利用参考电压注入的Buck变换器电感电容估计

电路的元件参数，尤其是电感和电容值，严重影响着Buck变换器的控制性能。提出了一种参考电压脉冲注入法用于电感和电容的在线估计。为了提高Buck变换器中电感和电容值的估计精度，利用原稳态和新稳态构建满秩状态方程，在线推导算法所需寄生参数和负载电阻。研究基于电感伏秒特性和电容电荷平衡特性的精确离散时间变换器模型，为元件参数估计奠定了基础。通过给参考电压注入短脉冲信号，并使用PID控制器对电路中的电感电流和输出电压进行调节，建立了用于参数估计的瞬态和新稳态。利用瞬态中采样的电压和电感电流估计电感和电容值，避免了稳态时的收敛问题。基于提出的平均电感电流估计算法，电流采样频率降低至开关频率。最后，在Matlab/Simulink平台上进行了仿真验证，结果表明：即使在考虑实际噪声的情况下，电感和电容值的最大估计误差分别小于2%和4.2%;相较于其他参数估计算法，参考电压脉冲注入方法的引入有效提高了参数辨识的估计精度，有助于Buck变换器系统控制性能的提升。

Inductance and capacitance estimation by reference voltage injection for Buck converters

The component parameters of the circuit significantly affect the control performance of Buck converters, especially the inductance and capacitance. A reference voltage pulse injection method is proposed for the online estimation of inductance and capacitance. The full-rank state equation is constructed using the original steady state and the new steady state to improve the estimation accuracy of inductance and capacitance in the Buck converter. The parasitic parameters and load resistance required by the algorithm are derived online. The precise discrete-time converter model based on the volt-second characteristic of the inductor and the charge balance characteristic of the capacitor is studied, which lays the foundation for parameter estimation. A short pulse signal is injected into the reference voltage, and using a PID controller to regulate the inductor current and output voltage in the circuit, a transient state and a new steady state for parameter estimation are established. The inductance and capacitance values are estimated using the voltage and inductor current sampled in the transient state, which avoids the convergence problem in the steady state. Based on the proposed average inductor current estimation algorithm, the current sampling frequency is reduced to the switching frequency. Finally, the simulation verification is carried out on Matlab/Simulink platform, and the results show that the maximum estimation errors of the inductor and capacitor values are less than 2% and 4.2%, respectively, even when considering the actual noise. Compared with other parameter estimation algorithms, the introduction of the reference voltage pulse injection method can effectively improve the estimation accuracy of parameter identification and contribute to the improvement of the control performance of the Buck converter system.