A system and control method for realizing multi-machine parallel operation of SVG devices

Abstract

The invention discloses a system and a control method for realizing multi-machine parallel operation of SVG devices. The system includes multiple SVG devices. Each SVG device is equipped with a pair of optical fiber ports for receiving and sending optical signals respectively. Each SVG device Between them is a ring topology in which the first and last SVG devices are connected in series through optical fiber ports to form an optical fiber ring network. The master in each SVG device transmits control commands to the remaining slaves through the optical fiber ring network, and the control output needs to be compensated. Reactive power: In this control method, the SVG device configured as the host determines a unified distribution coefficient for reactive power distribution in real time according to the power to be compensated, and each SVG device performs power compensation according to the unified distribution coefficient and rated output capacity. The invention can realize the fast cooperative operation of multiple SVG devices, and has the advantages of simple structure, strong anti-interference ability, stable operation of the system, high redundancy, and the like.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a system and a control method for realizing multi-machine parallel operation of SVG (Static Var Generator, static var generator) devices. Background technique [0002] As one of the important devices in the field of power electronics, reactive power compensation devices often need to be expanded. For example, enterprises need to increase production capacity with the improvement of efficiency, so that the load power will increase accordingly. At this time, the existing power lines need to be It needs to be expanded for transformation and upgrading, and if the load power increases and the line is expanded, the reactive power compensation device needs to be expanded to meet the requirements; in addition, with the current rapid development of new energy power generation industries such as wind power and photovoltaics, a large number of wind power and photovoltaic power plant...

AI Technical Summary

Problems solved by technology

[0004] In the above scheme to realize the parallel operation of SVG devices, when 485 interface communication and CAN bus are used, the communication speed is slow and the anti-interference ability is weak; although the communication speed is fast when Ethernet communication is used, it is vulnerable to high voltage and strong electromagnetic field environment. Interference and poor real-time performance; the solution using optical fiber communication has fast communication speed and strong anti-interference ability, but in the current parallel connection scheme of SVG devices based on optical fiber communication, optical fiber connection is usually required between the master and the slave, and between the slave and the slave. Therefore, the more the number of parallel connections, the more the number of fiber optic lines required, which makes the connection method complex, the amount of information processing is large, and the interconnection communication system is complicated. There is no connection between the machine and the slave, but when the master fails, the slave cannot be switched to the master, and the entire system cannot work at this time, and the redundancy of the system is poor.

For the reactive power distribution method, in the SVG parallel connection method connected by communication, it is usually necessary to judge the number of SVG devices that are put into use, or after judging the number of SVG devices that are put into use and the capacity of each SVG device, and then calculating the shunt coefficient to obtain each SVG device. The reactive power command, the reactive power distribution method is complex; and in the parallel mode where each SVG device does not establish a communication connection, when reactive power distribution requires each SVG device to collect the voltage and current signals of the bus to calculate the required compensation power , since the AD sampling and tracking adjustments of each SVG device are not synchronized, the calculated reactive power will be different, and it is likely to cause reactive power internal friction in the compensation of each device when the load changes rapidly. Therefore, this type of reactive power distribution method It will also cause reactive power oscillation of the busbar

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