Application of Hongge i7188ex in frequency convers

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Application of Hongge i-7188ex in oil field variable frequency pumping control system

in order to improve the real-time comprehensive testing and control level of working state parameters of oil production equipment in Shengli Oilfield, ensure high-yield and efficient production of oil wells, timely find and deal with possible hidden dangers or faults of equipment, and timely monitor and stop oil theft and other behaviors, The automatic monitoring of oil production must be the product control and management of bacteria in unbalanced growth conditions. At the same time, among the oil production equipment in Shengli Oilfield, the beam type kowtow oil production machine is the most widely used and the number is also the largest. However, the traditional kowtow machine generally has many problems, such as large starting impact, high power consumption in operation, low efficiency, etc. in addition, the oil well situation is complex, rod breaking, motor burning and other phenomena often occur, there is no reliable protection function for the motor, and there is a large amount of equipment maintenance, so it is urgent to transform the existing oil recovery machine equipment. Therefore, we use Hongge's i-7188exd and I-7000 modules to adopt the distributed variable frequency oil production control mode for 12 oil production equipment in dashazhuang, and its application effect is very obvious

2 working principle

2.1 the disadvantages of constant speed oil production and the necessity of variable frequency oil production

as an oil production equipment, its movement is to repeatedly lift up and down, lifting once in a stroke, and its power comes from two steel sliders with considerable weight driven by the motor. When the slider is lifted, it is similar to the role of a lever to send the rod of the oil production machine into the well. When the slider is lowered, the rod is raised to bring oil to the wellhead. Because the motor speed is constant, During the decline of the slider, the load is reduced, and the energy generated by the motor drag is bound to enter the regenerative power generation state, resulting in the rise of the bus voltage of the main circuit. Frequent high-voltage shocks will damage the motor, and there is no reliable protection function for the motor. Once the motor is damaged, the production efficiency will be reduced and the amount of maintenance will be increased, which is extremely detrimental to the energy conservation and consumption reduction of pumping equipment, and has brought great economic losses to the enterprise

if the variable frequency speed regulation technology is adopted, the effect is completely different: according to the motor theory, the speed formula is: n=60f/p × (1-s)。 Among them, P is the pole number of the motor, s is the slip rate, f is the frequency of the power supply, and N is the speed of the motor. It can be seen that the speed of the motor is approximately proportional to the frequency. Changing the frequency can smoothly adjust the speed of the motor. For the frequency converter, the frequency adjustment range is very wide, which can be arbitrarily adjusted between 0 ~ 400Hz, so the speed of the motor can be adjusted in a wide range. At the same time, the variable frequency governor has low-speed soft start, the speed can be adjusted smoothly in a large range, and the motor protection functions are complete, such as short circuit, overload, overvoltage, undervoltage and stall. It can effectively protect the motor and mechanical equipment, ensure that the equipment works under safe voltage, and has many advantages, such as stable and reliable operation, improved efficiency, etc. it is an ideal scheme for the transformation of oil production equipment. In this system, the maximum frequency is set at 50Hz in order to prevent the influence of the lifting of the oil production slider on its bearings and windings and to prevent the motor from excessive wear and overheating

2.2 system architecture

according to the frequency conversion control principle analyzed above, the control system must have a controller and corresponding control module. Since the pumping equipment is working in the field and is basically in the "unattended" working state, it is obviously unreasonable to use controllers such as industrial computer, etc., while Hongge's embedded network controller i-7188ex has all the control functions of PC, as long as it is installed in rain proof, electricity proof and other occasions, It can work, and is conducive to on-site installation to meet the design requirements. For this reason, the demand for polymers in Europe will fall by 3% to 4% again this year around the i-7188ex controller The falling demand for polymers also shows that the changing function modules in the market can complete the control task only when they cooperate with them. Therefore, we choose the i-7024 analog output module, and let its output analog signal be used as the input control signal of the frequency converter, i-7060 as the control module of the corresponding control switch, and i-7017 collect the flow of the oil pipeline in real time. The architecture of the control system is shown in Figure 1

since there are 12 pumping units in Xiazhuang oil production team, in order to facilitate "centralized management and distributed control", a monitoring and control computer is installed in the control room of the team, which is mainly used to manage I such as softening-7188ex, and record the flow, work log and the health status of equipment operation in real time. Since the control room of the team is far away from the oil production statistics center of the oil production plant, the inspectors will regularly carry mobile laptops to download the recorded parameters of the control computer through the hub and the control computer using tcp/ip protocol, and then return to the oil production statistics center to summarize and count the recorded parameters of each oil production team, so as to achieve the purpose of comprehensive testing and management of the working state parameters of oil production equipment. The i-7188ex and I-7000 modules adopt RS-485 communication, and the i-7188ex and the control computer adopt tcp/ip to connect and communicate through the hub, so as to realize hierarchical control and hierarchical management, which is conducive to maintenance, installation, movement and disassembly. It is a relatively excellent oil production equipment control system

2.1 frequency conversion adjustment process of oil production

frequency conversion oil production is that when the sliding block is in the process of descending, after i-7188ex logic judgment, the control signal is sent to the frequency converter through i-7024, and the output frequency of the frequency converter is adjusted to make the sliding block descend at a variable speed according to the vacuum of the wellhead and the load carried by the motor. When the oil production sliding block is lifted, in order to prevent the occurrence of oil hammer, the start and stop of the oil production pump will adopt the linkage mode, that is, three oil pumps share an outlet valve. The frequency conversion linkage mode includes the fixed mode of frequency conversion pump and the circulating mode of frequency conversion pump. The fixed mode of variable-frequency pump can control up to 7 pumps, and the pump can be turned off in the order of "first on, first off" and "first on, then off"; The circulation mode of variable-frequency pump can control up to 4 pumps, and the system turns off the pump in the order of "first on, first off". This system adopts the frequency conversion pump circulation mode, so that the oil production pumps of three oil wells are used. Therefore, in the production and manufacturing of stainless steel, the cupping experiment is an indispensable frequency conversion linkage mode for oil production, which not only reduces energy consumption and protects the motor, but also makes the pressure of the oil pipeline constant and the flow constant, which is conducive to measurement and management

2.2 benefit analysis

in the early stage of exploitation, due to the large oil storage and sufficient liquid supply, in order to improve the efficiency, we adopted the method of increasing the speed to make the frequency converter operate to 65Hz, and the frequency increased by 1/3. Its comprehensive oil recovery rate can be 20% more than that under power frequency, and the work efficiency increased by 1.2 times. In the middle stage, we let the frequency converter operate to 50Hz, and the frequency converter operates under power frequency, and its oil recovery returns to normal state, Due to the use of a variety of control technologies, the oil production has been greatly increased in a short time, while the maintenance volume has been greatly reduced, which is conducive to the energy conservation and consumption reduction of equipment, reduces the labor intensity of oil workers, improves work efficiency, and the control system can be reused

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