Isolated DC–DC converters are preferred in the design of power supplies, for better safety and isolation purpose. Challenging task in the design of controllers for the converters is, compensating the effects of nonlinearity of switching and other components. This paper proposes the nonlinear controller design technique for isolated switching power supplies. Interleaved topology is chosen to achieve high output voltage and power. Voltage mode control of interleaved flyback converter (IFC) is illustrated using the Lyapunov direct method. It supports fast dynamic responses and simple to design. The Euler–Lagrangian model of the converter is used to derive the state model. It is based on energy equations that include dynamics of nonlinear inductive, resistive effects of transformer and switching devices. Flyback converters with different turns ratio are connected in cascade to attain high voltage gain. The primary side is designed with a parallel structure to handle the high current at the input side, and the secondary side is constructed with a series structure to have high output voltage at the output terminal. State observer is developed to ensure noise tolerant system design with reduced cost of implementation. It eliminates the use of the current sensor by estimating the primary current of each converter. The voltage spikes across the power semiconductor devices are suppressed by RCD snubber and interleaving topology to reduce switching losses. Circulating current between the converters is suppressed by non-overlapping switching. Fourth-order system is derived for interleaved converter. Stability analysis has been carried out for various values of system gain using describing functions harmonic linearization method. The converter is found to be stable for gains less than 0.55. Losses due to various components are analyzed and presented. Sixteen-bit control architecture is chosen to realize the digital controller. IFC (150 W) prototype is designed with the controller and implemented using Nexys 4 Artix-7 FPGA.

中文翻译：

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FPGA实现的Lyapunov直接法交错式反激变换器控制设计及稳定性分析

隔离式 DC-DC 转换器在电源设计中是首选，以获得更好的安全性和隔离性。转换器控制器设计中的挑战性任务是补偿开关和其他组件的非线性效应。本文提出了隔离开关电源的非线性控制器设计技术。选择交错拓扑以实现高输出电压和功率。使用李雅普诺夫直接法说明了交错式反激式转换器 (IFC) 的电压模式控制。它支持快速动态响应且易于设计。转换器的欧拉-拉格朗日模型用于导出状态模型。它基于能量方程，其中包括变压器和开关设备的非线性电感、电阻效应的动力学。具有不同匝数比的反激式转换器级联以获得高电压增益。初级侧设计为并联结构以处理输入侧的大电流，次级侧设计为串联结构以在输出端具有高输出电压。开发状态观察器是为了确保在降低实施成本的情况下进行抗噪系统设计。它通过估计每个转换器的初级电流而无需使用电流传感器。功率半导体器件上的电压尖峰由 RCD 缓冲器和交错拓扑抑制，以减少开关损耗。通过非重叠开关抑制转换器之间的循环电流。为交错式转换器推导出四阶系统。使用描述函数谐波线性化方法对系统增益的各种值进行了稳定性分析。发现转换器对于小于 0.55 的增益是稳定的。分析并介绍了由于各种组件造成的损失。选择十六位控制架构来实现数字控制器。IFC (150 W) 原型与控制器一起设计并使用 Nexys 4 Artix-7 FPGA 实现。