Off-grid grid-connected hybrid photovoltaic power generation control system and economical operation optimization method thereof

Abstract

The invention relates to an off-grid grid-connected hybrid photovoltaic power generation control system and an economical operation optimization method of the off-grid grid-connected hybrid photovoltaic power generation control system. The control system is composed of a photovoltaic array, a grid-connected inverter, a storage battery pack, a bi-directional inverter, a load, a power meter, a public grid, a demand response control system and a switch set. The photovoltaic array is connected into an alternating-current side through the grid-connected inverter, and the storage battery pack is connected into the alternating-current side through the bi-directional inverter. The grid-connected inverter is connected with the bi-directional inverter through a switch, and the public grid and the load are connected through the switch set (S1-S4). The whole off-grid grid-connected hybrid photovoltaic power generation control system is uniformly managed and controlled by the demand response control system. Through the turn-on and turn-off combination of the switch set, the system supports eight different operation modes to achieve the optimization of economic benefits and peak shifting of the grid, and the service life of the system is prolonged through the method of limiting the discharging depth and charging and discharging power of storage batteries.

Description

technical field [0001] The invention relates to the field of new solar energy power generation and application, in particular to an off-grid and grid-connected hybrid photovoltaic power generation control system and an economical operation optimization method thereof. Background technique [0002] With the intensification of the energy crisis, while developing and utilizing renewable energy, how to use energy more reasonably has gradually become a social concern. In recent years, the growth rate of electric energy load is faster than that of electric quantity, which leads to the decrease of load rate of power grid and the increase of peak-to-valley difference. For power users, this will greatly increase the cost of electricity consumption, which is not conducive to economic benefits, and for public power grids, this will affect the reliability and stability of power grid operation. Therefore, it is of great significance to comprehensively utilize photovoltaic power generati...

AI Technical Summary

Problems solved by technology

Although individual systems can support peak and valley electricity prices, the scheduling schemes of these systems are relatively simple, and the mode switching is only performed according to a few thresholds or conditions. Although this can reduce operating costs to a certain extent, it has not been optimized from the perspective of global optimality control, so the optimization effect is limited

[0005] 2. Existing systems usually lack the forecast of photovoltaic power generation in each time period. Although some systems involve power generation forecasting, the forecasting algorithm is relatively simple and the reliability of the forecast value is low

Without the forecast of power generation in each time period, it is impossible to arrange the scheduling plan of the day through the power generation, and it is difficult to achieve economic optimization

[0006] 3. The existing system does not consider the service life of the battery. During operation, the discharge depth of the battery cannot be controlled, and deep discharge will greatly reduce the service life of the battery.

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