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High-power Bi-directional Dc-dc Converter Topology And The Theory Research

Posted on:2006-08-21Degree:DoctorType:Dissertation
Country:ChinaCandidate:H P XuFull Text:PDF
GTID:1112360182499722Subject:Power electronics
Abstract/Summary:PDF Full Text Request
High power Bi-directional DC-DC converter can be applied in the fields of the electric vehicles, electric storage systems, electric power quality regulation systems, renewable energy generation systems, superconductor electric power systems, and so on. In this dissertation, the Bi-directional DC-DC converter topology, Bi-directional power flow PWM technology, the method of converter modeling and design, and digital control technology are researched thoroughly.Aim at the high power converter application, the Bi-directional DC-DC converters based on PEBB (Power Electronic Building Block) with the half bridge configuration are put forward in the first time. Those converters include the isolation topology, non-isolation topology, and many novel topologies, such as multi-phase topology, cascade structure topology, combination structure topology and complex structure topology etc.This dissertation propose two methods of Bi-directional DC-DC converter modeling and analysis, which are named as Modified State Space Averaged method (MSSA) and novel Modified Switching signal Flow Graph method (MSFG), and found the basic framework of the system analysis and design theory. Based on the MSFG method, the algebraic models and circuit models of Bi-directional converters are combined effectively, the electrical characteristics of the converters are analyzed straightly, the DC static models, AC dynamic models and large signal models of the converters are constructed contemporary.Three kinds of typical topologies, including BUCK/BOOST Bi-directional DC-DC converter topology, Interleaved Dual phase Bi-directional DC-DC topology and Dual Active Bridge Bi-directional DC-DC topology, are investigated and verified by the experiment. The complementary PWM method, multi-phase PWM method and Dual Active Bridge phase-shift PWM method are proposed to those converters topologies respectively. The circuit principles, the working modes, the Bi-directional power flow and soft switching characteristics of the converters are expatiated thoroughly. Based on the MSSA and MSFG method, the system models of those three kinds of Bi-directional DC-DC converters are constructed. The static performances, the small signal transfer function characteristics and large signal dynamic performances of the converters are studied by simulation. The models constructed by MSSA and MSFG method respectively are identical. It is verified the proposed modeling method.This dissertation expatiate the design method and process of the controller, present an analysis of voltage and current control mode of DC-DC converter, and propose a multi-purpose controller working in constant voltage/constant current/constant power states alterable. Furthermore, aim at the nonlinear, parameter changing and time-variant high-frequency switch system, a novel PID regulator is used to improve the system's stability and dynamic performance. A large signal controller is put forward in theand the system stability of the large signal is proved theoretically. Several kinds of the STATE SWITCHING methods for Bi-directional DC-DC converters are bring forward to ensure the changing of the Bi-directional power flow smoothly.The principle of design digital controller key parameters, such as sampling rate, bits of AD conversion, DPWM resolution and switch frequency are discussed in this dissertation. Meanwhile, an asynchronous sampling method is proposed to ensure the precision of feedback signal, such as output voltage and current.Finally, with the DSP-TI320F2407 as the main control unit, a set of 75kW BUCK/BOOST Bi-directional DC-DC converter BBBC, two sets of 150 kW Interleaved Dual phase Bi-directional DC-DC converter IDBBC and a set of 5kW isolated Dual Active Bridge Bi-directional DC-DC converter DABBC are developed. The efficiency of those systems with high voltage output are large than 97%. the power density are large than 3k W/kg and 3kW/L. Experiment with them show that the systems have excellent properties. The dynamic response times of the converters are less than 100ms, and the system control error are less than 1 percent.In conclusion, this dissertation focus on the most important aspects of the high power Bi-directional DC-DC converter, provide the system theory to converter design and analysis, and are validated in the project applications.
Keywords/Search Tags:DC-DC Converter, Bi-directional DC-DC Converter, Bi-directional Topology, Bi-directional Power Flow, PEBB, Power Electronic Building Block, Switching Converter Modeling, PWM technology, Digital Control.
PDF Full Text Request
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