Traction power supply system photovoltaic energy storage grid connecting device and control method thereof

Abstract

The invention discloses a traction power supply system photovoltaic energy storage grid connecting device and a control method thereof. The method comprises detecting in real time the bus voltage and the feeder current of two power supply arms, the output power of a photovoltaic system and the charging and discharging power of an energy storage system to dynamically distribute the charging and discharging power set value of the energy storage system; computing the current set values of two four-quadrant converters to equate the internal feeder current of the two power supply arms with the sum of the phase quantity of the current of the four-quadrant converters as well as the phase of synthesized current with the voltage phase of a power system; controlling the charging and discharging power of the energy storage system to follow the set value, control the current of the two four-quadrant converter to follow the set values. Therefore, grid connection of the photovoltaic system and the energy storage system can be achieved, and meanwhile, the aim of reactive negative-sequence comprehensive compensation of a traction power supply system can be achieved.

Description

Technical field [0001] The invention belongs to the technical field of traction power supply, and particularly relates to a photovoltaic energy storage grid-connected device and a control method of a traction power supply system. Background technique [0002] As of 2015, my country’s railway operating mileage is 121,000 kilometers. By 2020, the railway network will reach 150,000 kilometers, and the industry’s annual electricity consumption will reach 40 billion kWh, which is equivalent to consuming 16 billion kilograms of standard coal each year and carbon dioxide emissions. About 40 billion kilograms, sulfur dioxide emissions are about 1.2 billion kilograms, and nitrogen oxides emissions are about 600 million kilograms; of which, more than 60% of power consumption and pollutant emissions are caused by the railway traction power supply system. [0003] Air pollution and energy security issues caused by the energy consumption structure dominated by fossil energy such as coal have wid...

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Problems solved by technology

[0007] However, the power converter in the existing photovoltaic traction power supply system cannot realize the reactive power and negative sequence comprehensive compensation of the traction power supply system; Requirements for power quality when connected to the grid through the traction power supply system; and the existing photovoltaic traction power supply system cannot stabilize the output power of the photovoltaic system, thus causing instability to the traction power supply system; and the economic performance of the traction power supply system is poor

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