1 Overview

1.1 Scope of Application

The WKB-801A microcomputer parallel reactor protection device is suitable for parallel reactors of various voltage levels of 500kV and above. The WKB-801A device integrates all electrical quantity protection of a parallel reactor. It can meet the requirements of dual main and dual rear configurations for parallel reactors of various voltage levels, as well as fully independent configurations for non electric quantity protection.

1.2 Product Features

Based on the high-performance and highly redundant Xuji next-generation hardware platform, visual logic development tools are used to achieve transparent protection design. The principle of variable action characteristics comprehensively improves protection performance. The main features of this protection device include the "log system" and "black box" fault location technology for device memory.

1.2.1 Protection Performance

High sensitivity inter turn protection

This device adopts a turn to turn protection mainly based on the amplitude ratio zero sequence direction principle, supplemented by the adaptive zero sequence power direction principle, which can well reflect the turn to turn short circuit and single-phase grounding fault of the reactor

Reliable phase differential protection

By using a multi segment and multi line method, it is possible to quickly remove serious faults within the area, while also ensuring sensitivity to minor and complex faults. The use of multiple algorithms combining long and short data windows greatly improves the software's anti-interference ability.

1.2.2 High performance and high redundancy Xu Ji's next-generation software and hardware platform

High performance and high reliability hardware structure

Adopting a hardware structure with 3 CPUs working in parallel, using a 32-bit high-performance DSP processor, 32-bit logic processor, and 16 bit high-speed AD, the protection outlet tripping adopts a "start+protection action" method to prevent misoperation caused by hardware failure of the protection device.

Strong anti-interference ability

Adequate anti-interference measures are taken in the design of software and hardware, with a 6U fully enclosed chassis, an overall panel, and strict separation of strong and weak electricity. The anti-interference ability of the device is greatly improved, and the external electromagnetic radiation also meets relevant standards.

Powerful self checking function

A complete A/D sampling circuit self-test can avoid device misoperation caused by A/D sampling errors; Open circuit self-test can accurately detect any open circuit breakdown fault, issue an alarm, and reliably lock protection; Fixed value self-test can detect errors in the fixed value storage area, fixed value exceeding limits, etc; Equipped with+5V and ± 15V power self-test function, the device sends an alarm message and locks protection when the power supply voltage is abnormal.

Visual logic development

Using the visual logic development tool VLD, all protection logic in the VLD development environment is composed of different visualized flexible relays, achieving a fully transparent design of microcomputer protection.

1.2.3 Convenient operation and use

L Friendly human-machine interface

Color LCD large screen display, using a fully Chinese Windows menu mode with clear structure. Through menu prompts, all device operations can be completed, making it easy to use.

The main page displays a colorful main wiring diagram with rich real-time data, which is beautiful and practical.

Unique transmission test design

It is possible to inspect the wiring of each tripping circuit on site through transmission testing without applying current or voltage.

Convenient communication point-to-point function

On site, without the conditions for protective function testing, the device can conveniently conduct communication point-to-point testing by sending relevant protection action information, alarm information, etc. to the automation monitoring system through the communication point-to-point menu.

Complete event recording function

It can record 100 faults, 8 fault waveforms, and 200 abnormal information. The recorded data is compatible with COMTRADE.

Complete printing function

It has a manual start recording and printing function, which can print the amplitude and phase of the current and voltage on each side under normal conditions, making it convenient for users to verify the polarity of the current and voltage on each side when the reactor is put into operation.

1.3 Protection configuration

The WKB-801A/R1 device can provide all the power protection required for a parallel reactor, and the main protection and backup protection can share the same TA. These protections include:

Phase differential protection

Zero sequence differential protection

Interturn protection

Main reactance overcurrent protection (one time limit for each section)

Main reactance zero sequence overcurrent protection (one time limit for each section)

Neutral point small reactance overcurrent protection

In addition, it also includes the following abnormal alarm functions:

Main reactance overload alarm

Neutral point small reactance overload alarm

TA abnormal alarm

TV abnormal alarm

The following figure shows the application configuration scheme of WKB-801A/R1 in a typical 500kV parallel reactor connection (main and rear common TA).

Figure 1-3-1Typical application configuration of WKB-801A/R1

In the picture:

The protection shown in L is implemented in one device, and all AC traffic is only connected to the device once.

When there is no dedicated TA (i.e. no TA3) for the neutral point small reactance, the current for overcurrent (load) protection of the small reactance can be synthesized by the three-phase current at the tail end of the reactor.

Utilize the second set of TA and the second device to complete the second set of protection functions, achieving dual main and dual rear.