The Basic Problem of Islanding Effect
Author: Source: Datetime: 2016-10-05 01:31:38
When the PV arrays are connected in series, the local maximum power point will appear in the curve of the PV array. In this case, if the PV array curve based on the single peak pattern is used, Therefore, it is necessary to study the method for the local maximum power point. Here are two basic methods.
Assuming that the system is running at a certain voltage point, the system should increase the disturbance voltage according to the previous judgment. If the irradiance decreases, the output power of the operating point corresponding to the voltage may be smaller than the output of the original operating point Power, that is, at this time the system will misjudge the direction of the voltage disturbance error, so that the operating point in the work away from the maximum power point. If the irradiance continues to drop, there may be continuous misjudgment of the control system, so that the operating voltage constantly moving to the left, for the grid system, this misjudgment on the one hand will increase the power loss, on the other hand Due to the DC side voltage drop and make the grid current out of control,
However, the efficiency of the grid-connected inverter itself is only the static conversion efficiency of the PV system energy. With the application of grid-connected photovoltaic power generation, it has been found that a single static conversion efficiency index is difficult to fully describe the conversion efficiency of grid-connected inverter. This is because the grid-connected inverter not only completes the DC-to-AC conversion and grid-connected control, but also controls whether or not the PV cell is running and whether the PV cell is running will directly affect the conversion efficiency of the solar power generator system. The tracking efficiency, and how to measure the efficiency of fair and accurate is an important issue in the research of solar power generator.
Test Steps for Simulated Intermittent Cloud Closures> A fast ramp is designed to simulate the effect of accumulated clouds moving from the sun. The purpose of this test is to determine how quickly the device under test reacts to changes in the output power of the array It is important to note that since the temperature does not change and the irradiance-voltage variations for the three array types are nearly identical, there is little change in the shape of the curve. TAG: Multi-Storage Reliability Shell Manganese 200MW Ørsted Micro ABB Programs Volvo 65MW Porsche Largest Volkswagen Lease
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