A method for active pressure relief of a raised seat based on pressure field reconstruction and extremum locking

Abstract

The application discloses a kind of based on pressure field reconstruction and extreme locking elevation seat active pressure relief method.The method comprises the following steps: step 1, a plurality of optical fiber pressure sensors are arranged in the inner wall of the elevation seat along the same horizontal section circumferential direction, and an electromagnetic translational disc type pressure relief valve is installed at the pressure relief port;Step 2, the dynamic pressure signals of multiple measuring points inside the elevation seat are collected in real time, the space-time reconstruction of the pressure field inside the elevation seat is carried out, and the pressure extreme point and the corresponding wave source center pressure value are determined;Step 3, based on the wave source center pressure value, the dynamic pressure relief trigger factor is calculated by pressure variation rate;Step 4, the input current of electromagnetic driving mechanism is controlled according to the dynamic pressure relief trigger factor, and electromagnetic driving force acting on the translational disc is generated.Compared with the prior art, the application makes up for the shortcomings of the existing device action lag and the inability to adapt to fault energy, significantly improves the anti-explosion ability and operation reliability of the transformer elevation seat.

Description

Technical Field

[0001] This invention relates to the field of power equipment safety protection technology, and more specifically, to an active pressure relief method for a riser seat based on pressure field reconstruction and extreme value locking. Background Technology

[0002] The riser block of an oil-immersed transformer is a key component connecting the main transformer tank and the high-voltage bushing. Its internal space is narrow and has a near-cylindrical structure. Unlike the larger main transformer tank, the riser block has a smaller internal oil volume and directly houses the high-voltage leads. When bushing breakdown, surface flashover, or other insulation faults occur inside the riser block, the fault arc releases a large amount of energy in a very short time, causing the insulating oil to vaporize and expand instantaneously, resulting in a rapid increase in pressure within the riser block.

[0003] Currently, protection against overvoltage faults inside transformers mainly relies on mechanical pressure relief valves installed on the top of the tank. However, for the riser seat, a locally enclosed area with more drastic pressure changes, traditional mechanical pressure relief methods have significant shortcomings. On the one hand, mechanical valves rely on spring preload for passive operation, requiring the pressure wave to reach the valve port and overcome the mechanical inertia of the valve core before opening, making it difficult to respond promptly to rapidly developing transient impact pressures within the riser seat. On the other hand, the riser seat is adjacent to the high-voltage bushing, and faults are often accompanied by strong electromagnetic transient interference. Traditional piezoelectric and capacitive sensors are susceptible to electromagnetic coupling in this area, leading to signal distortion, false alarms, or missed alarms, which is detrimental to building a reliable active protection system.

[0004] Therefore, there is an urgent need to propose a technical solution that can adapt to the characteristics of the locally enclosed space of the transformer riser, has strong anti-electromagnetic interference capabilities, and can achieve rapid and active pressure relief according to the evolution of the internal pressure field, so as to improve the explosion-proof protection capability and operational safety of the transformer riser under fault impact conditions. Summary of the Invention

[0005] To achieve the above objectives, this invention provides an active pressure relief method for a transformer riser based on pressure field reconstruction and extreme value locking. The system comprises an internal pressure field sensing array, an intelligent control terminal, and an electromagnetic direct-drive translational pressure relief device. The internal pressure field sensing array is arranged on the inner wall of the transformer riser, consisting of multiple fiber optic pressure sensors spaced at intervals along the circumference of the same horizontal cross-section of the riser, used to capture millisecond-level pressure wave signals in a strong electromagnetic environment. The explosion-proof intelligent control terminal includes an optical signal demodulation module, a high-speed data processing unit, and a power drive circuit. The high-speed data processing unit incorporates a pressure field reconstruction based on a cylindrical coordinate system. An algorithm and dynamic triggering factor calculation model are used to calculate the pressure wavefront characteristics in real time and output pulse drive commands. The electromagnetic direct-drive translational pressure relief device is installed at the pressure relief port of the riser seat, replacing the traditional purely mechanical valve. Its structure includes: a valve seat with a standard pressure relief diameter; a translational disc as a movable sealing component, which works with a sealing ring to achieve normal sealing; a return spring to provide basic sealing pre-tightening force; and an electromagnetic repulsion drive mechanism, consisting of a fixed excitation coil and an electromagnetic repulsion disc connected to the translational disc valve core. The fixed excitation coil is electrically connected to the explosion-proof pressure relief intelligent control terminal and is used to generate instantaneous electromagnetic repulsion when a drive command is received, overcoming the mechanical inertia of the valve core to achieve active opening.

[0006] Furthermore, the system, comprising a transformer internal pressure field sensing array, an intelligent control terminal, and an electromagnetic direct-drive translational pressure relief device, includes the following steps:

[0007] Step 1, Sensor Array and Pressure Relief Valve Arrangement: Multiple fiber optic pressure sensors are installed on the inner wall of the transformer riser base. The multiple fiber optic pressure sensors are arranged at intervals along the circumferential direction of the same horizontal cross section of the riser base to collect dynamic pressure signals from multiple measuring points inside the riser base. An electromagnetic translational disc-type pressure relief valve is installed at the pressure relief port of the riser base. The pressure relief valve includes a valve seat, a translational disc, a return spring, and an electromagnetic drive mechanism.

[0008] Step 2, Pressure Data Acquisition and Pressure Field Reconstruction: The pressure signals output by the multiple fiber optic pressure sensors are acquired in real time. Based on the dynamic pressure data of multiple measuring points, a cylindrical coordinate system is established inside the riser. The pressure field inside the riser is reconstructed in time and space. The pressure extreme points are determined in the reconstructed pressure field, and the pressure value of the wave source center corresponding to the pressure extreme points is extracted.

[0009] Step 3: Calculation of dynamic pressure relief trigger factor: Based on the pressure value, pressure change rate and pressure accumulation characteristics corresponding to the pressure extreme point, calculate the dynamic pressure relief trigger factor to characterize the degree of danger of the internal fault pressure wave of the riser seat.

[0010] Step 4, Active pressure relief control: The input current of the electromagnetic drive mechanism is controlled according to the dynamic pressure relief trigger factor to generate an electromagnetic driving force acting on the translational disk, which drives the translational disk to overcome the preload of the reset spring and open the pressure relief valve, thereby realizing active pressure relief that is adapted to the characteristics of the fault pressure wave.

[0011] In step 2, the internal space of the riser is meshed based on the cylindrical coordinate system (x, θ, z), and the internal pressure field of the riser is reconstructed according to the dynamic pressure values ​​collected by each fiber optic pressure sensor at time t, to obtain the reconstructed pressure value P(r, t) at any spatial location r. The reconstructed pressure value P(r, t) is calculated as follows:

[0012] ;

[0013] ;

[0014] In the formula, P(r,t) is the reconstructed pressure value at spatial location r at time t; n is the number of sensors in the sensor array; P i (t) represents the dynamic pressure value measured by the i-th sensor at time t; ∥rr i ∥ represents the Euclidean distance from the reconstructed point to the i-th sensor; ε is the spatial weighting coefficient; α is the attenuation coefficient of the pressure wave in the insulating oil; ϵ is a small constant to prevent the denominator from being zero;

[0015] After obtaining the reconstructed pressure field, a search is first performed within the geometric center axis of the raised seat and its neighborhood, and a corrected search is performed within the reconstructed space if necessary, to determine the pressure extreme points. The pressure value corresponding to the pressure extreme points is then taken as the pressure value at the center of the wave source. .

[0016] In step 3, the dynamic pressure relief trigger factor F trigger (t) is calculated as follows:

[0017] ;

[0018] In the formula, P core P represents the pressure value at the center of the wave source. th P0 is the reference opening pressure threshold of the pressure relief valve; P0 is the rated static oil pressure of the transformer during normal operation. This is the time response coefficient, measured in seconds (s). This is the integral normalization coefficient, with units of 1 / s.

[0019] In step 4, the electromagnetic driving force F acting on the translational disk 3 mag The calculation method for (t) is as follows:

[0020] ;

[0021] In the formula, K gain To drive the calibration pressure parameter, the value is equal to the design pressure required for the pressure relief valve to be fully open; S disk P is the force-bearing area of ​​the pressure relief valve core; local (t) represents the actual fluid pressure experienced at the valve core; F preload This refers to the initial preload applied to the valve core by the elastic component.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] This invention abandons the traditional mode of valves passively waiting for pressure to exceed a threshold. By calculating the pressure wavefront characteristics, it intervenes in advance and uses electromagnetic force to force open the valve before the mechanical spring is compressed, achieving a near-zero delay response. By establishing a mapping relationship between the triggering factor and the electromagnetic force output by the controller, it achieves precise response to different levels of faults, which can cope with high-energy explosions and avoid excessive pressure relief under minor faults. Attached Figure Description

[0024] Figure 1 This is a flowchart of the active pressure relief method for the riser seat based on pressure field reconstruction and extreme value locking in this invention;

[0025] Figure 2 This is a schematic diagram illustrating the structure and control principle of the electromagnetic translational disc-type pressure relief valve in this invention;

[0026] In the diagram, 1-Transformer riser flange interface; 2-Valve seat; 3-Translation disc; 4-Reset spring; 5-Electromagnetic repulsion disc; 6-Excitation coil; 7-Fiber optic pressure sensor; 8-Optical signal modulation module; 9-Logic control module;

[0027] Figure 3 This is a schematic diagram of a fiber optic pressure sensor array. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] This embodiment proposes an active pressure relief method and system for riser seats based on pressure field reconstruction and extreme value locking.

[0031] like Figure 1The flowchart shown is a process for the active pressure relief method of the riser seat based on pressure field reconstruction and extreme value locking in this embodiment.

[0032] like Figure 2 As shown, the structure described in this embodiment includes: a transformer riser flange interface 1; an optical fiber pressure sensor 7 arranged on the inner wall of the riser for collecting pressure signals in a strong electromagnetic interference environment; and an electromagnetic translational disc-type pressure relief valve installed at the pressure relief port of the riser. The pressure relief valve includes a valve seat 2, a translational disc 3, a return spring 4, and an electromagnetic drive mechanism; the electromagnetic drive mechanism consists of an electromagnetic repulsion disc 5 and an excitation coil 6. The system also includes an optical signal modulation module 8 and a logic control module 9, which are connected to the optical fiber pressure sensor 7 via optical fiber and to the excitation coil 6 via a power cable.

[0033] The specific implementation steps of this embodiment are as follows:

[0034] Step 1, Sensor Array and Pressure Relief Valve Arrangement: Multiple fiber optic pressure sensors 7 are installed on the inner wall of the transformer riser base. The multiple fiber optic pressure sensors 7 are arranged at intervals along the circumferential direction of the same horizontal cross section of the riser base to collect dynamic pressure signals from multiple measuring points inside the riser base. An electromagnetic translational disc-type pressure relief valve is installed at the pressure relief port of the riser base. The pressure relief valve includes a valve seat 2, a translational disc 3, a return spring 4, and an electromagnetic drive mechanism.

[0035] To address the cylindrical geometry of the riser, an axisymmetric circumferential topology is used to arrange the fiber optic pressure sensors 7. Specifically, on the same horizontal cross-section of the inner wall of the riser, four fiber optic pressure sensors 7 are installed at equal intervals of 90 degrees along the circumference, as shown below. Figure 3 As shown.

[0036] Step 2, Pressure Data Acquisition and Pressure Field Reconstruction: The pressure signals output by the multiple fiber optic pressure sensors 7 are acquired in real time. Based on the dynamic pressure data of multiple measuring points, a cylindrical coordinate system is established inside the riser. The pressure field inside the riser is reconstructed in time and space. The pressure extreme points are determined in the reconstructed pressure field, and the pressure value of the wave source center corresponding to the pressure extreme points is extracted.

[0037] The process involves acquiring optical signals and reconstructing the pressure field based on cylindrical coordinates: the optical signal modulation module 8 in the intelligent control terminal demodulates the optical signal from the fiber optic pressure sensor 7 in real time to obtain the dynamic pressure values ​​at each measuring point. .

[0038] The calculation method for spatiotemporal reconstruction of the pressure field is as follows:

[0039] ;

[0040] ;

[0041] In the formula, P(r,t) is the reconstructed pressure value at spatial coordinate r at time t; n is the number of sensors in the sensor array; P i Let be the pressure value measured by the i-th sensor at time t; ∥rr i ∥ represents the Euclidean distance from the reconstructed point to the i-th sensor; ε is the spatial weighting coefficient; α is the attenuation coefficient of the pressure wave in the insulating oil; ϵ is a small constant to prevent the denominator from being zero.

[0042] Furthermore, in order to obtain the wave source center pressure value used to calculate the dynamic pressure relief trigger factor... This step also includes wave source localization and feature value extraction. Specifically, the intelligent terminal pre-establishes a three-dimensional spatial mesh model (x, θ, z) inside the transformer riser. The pressure field distribution at any time t is then calculated using the aforementioned reconstruction formula. Then, the wave source center is searched in the spatial domain (x,θ,z).

[0043] Define the coordinates of the wave source center To reconstruct the spatial location of the maximum pressure value in the pressure field, i.e.:

[0044] ;

[0045] Therefore, the pressure value corresponding to this location is determined as the pressure value at the center of the wave source. :

[0046] .

[0047] Step 3: Calculation of dynamic pressure relief trigger factor: Based on the pressure value, pressure change rate and pressure accumulation characteristics corresponding to the pressure extreme point, calculate the dynamic pressure relief trigger factor to characterize the degree of danger of the internal fault pressure wave of the riser seat.

[0048] Dynamic pressure relief trigger factor (t) is calculated as follows:

[0049]

[0050] In the formula, P core P represents the pressure value at the center of the wave source. th P0 is the reference opening pressure threshold of the pressure relief valve; P0 is the rated static oil pressure of the transformer during normal operation. This is the time response coefficient, measured in seconds (s). This is the integral normalization coefficient, with units of 1 / s.

[0051] It incorporates the rate of pressure rise. This allows the system to operate even when the pressure amplitude has not yet reached the traditional mechanical threshold. However, when the shock wave intensity is extremely high, the trigger signal can be output in advance.

[0052] Step 4, Active pressure relief control: Based on the calculated dynamic pressure relief trigger factor, the input current of the electromagnetic drive mechanism is adjusted to apply active electromagnetic force, driving the translational disk 3 to reach the target lift within milliseconds, thereby achieving adaptive pressure relief that matches the fault energy level.

[0053] The electromagnetic force output by the controller in step 4 is calculated as follows:

[0054] ;

[0055] In the formula, K gain To drive the calibration pressure parameter, the value is equal to the design pressure required for the pressure relief valve to be fully open; S disk P is the force-bearing area of ​​the pressure relief valve core; local (t) represents the actual fluid pressure experienced at the valve core; F preload This refers to the initial preload applied to the valve core by the elastic component.

[0056] The terminal control pulse power generator injects a large current into the excitation coil 6, which generates an electromagnetic repulsion force on the electromagnetic repulsion disk 5 that matches the fault energy, driving the translational disk 3 to overcome the preload and mechanical inertia of the reset spring 4.

[0057] The above description is merely an illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific structure described, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, and all such modifications or additions should fall within the protection scope of the present invention.

Claims

1. A method for active pressure relief of a riser seat based on pressure field reconstruction and extreme value locking, characterized in that, The method includes the following steps: Step 1, Sensor array and pressure relief valve arrangement: Multiple fiber optic pressure sensors (7) are set on the inner wall of the transformer riser base. The multiple fiber optic pressure sensors (7) are arranged at intervals along the circumferential direction of the same horizontal cross section of the riser base to collect dynamic pressure signals of multiple measuring points inside the riser base. An electromagnetic translational disc pressure relief valve is installed at the pressure relief port of the riser base. The pressure relief valve includes a valve seat (2), a translational disc (3), a reset spring (4), and an electromagnetic drive mechanism. Step 2, pressure data acquisition and pressure field reconstruction: The pressure signals output by the multiple fiber optic pressure sensors (7) are acquired in real time. Based on the dynamic pressure data of multiple measuring points, a cylindrical coordinate system is established inside the lifting seat. The pressure field inside the lifting seat is reconstructed in time and space. The pressure extreme point is determined in the reconstructed pressure field, and the pressure value of the wave source center corresponding to the pressure extreme point is extracted. Step 3: Calculation of dynamic pressure relief trigger factor: Based on the pressure value, pressure change rate and pressure accumulation characteristics corresponding to the pressure extreme point, calculate the dynamic pressure relief trigger factor to characterize the degree of danger of the internal fault pressure wave of the riser seat. Step 4, Active pressure relief control: Control the input current of the electromagnetic drive mechanism according to the dynamic pressure relief trigger factor to generate an electromagnetic driving force acting on the translation disk, drive the translation disk to overcome the preload of the reset spring (4) to open the pressure relief valve, and realize active pressure relief that is adapted to the characteristics of the fault pressure wave.

2. The active pressure relief method for a riser based on pressure field reconstruction and extreme value locking according to claim 1, characterized in that, In step 2, the internal space of the lifting seat is divided into grids based on the cylindrical coordinate system (x,θ,z), and the internal pressure field of the lifting seat is reconstructed according to the dynamic pressure values ​​collected by each fiber optic pressure sensor (7) at time t, so as to obtain the reconstructed pressure value P(r,t) at any spatial position r. The reconstructed pressure value P(r,t) is calculated as follows: ； ； In the formula, P(r,t) is the reconstructed pressure value at spatial location r at time t; n is the number of sensors in the sensor array; P i (t) represents the dynamic pressure value measured by the i-th sensor at time t; ∥rr i ∥ represents the Euclidean distance from the reconstructed point to the i-th sensor; ε is the spatial weighting coefficient; α is the attenuation coefficient of the pressure wave in the insulating oil; ϵ is a small constant to prevent the denominator from being zero; After obtaining the reconstructed pressure field, a search is first performed within the geometric center axis of the raised seat and its neighborhood, and a corrected search is performed within the reconstructed space if necessary, to determine the pressure extreme points. The pressure value corresponding to the pressure extreme points is then taken as the pressure value at the center of the wave source. .

3. The active pressure relief method for a riser based on pressure field reconstruction and extreme value locking according to claim 1, characterized in that, In step 3, the dynamic pressure relief trigger factor F trigger (t) is calculated as follows: ； In the formula, P core P represents the pressure value at the center of the wave source. th P0 is the reference opening pressure threshold of the pressure relief valve; P0 is the rated static oil pressure of the transformer during normal operation. This is the time response coefficient, measured in seconds (s). This is the integral normalization coefficient, with units of 1 / s.

4. The active pressure relief method for a riser based on pressure field reconstruction and extreme value locking according to claim 1, characterized in that, In step 4, the electromagnetic driving force F acting on the translational disk mag The calculation method for (t) is as follows: ； In the formula, K gain To drive the calibration pressure parameter, the value is equal to the design pressure required for the pressure relief valve to be fully open; S disk P is the force-bearing area of ​​the pressure relief valve core; local (t) represents the actual fluid pressure experienced at the valve core; F preload This refers to the initial preload applied to the valve core by the elastic component.

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