Analysis and Design of Multicell DCDC Converters Using Vectorized Models

<p>CHAPTER 1. GENERAL PROPERTIES OF MULTILEVEL CONVERTERS 1</p>
<p>1.1. Time–domain: multilevel waveform and apparent switching frequency 1</p>
<p>1.2. Frequency domain: harmonic cancellation 4</p>
<p>1.3. Transient response 5</p>
<p>1.4. Conclusion 6</p>
<p>CHAPTER 2. TOPOLOGIES OF MULTILEVEL DC/DC CONVERTERS 9</p>
<p>2.1. Series connection 9</p>
<p>2.1.1. Direct series connection with isolated sources 9</p>
<p>2.1.2. Flying capacitor 11</p>
<p>2.2. Parallel connection 14</p>
<p>2.2.1. Interleaved choppers with star–connected inductors 14</p>
<p>2.2.2. Interleaved choppers with InterCell Transformers (ICTs) 17</p>
<p>2.3. Series–parallel connection 20</p>
<p>CHAPTER 3. CONCEPT OF VECTORIZATION IN PLECS 23</p>
<p>3.1. Vectorized components 23</p>
<p>3.2. Star–connection block and parallel multicell converter 25</p>
<p>3.3. Series connection block and series multicell converter 27</p>
<p>3.4. Generalized multicell commutation cell 28</p>
<p>3.5. Practice 34</p>
<p>3.5.1. How to? 34</p>
<p>3.5.2. Basic blocks 34</p>
<p>CHAPTER 4. VECTORIZED MODULATOR FOR MULTILEVEL CHOPPERS 37</p>
<p>4.1. General principle 37</p>
<p>4.2. xZOH: equalizing multisampler for multilevel choppers 38</p>
<p>4.2.1. Control as the main source of perturbation 38</p>
<p>4.2.2. Handling duty cycle variation 38</p>
<p>4.2.3. Frequency response of the equalizing sampler and modulator 51</p>
<p>4.3. Practice 53</p>
<p>CHAPTER 5. VOLTAGE BALANCE IN SERIES MULTILEVEL CONVERTERS 57</p>
<p>5.1. Basic principles 57</p>
<p>5.2. Linear circuits 58</p>
<p>5.2.1. Internal balancers 58</p>
<p>5.2.2. External balance boosters 59</p>
<p>5.2.3. Pros and cons of internal/external balance boosters 64</p>
<p>5.3. Nonlinear variants 65</p>
<p>5.3.1. Internal balance boosters 65</p>
<p>5.3.2. External balance boosters 66</p>
<p>5.4. Loss–based design 67</p>
<p>5.4.1. Introduction 67</p>
<p>5.4.2. Internal balance boosters 68</p>
<p>5.4.3. External balance boosters 68</p>
<p>5.5. Vectorized models of balance boosters 69</p>
<p>CHAPTER 6. FILTER DESIGN 75</p>
<p>6.1. Requirements 75</p>
<p>6.1.1. Steady state: current ripple, voltage ripple and standards 75</p>
<p>6.1.2. Transients 83</p>
<p>6.1.3. Extra design constraints 84</p>
<p>6.2. Design process 85</p>
<p>CHAPTER 7. DESIGN OF MAGNETIC COMPONENTS FOR MULTILEVEL CHOPPERS 89</p>
<p>7.1. Requirements and problem formulation 89</p>
<p>7.2. Area product 92</p>
<p>7.2.1. Low frequency low ripple formulation for filtering inductors 92</p>
<p>7.2.2. General formulation for filtering inductors 94</p>
<p>7.2.3. Application to inductors for interleaved converters 95</p>
<p>7.2.4. Extension to InterCell Transformers 97</p>
<p>7.3. Optimal area product of magnetic components for interleaved converters 99</p>
<p>7.3.1. Optimal area product for inductors 99</p>
<p>7.3.2. Optimal area product for InterCell Transformers 101</p>
<p>7.4. Weight–optimal dimensions for a given area product 101</p>
<p>7.4.1. For inductors 101</p>
<p>7.4.2. For InterCell Transformers 107</p>
<p>7.5. Volume–optimal dimensions for a given area product 118</p>
<p>7.6. Number of turns and air gap 120</p>
<p>7.7. Accounting for current overload 123</p>
<p>7.8. Optimal phase sequence for InterCell Transformers 123</p>
<p>7.9. Vectorized reluctance model of magnetics 125</p>
<p>7.9.1. Inductors 125</p>
<p>7.9.2. Cyclic cascade InterCell Transformers 126</p>
<p>7.9.3. Monolithic InterCell Transformers 128</p>
<p>7.10. Design process 130</p>
<p>CHAPTER 8. CLOSED–LOOP CONTROL OF MULTILEVEL DC/DC CONVERTERS 131</p>
<p>8.1. Principle 131</p>
<p>8.2. Corresponding PLECS block 133</p>
<p>8.3. Average model of the macrocommutation cell for transient studies 136</p>
<p>8.4. Conclusion 140</p>
<p>BIBLIOGRAPHY 141</p>
<p>INDEX 145</p>