Increasing railway capacity with the installation of reactive power compensation

The article considers existing regulated installations of transverse capacitive compensation for increasing the capacity of sections of the traction network of 25 and 2×25 kV of Russian railways. Characteristics of a static reactive power generator based on bipolar IGBT transistors (manufactured by LLC NPP “RU-Engineering”, Naberezhnye Chelny), a switchable filtercompensating unit (manufactured by the Gorkovskaya Railway and the Nizhny Novgorod branch of SamGUPS), a three-stage switchable filter-compensating unit. To increase the capacity, all installations are switched on at the traction network sectioning posts. Long-term operation of the static reactive power generator and switchable filter-compensating unit have proven their operational efficiency. At the same time, the following upgrades are proposed: in a static reactive power generator it is proposed to reduce the installed power, replacing it with unregulated compensation, and in a switchable filter-compensating installation, it is proposed to switch in 400–500 V steps to normalize the traction mode of the electric rolling stock.It is shown that in terms of technical characteristics, a switchable filter-compensating installation with a thyristor switch is not inferior to a static generator of reactive power in terms of increasing the capacity, and in some respects it surpasses it. On the whole, in terms of payback period, a switchable filter-compensating installation surpasses a static generator of reactive power due to the high cost of the latter. The following options for using the considered installations are proposed. With the required power of transverse capacitive compensation units up to 5–6 MVAr, to increase the capacity, switchable filter-compensating units should be installed. Taking into account real loads, such a solution will be implemented at most sectioning posts. For installations with a capacity of more than 5–6 MVAr, the option of using a static reactive power generator of reduced power should be considered: at high loads, its efficiency will increase.

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The Research of the New High Voltage Reactive Power Compensation Device Based on the Compound Switch

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.496-500.1097 ◽

2014 ◽

Vol 496-500 ◽

pp. 1097-1100 ◽

Cited By ~ 1

Author(s):

Yin Sheng Wang ◽

Xue Di Qiao

Keyword(s):

Reactive Power ◽

Power Grid ◽

Reactive Power Compensation ◽

Parallel Capacitor ◽

Thyristor Switch ◽

Compensation Device ◽

Equipment Utilization ◽

Contact Switch ◽

Current Zero ◽

The Impact

With the increase of power system load, the demand for reactive power is also increasing. In order to ensure the power quality and improve equipment utilization, transmission of reactive power in power grid can lead to network loss and the voltage of the electricity. Installing reactive power compensation device in power grid is the essential means to meet the demand of power grid reactive power [1].The parallel capacitor reactive power compensation device is equipped in the coal mine 3.3 kV system reactive power compensation [2]. Introducing the parallel capacitor reactive power compensation principle and related problems, analysis of the current commonly uses contactor, relay and thyristor switch device, chooses the contactor and breaks pipe parallel composite switch which can have contact and non-contact switch to solve their problems [3]. Using software EMTP simulation composite switch voltage zero input, the result is very good to restrain the impact flow; Compound switch off after current zero avoids the contactor breaking arc, the simulation thyristor compound switch and diode in parallel.

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Reduction of electric power losses by the reactive power compensation unit at the point of AC electric traction network sectioning

Vestnik of the Railway Research Institute ◽

10.21780/2223-9731-2019-78-5-302 ◽

2019 ◽

Vol 78 (5) ◽

pp. 297-302

Author(s):

Leonid A. German ◽

Aleksander S. Serebryakov

Keyword(s):

Electric Power ◽

Carrying Capacity ◽

Reactive Power ◽

Reactive Power Compensation ◽

Baseline Data ◽

Power Losses ◽

Method Of Calculation ◽

Traction Network ◽

Electric Traction ◽

Positive Effect

Changes of electric traction network with regulated and not-regulated reactive power compensation units (CU) are required due to switching on the reactive power static generators at the AC electric traction network sectioning points the specifying calculations of the reactive power. The method of calculation of power losses in the traction network with regulated and not-regulated cross capacity compensation units at the sectioning point was developed. The main positive effect of CU at the sectioning point is increasing of the carrying capacity of the railroad sections. However, calculation of CU effectiveness for reduction of electric power losses, as well as calculation of continuously controlled CU requires appropriate calculations. It is demonstrated that CU effectiveness at the sectioning points of reactive power compensation is reduced in connection with distribution of the draft load; CU regulation effectiveness is also reduced as a response to increase of the carrying capacity of the railroad section, which allows assessing the proposed calculation formulae. Presented examples of calculation for the actual baseline data demonstrate that full losses in the traction network (assumed as 100%) can be reduced by using of CU of the sectioning point up to 21% maximum with continuously controlled units and up to 13.4% with uncontrolled CU. As automatics of the reactive power static generator is designed for increasing the carrying capacity of the railroad, its operation frequently complies with the reactive power overcompensation regime when losses in the traction network are increased.

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