A phase-commutation energy storage type three-phase load unbalance control device and method

Abstract

The invention discloses a phase-change energy-storage type three-phase load unbalance treatment device and method. The phase-change energy-storage type three-phase load unbalance treatment device comprises a control mechanism and an executing mechanism. The executing mechanism comprises a switch array and an energy storage system. The energy storage system comprises an energy storage device and asingle-phase inverter corresponding to the energy storage device. The control mechanism comprises an energy storage charging-discharging controller and a main controller. The main controller is used for analyzing and processing the state of the energy storage system, the switching value information of the switch array and the real-time data of the three-phase current and phase sequence of the lowvoltage side of a transformer, and sending an optimal control instruction to the switch array and the energy storage charging-discharging controller. The phase-change energy-storage type three-phase load unbalance treatment device has the advantages that the device is good in controllability, each phase is controlled independently, and unbalance load regulation on a three-phase circuit can be realized through the charging and discharging switching of the energy storage device among three phases.

Description

technical field [0001] The invention relates to the technical field of intelligent power distribution, in particular to a phase-commutation energy storage type three-phase load unbalance control device and method. Background technique [0002] The distribution network is located at the end of the power system and undertakes the important task of providing stable, reliable and high-quality power to customers. It is characterized by long transmission distances, low voltage levels, multiple points and wide areas, and its operation status is affected by the operation mode and load of the power grid. Changes have a greater impact. my country's three-phase four-wire distribution network mainly supplies power for rural power systems and urban residents. There are many users in the power supply area and the distribution is uneven, which makes a large number of uneven temporal and spatial distributions in the distribution network with high The random single-phase load leads to the in...

AI Technical Summary

Problems solved by technology

Due to the randomness and uncertainty of the power load, it is difficult to adjust the commutation according to the actual load imbalance, and the continuity of the user's power supply will be inevitably affected during the commutation, and there will be safety hazards to a certain extent

[0005] Distribution network reconfiguration is an effective means of distribution system operation optimization. It realizes the load transfer between feeders and transformers by changing the switch opening and closing states in the distribution network, but in fact, only through distribution network reconfiguration cannot Effectively reduce the three-phase unbalance of the system

Moreover, distribution network reconfiguration is actually a complex nonlinear multi-objective combinatorial optimization problem, most of which are still in the theoretical research stage, and are rarely used in practice.

[0006] Load compensation is mainly to compensate the three-phase unbalanced load by connecting a compensation network in parallel on the power supply side or the load side of the distribution network, so as to reduce the unbalanced degree of the three-phase current and adjust the system from an unbalanced state to a balanced state. The calculation of the compensation admittance is the key, this method needs to increase the parallel compensation network, usually the control is complicated, and the cost is high

[0007] The above-mentioned methods to solve the three-phase load imbalance problem have their own advantages and disadvantages. In the current distribution network, the solution is mainly based on the principle of load phase sequence balance. Most of the distribution network reconstruction and load compensation are still in the theoretical research stage.

[0008] The current distribution network is based on the principle of load phase sequence balance, and usually manually switches the load phase sequence or uses automatic switching capacitor banks for compensation to alleviate the adverse effects of three-phase imbalance on the stable operation of the distribution network. The method cannot be adjusted in real time and has poor economy, which not only affects the continuity of power supply, but also has certain safety hazards; although there are some automatic phase change devices based on the principle of load balancing, most of them are only suitable for different load branches. There are many low-voltage distribution networks, and the load balancing capacity and scope of use are limited

[0009] To sum up, there is still no effective solution to the problem of unbalanced three-phase load in the distribution network in the prior art

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