An active-passive combination intelligent anti-islanding system for distribution network and its configuration and operation method

Abstract

The invention discloses an active- and passive-measure integrated intelligent anti-islanding system of a power distribution network and a configuration running method. The system comprises an active anti-islanding device based on a variable disturbance load and a passive anti-islanding detection and isolation device, wherein the active anti-islanding device based on the variable disturbance load is arranged at an area side of the power distribution network and is used for acquiring voltage and current signals of the area side of the power distribution network when the power distribution network is in a circuit detection state, calculating and controlling a grid-connected variable disturbance load parameter and giving out an anti-islanding interference signal after the variable disturbance load is accessed to the power distribution network, one end of the passive anti-islanding detection and isolation device is connected with a user-side power distribution network, the other end of the passive anti-islanding detection and isolation device is connected with a distributed power generation system, the passive anti-islanding detection and isolation device is used for acquiring voltage and current signals of the user-side power distribution network in real-time and all-weather way, further extracting the anti-islanding interference signal given out from the active anti-islanding device and controlling a grid-connected switch to be switched off or switched on for recovery according to comparison with a set steady-state working threshold value, so that the anti-islanding function is achieved.

Description

Technical field [0001] The invention belongs to the field of power distribution network maintenance and islanding prevention, and in particular relates to an active and passive power distribution network intelligent anti-islanding system and a configuration operation method. Background technique [0002] With the rapid development of distributed power generation systems and the spread of large-scale applications, the penetration rate of wind and new energy distributed power generation systems in rural or urban low-voltage power distribution networks in such power grids continues to increase. Among them, a large number of small and medium-sized distributed power generation systems connected to the grid in rural or urban distribution networks are prone to local islanding effects. Relying solely on grid-connected inverters of different quality for anti-islanding not only has low reliability, but also affects local load and self-organized network operation. This type of distributed ...

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Problems solved by technology

Simply relying on grid-connected inverters of varying quality for anti-islanding not only has low reliability, but also affects local loads and ad hoc network operation

This kind of distributed power generation system equipment has various types and a large number of grid-connected detection is difficult, and because it is close to the load end, it is easy to form a local balance of power supply and use, resulting in island effect

However, for complex user groups, different operation methods, and the unpredictability of system application scenarios, it is easy for a large number of grid-connected inverters to be used in parallel at multiple temporal and spatial scales, resulting in mutual interference and failure, which greatly reduces the protection of the grid-connected inverter’s anti-islanding function. reliability

[0003] Therefore, when the maintenance personnel perform power-off maintenance on the line, part of the distribution network may be in an island operation state, endangering the safety of the maintenance personnel and equipment

However, traditional anti-islanding devices or systems that rely on grid-connected inverters for island detection and disconnection cannot guarantee the operation of local loads or self-organizing grids after the distribution network loses power, and it is also difficult to automatically close the switch and connect to the grid after the power supply of the distribution network is restored. generate electricity

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