Controllable series compensation device based on parallel connection of double TCR (Thyristor Controlled Reactor) branch circuits and control method thereof

Abstract

The invention provides a controllable series compensation device based on parallel connection of double TCR (Thyristor Controlled Reactor) branch circuits and a control method thereof, which belong to the field of controllable series compensation in the field of flexible alternating current power transmission. The controllable series compensation device uses parallel connection of two TCR (Thyristor Controlled Reactor) branch circuits and makes current passing through each TCR (Thyristor Controlled Reactor) branch circuit be smaller, so that the problem that the current thyristor valve has insufficient through-current capability in ultrahigh voltage controllable series compensation is solved. The TCR (Thyristor Controlled Reactor) branch circuit is formed in a manner that two inverse parallel thyristor valves are connected in series with a reactor, and the two TCR (Thyristor Controlled Reactor) branch circuits are connected in series to form a controllable series compensation device; or the two TCR (Thyristor Controlled Reactor) branch circuits are connected in parallel and then are connected in series with a common reactor to form a controllable series compensation device; and the current equalizing and impedance requirements of branch circuits are realized by control of equal circuit amplitudes of the two TCR (Thyristor Controlled Reactor) branch circuits of the series compensation device and control of fundamental wave impedance. The device can meet the requirements of the impedance control, and has simple control process and uses linear control; and the device is easy to realize in engineering, along with good control stability.

Description

technical field

[0001] The invention belongs to the field of Thyristor Controlled Series Capacitor (TCSC) in the field of flexible alternating current transmission, and specifically relates to it. Background technique

[0002] At present, my country has begun to build a 1000kV UHV transmission network, and has put into operation a 1000kV Jindongnan-Nanyang-Jingmen UHV AC test project. UHV AC transmission has obvious advantages in terms of transmission capacity, transmission distance, and power loss. However, due to the long-distance, large-capacity characteristics of the UHV line itself, as well as the system's transient stability and other requirements, the transmission capacity of some UHV transmission lines is limited, and it is difficult to play its due role. The advantages. With the help of the development experience of the ultra-high voltage power grid, installing a series compensation device on the ultra-high voltage transmission line can significantly improve the t...

Examples

Embodiment 1

[0100] 1. Acquisition of TCR branch current amplitude

[0101] The sampling signal pulse is generated by detecting the zero-crossing point of the capacitor voltage, and the TCR branch current is sampled. from image 3 It can be seen from the timing diagram that when the capacitor voltage u c When crossing zero, the current of the TCR branch (in the figure i L1 and i L2 ) reaches the maximum absolute value. Using this relationship, by detecting the zero-crossing point of the capacitor voltage, a sampling pulse signal is generated, and the currents of the two TCR branches are respectively sampled. After obtaining the sampling value, the absolute value is taken as the amplitude of the two branch currents, and It is used in the following algorithms and control strategies.

[0102] 2. Control of equal current amplitudes in two TCR branches

[0103] by figure 1 Take the parallel scheme shown as an example (maybe let L 1 2 ), the specific implementation manner in which the cu...

Embodiment 2

[0132] According to the above, using Figure 7 As shown in the simple circuit, the method and method of the present invention are simulated and analyzed to verify the feasibility of the present invention. still with figure 1 The described scheme is used as an example. Figure 7 , the voltage source amplitude is 500kV, and the line equivalent resistance R L =11.0Ω, line equivalent reactance X L =111.15Ω, the basic capacitance value of controllable series compensation C=190.5μF, the inductance of the two valve series reactors takes the maximum manufacturing process error ±5%, L 1 =0.01729H, L 2 =0.01911H.

[0133] According to the main circuit parameters and formula (3) of the simulation circuit, the impedance characteristic table suitable for the parallel connection of double TCR branch TCSC can be established, as shown in attached table 1. In Table 1, only a few points are selected for illustration. In actual application, dense points should be selected according to the ...

technical field

[0001] The invention belongs to the field of Thyristor Controlled Series Capacitor (TCSC) in the field of flexible alternating current transmission, and specifically relates to it. Background technique

[0002] At present, my country has begun to build a 1000kV UHV transmission network, and has put into operation a 1000kV Jindongnan-Nanyang-Jingmen UHV AC test project. UHV AC transmission has obvious advantages in terms of transmission capacity, transmission distance, and power loss. However, due to the long-distance, large-capacity characteristics of the UHV line itself, as well as the system's transient stability and other requirements, the transmission capacity of some UHV transmission lines is limited, and it is difficult to play its due role. The advantages. With the help of the development experience of the ultra-high voltage power grid, installing a series compensation device on the ultra-high voltage transmission line can significantly improve the t...

Examples

Embodiment 1

[0100] 1. Acquisition of TCR branch current amplitude

[0101] The sampling signal pulse is generated by detecting the zero-crossing point of the capacitor voltage, and the TCR branch current is sampled. from image 3 It can be seen from the timing diagram that when the capacitor voltage u c When crossing zero, the current of the TCR branch (in the figure i L1 and i L2 ) reaches the maximum absolute value. Using this relationship, by detecting the zero-crossing point of the capacitor voltage, a sampling pulse signal is generated, and the currents of the two TCR branches are respectively sampled. After obtaining the sampling value, the absolute value is taken as the amplitude of the two branch currents, and It is used in the following algorithms and control strategies.

[0102] 2. Control of equal current amplitudes in two TCR branches

[0103] by figure 1 Take the parallel scheme shown as an example (maybe let L 1 2 ), the specific implementation manner in which the cu...

Embodiment 2

[0132] According to the above, using Figure 7 As shown in the simple circuit, the method and method of the present invention are simulated and analyzed to verify the feasibility of the present invention. still with figure 1 The described scheme is used as an example. Figure 7 , the voltage source amplitude is 500kV, and the line equivalent resistance R L =11.0Ω, line equivalent reactance X L =111.15Ω, the basic capacitance value of controllable series compensation C=190.5μF, the inductance of the two valve series reactors takes the maximum manufacturing process error ±5%, L 1 =0.01729H, L 2 =0.01911H.

[0133] According to the main circuit parameters and formula (3) of the simulation circuit, the impedance characteristic table suitable for the parallel connection of double TCR branch TCSC can be established, as shown in attached table 1. In Table 1, only a few points are selected for illustration. In actual application, dense points should be selected according to the ...

Images