Constant-current source intelligent control cabinet for crude oil electric dehydration

[0017] The specific structure of the intelligent control cabinet of the present invention will be further described in detail with reference to the accompanying drawings.

[0018] Such as figure 1 with figure 2 Shown. The constant current source intelligent control cabinet for crude oil electric dehydration of the present invention is composed of a cabinet body, a power main circuit and a control circuit installed in the cabinet body. The main circuit of the power supply is connected with a thyristor device as a switch to control the on and off of the main circuit. The selection and control of the inductor in the main circuit is also controlled by the thyristor device as a switch. Each thyristor device is turned on and off by an intelligent dedicated controller. For control, the detection, display, and control devices for working status are all connected to a PLC controller for control.

[0019] The said thyristor is controlled by a dedicated controller, which is composed of GY-DCF02A module. All the control poles and main electrodes 1 of five thyristors T1, T2, T3, T4 and T5 are connected to GY-DCF02A module. On the corresponding pins.

[0020] The main electrode 2 of the thyristor T1 of the main circuit of the power supply as a switching device is connected to the output terminal A1 of the main circuit inlet switch, and the main electrode 1 of the thyristor T1 is connected to the output terminal point 03 of the main circuit; The main electrode 2 of the thyristor T2 is connected to the output terminal 01 of the main circuit entry switch, and the main electrode 1 of the thyristor T2 is also connected to the output terminal 03 of the circuit, and the main electrode 2 of the thyristor T3 in the inductor control loop is connected To the output terminal B1 of the incoming switch and the A3 terminal of the inductor L1, the main electrode 1 of the thyristor T3 is connected to the main electrode 2 of the thyristor T4 and the A5 terminal of the inductor L2, and the main electrode 1 of the thyristor T4 is connected to the inductor The A4 terminal of L1 and the main electrode 2 terminal of the thyristor T5, the main electrode 1 of the thyristor T5 is connected to the A6 terminal of the inductor L2, and a wire is drawn from the A6 terminal of the inductor L2 and passed through the current transformers TA1 and TA2 to become external The output line, its end point is A6; the control pole 1 and control pole 2 and the main electrode 1 of all thyristors are controlled by the controller module; the output terminal of the current transformer TA1 is connected to the input terminal of the current transmitter A1, and the current changes The output terminal of the transmitter A1 is connected to the analog input terminal of the expansion module of the PLC controller. When the thyristor T1 is bidirectionally conducted, the output voltage between the 03 terminal and the A6 terminal of the main circuit is 380V, when the thyristor T2 is bidirectionally conducted When the output voltage between terminal 03 and terminal A6 of the main circuit is 220V.

[0021] When the thyristor T1 of the main circuit of the power supply is turned on and the thyristor T2 is turned off, and the thyristor T3 and the thyristor T5 in the inductor control loop are turned on at the same time and the thyristor T4 is turned off, the inductors L1 and L2 operate in parallel. When the main circuit output voltage is 380V; and when the thyristor T2 of the main circuit of the power supply is turned on and the thyristor T1 is turned off, and the thyristor T3 and the thyristor T5 in the inductor control loop are turned on at the same time and the thyristor T4 is turned off, the inductor L1 , L2 is parallel operation, the output voltage of the main circuit is 220V at this time; when the thyristor T2 of the main circuit of the power supply is turned on and the thyristor T1 is turned off, and the thyristor T3 and thyristor T5 in the inductor control loop are turned off at the same time, and the thyristor T4 is turned on When on, the inductors L1 and L2 operate in series, and the output voltage of the main loop is 220V at this time.

[0022] The said PLC controller is composed of Siemens S7-200SMART series CPU ST40 and expansion module EM AE04. The output ports on the CPU ST40 module are respectively connected with oil output relay (1), oil output relay (2), and debugging output. Relay, alarm output relay, low water level indicator, middle water level indicator, high water level indicator, start indicator, stop indicator, and reset indicator. The input ports are respectively connected with start button contacts, stop button contacts, recovery button contacts, Low water level signal alarm contact, medium water level signal alarm contact, high water level signal alarm contact, oil quality selection switch contact 1, oil quality selection switch contact 2 and debugging selection contact; expansion module EM AE04 is connected to the voltage transmitter AV1 respectively The output signal, the output signal of the voltage transducer AV2 and the output signal of the current transducer A1.

[0023] image 3 It is the chip pin diagram of the intelligent controller of the constant current source intelligent control cabinet for crude oil electric dehydration. The chip GY-DCF02A is mainly used to control the turn-on and turn-off of thyristors T1 to T5, thereby controlling the work of the cabinet.

[0024] Figure 4 It is the working power circuit diagram of the constant current source intelligent control cabinet for crude oil electric dehydration. The AC 220V power source drawn from the output terminals A1 and 01 of the switch in the cabinet becomes a DC24V power source through the switching power supply. The DC24V power supply is supplied to the PLC's CPU module and expansion module AE04. It also supplies the dedicated control module GY-DCF02A of the thyristor, the voltage transmitter AV1 and AV2, and the current transmitter A1, as well as the DC power supply for the water level sensor.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. Since the present invention uses a thyristor device as a switch to control the on and off of the main power supply and the selection of the working mode of the two inductors, compared with the device using a contactor, not only can it save maintenance work and costs, but also greatly The service life is improved, and the explosion-proof grade and safety of the cabinet are improved.

[0027] 2. Since the present invention uses a PLC controller to detect, display and control the electrical working status of the cabinet, it not only improves the reliability of the detection and control work, but also, because it has the characteristics of software programming control, its control method is more In order to be flexible and convenient, it is convenient for the expansion of the system and suitable for the changes of site conditions.