Coordinated control method for distributed photovoltaic energy storage system

Abstract

The invention relates to a distributed photovoltaic energy storage system coordinated control method. The control method comprises steps that the power of a photovoltaic array, the energy storage power, the photovoltaic energy storage combined grid-connected power and a state of charge of an energy storage system are monitored in real time; the power of the photovoltaic array is substituted into afiltering function; Step a3, a high frequency portion and a low frequency portion are calculated; the low frequency volatility is calculated; whether the low frequency volatility exceeds the volatility limit is determined, if yes, the filtering function gain is adjusted, then the process returns to a step a3, otherwise, the high frequency portion is utilized as a power command value of the energystorage system; the state of charge of the energy storage system after execution of the power command value is calculated; whether the state of charge of the energy storage system is optimal is determined, if yes, the high frequency portion is executed as a power command of the energy storage system, otherwise, a state of charge regulator is entered to adjust the filtering function gain, and thenthe process returns to the step a3. The control method is advantaged in that while the photovoltaic power volatility strictly meets index requirements, economical property of the energy storage system is further considered.

Description

Technical field: [0001] The invention relates to the field of distributed photovoltaic and energy storage, in particular to a coordinated control method for a distributed photovoltaic energy storage system. Background technique: [0002] As the scale of distributed photovoltaic power generation participating in grid connection continues to increase, its randomness and volatility pose severe challenges to the security and stability of distribution networks. In order to improve the ability of distributed photovoltaic power generation to be connected to the grid, it is necessary to stabilize the fluctuation of photovoltaic power connected to the grid. Because the energy storage system can absorb or release energy dynamically, it can effectively stabilize the fluctuation of photovoltaic power. [0003] Most of the existing control methods aim at reducing the photovoltaic fluctuation rate, and the filter functions used are mostly fixed-gain filter functions, which are suitable f...

AI Technical Summary

Problems solved by technology

However, for distributed photovoltaics with multiple access and distribution networks, the fluctuation rate exceeding the limit is not only an economic issue but also a safety issue, so the requirements for the volatility rate are more stringent

At the same time, the fixed gain filter function does not realize the operation economy of the energy storage system

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