BD100 series power transmitter application in substation

Ren Yunye (Jiangsu Ankerui Microgrid Research Institute Co.
, Ltd.
, Jiangyin 214405, Jiangsu) [Abstract] In the field of automatic control, it is often encountered the problem of intelligent control of strong current equipment, of which how to use low-voltage, small-current programmable devices to control high-voltage, high-current strong current equipment is a difficult point
in control.

The current transmitter can convert AC current/AC voltage into DC current/voltage to connect to controllers such as PLCs, so that the intelligent control and monitoring tasks
of production equipment can be easily completed.

Current transmitters play a vital role in this process
.

【Keywords】Power transmitter; Anti-interference; The power transmitter introduced by the substation is an instrument that can convert the large signal of the automatic control application site into a DC voltage or current output according to the proportion of the lead, and the product is widely used in electrical installation, automatic control and dispatching system
of electric power, water treatment, pharmaceutical, smelting and other departments.

First, BD100 series power transmitter in the substation incoming line switch application of a cyclohexanone D25# used in the low-voltage busbar segmented operation of the control mode, normal operation, two busbars run separately, each main transformer with a busbar
.

The substation is designed at #1 and #2, and the main control room cannot see #1 and #2
.

If there is a period of excessive load, then the operator wants to pour a large power equipment, there will be a trip due to the starting current of the ambassador of this inlet switch, resulting in an accident
of stopping the cyclohexanone device.

Now the current transformer on the #1, #21QF, and 2QF sides plus two BD100 current transmitters on the secondary side to put the #1 and #2DCS
.

The BD100 current transmitter uses 4mA to represent the zero signal and 20mA to represent the full scale of the signal, while signals below 4mA or above 20mA are used for various fault alarms
.

The current value can be seen by the operator on the DCS display, and they can adjust
it to the size of each load before reversing the power of the higher equipment.

When the load needs to be adjusted, the circuit breaker 3QF is used to reverse the gate operation, first adjust the load in the line that needs to start the high-power equipment to another line, and then start the high-power equipment, so as to avoid the accident
of tripping the inlet switch due to the starting current, resulting in the suspension of the cyclohexanone device.

The circuit diagram of the cyclohexanone D25# system is shown in
Figure 1.

Figure 1 cyclohexanone D25# system circuit diagram after the transformation of cyclohexanone D25# new substation incoming line system features one, BD100 current transmitter original secondary side of the high degree of isolation, the use of no need to change the main circuit, directly the test of the main loop AC current conversion into a linear proportional output of DC4 ~ 20mA constant current source standard signal, and then sent to the monitoring system receiving device DCS display
through a pair of twisted pairs.

Second, the BD100 current transmitter adopts four-wire output wiring, auxiliary working power supply DC24V or AC/DC 85V~265V and output signal line DC4~20mA isolation, and the signal is transmitted in the form of current, strong anti-interference ability, and voltage output can meet the customer's field application of a variety of choices
.

Third, the BD100 current transmitter has a variety of protection functions, namely input overload protection, output overcurrent limit protection, output current long-term short-circuit protection, two-wire port transient induction mine and inrush current TVS control protection, working power supply DC 24V reverse connection protection, which also protects the inlet system of cyclohexanone D25# substation
.

After the implementation of this project, it not only avoids the tripping of the inlet circuit breaker due to excessive load in the case of equipment with large reverse power, but also avoids the unplanned shutdown
of cyclohexanone devices.

An unplanned shutdown of a cyclohexanone device will cause economic losses of about 200,000 yuan
.

Cyclohexanone units avoid an unplanned shutdown, which not only reduces production costs, but also reduces pollution
to the surrounding environment.

Second, BD100 series power transmitter BD100 series power transmitter is a kind of current and voltage electrical parameters in the power grid, through isolation into a linear DC analog signal or digital signal device
.

Products in line with GB/T13850-1998, IEC-688 standards
.

Products are widely used in various types of industrial automation systems, electric power, smelting, railway, municipal and other departments of electrical installation, automatic control and dispatching systems
.

The form factor and installation are shown in
Figure 2 and Figure 3.

BD100 series power transmitter features  high accuracy level: 0.
2  the entire range has a high linearity  output load capacity, signal transmission distance up to several hundred meters  through 485 communication, the measurement data transmission to the background  high degree of integration, simple structure, excellent temperature characteristics and long-term work stability  shape A output supports manual dialing autonomously switching output, the output contains 5 kinds of transmitter signal product model three.
Conclusion Through the BD100 series transmitter, the large signal isolation of the automatic application site is converted into a recognizable 4-20mA signal , transferred to the PLC for processing, can effectively control and protect
the field equipment.

Whether in terms of economy or practicality, the BD100 series transmitters have a wide range of promotional significance
.

References:[1] Ding Zhensheng, eds.
Application of sensor and sensing technology[J],1998.
[2] Enterprise microgrid design and application manual.
2020.
6 Author profile: Ren Yunye, male, electronic information engineering, mainly engaged in the research and development
of power sensors.