CN217607699U

CN217607699U - Slow starting device of three-phase grid-connected star-connected chain type current converter

Info

Publication number: CN217607699U
Application number: CN202221343131.6U
Authority: CN
Inventors: 刘文华; 陈远华
Original assignee: Beijing Sinewell Converter Technology Co ltd
Current assignee: Beijing Sinewell Converter Technology Co ltd
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2022-10-18
Anticipated expiration: 2032-05-31

Abstract

The utility model belongs to the technical field of electrical automation equipment, a three-phase is incorporated into power networks star and is connect slow starting drive of chain transverter is related to. The three slow starting resistors are respectively connected between one end of a phase converter circuit in the three-phase grid-connected star-connected chain type current converter and a star connection point in series, three main contacts of the single-phase bypass switch are respectively connected to two ends of the three slow starting resistors in parallel, and an auxiliary contact and a closing and tripping coil of the single-phase bypass switch are respectively connected to a signal terminal of the starting control board; the optical transceiver of the starting control board is connected with a commutation controller of the three-phase grid-connected chain type converter through optical fibers, a power terminal of the optical transceiver is connected with a low-voltage side winding of the isolation power transformer, and a high-voltage side winding of the isolation power transformer is connected to an external low-voltage alternating-current power supply. The utility model discloses a three-phase is incorporated into power networks star and connects slowly starting drive of chain converter can adopt the bypass switch of lower voltage level for the three-phase is incorporated into power networks star and connects slowly starting drive of chain converter with low costs, small moreover, and it is nimble convenient to use.

Description

Slow starting device of three-phase grid-connected star-connected chain type current converter

Technical Field

The utility model belongs to the technical field of electrical automation equipment, particularly, relate to a three-phase is incorporated into power networks star and connects slow starting drive of chain converter.

Background

The three-phase grid-connected chain type converter can be applied to devices such as a chain type static synchronous compensator (SVG) or a chain type battery energy storage voltage source converter (PCS) and the like, the grid-connected converter generally adopts a self-excited starting mode, namely a slow starting circuit formed by connecting a slow starting resistor and a bypass switch main contact in parallel is connected in series in an alternating current circuit of the three-phase converter, the grid-connected converter is directly connected firstly and charges an energy storage capacitor of the converter through slow starting resistor current limiting, the bypass switch main contact bypass slow starting resistor is closed after charging is finished, and then the converter enters normal operation. When the rated alternating voltage of the converter is higher, a bypass switch with a corresponding voltage grade needs to be adopted, so that the device volume and the cost are higher. A new slow start device is therefore needed to address this size and cost issue.

Disclosure of Invention

The utility model aims at providing a three-phase is incorporated into power networks star and connects slow starting drive of chain converter to overcome prior art not enough, solve the three-phase and incorporated into power networks star and connect the volume that high withstand voltage level of starting contactor leads to and the higher problem of cost when chain converter adopts the self-excited starting mode.

The embodiment of the utility model provides a slow starting device of three-phase grid-connected star-connected chain converter, including three slow starting resistance, three single-phase bypass switches, a start control panel and an isolation power transformer; the three slow starting resistors are respectively connected between one end of a phase converter circuit in the three-phase grid-connected star-connected chain type current converter and a star contact in series, the main contacts of the three single-phase bypass switches are respectively connected in parallel with two ends of the three slow starting resistors, and the auxiliary contacts and the closing and tripping coils of the three single-phase bypass switches are respectively connected to the signal terminals of the starting control board; the optical transceiver of the starting control board is connected with a commutation controller of the three-phase grid-connected chain type converter through optical fibers; and a power terminal of the starting control board is connected with a low-voltage side winding of the isolation power transformer, and a high-voltage side winding of the isolation power transformer is connected to an external low-voltage alternating-current power supply.

The utility model provides a three-phase is incorporated into power networks star and connects gentle starting drive of chain transverter, its advantage:

compare with the gentle starting drive that has the three-phase star that is incorporated into the power networks and connects chain converter, the utility model discloses a low voltage level's bypass switch can be adopted to the gentle starting drive that three-phase star that is incorporated into the power networks connects chain converter for the slow starting drive that three-phase star that is incorporated into the power networks connects chain converter is with low costs, and is small moreover, and it is nimble convenient to use.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is clear that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can also be derived from them without inventive effort.

Fig. 1 is a schematic diagram (within a dashed line frame) of a slow start device of a three-phase grid-connected star-connected chain type current converter provided by the utility model.

In fig. 1, 1 is a slow start resistor, 2 is a bypass switch, 3 is a start control board, and 4 is an isolation power transformer.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiment is only one embodiment of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the utility model provides a three-phase is incorporated into power networks star and connects slow starting device of chain converter, its schematic circuit diagram is shown as figure 1, in figure 1, is the slow starting device in the dotted line frame, including three slow starting resistance 1 (RA/RB/RC), three single-phase bypass switch 2 (JA/JB/JC), a start control panel 3 (KZ) and an isolation power transformer 4 (TR); the three slow starting resistors 1 (RA/RB/RC) are respectively connected between one end of a phase converter circuit in the three-phase grid-connected star-connected chain converter and a star connection point in series, main contacts of three single-phase bypass switches 2 (JA/JB/JC) are respectively connected to two ends of the three slow starting resistors 1 (RA/RB/RC) in parallel, and auxiliary contacts and closing and tripping coils of the three single-phase bypass switches 2 (JA/JB/JC) are respectively connected to signal terminals of the starting control panel 3 (KZ); the optical transceiver of the starting control plate 3 (KZ) is connected with a commutation controller of the three-phase grid-connected chain type converter through optical fibers; and a power supply terminal of the starting control board 3 (KZ) is connected with a low-voltage side winding of the isolation power transformer 4 (TR), and a high-voltage side winding of the isolation power transformer 4 (TR) is connected to an external low-voltage alternating-current power supply.

The following combines the attached drawing, the detailed description the utility model discloses the theory of operation of the slow starting device of three-phase star that is incorporated into power networks that the embodiment provided connects chain converter:

after the slow starting device of the three-phase grid-connected star-connected chain type converter is connected to a power grid, a direct current capacitor of a power module in the three-phase grid-connected star-connected chain type converter is subjected to current-limiting charging through three slow starting resistors RA/RB/RC, three single-phase bypass switches JA/JB/JC close and bypass the three slow starting resistors RA/RB/RC after charging is finished, and the converter enters an operating state. The insulation voltage withstand level between the high-voltage side and the low-voltage side of the isolation transformer TR is the same as the insulation voltage withstand level of the main circuit of the three-phase grid-connected star-connected chain type converter to the ground, so that circuits such as the main contact and the auxiliary contact of the three single-phase bypass switches JA/JB/JC to the ground do not need to bear the same high voltage of the main circuit of the three-phase grid-connected star-connected chain type converter to the ground, and the size and the cost of the three single-phase bypass switches JA/JB/JC are reduced. The starting control board receives a closing or opening instruction of the three single-phase bypass switches JA/JB/JC sent by a commutation controller of the three-phase grid-connected star-connected chain type converter through an optical fiber, transmits the closing or opening instruction to closing or tripping coils of the three single-phase bypass switches JA/JB/JC through a signal terminal, and returns auxiliary contact state signals of the three single-phase bypass switches JA/JB/JC to the commutation controller of the three-phase grid-connected star-connected chain type converter.

In one embodiment of the utility model, the used starting control board is produced by Beijing Xiwei Qing Tu technological Limited, and the product model is GCURMES-2; the used converter controller is produced by Beijing Xiwei Qing Tu technology Limited, and the model is SVGKZ-35YXX.

The utility model discloses the circuit also can be applied to in the three-phase chain voltage source transverter device that adopts the triangular connection, any is based on the utility model discloses the equivalent transformation circuit that the circuit was done all belongs to the utility model discloses a protection scope.

Claims

1. A slow starting device of a three-phase grid-connected star-connected chain type current converter is characterized by comprising three slow starting resistors, three single-phase bypass switches, a starting control board and an isolation power transformer; the three slow starting resistors are respectively connected between one end of a phase converter circuit in the three-phase grid-connected star-connected chain type current converter and a star contact in series, the main contacts of the three single-phase bypass switches are respectively connected in parallel with two ends of the three slow starting resistors, and the auxiliary contacts and the closing and tripping coils of the three single-phase bypass switches are respectively connected to the signal terminals of the starting control board; the optical transceiver of the starting control board is connected with a commutation controller of the three-phase grid-connected chain type converter through optical fibers; and a power terminal of the starting control board is connected with a low-voltage side winding of the isolation power transformer, and a high-voltage side winding of the isolation power transformer is connected to an external low-voltage alternating-current power supply.