Electric energy quality comprehensive control device for power distribution network

Abstract

The invention belongs to the technical field of electric energy quality management of electric power systems, particularly relates to an electric energy quality comprehensive control device, and aims at providing an electric energy quality comprehensive control device for a power distribution network. The electric energy quality comprehensive control device for the power distribution network integrates the functions of reactive compensation, harmonic compensation, unbalance compensation and low voltage compensation. According to the technical scheme, the electric energy quality comprehensive control device for the power distribution network is connected between a power supply U1 and a load FZ1 in series; the electric energy quality comprehensive control device comprises a main circuit and a control circuit, and the main circuit comprises a transformer TR, a filter component LC, a filter reactor La, a first three-level inverter CON1 and a second three-level inverter CON2. The electric energy quality comprehensive control device is suitable for electric power systems.

Description

technical field [0001] The invention belongs to the technical field of power quality management of electric power systems, and in particular relates to a power quality comprehensive control device. Background technique [0002] Nowadays, the scale, line length, and 400V / 220V low-voltage lines of my country's rural low-voltage distribution network are in zero-distance contact with the majority of users. With the development of the rural economy and the development of the policy of sending home appliances to the countryside, various high-power household appliances appear in the homes of farmers, and the electricity consumption in rural areas increases rapidly. [0003] The following operating conditions often occur in rural distribution areas: the agricultural production and mobility of rural migrant workers cause large load fluctuations in rural power grids; the terminal voltage far away from the substation and heavy load is low, when the voltage regulation of the substation,...

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Problems solved by technology

[0003] The following operating conditions often occur in rural distribution areas: the agricultural production and mobility of rural migrant workers cause large load fluctuations in rural power grids; the terminal voltage far away from the substation and heavy load is low, when the voltage regulation of the substation, the voltage is too high, If the light load is too high, the equipment will be burned; there are many small hydropower stations in some areas, the 400V line voltage is too high in the rainy season, and the serious phase voltage can reach 295v, which may cause damage to user equipment; in the low-voltage three-phase four-wire power supply system In the middle, due to the user's single-phase load or single-phase and three-phase load and load structure, the time and power of the size are different, so the unbalanced three-phase load exists, which will increase the influence of the power loss of the transformer, and when it is serious, it will Burning distribution transformers; the rapid growth of non-linear loads makes harmonic problems appear, which poses a huge threat to the safe operation of low-voltage power grid reactive power compensation devices

[0004] With the emergence of the above-mentioned operating conditions, the low-voltage distribution network has problems such as low power factor, unbalanced three-phase, unqualified voltage, and harmonics, which affect the quality of power supply.

At present, the general management device has a single function, large volume, poor adjustment accuracy, cannot solve the power quality problem, and affects the safety of the equipment. They all use low-voltage active power filters to control harmonics and low-voltage static var generators alone. To control reactive power compensation, use low voltage control devices to control low voltage, lack of a comprehensive comprehensive device that can control harmonics, low power factor, three-phase unbalance and low voltage

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