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Transient Analysis
Published in Chengshan Wang, Jianzhong Wu, Janaka Ekanayake, Nick Jenkins, Smart Electricity Distribution Networks, 2017
Chengshan Wang, Jianzhong Wu, Janaka Ekanayake, Nick Jenkins
The control system adopts a dual-loop control structure. The outer loop implements the MPPT control and the reactive power control. Compared with the dual-loop structure in Figure 7.13, the MPPT control is unique to the PV system. The reference signal of the DC voltage yDCref is computed based on the current IPV and the voltage yDC of the PV array. The measured DC voltage yDC and the reactive power of the inverter are fltered and compared to their reference signals yDCref and Qref. The deviations are corrected by the PI block, which generates the reference signals idref and jqref for the inner current loop. When the working condition is changed (solar radiation, ambient temperature or the network topology), the deviation signal of the DC voltage or reactive power is non-zero, and the PI block will adjust the current reference accordingly until the deviation is eliminated.
Power Management IC Design for Efficient DVFS-Enabled On-Chip Operations
Published in Iniewski Krzysztof, Integrated Microsystems, 2017
This additional criterion has led to further sophistication in the feedback control of switching converters, through the introduction of the dual-loop design. The dual-loop controller achieves both feedback and feedforward control, to ensure that the converter can provide a constant output voltage, irrespective of line or load variations. Based on this concept, the work [40] presents an adaptive buck converter, which is controlled using a one-cycle control technique. As illustrated in Figure 2.16, the one-cycle control is a feedforward nonlinear control technique that is based on extracting voltage information from the switching node of the DC–DC converter, along with the output node. The design also uses dual error correction loops for effective load regulation. The converter is characterized by a very high maximum efficiency and fast up/down DVS-tracking speeds. The adaptive output, one-cycle control-based converter is further extended in [41], which introduces an SC-based controller with dynamic loss control for improved efficiency. This design is considerably more compact and area- and power-efficient, while still retaining the advantages of a fast dynamic response to transient and DVS changes. The SC-based controller in [40] inspired the design of the adaptive switching DC–DC converter presented in [42]. This converter employs a Δ–Σ modulator to perform noise shaping for a well-regulated, variable output voltage, by significantly reducing the noise tones, when compared to conventional PWM-based converters. In order to ensure fast line/load regulations, this design also introduces an observation-based line and load regulation circuit that helps in determining the switching actions of the power stage.
Bandwidth oriented approach for the design of a PI controller for a three phase two-stage grid-connected PV system
Published in International Journal of Electronics, 2023
Anshu Prakash Murdan, Iqbal Jahmeerbacus, S Z Sayed Hassen
The dc-dc converter controls the PV power, while the dc–ac converter (inverter) ensures that the extracted power is properly fed to the grid. This is done by regulating the dc–link voltage, as this voltage must be kept constant for the dc power and ac power to balance. This method is commonly called the voltage control method, whereby the current is controlled indirectly, by measuring and adjusting the dc-link and the supply voltage. This technique is also commonly referred to as ‘indirect current control’ (Dixon & Ooi, 1988). A dual-loop control structure is typically used, whereby the outer control loop is concerned with the voltage or power control, which produces the inner control loop current references. The inner control may be implemented in different reference frames, namely the frames.