CN212515444U - PLC-based power distribution cabinet control system - Google Patents

Abstract

The utility model discloses a PLC-based power distribution cabinet control system, which comprises a PLC control loop and an electric loop; the PLC control loop comprises a processing module, a digital quantity module and a plurality of analog quantity modules, wherein the digital quantity module and the analog quantity modules are respectively and electrically connected with the processing module; the electrical loop includes a plurality of current transducers for monitoring loop current; each analog quantity module is electrically connected with a plurality of current transducers and used for detecting the current of the electric loop. The utility model can realize the most basic control of the on-off of each loop of the lighting load and the remote control and the manual and remote mode switching by utilizing the communication between the PLC and the HMI through the PLC controller; when a remote network fault occurs, switching to a manual mode; the remote mode can be started at regular time without independently adding a clock module, and is switched back to the remote mode after fault recovery, and the remote mode can utilize Ethernet connection nearby equipment, so that communication can not be interrupted under the condition of network stability.

Description

PLC-based power distribution cabinet control system

Technical Field

The utility model relates to a supply distribution system technical field, in particular to switch board control system based on PLC.

Background

The distribution cabinet (case) is a final-stage device of a distribution system and is a general name of a motor control center. The power distribution cabinet is used in the occasions with dispersed loads and less loops; the motor control center is used for occasions with concentrated loads and more loops.

The power distribution system of the lighting power distribution cabinet is mainly characterized by a large number of power supply loops and long continuous load operation time, and a traditional intelligent control mode is that a main switch is added before a three-phase loop is shunted; taking a three-phase 24 loop as an example, 8 loop loads are respectively borne by three phases of the system A, B, C, and at the moment, a circuit breaker is additionally arranged on each phase of 8 loops to realize the common on-off of the 8 loops by matching with a three-phase alternating current contactor and an intelligent module. This kind of mode can only realize the forceful electric power control of illumination switch board "surface course", if want to accurate "some layer", need use the intelligent control module who has 24 delivery outlets, but the more intelligent control module's that exports is higher cost also more.

With the expansion of the number of control loops and the control surface, the control mode is easy to have faults such as remote communication interruption, module misoperation or no action and the like, and has great influence on the stability of large-scale light linkage or large-area light centralized control, so that the finding of a stable, reliable and high-economic-value control system has important significance.

SUMMERY OF THE UTILITY MODEL

To the problem that prior art exists, the utility model provides a switch board control system based on PLC.

In order to achieve the above purpose, the utility model discloses technical scheme as follows:

a power distribution cabinet control system based on PLC comprises a PLC control loop and an electric loop; the PLC control loop comprises a processing module, a digital quantity module and a plurality of analog quantity modules, wherein the digital quantity module and the analog quantity modules are respectively and electrically connected with the processing module; the electrical loop includes a plurality of current transducers for monitoring loop current; each analog quantity module is electrically connected with a plurality of current transducers and used for detecting the current of the electric loop.

Preferably, the processing module is selected from Siemens CPU with model number S7-200 CN; the input ends I0.0 and I0.1 of the Siemens CPU are manually/automatically switched input.

Preferably, the PLC control circuit further includes a plurality of intermediate relays; the number of output ports of the Siemens CPU is 16, the number of output ports of the digital quantity module is 8, correspondingly, the addresses are I0.0-I0.7, I1.0-I1.7 and I2.0-I2.7 respectively, and each output port is connected with one end of an intermediate relay; the model number of the digital quantity module is EM 222.

Preferably, each analog module is an EM231, and the analog module is provided with 8 input signal ports, and correspondingly, the input signal ports are connected to the current transmitter for detecting the loop currents.

Preferably, the electric circuit further comprises a plurality of alternating current contactors; each of the current transformers is mounted between an ac contactor and a load.

Preferably, the electric circuit further comprises a plurality of circuit breakers, and each of the ac contactors is disposed between a circuit breaker and a current transformer.

Preferably, the electrical circuit also employs cables of the type WDZB-YJY-3X4-SC25, each of which is disposed between a current transducer and a load.

Preferably, the model of the breaker is C65N-C32/2P.

Adopt the technical scheme of the utility model, following beneficial effect has: the utility model can realize the most basic control of the on-off of each loop of the lighting load and the remote control and the manual and remote mode switching by utilizing the communication between the PLC and the HMI through the PLC controller; when a remote network fault occurs, switching to a manual mode; the remote mode can be started at regular time without independently adding a clock module, and is switched back to the remote mode after fault recovery, and the remote mode can utilize Ethernet connection nearby equipment to ensure that communication cannot be interrupted under the condition of network stability; and the screen display equipment can be used for visually reading the current data of each loop monitored by the PLC, alarm parameters can be set at the software end, and when the current exceeds a certain value, the software end displays early warning information, so that the early warning device is convenient for a worker to prepare and process in advance.

Drawings

FIG. 1 is the overall design diagram of the PLC control circuit of the present invention;

FIG. 2 is an enlarged view of FIG. 1A;

FIG. 3 is an enlarged view of FIG. 1B;

FIG. 4 is an enlarged view of FIG. 1C;

FIG. 5 is an enlarged view of FIG. 1D;

FIG. 6 is an enlarged view of FIG. 1E;

FIG. 7 is a schematic view of the CPU of the present invention;

FIG. 8 is a partial schematic view of FIG. 1;

fig. 9 is a design diagram of the electric control circuit of the present invention;

FIG. 10 is a schematic diagram of a main program of the present invention;

FIG. 11 is a schematic diagram of a main program of the present invention;

fig. 12 is a schematic diagram of a main program of the present invention;

fig. 13 is a schematic diagram of a main program of the present invention;

fig. 14 is a schematic diagram of a main program of the present invention;

fig. 15 is a schematic diagram of a main program six according to the present invention;

fig. 16 is a schematic diagram of an output control procedure of the present invention;

fig. 17 is a schematic view of the current display procedure of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to 9, the utility model provides a power distribution cabinet control system based on a PLC, which comprises a PLC control loop 1 and an electric loop 2; the PLC control loop 1 comprises a processing module, a digital quantity module 102 and a plurality of analog quantity modules 103 which are respectively and electrically connected with the processing module; the electrical loop 2 comprises a number of current transducers 203 for monitoring the loop current; each analog quantity module 103 is electrically connected to a plurality of current transducers 203 for detecting the current of the electrical loop.

The processing module is selected from Siemens CPU101 with model number of S7-200CN, can realize complex control function no matter single machine operation or network connection, and has processing speed of 0.8-1.2ms, memory 2k, digital quantity 248 points and analog quantity 35 paths; the input ends I0.0 and I0.1104 of the Siemens CPU101 are manual/automatic switching input.

The PLC control loop also comprises a plurality of intermediate relays 105; the number of output ports of the Siemens CPU101 is 16, the number of output ports of the digital quantity module 102 is 8, correspondingly, the addresses are I0.0-I0.7, I1.0-I1.7 and I2.0-I2.7(106), and each output port is connected with one end of an intermediate relay 105; the digital quantity module 102 is of the type EM 222.

The model of each analog quantity module 103 is EM231, the analog quantity module 103 is set as an 8-channel input signal port, and correspondingly, the input signal port is connected to the current transducer 203 for detecting the current of each loop.

The electrical circuit further comprises a plurality of ac contactors 202; each current transducer 203 is installed between an ac contactor 202 and a load, and the principle is that the current transducer 203 induces a loop current, converts the loop current into a 4-20mA dc signal output in a linear proportion through its internal resistance, and feeds the dc signal back to the analog quantity module 103 so as to be read by the PLC.

The electrical circuit further comprises a plurality of circuit breakers 201, and each of the ac contactors 202 is disposed between a circuit breaker 201 and a current transformer 203.

The corresponding end of the ac contactor 202 is also connected to the other end of the intermediate relay 105.

The electrical circuit also employs cables of the type WDZB-YJY-3X4-SC25, each of which is disposed between a current transducer 203 and the load.

Preferably, the model of the breaker 201 is C65N-C32/2P.

The electric loop also comprises electric main switches, surge protectors, surge front switches and other circuit protective devices.

In this example, the input port of the CPU only utilizes I0.0 and I0.1104 as the manual/automatic switching port, and the output port 106 is set to I0.0-I1.7 of the CPU and I2.0-I2.7 of the digital quantity module 102, for a total of 24 outputs.

In the design of the electrical circuit 2 in the embodiment, the installation position of the ac contactor 202 is different from the conventional design, and is arranged behind the circuit breaker 201, so as to ensure that the power supply can be cut off at the front end of the control circuit when the control fault is abnormal and cannot be operated, and simultaneously, to facilitate the stopping of all power supply after the circuit breaker 201 during the period of system stop.

The current transducer 203 in this embodiment functions like a current transformer, and is intended to sense the current in the loop, so that it needs to be installed at the end of the loop close to the load to ensure the accurate current value of the loop.

Referring to fig. 10 to 17, the PLC-based power distribution cabinet control system is further provided with a PLC program, and the PLC program is composed of a main program, an output control program, and a current display program.

The manual/automatic switching input ends I0.0 and I0.1(104) can realize the opening of a screen and remote functions when the automatic mode is switched through the logic control of a PLC program, and the system is in comprehensive automatic control; when the manual mode is switched, the automatic control is closed.

The main function of the main program is to realize the starting, manual/automatic switching, timing setting and starting of a subprogram of the system.

The output control program has a main function of outputting different potentials by a program to operate the intermediate relay 105, thereby controlling the on/off of each circuit of the circuit.

The current display program 303 converts the analog quantity into a digital quantity by collecting the current feedback signal of the analog quantity module 103, and outputs the digital quantity to the screen display device for reading the current state of each loop.

In the embodiment, the PLC program design 3 adopts the matched programming software V4.0 STEP7 MicroWIN of Siemens PLC, and after the program is compiled, the simulation test can be carried out through SIM software.

The utility model discloses the theory of operation as follows:

step one, designing an electric loop 1: selecting the specifications of the circuit breaker 201, the alternating current contactor 202 and the current transducer 203 according to actual engineering requirements;

step two, selecting a PLC core unit CPU101, a digital quantity module 102 and an analog quantity module 103 which are suitable for the model according to the functions and loop numbers required by the system, and familiarizing the number and the functions of each input/output port;

step three, designing a PLC control loop 1: the ports of the PLC and the expansion module thereof are distributed and numbered according to functions, the port connection numbers between the two devices are kept consistent, and the corresponding wiring sequence is convenient to check during later adjustment or maintenance;

step four, comparing the electric circuit 2 with the PLC control circuit 1, listing all equipment lists, wherein parameter specifications and quantity are marked;

fifthly, according to the list listed in the step four, the installation and wiring of the real object are completed according to the electric circuit 2, the PLC control circuit 1 and the PLC control circuit;

step six, compiling the PLC program, namely compiling the main program and the output control program and compiling the current display program continuously after the compiling and compiling of the main program and the output control program are completed without errors;

step seven, simulating the PLC program in the step six by using SIM2.0, recording a program bug and timely correcting to complete a correct program;

step eight, downloading a program to the PLC, and compiling the HMI panel by using configuration software;

and step nine, keeping the system in idle load, and electrifying to test the running state of the system.

The above only be the preferred embodiment of the utility model discloses a not consequently restriction the utility model discloses a patent range, all are in the utility model discloses a conceive, utilize the equivalent structure transform of what the content was done in the description and the attached drawing, or direct/indirect application all is included in other relevant technical field the utility model discloses a patent protection within range.

Claims (8)

1. A power distribution cabinet control system based on a PLC is characterized by comprising a PLC control loop and an electric loop; the PLC control loop comprises a processing module, a digital quantity module and a plurality of analog quantity modules, wherein the digital quantity module and the analog quantity modules are respectively and electrically connected with the processing module; the electrical loop includes a plurality of current transducers for monitoring loop current; each analog quantity module is electrically connected with a plurality of current transducers and used for detecting the current of the electric loop.

2. The PLC-based power distribution cabinet control system according to claim 1, wherein the processing module is selected from Siemens CPUs with model numbers S7-200 CN; the input ends I0.0 and I0.1 of the Siemens CPU are manually/automatically switched input.

3. The PLC-based power distribution cabinet control system according to claim 2, wherein the PLC control loop further comprises a plurality of intermediate relays; the number of output ports of the Siemens CPU is 16, the number of output ports of the digital quantity module is 8, correspondingly, the addresses are I0.0-I0.7, I1.0-I1.7 and I2.0-I2.7 respectively, and each output port is connected with one end of an intermediate relay; the model number of the digital quantity module is EM 222.

4. The PLC-based power distribution cabinet control system according to claim 1, wherein each analog module is EM231 in type, each analog module is provided with 8 input signal ports, and each input signal port is correspondingly connected with a current transmitter for detecting the current of each loop.

5. The PLC-based power distribution cabinet control system of claim 1, wherein the electrical loop further comprises a plurality of ac contactors; each of the current transformers is mounted between an ac contactor and a load.

6. The PLC-based power distribution cabinet control system according to claim 5, wherein the electrical loop further comprises a plurality of circuit breakers, and each of the AC contactors is disposed between a circuit breaker and a current transformer.

7. The PLC-based power distribution cabinet control system of claim 6, wherein the electrical loop further employs cables of the type WDZB-YJY-3X4-SC25, each of the cables being disposed between a current transducer and a load.

8. The PLC-based power distribution cabinet control system according to claim 6, wherein the circuit breaker is C65N-C32/2P in model number.

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