Abstract:

Considering the output randomness and uncertainty of photovoltaic power generation system,the reactive power of the system is optimized by using the photovoltaic inverter with residual capacity as a continuously adjustable reactive power source.Based on the analysis,an 8-node chain distribution network model is established to evaluate the constraint relationship between distribution network voltage and photovoltaic grid-connected capacity after distributed photovoltaic access to distribution network.The probability distribution model of photovoltaic power supply output is established,and the reactive power of distribution network is optimized by taking the minimum sum of active power loss and total voltage deviation as the objective function.The discrete data of the system are processed by adaptive genetic algorithm (AdapGA),and the optimal solution is found.An example of IEEE33-bus system shows that the model and method are practical.Interoperability can reduce the node voltage loss of distribution feeder,reduce the active power loss of distribution network,and ensure the stable operation of distribution network when intermittent power supply is connected to the grid.The correctness and validity of the model and method in this paper are verified.

Key words: chain distribution network, intermittent photovoltaic power supply, self-adaptive genetic algorithm, IEEE33