Underground metal polarization potential intelligent control instrument

Abstract

The invention discloses an underground metal polarization potential intelligent control instrument. The underground metal polarization potential intelligent control instrument comprises a shell, a control main board provided with a DSP is arranged in the shell, the control main board and a power signal acquisition board are connected in parallel, and the power signal acquisition board includes a pipeline potential collecting end and a ground bed potential collecting end. A positive polarity chopping power output unit, a negative polarity chopping power output unit and a lightning protection output unit are connected to the control main board in parallel, the positive polarity chopping power output unit and the negative polarity chopping power output are separately connected with an alternating current fuse breaker unit and an alternating current input power source sequentially in series, and a pipeline potential acquisition end and a ground bed potential acquisition end are separatelyconnected in series at both ends of the lightning protection output unit. The underground metal polarization potential intelligent control instrument can guarantee that underground metals obtain the standard permissible polarization potential, that is, the polarization potential is between -0.85 to -1.20.CSE, the underground metals are fully and effectively protected, and an entire equipment system has high integration, high control precision, and is convenient to construct and install.

Description

technical field [0001] The invention relates to a potential controller, in particular to an underground metal potential intelligent control instrument. Background technique [0002] With the acceleration of economic construction in various countries in the world, the demand for electricity continues to increase. A large number of high-voltage DC and AC transmission line projects are constructed and operated, such as the operation of traction systems with 1-4MW output power in high-speed rail subways, causing serious electric field pollution to the earth environment. In particular, the corrosion problem caused by the electric field pollution of urban subways is becoming more and more serious. If it is not treated and protected, it will bring catastrophic and devastating damage to buildings and structures. [0003] High-rise buildings, bridges, underground oil, gas, water and other underground metals are composed of a large number of steel structures, which bear the main ove...

AI Technical Summary

Problems solved by technology

[0004] For the above severe corrosion damage, countries around the world have already issued a large number of research results and technical standards, but these technical standards have certain defects and deficiencies, and cannot effectively alleviate AC and DC stray current interference.

Testing the A / V curves of solid-state couplers used for corrosion protection at home and abroad shows that these devices use high-power diodes to discharge current in one direction, and the positive current cannot be discharged negatively, resulting in a negative potential of more than 30 volts for metal structures, while the standard stipulates that If the polarization potential exceeds -1.2V.CSE, it will cause the risk of hydrogen embrittlement of metal materials; in fact, the measured rail-to-ground potential on site has a voltage exceeding minus 100V, and the pipeline potential exceeds ±120V.CSE when the high-voltage grounding electrode is unipolar.

[0005] For the subway traction leakage current, the diode is used for unidirectional conduction and connected to the zinc anode for grounding. The problem is: the starting voltage of the high-power thyristor device is too high, and in most cases it is impossible to control the potential of the metal structure within the standard range; the second is It basically has no effect on the huge impulse voltage when the subway traction starts and stops and the large current that occurs in the sudden fault state of the line, and it will also cause corrosion damage to underground metal buildings and structures

Once the underground metal is affected by the surrounding strong stray electric field and the potential between the pipe and the ground exceeds its control range, the cathodic protection potentiostat will automatically switch to the constant current working mode, and a direct alarm will be issued if the range is seriously exceeded, and normal operation cannot be maintained. work, so it is difficult to effectively protect the underground metal

[0010] 2. It does not have an energy-saving and power-saving working mode

The situation of using this equipment is: when the underground metal is disturbed by the surrounding stray electric field, if the pipe-ground potential is just within the preset specified range at this time, the drainage mode will not work, so as to achieve energy saving Eco mode, but existing potentiometers do not have this function mode

[0011] 3. It does not have the function of an intelligent control instrument. The voltage output polarity control is only for negative voltage, which is unipolar, and can only play a limited role in the negative bias of the tube-ground potential; in addition, when the underground metal is subjected to the surrounding strong stray electric field When the negative bias of the interference potential is large, the potentiostat cannot control the potential within the range required by the standard

[0012] 4. The potentiostatic instrument cannot respond quickly to the dynamic stray current, and cannot respond in real time. The reason is that the potentiostatic instrument uses a diode device, and the reflection rate is below 1000HZ; field measurements show that the frequency of dynamic stray current changes exceeds 100KHZ. Ordinary IGBT devices are difficult to adapt to

Therefore, high-speed high-frequency devices are required to adapt, or dynamic stray currents cannot be suppressed

Images