Photovoltaic miniature inverter produced by American Phase Energy Co., Ltd. is shown in Figure 7.15. The front stage uses an active clamp interleaving flyback converter for sinusoidal PWM wave modulation, forms a power frequency sinusoidal half wave envelope through a high-frequency flyback transformer and a fast recovery diode rectifier circuit, and the rear stage uses […]
Analysis of some shadow problems
1.The impact of part of the shadowSome shadows are divided into hard shadows and soft shadows. Soft shadow refers to some shadow problems caused by dust, fallen leaves, clouds, snow, shadows, tall buildings, etc. The hard shadow components of the hard shadow are aging due to different orientation, angle, parameters, and some battery components. The […]
What are the active inhibitory DC current components?
1. Parallel transformer detection methodThe detection circuit of the parallel transformer detection method consists of a small -power industrial frequency transformers with a Tan ratio of 1: 1, and the sub -filter circuit of the sub -edge of the sub -edge of the small power. The DC voltage component in the power grid is mainly […]
What problems can arise when the DC current component is injected into the grid? How to suppress it?
In recent years, the photovoltaic industry has developed rapidly, the non-isolated photovoltaic grid-connected power generation system has developed rapidly, and the photovoltaic grid-connected capacity has increased significantly. Therefore, the impact of the injection of the DC current component into the AC grid has attracted more and more attention, and the problem of injection of the […]
Refusol three-phase photovoltaic grid-connected power generation circuit/Steca single-phase photovoltaic grid-connected power generation circuit
1.Refusol three-phase photovoltaic grid-connected power generation circuit: Refusol three-phase photovoltaic grid-connected power generation circuit consists of three single-phase circuits, which share two symmetric BOOST converters, and their common connection nodes are V1, V2, Vn, V3 and V4, as shown in FIG. 6.29. Each single phase has BUCK and BOOST working modes in half A grid […]
Three-switch bridge arm circuit/double buck circuit/three-level full bridge circuit
Three-switch bridge arm circuit The design idea of this circuit is also derived from the HERIC circuit [121], as shown in Fig. 1(a) and (b). Obviously, the efficiency of this circuit is reduced due to the higher conduction loss than the HERIC circuit. The full-load efficiency of the whole machine is about 97% [122]. Its […]
What is a common mode current suppression circuit ?
1) Full bridge inverter Bipolar PWM modulation mode is adopted. As shown in Figure 1.11, in a switching cycle, when S1 and S4 are on, S2 and S3 are off, S1 and S4 are off, and S2 and S3 are on, it can be seen that as long as VPV remains constant, the common mode […]
The principle of common mode current is explained in detail with pictures and texts
The area of the photovoltaic array is generally large, and the parasitic capacitance to the ground can reach 200nF/kWp in a rainy or humid environment. The power switching action of the grid-connected inverter may generate high-frequency voltage changes. Due to the existence of the parasitic capacitance of the photovoltaic array to the ground, a common […]
Design requirements for photovoltaic grid-connected power generation circuit topology
Different classification methods of photovoltaic grid-connected power generation circuit topology can be obtained from different angles. In practical applications, it is necessary to select an appropriate circuit topology according to different usage occasions and grid-connected requirements. The key index factors of the topology structure of power electronic conversion circuit are: ◆High efficiency (power loss, number […]
Classification and characteristics of topology structure of unschedulable photovoltaic grid-connected power generation circuit
Different focus points make the classification of photovoltaic grid-connected power generation systems slightly different. The following three aspects are classified and explained. According to the connection method of photovoltaic cell modules and power electronic conversion circuits From the perspective of the connection method between photovoltaic cell modules and power electronic conversion circuits, photovoltaic grid-connected power […]