CN112104054A - 12-pulse digital charging system for transformer substation - Google Patents

Abstract

The invention discloses a 12-pulse digital charging system for a substation, comprising a transformer, the primary winding of the transformer is connected to an external input power supply, the secondary winding of the transformer is connected to a rectifier module, and the rectifier module is connected to a thyristor trigger module and Filtering module, the filtering module is connected to the output control module and the feedback sampling module, the output control module is connected to the current sharing control module, the current sharing control module is connected to the feedback sampling module, and the feedback sampling module is connected to the protection circuit module and the microprocessor The microprocessor is connected to the RS485 communication interface and the thyristor trigger module. This device is fully intelligently designed, and through serial communication, it can automatically realize: module on/off, charging mode conversion, output voltage regulation, output current limiting point setting, conversion synchronization and other functions.

Description

A 12-pulse digital charging system for substations

technical field

The invention relates to the technical field of charging, in particular to a 12-pulse digital charging system for a substation.

Background technique

The power operating power supplies in power plants and substations are all DC power supplies today, which provide power for control loads, power loads, and DC accident lighting loads, and are the basis for contemporary power system control and protection. The DC panel consists of an AC power distribution unit, a rectifier unit, a step-down unit, a battery unit and a monitoring module unit. Mainly used in small and medium-sized power plants, hydropower stations, various substations and other users of DC equipment in the power system, suitable for switch opening and closing and instruments, meters, relay protection and fault lighting in the secondary circuit.

For the rectifier unit, most of the DC panel manufacturers in the market now use high-frequency switching power supplies. With its modular design, N+1 hot backup, hot swappable, low average maintenance time, and output current sharing effect between modules good to be widely used.

However, the operating environment of the DC screen is quite different. The poor quality of the factory power grid, the large fluctuation, the large interference of the harmonic source, the humid environment, the large dust, the large vibration, the high temperature without air conditioning and other harsh environments will seriously affect the service life of the high frequency switching power supply, that is, Reduced the reliability of the whole DC screen.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a 12-pulse digital charging system for substations to solve the problems raised in the above background art. In order to achieve the above purpose, the present invention provides the following technical solutions: a 12-pulse digital charging system for a substation, comprising a transformer, the primary winding of the transformer is connected to an external input power supply, the secondary winding of the transformer is connected to a rectifier module, and the rectifier is connected to a rectifier module. The module is connected to the thyristor trigger module and the filter module, the filter module is connected to the output control module and the feedback sampling module, the output control module is connected to the current sharing control module, the current sharing control module is connected to the feedback sampling module, the feedback sampling module is connected The module is connected with the protection circuit module and the microprocessor, and the microprocessor is connected with the RS485 communication interface and the thyristor trigger module.

Preferably, the output control module is connected to an isolation diode, and the isolation diode is connected to the output terminal.

Preferably, the transformer is a phase-shift isolation transformer, the primary winding of the transformer is connected in delta, and the secondary of the transformer is provided with two windings, one winding is star-connected, the other winding is delta-connected, and the delta-connection is used. The windings are 300 degrees ahead of the star-connected windings.

Preferably, the rectifier module is two sets of three-phase fully-controlled rectifier bridges, and the thyristor of the rectifier module is connected to the thyristor trigger module.

Preferably, the thyristor trigger module, the feedback sampling module, the protection circuit module, the current sharing control module and the microprocessor are integrated in the charger control module.

The technical effects and advantages of the present invention: the device is fully intelligently designed, and through serial communication, it can automatically realize: module on/off, charging mode conversion, output voltage regulation, output current limiting point setting, conversion synchronization and other functions; the charging module Equipped with a standard RS-485 interface, it is convenient to connect to the automation system, and realize "four remotes" and unattended;

Description of drawings

Fig. 1 is the structural block diagram of the present invention;

FIG. 2 is a circuit diagram of the present invention.

In the picture: 1-transformer, 2-rectifier module, 3-output control module, 4-RS485 communication interface, 5-isolation diode, 6-charger control module.

Detailed ways

In order to make the technical means, creation features, goals and effects of the present invention easy to understand, the present invention will be further described below in conjunction with the specific figures. In the description of the present invention, it should be noted that unless otherwise specified and Definition, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, an integral connection or a mechanical connection, or an electrical connection; Direct connection, indirect connection through intermediate media, internal communication between two components.

Example 1

As shown in FIG. 1 , a 12-pulse digital charging system for a substation includes a transformer 1, the primary winding of the transformer 1 is connected to an external input power supply, the secondary winding of the transformer 1 is connected to a rectifier module 2, and the rectifier module 2 Connect the thyristor trigger module and the filter module, the filter module is connected to the output control module 3 and the feedback sampling module, the output control module 3 is connected to the current sharing control module, the current sharing control module is connected to the feedback sampling module, the feedback The sampling module is connected to the protection circuit module and the microprocessor, and the microprocessor is connected to the RS485 communication interface 4 and the thyristor trigger module.

Example 2

As shown in FIG. 1 and FIG. 2, a 12-pulse digital charging system for substations includes a transformer 1, the primary winding of the transformer 1 is connected to an external input power supply, the secondary winding of the transformer 1 is connected to the rectifier module 2, and the The rectifier module 2 is connected to the thyristor trigger module and the filter module, the filter module is connected to the output control module 3 and the feedback sampling module, the output control module 3 is connected to the current sharing control module, and the current sharing control module is connected to the feedback sampling module, The feedback sampling module is connected to the protection circuit module and the microprocessor, and the microprocessor is connected to the RS485 communication interface 4 and the thyristor trigger module.

Preferably, the output control module is connected to an isolation diode 5, and the isolation diode 5 is connected to the output terminal.

Preferably, the transformer 1 is a phase-shift isolation transformer, the primary winding of the transformer 1 is connected in delta, and the secondary of the transformer is provided with two windings, one winding is star-connected, the other winding is delta-connected, and the delta The connection winding is 300 degrees ahead of the star connection winding.

Preferably, the rectifier module 2 is two sets of three-phase fully-controlled rectifier bridges, and the thyristor of the rectifier module 2 is connected to the thyristor trigger module.

Preferably, the thyristor trigger module, the feedback sampling module, the protection circuit module, the current sharing control module and the microprocessor are integrated in the charger control module 6 .

The technological process and working principle of the invention are as follows: 380V voltage is connected through the primary winding of the transformer 1 in a delta connection, one secondary winding is connected in a star, and the other winding is connected in a delta, and the delta winding is 300 degrees ahead of the star winding, and two sets of three-phase The fully-controlled bridge rectifier constitutes 12-phase pulse rectification, the microprocessor generates the thyristor trigger signal, and the thyristor trigger module drives the thyristor of the rectifier module, and the conduction angle of the thyristor is controlled by the microprocessor; when the charging voltage When the charging current and the charging current change due to the increase or decrease of the load or the fluctuation of the power grid, the feedback sampling signal sent by the feedback sampling module also changes with it. The charging current is always stable within the specified value, and the charging module can realize serial communication with the host computer and serial communication between modules through the RS485 communication interface 4.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the The technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be equivalently replaced, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included. within the protection scope of the present invention.

Claims (5)

1. A 12-pulse digital charging system for a substation, comprising a transformer, characterized in that: the primary winding of the transformer is connected to an external input power supply, the secondary winding of the transformer is connected to a rectifier module, and the rectifier module is connected to a thyristor trigger module and filter module, the filter module is connected to the output control module and the feedback sampling module, the output control module is connected to the current sharing control module, the current sharing control module is connected to the feedback sampling module, the feedback sampling module is connected to the protection circuit module and The microprocessor is connected with the RS485 communication interface and the thyristor trigger module. 2 . The 12-pulse digital charging system for a substation according to claim 1 , wherein the output control module is connected to an isolation diode, and the isolation diode is connected to the output terminal. 3 . 3. A 12-pulse digital charging system for a substation according to claim 1, wherein the transformer is a phase-shift isolation transformer, the primary winding of the transformer is connected in a delta, and the secondary of the transformer is provided with two Windings, one winding is star-connected, the other is delta-connected, and the delta-connected winding is 300 degrees ahead of the star-connected winding. 4. The 12-pulse digital charging system for a substation according to claim 1, wherein the rectifier module is two sets of three-phase fully-controlled rectifier bridges, and the thyristor of the rectifier module is connected to a thyristor to trigger module. 5. A 12-pulse digital charging system for a substation according to claim 1, wherein the thyristor trigger module, the feedback sampling module, the protection circuit module, the current sharing control module and the microprocessor are integrated in the charging in the machine control module.

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