| 1. | In this dissertation genetic arithmetic is used to find periodic fixed point of dc / dc converter system . while a new crossover operator is submitted to accelerate the convergence speed of ga
本文首先应用遗传算法来求取dc / dc变换器系统的不稳定不动点，同时提出一种新的杂交算子，以解决算法收敛慢的不足。 |
| 2. | Combinations of igbts controlled by four - step current commutation algorithm , was implemented by the cpld , which was also forecasted and validated by the simulation and experiment
为进行对矩阵式变换器系统的实验研究，采用cpld (复杂可编程逻辑器件)实现了igbt组合双向开关的四步换流逻辑控制，并通过仿真和实验进行了预测和验证。 |
| 3. | Dual randomized modulation technique is more effective than existing simple random modulation schemes , such as random position modulation or random switching frequency modulation , in dispersing the power spectrum
与已经存在的任何一种单随机方案相比，双随机调制技术驱散谐波能量而使之具有更宽的带宽，能更加有效地减少功率变换器系统的离散谱峰值。 |
| 4. | This paper mainly describes the small signal model and properties of the dc / dc converter , the optimum control model of the dc / ac inverter and analyses the stability and dynamic characteristics of the system . the experimental results show that the static inverter achieves high performance target
本文主要对6kva电源变换器系统进行了分析，包括前级dc dc变换器的小信号特性，后级dc ac逆变器的最优控制模型，分析了系统的稳定性和动态性能，仿真和实验表明该电源变换器具有高的性能指标。 |
| 5. | ( 3 ) modeling of the asymmetrical half bridge converter in the thesis , a small average circuit model of asymmetrical half bridge converter power stage is established by method of state space averaging . in term of it , a system model of total converter is founded . the characteristic of stabilization and dynamic is analysed and the compensator is designed basing of it
( 3 )不对称半桥dc dc变换器的建模分析采用状态空间平均法建立了不对称半桥变换器功率级的小信号平均电路模型，在此基础上建立整个变换器系统模型，对系统的动态特性和稳定性进行了分析并设计了补偿器。 |
| 6. | Firstly , the basic theory of full - bridge phase - shift zvs pwm converters are expatiated and another three kinds of circuits of full - bridge phase - shift zvs pwm converters are discussed . there are four kinds of problems which are emphasized : how to expand the zvs range ; how to reduce the circulation in the primary side of the transformer in order to minimize the on state losses ; how to decrease the loss of effective duty circle and how to eliminate the parasitic oscillation of the output rectifiers
本文首先分析了基本的全桥移相zvsdc dc变换器的工作原理，为解决滞后桥臂不易实现零电压开关( zvs )的情况，讨论了另外三种全桥移相zvsdc dc变换器的电路拓扑，重点分析并解决了四个方面的问题：如何扩大zvs的负载范围；减小变压器原边环流，降低变换器系统通态损耗；减少变压器次边有效占空比丢失；消除输出整流二极管的寄生振荡。 |
| 7. | But if we use chaotic phenomenon directly , three disadvantages exist : ( 1 ) the applied range was limited by dynamic character of the dc / dc converter system ; ( 2 ) high current fluctuation is found , and it is hard to be controlled ; ( 3 ) high output voltage fluctuation
但是利用dc / dc变换器系统本身的混沌现象来提高电路的电磁兼容性，存在着三个方面的不足： （ 1 ）应用范围受到系统本身动力学性质的限制； （ 2 ）电路中的电流波动大，难以控制； （ 3 ）输出电压波动大。 |
