Centralized-local comprehensive voltage control method and device for power distribution network with photovoltaic access

Abstract

The invention discloses a centralized-local comprehensive voltage control method and device suitable for a power distribution network with high-proportion photovoltaic access. The method comprises thefollowing steps: in a centralized control phase, acquiring photovoltaic and load prediction data of a power distribution network at a first sampling interval, and optimally calculating and updating the inverter droop slopes of each photovoltaic access node by using a pre-constructed centralized control model and taking the minimum loss of the power distribution network as an optimization target and considering a network power flow constraint, an inverter droop curve slope constraint and an inverter reactive output constraint; and in a local control stage, acquiring the real-time measurement voltages of each photovoltaic access node at a second sampling interval in the first sampling interval, and determining a voltage-reactive droop curve according to the current droop slopes of the inverters of each photovoltaic access node so as to perform local control on the corresponding node. According to the invention, optimization of reactive power control is realized by combining centralizedcontrol and local control modes, so that photovoltaic prediction errors and power fluctuation can be quickly responded, and effective coordination among equipment can be realized.

Description

technical field [0001] The invention relates to the technical field of electricity consumption information collection and analysis, in particular to a centralized-on-site comprehensive voltage control method and device suitable for a distribution network with a high proportion of photovoltaic access. Background technique [0002] In recent years, the photovoltaic grid-connected installed capacity of medium and low voltage distribution networks has grown rapidly, and photovoltaics in medium and low voltage distribution networks have shown a development trend of "decentralized development and nearby consumption". At the same time, the high proportion of photovoltaic grid-connected also has a significant negative impact on the low-voltage distribution network, manifested in: 1) the power flow changes from one-way flow to two-way flow, especially in the case of strong sunlight, it is easy to appear obvious reverse power flow, which leads to The voltage exceeds the upper limit; 2...

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Problems solved by technology

Although the centralized control can effectively coordinate the reactive power output of different photovoltaic inverters, the data transmission delay and the large amount of calculation restrict the response of the centralized control to the rapid change of photovoltaic power, and the prediction error will also significantly affect the centralized control. Effect

[0005] Aiming at the difficulty of local control coordination, some studies have pointed out that the coordination of local control parameters can be achieved based on historical data, network topology and parameters, but changes in network structure or line parameters will lead to resetting of inverter parameters; Some studies use local communication technology and distributed control to improve the coordination of control in low-voltage distribution network, but the global optimization of control has not been considered yet.

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