【作者】 孙向东；

【导师】 钟彦儒；

【作者基本信息】 西安理工大学 ， 电力电子与电力传动， 2003， 博士

【摘要】 在对移相控制技术和高频链逆变技术的研究现状综述、评价基础上，对新型单相和三相组合式软开关高频链逆变器的关键技术进行了深入研究与探讨。 从功率单向流动角度出发，提出了一种LCC谐振型恒频移相单相高频链逆变电路拓扑，在调制系数0.1≤m≤0.5情况下，控制移相角θ按正弦规律变化，使谐振电压脉冲列的幅值追踪参考正弦电压信号，经过整流、滤波、低频逆变，从而获得正弦度较好的输出电压。理论分析和实验结果证明对于阻性负载或阻感性负载，移相全桥具有超前桥臂零电压开通，滞后桥臂或者零电压开通（θ＜θ₀）或者零电流关断（θ＞θ₀）的软开关特性，而低频逆变器的各个开关均实现零电压条件下的开通与关断。实测整机在额定负载时效率达到88％以上。 在研究LCC谐振网络电压传输特性的基础上，推导出满足可变宽度和幅度的谐振网络输出电压脉冲列的参数组合。设计f＿n＞3、K＞3或C_p/C_s＞8时，谐振网络具有自然稳压特性，因此本文提出并实验验证了一种整机为降电压时的开环控制策略。当利用谐振网络提升整机输出电压时，由于负载R对Q值的影响，因此必须采用所提出的闭环控制方法才能保证良好的稳压功能。 论文提出一种新型移相全桥软开关周波变流型三相高频链逆变器，电路的主要优点是：前级移相全桥的移相角θ控制在θ_d＜θ_i＜θ和θ≥θ_overlap-θ_d条件下，超前桥臂零电压开通，滞后桥臂零电流关断，并使周波变流器所有开关在零电压期间重叠换相，使整机开关最大程度地实现了软开关，并可靠解决了高频变压器漏感储能引起的电压尖峰问题。理论分析和实验结果证明这是一种有实用前景的软开关型高频链逆变器，可用于需要与供电电源隔离的特殊三相电机驱动的场合。西安理工大学博士学位论文 针对这种前级移相全桥软开关周波变流型三相高频链逆变器结构和控制的复杂性，提出了一种实现简单而整体优化的VVVF控制策略:将空间电压矢量产生P姗的方法SVM和等效载波频率fe=1/Te引入到周波变流器的PDM控制;按高频电压脉冲前后沿软化等效P翎波;用移相调节高频脉冲宽度和等效P姗调压协调控制逆变器输出电压，在满足输出电压条件下使谐波最小。设计的基于DSP的数字控制系统实现了上述控制策略，并经整机实测验证了控制策略的可行性和正确性。 论文还研究了移相全桥开关频率fs、周波变流器等效载波频率fe及输出频率fo之间的最佳配合关系，提出在满足fs 23.5fe且fe之12fo条件下，该高频链逆变器输出电压具有较好的正弦度。更多还原

【Abstract】 On the basis of the research on the phase-shift-controlled technology and the high-frequency (HF)link inverting technology, and the key technical problems of the novel single-phase and three-phase compounded HF link inverter for soft-switching are studied and discussed in detail .From the viewpoint of the direction of power flow, a single-phase HF link inverter circuit topology on the basis of LCC-type resonant circuit with constant-frequency phase-shifted control is proposed. Under the condition of 0. 1 m 0.5 , the phase-shifted angle 6 is controlled in term of sine law which makes the magnitude of resonant voltage track a reference sine voltage , and the resonant voltage is rectified , filtered, inverted and then the better sine-voltage output is obtained , Theoretical analysis and experimental results show that for the resistive load and inductive load, the switches of leading leg of the phase-shift-controlled circuit are always turned on at ZVS, and ones of lagging leg are turned on at ZVS( < 0 ) or turned off at ZCS( ( > 0 ), moreover, all switches in the low-frequency inverter are always turned on and off at ZVS , the measured circuit efficiency for rated load reaches up to 88% .Based on the study of transferring characteristics of the LCC-type resonant voltage, the parameter combinations, which make widths and magnitudes of voltage pulses of resonant network adjustable, arededucedo When the following requirements are met: fn>3, K>3 or Cp/Cs>8, the above circuit is of natural voltage-stabilized characteristics, thus open-loopcontrol method for bucking voltage is presented and the experimental results verify that the method is feasible., For the purpose of boosting voltage, because of the effect of the load R on Q, the proposed close-loop control method is the best choice to ensure the stable output voltage .A novel cycloconverter-rype three-phase HF link inverter topology for soft-switching based on phase-shifted full-bridge mode is proposed, whose main advantages are as follows: under the conditions of d < i < and overlap - d, the switches of the leading leg are turned on at ZVS and the switches of the lagging leg are turned off at ZCS and all switches of the cycloconverter circuit are commutated in the overlapping mode in the interval of zero voltage, which makes the circuit realize soft switching to the utmost extent and reliably solve the problem of peak voltage caused by the storing energy of leakage inductance of HF transformer. Theoretical analysis and experimental results prove that the HF link inverter for soft-switching is prospective and it can be used in driving specific three-phase motors isolated from power supply .Due to the complexity of the structure and control of cycloconverter-type three-phase HF link inverter for soft-switching based on phase-shift-controlled full-bridge mode, a simple and optimized VVVF control strategy is proposed . This control strategy includes: produced PWM by space voltage vector ( SVM ) and equivalent carrier frequency fe =1/Te are introduced into the PDM Control of the cycloconverter; softened equivalent PWM wave is generated at the notches of HF voltage pulses; the harmonious control between regulating pulse width by phase-shifted angle and regulating voltage of equivalent PWM is to minimize the harmonics content of output voltage of the inverter. Digital control system based on DSP is designed and it realizes the above control strategy, the feasibility and validity of the control are verified by experiments .The optimal relationships among switch frequency fs of the phase-shifted full-bridge circuit , equivalent carrier frequency fe of the cycloconverter and output frequency fo are also studied, and under the conditions of fs 3.5 feand fe 12 fo, the output voltageof the HF link inverter has the good sinusoidal characteristics.更多还原