Microgrid system of considering operating characteristics of microsources and power frequency division control method for microgrid system

Abstract

The invention discloses a microgrid system of considering operating characteristics of microsources and a power frequency division control method for the microgrid system. According to the system, load demand power is divided into an ultra-low frequency band, a low-frequency band and a medium-high frequency band, wherein a storage battery pack works on the low-frequency band and the stability of DC bus voltage is maintained by adopting a voltage control mode; a diesel generator set and a new energy power generation system work on the ultra-low frequency band and ultra-low frequency power required by load is output by adopting a current control mode; and a supercapacitor works on the medium-high frequency band to stabilize high-frequency power fluctuation of the load. The invention providesan algorithm for decomposing the power required by the load according to the bands and a secondary distribution method of the ultra-low frequency power. By adopting the system and the control methoddisclosed by the invention, power balance of a source end and a load end of a microgrid can be achieved, the harm of the high-frequency power fluctuation to sensitive microsources, such as storage batteries can also be effectively reduced, the service life of equipment is prolonged and the operation efficiency of the system can be significantly improved.

Description

technical field [0001] The invention relates to a distributed power supply system, in particular to a micro-grid system and a power frequency division control method thereof taking into account the operating characteristics of micro-sources. Background technique [0002] In recent years, with the rapid development of new energy power generation technology and power electronics technology, "microgrid" as a flexible power production, transmission and distribution scheme has received continuous and extensive attention from the industry. Generally, a microgrid system is mainly composed of microsources (distributed power supply systems), energy storage devices, converters, control systems, and local loads. At present, micro-grid technology has been mainly applied in the following aspects: first, as an effective means of grid-connected large-scale renewable energy (such as wind energy, solar energy); The third is as a power supply and distribution technology for ships, aircraft a...

AI Technical Summary

Problems solved by technology

Long-term high-frequency current charging and discharging will cause the temperature of the battery to rise. If the temperature rises too much, it will further lead to more serious diffusion and uncontrollable ion concentration. In extreme cases, gasification or liquefaction may occur in the battery

Another example is that in off-grid microgrid systems, diesel generator sets are usually used as the main power supply. At this time, if the engine operating point is adjusted in real time according to the instantaneous power demand of the load, it may lead to problems such as low fuel efficiency.

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