SU691997A1 - Arrangement for coupling two power supply systems - Google Patents

Description

The invention relates to the field of transmission of electrical energy through AC lines, and more specifically is a combination of a static (DC link) and an electromechanical frequency converter, and is intended for communication of power systems with different frequencies.

Arrangements are known for the communication of electric power systems, which consist of a combination of a rectifying and an inverter substation at a zero-long length of direct current .1.

Power transformers, filters of higher harmonic components, sources of reactive power, reactors, arresters and valve control equipment are included in the equipment package of this device. Synchronous compensators or static capacitor batteries are used as sources of reactive power. The presence of filters of higher harmonics and sources of reactive monasticity in the composition of the equipment is a significant drawback and increases without

t

In addition, high estimated communication costs. .-,

In the known device, the reactive power consumed as rectified power; as well as the inverter link, makes up approximately 50% of the transmitted active power, and installed synchronous compensators are calculated at its output. High harmonic filters provide the required quality of electricity, - &

reactive power is also output at the main frequency. Installing high power filters with higher power. MONIC and electric machines, which are sources of reactive and active power consumers, are a significant disadvantage of this device and reduces the possibilities of its effective use.

The purpose of the present invention is to reduce the power installed

higher harmonic filters, more efficient use of installed sources of reactive power and improved economic no {telephones of the communication device as a whole.

This goal is achieved due to the fact that the device for the connection of two energy systems, containing power transformers, the primary windings of which are connected to the power system buses, and the secondary windings of which are connected to a rectifier-j inverter link, filters the highest harmonic components and electrical masses as source of reactive power, equipped with an adjustable frequency converter, additional transformers and a driver for each hour of the excitation voltage; With two excitation windings and their rotors are united by a common shaft, the primary winding of each additional face of the formatter is connected to the same winding of the corresponding power transformer as the electric machine, and the secondary winding of each additional transformer is connected to the appropriate frequency converter, To the input of which the driver of the frequency of the excitation voltage is connected, and. The excitation windings of the corresponding electric machine are connected to the output.

The drawing shows the device layout jj ...-. ;;:.; l; . ,,.

The COMMUNICATION device consists of connecting the plug to the network through power transformers i rectifyingly invert- ern-level link 2 and electric machines 3, combined with our shaft 4, windings. excitation 5 of which 30 are connected via frequency converters 6 to frequency drivers of excitation voltage 7. Frequency converters 6 by means of transformers 8 are connected to the low voltage of power transformers jj 1. Part of high harmonics filters 9 are connected to low voltage buses of power transformers 1 and the other part is connected to the higher voltage supply of the same transformers. , .- .. In the device for the connection of two power systems W, the active power P is divided into two components, Pu, flowing through respectively the inverter link 2 and the electromechanical frequency converter formed by j machines 3. In a rectifier-inverter The link 2 controls the gyutec power P by adjusting the ignition angle of the valves (thyristors), and in the electromechanical converter the regulation P occurs ja; an account of a harmonically changing example}) excitation with frequency:

t6.:,:

where fc.- h; astrostatic voltage;

- clean rotor rotation; ,,

 voltage frequency When the frequency changes in the associated

power systems (in a certain range, regulation of excitation of electric machines 3 according to this law ensures stability of the converter operation and preserves the flow of active and reactive power, while changing the speed of rotation of the shaft 4 and the stored imine kinetic energy. The presence of two excitation windings 5 allows to provide separate control of any two independent parameters of the mode, i.e., in addition to the active power P, the flow of reactive power can be controlled. Depending on the direction of flow power, one of the electric machines 3 operates in the motor mode, and the other in the generator mode. When the direction of the transferred power flow is changed, due to the reversibility of the electric machines, they will work in the motor mode and then in the generator mode. frequency 6, which is supplied with power from the transformer 8 and the signals for changing the frequency of the excitation voltage from the driver 7. When coscf 0.8 electric-machines 3, the reactive power output awn is:

Q l cosV-Р. 0, br. ,

According to the working condition of the inverter link 2, its elements consume reactive power

Q 0.5 P.

Therefore, if Pb: p., Then there is some reserve of reactive power, equal to 0.1P, for each electric machine 3 of the converter. This power, depending on the mode, can be transmitted to the grid.

In contrast to the known device, in this communication device, it is possible to control, as by active flow, as well as reactive power. In the presence of a reactive power reserve. (S; 0, l Р can be controlled by the Intersystem power transmission mode. Reducing the active power flowing through the inverter link to Р Р-Pf reduced the power of the installed filters of high harmonic components. Frequency start Electromechanical Tipe-drivers can be realized without any additional starting devices by connecting to the network through a parallel operating rectifier-inverter link.

Claims (1)

1. Electrical systems. Edited by V. A. Venikova, vol. 3. M., “Higher School, 1972, p. 368.