Early warning system and method for operating personnel of transformer substation

Abstract

The invention discloses a substation operator early warning system and method. The substation operator early warning system comprises wearable safety equipment and a substation intelligent monitoring system, wherein the wearable safety equipment comprises an electric field sensor and an alarm; the electric field sensor comprises a head electric field sensor, a fingertip electric field sensor and a body electric field sensor; when a substation operator wears the safety equipment with the built-in electric field sensor and the built-in alarm and enters the substation, the electric field sensor monitors the surrounding electric field of the substation operator, and an alarm is given out through the alarm after a safety early warning value is exceeded; and meanwhile, monitoring information and alarm information are sent to a transformer substation intelligent monitoring system. According to the technical scheme of the invention, protection and early warning are provided for transformer substation operators.

Description

Technical Field

[0001] The present invention belongs to the technical field of substation operation, and in particular relates to a substation operator early warning system and method, which is suitable for sending out early warning signals when the electric field strength of the operator exceeds a threshold during the operation of the substation operator. Background Art

[0002] As the hub and node of the power grid, the substation is also a high-risk working area for the production and operation of the power grid, and its operation safety management is particularly important. In order to improve the safety management level of the substation, the management department has not only formulated a series of regulations and systems, but also configured the substation with a comprehensive automation system, video monitoring system, five-defense system, electrical equipment online monitoring system, etc. The above technical facilities have greatly improved the automation level of the substation and provided certain technical support for the operation safety management of the substation. However, the configuration of the above system mainly judges the state of the power grid based on the changes and abnormalities of electrical and chemical quantities. It can neither fully cover the substation nor locate and warn in real time. It can only provide data recording and analysis for the cause analysis of the accident during or after the accident, and cannot take precautions and warn of dangerous factors in advance. The personal and equipment safety of the substation site has not been technically guaranteed due to the influence of human factors such as personnel violations, chaotic on-site operations, inadequate on-site management, and non-regulatory inspections, resulting in some safety hazards based on human factors that cannot be avoided.

[0003] At present, researchers at home and abroad have achieved results in the accuracy, range and sensitivity of electric field measurement. However, due to the fact that the existing electric field measurement devices are usually large in size, heavy in weight, complex in processing technology and high in cost, they are difficult to apply to wearable power safety warning equipment such as helmets and safety vests, and there are few separate power frequency electric field sensors. In the substation operating environment, it is necessary to measure the electric field of the operators in motion, so higher requirements are put forward for the wearable safety warning equipment of the operators. It is necessary to design miniaturized, portable, lightweight and low-cost wearable warning safety equipment to achieve near-electricity safety warning for substation operators.

[0004] There are few finished high-voltage early warning devices available at present. Among them, the high-voltage near-electricity test pen can test electricity, but its induction of the electric field only relies on a wire. In places with complex electromagnetic environments such as substations, there will be problems of false alarms and missed alarms. There are also high-voltage early warning monitors. This type of early warning device senses the industrial frequency electric field strength through a large copper sheet installed on the front of the shell, and measures the electric field through a signal processing circuit. If it exceeds the threshold, it will issue an early warning. In general, the research on wearable safety devices with built-in electric field sensors is not yet mature, and there are mainly the following problems:

[0005] First, existing electric field sensors may show insufficient sensitivity or reduced accuracy in complex electromagnetic environments (such as strong electric fields or multi-source interference fields), resulting in false alarms or missed alarms. In a rapidly changing electric field environment, it may be difficult for the sensor to capture changes in electric field strength in real time, affecting real-time performance.

[0006] Second, in electric fields of different intensities, the sensor may experience measurement nonlinearity or saturation problems, especially near ultra-high voltage equipment.

[0007] 3. The design of sensors and related electronic modules may increase the weight or volume of the equipment, affecting the wearing comfort and long-term durability of construction workers. In addition, the installation location of the electric field sensor may not fully cover all possible dangerous areas, resulting in monitoring blind spots.

[0008] 4. The high power consumption of electric field sensors and communication modules may lead to insufficient battery life and affect the demand for all-weather use. Frequent charging or battery replacement may increase the burden of use and reduce the efficiency of on-site application of the equipment. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a warning system and method for substation operators, so as to provide protection and warning for substation operators.

[0010] To achieve the above object, the present invention adopts the following technical solution:

[0011] A substation operator early warning system, comprising: a wearable safety device and a substation intelligent monitoring system; wherein the wearable safety device comprises: an electric field sensor and an alarm; the electric field sensor comprises: a head electric field sensor, a fingertip electric field sensor and a body electric field sensor;

[0012] Among them, when the substation operators enter the substation wearing safety equipment with built-in electric field sensors and alarms, the electric field sensors monitor the electric field around them and sound an alarm through the alarm when the safety warning value is exceeded; at the same time, the monitoring information and alarm information are sent to the substation intelligent monitoring system.

[0013] Preferably, the electric field sensor is a cylindrical electric field sensor.

[0014] Preferably, the relationship between the external electric field calculated by the fingertip electric field sensor and the measured voltage is:

[0015]

[0016] Preferably, the body electric field sensor calculates the relationship between the measured voltage and the electric field strength as follows:

[0017]

[0018] The present invention also provides a transformer substation operator early warning method, comprising:

[0019] Step S1: When a substation operator enters the substation wearing safety equipment with built-in electric field sensors and alarms, the electric field sensors monitor the electric field around them and sound an alarm through the alarm when the safety warning value is exceeded; wherein the electric field sensors include: head electric field sensors, fingertip electric field sensors and body electric field sensors;

[0020] Step S2: Send monitoring information and alarm information to the substation intelligent monitoring system.

[0021] Preferably, the electric field sensor is a cylindrical electric field sensor.

[0022] Preferably, the relationship between the external electric field calculated by the fingertip electric field sensor and the measured voltage is:

[0023]

[0024] Preferably, the body electric field sensor calculates the relationship between the measured voltage and the electric field strength as follows:

[0025]

[0026] The present invention uses wearable safety equipment with built-in sensors and alarms in conjunction with intelligent monitoring to provide early warning to operators; at the same time, by coordinating the wearable safety equipment with the substation intelligent monitoring system, protection and early warning are provided to substation operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 The figure is a schematic diagram of the structure of the early warning system for substation operators according to an embodiment of the present invention.

[0029] Figure 2 Placement of safety vest sensors;

[0030] Figure 3 This is the circuit diagram of the fingertip electric field sensor;

[0031] Figure 4 The equivalent circuit diagram of the fingertip electric field sensor circuit is

[0032] Figure 5 Calculate schematic diagram for body electric field sensor;

[0033] Figure 6 Schematic diagram of head electric field sensor calculation. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Embodiment 1:

[0037] like Figure 1 As shown, an embodiment of the present invention provides a substation operator warning system including: a wearable safety device and a substation intelligent monitoring system; wherein the wearable safety device includes: an electric field sensor and an alarm.

[0038] The electric field sensor must be small, lightweight, and easy to carry. The embodiment of the present invention designs a head electric field sensor, a fingertip electric field sensor, and a body electric field sensor based on the human body posture characteristics. The design of the electric field sensor also needs to consider the wearing comfort of the substation workers, so a cylindrical electric field sensor is selected.

[0039] By placing sensors in wearable safety equipment, safety equipment with built-in sensors can reflect the electric field strength of the operator's location and protect the operator. Therefore, it is necessary to place head electric field sensors on the helmet, fingertip electric field sensors on the middle finger of the glove, and body electric field sensors on the safety vest, such as Figure 2 shown.

[0040] When the substation operators wear safety equipment with built-in electric field sensors and alarms and enter the substation, they need to monitor the electric field around them through the system and issue an alarm when the safety warning value is exceeded. The system's measurement, result display and alarm should exist independently, with the prerequisite of not hindering the close-range measurement of the electric field and ground personnel receiving the measurement results at a safe distance. The alarm will remind the staff according to the maximum electric field strength in the maintenance personnel's body. The reminder method is a beep with different intensities at a certain interval. If the electric field strength is weak, the beep interval is long and the sound intensity is weak. As the electric field strength increases, the beep interval will become shorter and the intensity will become stronger, until a continuous beep appears when approaching the safe distance, reminding the staff to stay away from the maximum intensity electric field.

[0041] As an implementation method of the embodiment of the present invention, Figure 3 As shown in the figure, the relationship between the induced voltage and the electric field strength between the two plates is designed. If the electric field sensor is placed in an alternating electric field with a field strength of E(t), and the inner plate of the sensor is grounded, the outer surface of the sensor will generate corresponding alternating charges due to electrostatic induction. The radius of the sensor is r, and the height is h. The outer surface area of ​​the electric field sensor is 2πrh, and the charge surface density is σ(t). The magnitude of the induced charge is:

[0042] Q(t)=∫σ(t)dA (1)

[0043] The charge Q(t) on the plate is proportional to the actual field strength E(t), and the relationship is:

[0044] Q(t)=ε0SE(t) (2)

[0045] The induced charge will form a relatively weak alternating voltage signal on the sampling capacitor.

[0046] U(t)=Q(t) / C M (3)

[0047] Then we can get

[0048] U(t)=KE(t) / C M (4)

[0049] That is, by measuring C M The electric field signal E(t) can be obtained by the voltage signal on the surface, which is the basic principle of the electric field sensor in the embodiment of the present invention.

[0050] In field detection, the electric field sensor of the embodiment of the present invention is used to measure the industrial frequency electric field signal, which has high requirements on the accuracy of the signal. Therefore, it is necessary to analyze the received signal of the electric field sensor to consider how large the electric field signal can be sensed by the designed electric field sensor and whether it can meet the requirements for measuring signal strength.

[0051] In actual design, after the structural dimensions of the fingertip electric field sensor and the filling medium between the plates are determined, the equivalent capacitance C M It is also determined that when performing capacitance equivalence, the two plates of the parallel plate capacitor are equivalent to the two electrodes of the capacitor, and a capacitor with a capacitance value of C1 is used for equivalence. The voltage signal is the input signal of the measuring device. Figure 4 In the figure, C1 is the equivalent capacitance between the two electrodes of the fingertip sensor; C M is the sampling capacitor; R i is the input resistance of the signal measurement circuit; U(t) is the induced voltage source of the fingertip sensor; U i (t) is the input voltage of the back-end signal measurement circuit.

[0052] For coaxial dielectric, the equivalent capacitance is as follows:

[0053] This fingertip electric field sensor is a cylindrical capacitor, whose internal electric field is axially symmetrically distributed, the internal electrode is grounded, and its electric lines point from the outside to the inside. There are no electric lines in the axial direction, and the electric field strength is 0. Figure 3 As shown, make a Gaussian surface, and assume that the charge per unit length of the plate on the axial direction of the cylinder is λ, then the formula is used to obtain:

[0054]

[0055] The relationship between the induced charge of the outer electrode plate and the external electric field is shown in the following formula:

[0056] Q(t)=∫σ(t)dS=2πε0R B LE(t) (6)

[0057] Among them, R B is the radius of the bottom surface of the outer electrode plate, L is the height of the electrode plate, and ε0 is the vacuum dielectric constant.

[0058] Then the charge per unit length of the plate λ can be obtained as shown in the following formula:

[0059]

[0060] According to equations (5) and (7), the relationship between the external electric field and the measured voltage can be obtained, as shown in the equation:

[0061]

[0062] Take the breakdown voltage U of epoxy resin M is 30 kV. Since the cylindrical sensor of the embodiment of the present invention needs to be similar to the width of a finger, R B =4cm, R A =3cm, vacuum dielectric constant ε0 = 8.854×10 -12 C2 / N·m 2 .

[0063] Then the maximum electric field strength that can be measured by the cylindrical fingertip electric field sensor can be obtained as:

[0064]

[0065] Through circuit-related knowledge, the relationship between the input voltage signal of the measurement circuit and the equivalent voltage source of the electric field sensor can be obtained:

[0066]

[0067] It can be concluded that

[0068]

[0069] like The initial phase angle is but:

[0070]

[0071] The effective value of the voltage after the input signal passes through the subsequent amplification circuit is U in , assuming the amplification factor is G, the amplitude of the output signal will be amplified, and the effective value of the input signal is The fingertip electric field sensor senses voltage Valid values ​​are:

[0072]

[0073] As an implementation of an embodiment of the present invention, the calculation of the head electric field sensor is similar to the calculation of the body electric field sensor. Therefore, the embodiment of the present invention performs calculation on the body electric field sensor.

[0074] like Figure 5 As shown, the body electric field sensor designed for the embodiment of the present invention is a parallel plate electric field sensor, in which two metal plates are selected as two electrodes, which are connected to the instrument through an insulating material epoxy resin, and the two electrodes are led out from the outside through wires.

[0075] The parallel plate type electric field sensor is in an alternating electric field with an electric field strength of E(t). The area of ​​the upper and lower plates is S = πR. 2 , according to the induced charge calculation formula

[0076] Q(t)=∫σdS=ε0πR 2 E(t) (14)

[0077] Where ε0 is the dielectric constant of vacuum, and E(t) is the normal component of the external alternating electric field on the electrode surface.

[0078] The formula for induced charge is as follows:

[0079]

[0080] Among them, ε r is the relative dielectric constant, the relative dielectric constant of epoxy resin is between 3-5; d is the distance between the upper and lower plates, which is 1 cm;

[0081] Then the relationship between the measured voltage and the electric field strength can be obtained as:

[0082]

[0083] The breakdown voltage of epoxy resin is 30kV-100kV, taking the voltage U M =30kV, the maximum electric field strength that can be measured is:

[0084]

[0085] like Figure 6 As shown in the figure, the calculation process of the head electric field sensor is given. The parallel plate type head electric field sensor is in an alternating electric field with an electric field strength of E(t), and the area of ​​its upper and lower plates is S=π(R B 2 -R A 2 ), according to the induced charge calculation formula

[0086]

[0087] Where ε0 is the dielectric constant of vacuum, and E(t) is the normal component of the external alternating electric field on the electrode surface.

[0088] The formula for induced charge is as follows:

[0089]

[0090] Among them, ε r is the relative dielectric constant, the relative dielectric constant of epoxy resin is between 3-5; d is the distance between the upper and lower plates, which is 1 cm;

[0091] Then the relationship between the measured voltage and the electric field strength can be obtained as:

[0092]

[0093] Embodiment 2:

[0094] The embodiment of the present invention also provides a method for early warning of substation operators, comprising:

[0095] Step S1: When a substation operator enters the substation wearing safety equipment with built-in electric field sensors and alarms, the electric field sensors monitor the electric field around them and sound an alarm through the alarm when the safety warning value is exceeded; wherein the electric field sensors include: head electric field sensors, fingertip electric field sensors and body electric field sensors;

[0096] Step S2: Send monitoring information and alarm information to the substation intelligent monitoring system.

[0097] As an implementation manner of the embodiment of the present invention, the electric field sensor is a cylindrical electric field sensor.

[0098] As an implementation of an embodiment of the present invention, the relationship between the external electric field calculated by the fingertip electric field sensor and the measured voltage is:

[0099]

[0100] As an implementation method of the present invention, the relationship between the measured voltage and the electric field strength calculated by the body electric field sensor is:

[0101]

[0102] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A substation operator early warning system, characterized in that: include: Wearable safety equipment and substation intelligent monitoring system; wherein the wearable safety equipment includes: electric field sensors and alarms; the electric field sensors include: head electric field sensors, fingertip electric field sensors and body electric field sensors; Among them, when the substation operators enter the substation wearing safety equipment with built-in electric field sensors and alarms, the electric field sensors monitor the electric field around them and sound an alarm through the alarm when the safety warning value is exceeded; at the same time, the monitoring information and alarm information are sent to the substation intelligent monitoring system.

2. The early warning system for substation operators according to claim 1, characterized in that: The electric field sensor is a cylindrical electric field sensor.

3. The early warning system for substation operators according to claim 2, characterized in that: The relationship between the external electric field and the measured voltage calculated by the fingertip electric field sensor is:

4. The early warning system for substation operators according to claim 3, characterized in that: The relationship between the body electric field sensor's measured voltage and electric field strength is:

5. A method for early warning of substation operators, characterized in that: include: Step S1: When a substation operator enters the substation wearing safety equipment with built-in electric field sensors and alarms, the electric field sensors monitor the electric field around them and sound an alarm through the alarm when the safety warning value is exceeded; wherein the electric field sensors include: head electric field sensors, fingertip electric field sensors and body electric field sensors; Step S2: Send monitoring information and alarm information to the substation intelligent monitoring system.

6. The early warning method for substation operators according to claim 5, characterized in that: The electric field sensor is a cylindrical electric field sensor.

7. The early warning method for substation operators according to claim 6, characterized in that: The relationship between the external electric field and the measured voltage calculated by the fingertip electric field sensor is:

8. The early warning method for substation operators according to claim 7, characterized in that: The relationship between the body electric field sensor's measured voltage and electric field strength is:

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