introduction -- 2.2 Basic VSC operation -- 2.2.1 Power transfer control -- 2.3 Main converter components -- 2.3.1 DC capacitor -- 2.3.2 Coupling reactance -- 2.3.3 The high-voltage valve -- 2.3.4 The anti-parallel diodes -- 2.4 Three-phase voltage source conversion -- 2.4.1 The six-pulse VSC configuration -- 2.4.2 Twelve-pulse VSC configuration -- 2.5 Gate driving signal generation -- 2.5.1 General philosophy -- 2.5.2 Selected harmonic cancellation -- 2.5.3 Carrier-based sinusoidal PWM -- 2.6 Space-vector PWM pattern -- 2.6.1 Comparison between the switching patterns -- 2.7 Basic current source conversion operation -- 2.7.1 Analysis of the CSC waveforms -- 2.8 Summary -- References -- 3 Multilevel Voltage Source Conversion -- 3.1 Introduction -- 3.2 PWM-assisted multibridge conversion -- 3.3 The diode clamping concept -- 3.3.1 Three-level neutral point clamped VSC -- 3.3.2 Five-level diode-clamped VSC -- 3.3.3 Diode clamping generalization -- 3.4 Theying capacitor concept -- 3.4.1 Three-level flying capacitor conversion -- 3.4.2 Multi-level flying capacitor conversion -- 3.5 Cascaded H-bridge conguration -- 3.6 Modular multilevel conversion (MMC) -- 3.7 Summary.

References -- 4 Multilevel Reinjection -- 4.1 Introduction -- 4.2 The reinjection concept in line-commutated current source conversion -- 4.2.1 The reinjection concept in the double-bridge configuration -- 4.3 Application of the reinjection concept to self-commutating conversion -- 4.3.1 Ideal injection signal required to produce a sinusoidal output waveform -- 4.3.2 Symmetrical approximation to the ideal injection -- 4.4 Multilevel reinjection (MLR)-the waveforms -- 4.5 MLR implementation-the combination concept -- 4.5.1 CSC configuration -- 4.5.2 VSC configuration -- 4.6 MLR implementation-the distribution concept -- 4.6.1 CSC configuration -- 4.6.2 VSC configuration -- 4.7 Summary -- References -- 5 Modelling and Control of Converter Dynamics -- 5.1 Introduction -- 5.2 Control system levels -- 5.2.1 Firing control -- 5.2.2 Converter state control -- 5.2.3 System control level -- 5.3 Non-linearity of the power converter system -- 5.4 Modelling the voltage source converter system -- 5.4.1 Conversion under pulse width modulation -- 5.5 Modelling grouped voltage source converters operating with fundamental frequency switching -- 5.6 Modelling the current source converter system -- 5.6.1 Current source converters with pulse width modulation -- 5.7 Modelling grouped current source converters with fundamental frequency switching -- 5.8 Non-linear control of VSC and CSC systems -- 5.9 Summary -- References -- 6 PWM-HVDC Transmission -- 6.1 Introduction -- 6.2 State of the DC cable technology -- 6.3 Basic self-commutating DC link structure -- 6.4 Three-level PWM structure -- 6.4.1 The cross sound submarine link -- 6.5 PWM-VSC control strategies -- 6.6 DC link support during AC system disturbances -- 6.6.1 Strategy for voltage stability -- 6.6.2 Damping of rotor angle oscillation -- 6.6.3 Converter assistance during grid restoration.

6.6.4 Contribution of the voltage source converter to the AC system fault level -- 6.6.5 Control capability limits of a PWM-VSC terminal -- 6.7 Summary -- References -- 7 Ultra High-Voltage VSC Transmission -- 7.1 Introduction -- 7.2 Modular multilevel conversion -- 7.3 Multilevel H-bridge voltage reinjection -- 7.3.1 Steady state operation of the MLVR-HB converter group -- 7.3.2 Addition of four-quadrant power controllability -- 7.3.3 DC link control structure -- 7.3.4 Verification of reactive power control independence -- 7.3.5 Control strategies -- 7.4 Summary -- References -- 8 Ultra High-Voltage Self-Commutating CSC Transmission -- 8.1 Introduction -- 8.2 MLCR-HVDC transmission -- 8.2.1 Dynamic model -- 8.2.2 Control structure -- 8.3 Simulated performance under normal operation -- 8.3.1 Response to active power changes -- 8.3.2 Response to reactive power changes -- 8.4 Simulated performance following disturbances -- 8.4.1 Response to an AC system fault -- 8.4.2 Response to a DC system fault -- 8.5 Provision of independent reactive power control -- 8.5.1 Steady state operation -- 8.5.2 Control structure -- 8.5.3 Dynamic simulation -- 8.6 Summary -- References -- 9 Back-to-Back Asynchronous Interconnection -- 9.1 Introduction -- 9.2 Provision of independent reactive power control -- 9.3 MLCR back-to-back link -- 9.3.1 Determining the DC voltage operating limits -- 9.4 Control system design -- 9.5 Dynamic performance -- 9.5.1 Test system -- 9.5.2 Simulation verification -- 9.6 Waveform quality -- 9.7 Summary -- References -- 10 Low Voltage High DC Current AC-DC Conversion -- 10.1 Introduction -- 10.2 Present high current rectication technology -- 10.2.1 Smelter potlines -- 10.2.2 Load profile -- 10.3 Hybrid double-group conguration -- 10.3.1 The control concept -- 10.3.2 Steady state analysis and waveforms -- 10.3.3 Control system.

10.3.4 Simulated performance -- 10.4 Centre-tapped rectier option -- 10.4.1 Current and power ratings -- 10.5 Two-quadrant MLCR rectication -- 10.5.1 AC system analysis -- 10.5.2 Component ratings -- 10.5.3 Multigroup MLCR rectifier -- 10.5.4 Controller design -- 10.5.5 Simulated performance of an MLCR smelter -- 10.5.6 MLCR multigroup reactive power controllability -- 10.6 Parallel thyristor/MLCR rectication -- 10.6.1 Circuit equations -- 10.6.2 Control system -- 10.6.3 Dynamic simulation and verification -- 10.6.4 Efficiency -- 10.7 Multicell rectication with PWM control -- 10.7.1 Control structure -- 10.7.2 Simulated performance -- 10.8 Summary -- References -- 11 Power Conversion for High Energy Storage -- 11.1 Introduction -- 11.2 SMES technology -- 11.3 Power conditioning -- 11.3.1 Voltage versus current source conversion -- 11.4 The SMES coil -- 11.5 MLCR current source converter based SMES power conditioning system -- 11.5.1 Control system design -- 11.6 Simulation verication -- 11.7 Discussion-the future of SMES -- References -- Index.