Operating Characteristic Monitoring System for Power Switch

Abstract

The present invention relates to a system for monitoring the operational characteristics of an electric power switch. The system for monitoring the operational characteristics of an electric power switch according to the present invention is characterized in that it includes an electrode sensor that is impregnated in a circular, square or pin-shaped structure inside a conventional insulator constituting the electric power switch, or is separately installed outside in the form of a detachable electrode sensor module, and detects an electrostatic voltage induced when the position of the main contact of the electric power switch moves, and an integrated monitoring means that simultaneously calculates and displays the opening and closing time, three-pole non-simultaneous opening and closing time, stroke and operating speed of each phase of the electric power switch based on the voltage value input from the electrode sensor, and outputs a control signal for an alarm or locking when the calculated output value deviates from a predetermined operational characteristic limit range.

Description

Technical Field

[0001] The present invention relates to an operating characteristic monitoring system for a power switch. Specifically, in order to always ensure the opening / closing and interrupting performance during use, the opening / closing time of each phase of the power switch, the three-pole non-simultaneous opening / closing time, the stroke, the operating speed, and other operating characteristics during opening / closing are monitored in real time, so that monitoring and control can be performed even in a remote location. By detecting the occurrence of a sudden change in the operating characteristic value, an output signal can be transmitted to the outside. The present invention relates to an operating characteristic monitoring system for a power switch.

Background Art

[0002] A power switch refers to a device that forms, changes, opens, and interrupts an electric circuit in order to efficiently and highly reliably connect and distribute the electric power produced at a power plant to consumers. It is roughly classified into a general switch used for a single purpose and a switchgear in which a circuit is formed by a plurality of switches and the system has a complex function.

[0003] A general switch means a power device that opens and closes the load current in a power supply line for line inspection or load inspection in a power supply system that supplies electricity such as a transmission system or a distribution system, and cuts off the power supply. After the inspection is completed, it means a power device for stably resupplying the load current. Depending on the purpose of use, it is divided into a circuit breaker (CB), a load breaker switch (LBS), an automatic transfer switch (ATS), an automatic section switch (ASS), an automatic load transfer switch (ALTS), an earth switch (ES), a disconnect switch, etc.

[0004] General switches can be divided into gas-insulated switchgears (GIS) and solid-insulated switchgears according to the insulation method, and can be further divided into overhead switches installed on utility poles for opening and closing overhead lines and underground switches installed in a grounded metal box for opening and closing underground cables according to the installation location. Currently, as overhead switches, molded solid-insulated switches introduced to prevent global warming are generally used. As for underground switches, both SF6 gas-insulated switchgears and solid-insulated switchgears are used, but in the future, they are expected to be replaced by environmentally friendly insulated gas switchgears.

[0005] From the aspect of the method of extinguishing the arc generated during the opening, closing, and interruption of current, conventionally, gas-insulated switchgears using SF6 gas with excellent arc extinguishing performance as the arc extinguishing medium were mainly used. However, when the problem of global warming caused by the use of SF6 gas emerged, a solid-insulated switching method was developed to solve it, and subsequently, a method using a vacuum interrupter is generally applied.

[0006] Generally, a gas-insulated switchgear (GIS) is a composite switchgear that not only opens and closes the load current under normal operating conditions in the power system but also safely protects the line in abnormal conditions such as accidents and short circuits. In a metallic enclosure filled and sealed with insulating gases such as SF6 gas, CO2, g3, and dry air, there are a circuit breaker (CB), a disconnecting switch (DS), an earth switch (ES), a potential transformer (PT), a current transformer (CT), a lightning arrester (LA), a bus (BUS), etc.

[0007] The hardware technology in power switches has already reached the completion stage. Recently, the development of environmentally friendly technologies such as dry air insulation, epoxy insulation, and the technology for increasing the breaking capacity of vacuum interrupters that are friendly to the environment has been concentrated. The efficiency of asset management of power equipment for maintenance management and equipment replacement considering the failure-free operation and economy in power equipment has been actively promoted.

[0008] When the number of opening and closing operations increases according to the period during which the power switch is applied and used in the system, due to the deterioration of electrical components, wear of parts of the mechanical operating device, bolt relaxation, damage, etc., the operating characteristic values during opening and closing such as the opening and closing time of each phase of the power switch, the three-pole non-simultaneous opening and closing time, stroke, and operating speed change. When the power switch has operating characteristics different from those at the initial installation and does not operate correctly, the opening and closing and breaking capabilities decrease, leading to damage and serious failures of power equipment and making it impossible to stably supply power to consumers. Therefore, it is very important to monitor and diagnose the operating characteristics during opening and closing of the power switch.

[0009] When evaluating the soundness of power equipment, technical evaluations are carried out through regular inspections to grasp the state of the equipment and online preventive diagnosis using sensors. The main inspection items of the power switch include the main circuit characteristics (insulation resistance, contact resistance) of the power equipment and the operating characteristics of the switch (opening and closing time, three-pole non-simultaneous opening and closing time, stroke, operating speed). The current preventive diagnosis items include gas state monitoring (moisture content, purity, SO2 amount in the gas), partial discharge measurement, etc. However, since the inspection of the power switch is carried out in a power-off (no voltage) state, the power supply by the power line where the switch is installed must be stopped. Therefore, in order to continuously supply power to consumers, a separate power line must be secured. Also, since it is not possible to power off all power lines simultaneously, the inspection must be carried out step by step, resulting in an increase in human and time costs, etc.

[0010] Therefore, there is an urgent need to develop and apply a monitoring technology that can monitor and diagnose in real time the operating characteristics of power switches, such as the opening and closing times of each phase, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed, by utilizing various forms of sensors in the operating state with voltage applied. The operating state data of the power switch collected in real time by the sensor is used for the soundness evaluation analysis of the power switch through comparative analysis with the initial data and the collected data. The analyzed data is provided not only as information for the asset owner or manager to determine equipment operation interruption and maintenance management, but also as information for giving accurate work instructions to on-site workers.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0012] The present invention installs an electrode sensor in a form impregnated inside a solid insulator, which is a component of a power switch, or installs a detection electrode sensor module that can be separately detached externally, and based on the characteristic that the voltage induced in the capacitance-type electrode sensor varies according to the spatial position change of the movable electrode due to the operation of the switch, monitors and diagnoses in real time the state changes of the operating characteristics of each phase of the power switch during operation, such as the opening and closing times, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed. When the operating characteristics of the power switch change rapidly, it aims to provide an operating characteristic monitoring system for the power switch that can output control signals for alarm and locking.

[0013] Furthermore, the present invention aims to provide an operating characteristic monitoring system for power switches that is equipped with a communication module that enables communication with an external computer in a remote location, thereby making it possible to easily monitor and control the operating characteristics of power switches even in a remote location. [Means for solving the problem]

[0014] The power switchgear operation characteristic monitoring system according to a first embodiment of the present invention is characterized by comprising: capacitance-type electrode sensors that are installed in a circular, rectangular, or pin-shaped structure inside an insulating partition spacer between a circuit breaker unit and a cable connection unit of an insulated switchgear and detect a voltage induced when a movable electrode moves in position due to circuit breaker operation; capacitance-type electrode sensors that are installed in a circular, rectangular, or pin-shaped structure inside an insulating partition spacer between a three-terminal switchgear unit (disconnector unit) and the circuit breaker unit of a gas-insulated switchgear and detect a voltage induced when a movable electrode moves in position due to circuit breaker operation; and integrated monitoring means that is connected to the electrode sensors, converts signals input from the electrode sensors into digital signals, calculates them, and simultaneously calculates, diagnoses, and displays the opening and closing times, three-pole non-simultaneous opening and closing times, strokes, and operating speeds of the circuit breakers and three-terminal switches (disconnectors) of the switchgear, and outputs a control signal for warning or locking when the calculated output value deviates from a predetermined limit range of the power switchgear operation characteristics.

[0015] The operating characteristic monitoring system for a power switch according to the second embodiment of the present invention is installed in a circular, rectangular, and pin-shaped structure inside and outside an epoxy insulator housing outside an opening / closing unit (vacuum interrupter and blade-type contact) electrically connected to the primary side lead-in part of a general switch. It includes a capacitance-type electrode sensor that detects the voltage induced during the positional movement caused by the vertical or rotational movement of the main contact of the opening / closing unit of the general switch, and integrated monitoring means that are respectively connected to the electrode sensors, convert and calculate the signals input from the electrode sensors into digital signals, simultaneously calculate, diagnose, and display the opening / closing time, three-pole non-simultaneous opening / closing time, stroke, and operating speed of each phase of the general switch, and output a control signal for alarm or locking when the calculated output value deviates from a predetermined operating characteristic limit range.

[0016] The operating characteristic monitoring system for a power switch according to the third embodiment of the present invention is installed in a separable and detachable structure outside an insulating partition spacer that constitutes the gas partition of the power switch. It includes an electrode sensor module that detects the voltage induced during the opening / closing operation of the power switch, and integrated monitoring means that are respectively connected to the electrode sensor module, convert and calculate the signals input from the electrode sensor module into digital signals, simultaneously calculate, diagnose, and display the opening / closing time, three-pole non-simultaneous opening / closing time, stroke, and operating speed of each phase of the power switch, and output a control signal for alarm or locking when the calculated output value deviates from a predetermined operating characteristic limit range.

Advantages of the Invention

[0017] The operating characteristic monitoring system for a power switch according to the present invention installs electrode sensors with a circular, rectangular, and pin-shaped structure impregnated inside a solid insulator, which is a component of a conventionally configured power switch, or installs a separate and detachable detection electrode sensor module outside. Therefore, it is possible to monitor and diagnose the operating characteristics of the power switch in real time under the condition of being energized and in operation.

[0018] The operation characteristic monitoring system for a power switch according to the present invention can display, in real time, the operation characteristic states such as the opening and closing time of each phase of the power switch, the three-pole non-simultaneous opening and closing time, the stroke, and the operation speed in the form of digital values and graphs in the state where voltage is applied and the switch is in operation. Even if the inspector does not move to the installation location of the power switch, the operation characteristic states of the power switch can be monitored in real time from a remote location. When the operation characteristics of the power switch change rapidly, control signals for alarm and locking can be output to perform alarm and locking control, and the power switch can be replaced and maintained at an appropriate time. Therefore, accidents and the spread of accidents of the power system and power equipment can be prevented in advance, and the operation reliability of the power system can be ensured.

[0019] The operation characteristic monitoring system for a power switch according to the present invention can accumulate, collect, compare, and analyze the data indicating the operation characteristics of the power switch, and can be utilized for asset management by evaluating and analyzing the soundness of power facilities. The analyzed data is provided not only as information for the asset owner or manager to determine the operation interruption and maintenance management of the equipment, but also used as information for giving accurate work instructions to the on-site workers.

Brief Description of the Drawings

[0020] [Figure 1] It is a structural diagram of a general three-phase integrated gas-insulated switchgear. [Figure 2A] It is a structural diagram of the three-terminal switch part of a general three-phase integrated gas-insulated switchgear. [Figure 2B] It is a structural diagram of the three-terminal switch part of a general phase-separated gas-insulated switchgear. [Figure 2C] It is a structural diagram of the breaker part of a general phase-separated gas-insulated switchgear. [Figure 3] It is a structural diagram of a general solid-insulated switch. [Figure 4] It is a conceptual diagram of the operation characteristic monitoring system for a power switch according to the present invention. [Figure 5A]This is an example in which the capacitance type electrode sensor of the power switch operating characteristic monitoring system according to the present invention is applied to a phase separation type gas insulated switchgear. [Figure 5B] This is an example in which the capacitance-type electrode sensor of the power switch operating characteristic monitoring system according to the present invention is applied to a three-phase insulating partition spacer of a three-phase integrated gas-insulated switchgear. [Figure 5C] This is an example in which the capacitance type electrode sensor of the power switch operating characteristic monitoring system according to the present invention is applied to a solid insulated switch. [Figure 6A] In the power switchgear operating characteristics monitoring system according to the present invention, part of the embedded metal fittings (nut type) of the insulating partition spacer (one part in the case of a phase separation type) is replaced with an impregnated, insulated pin-type electrode, and used directly as a capacitance-type electrode sensor. [Figure 6B] In the power switchgear operating characteristics monitoring system according to the present invention, an impregnated and insulated pin-type electrode (one in the case of a phase separation type) is added between the embedded metal fittings (nut type) of the insulating partition spacer, and used as a capacitance-type electrode sensor. [Figure 7A] 1 is a diagram showing an example of a detachable capacitance electrode sensor module of a power switch operating characteristic monitoring system for application to a phase-separated gas-insulated switchgear according to the present invention. [Figure 7B] 1 is an example showing a detachable capacitance electrode sensor module of a power switch operating characteristic monitoring system for application to a three-phase integrated gas-insulated switchgear according to the present invention. [Figure 8A] 10A and 10B are diagrams showing a potential distribution map and an induced voltage of an electrode sensor when a three-terminal switch of a gas-insulated switchgear is in an open state (DS / ES OPEN). [Figure 8B] 10A and 10B are diagrams showing a potential distribution map and an induced voltage of an electrode sensor when the three-terminal switch of the gas-insulated switchgear is in a disconnector closed (DS CLOSE) state. [Figure 8C] 10A and 10B are diagrams showing a potential distribution map and an induced voltage of an electrode sensor when the three-terminal switch of the gas-insulated switchgear is in an earthing switch closed (ES CLOSE) state. [Figure 9A] This is a diagram showing the measurement concept of the opening and closing times of each phase using the change in the induced voltage of a capacitance-type electrode sensor that appears when the three-terminal switch part of the gas-insulated switchgear according to the present invention performs the breaker closing (DS CLOSE), breaker opening (DS OPEN), and earthing switch closing (ES CLOSE) operations. [Figure 9B] This is a diagram showing the measurement concept of the three-pole non-simultaneous opening and closing time at closing and the three-pole non-simultaneous opening and closing time at opening due to the operation of the three-terminal switch part of the gas-insulated switchgear according to the present invention. [Figure 10A] This is a diagram showing the potential distribution diagram and the induced voltage of the electrode sensor when the breaker of the gas-insulated switchgear is in the open (OPEN) state. [Figure 10B] This is a diagram showing the potential distribution diagram and the induced voltage of the electrode sensor when the breaker of the gas-insulated switchgear is in the closed (CLOSE) state. [Figure 11A] This is a diagram showing the change in the induced voltage of the capacitance-type electrode sensor due to the distance between the fixed contact and the movable contact when the breaker of the gas-insulated switchgear according to the present invention operates from the closed state to the open state. [Figure 11B] This is a diagram showing the concept of measuring the operating stroke and speed of the breaker when the breaker of the gas-insulated switchgear according to the present invention receives an operation command and performs an opening and closing operation. [Figure 12] This is a schematic structural diagram showing the configuration of monitoring means for monitoring the operating characteristics such as the opening and closing times of each phase, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed of the switch for electric power according to the present invention.

Embodiments for Carrying Out the Invention

[0021] The operating characteristic monitoring system for a switch for electric power according to the present invention includes, in the switch for electric power, a capacitance-type electrode sensor that is installed outside the primary conductor and detects the electrostatic voltage induced during the opening and closing operation of the main contacts of the switch for electric power, and integrated monitoring means that diagnoses the operating characteristics for each phase based on the electrostatic voltage input from the capacitance-type electrode sensor and outputs a control signal for alarm or locking when deviating from a predetermined operating characteristic safety range. This is a constitutive feature.

[0022] The advantages, features and methods of achieving the present invention will become more apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various forms.

[0023] The present invention will be described in detail below with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 2 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 3 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 4 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 5 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 6 is a block diagram of a semiconductor device according to an embodiment of the present invention;

[0024] Throughout the specification, the same reference numerals refer to the same elements. Furthermore, the terms used (referred to) in this specification are used to describe the embodiments and do not limit the present invention. In this specification, the singular expression includes the plural expression unless otherwise specified. Furthermore, components and operations referred to as "including" do not exclude the presence or addition of one or more other components and operations.

[0025] Unless otherwise specified, all terms (including technical and scientific terms) used in this specification are used in the sense commonly understood by those having ordinary skill in the art to which the present invention belongs. Furthermore, terms defined in commonly used dictionaries should not be interpreted ideally or excessively unless otherwise specified. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0026] As shown in FIGS. 1, 2A, 2B, and 2C, a general gas-insulated switchgear 100 includes a housing 10 forming a case, a busbar section 20 provided in the upper part inside the housing 10, which consists of a main busbar 21 for connecting an incoming line through which a large current flows and a support insulator for supporting it, a three-terminal switch section 30 which is partitioned and formed by an insulating partition spacer 80 located in the upper part inside the housing 10, consists of a fixed electrode 31 connected to the main busbar 21, a ground electrode 33 connected to the ground, and a movable electrode 35 selectively connected thereto, and serves two roles: the role of a disconnect switch (DS) that enables separation and connection of the line in a no-voltage state, and the role of an earth switch (ES) used for a grounding switching operation for maintenance and inspection, a circuit breaker section 40 partitioned and formed in the central part inside, which protects load equipment and lines from large fault currents such as short circuits and ground faults occurring in the circuit, a cable connection section 50 to which a distribution line is connected, and a control panel 60 for operation, control, measurement, and monitoring of the gas-insulated switchgear.

[0027] All electrically charged conductors located inside the sealed housing 10 of the gas-insulated switchgear 100 are electrically insulated by the insulating gas 70 filled therein, and each component is gas-separated by the insulating partition spacer 80, and is formed so as to minimize the spread of an accident in one component to other components. Further, the metal housing 10 is connected to an external ground and is configured to maintain an electrical grounding state to ensure the safety of the operator during inspection and maintenance of the switchgear.

[0028] The circuit breaker section 40 of the gas-insulated switchgear 100 is partitioned and formed inside the housing 10 of the gas-insulated switchgear 100 filled with the insulating gas 70, is interposed between the three-terminal switch section 30 and the cable connection section 50, and protects load equipment and lines from fault currents. It is classified into a vacuum circuit breaker, a gas circuit breaker, etc. depending on the arc quenching medium generated during opening and closing and interruption. Generally, in the transmission voltage class (154 kV class or higher), a gas circuit breaker using SF6 gas as the arc quenching medium is mainly used, and in the distribution voltage class having a rated voltage lower than that, a vacuum interrupter having excellent arc quenching and insulation performance is mainly used.

[0029] As shown in FIG. 2C, in the case of the breaker section 40 of the gas-insulated switchgear composed of a vacuum interrupter, a fixed electrode section 142 and a movable electrode section 143 are coaxially arranged in a cylindrical ceramic insulating tube 141 whose interior is sealed with a vacuum. A shielding plate 145 is included which is attached to the inner wall of the ceramic insulating tube 141 to prevent metallic ions released due to the generation of an arc during the switching operation of the contacts from adhering to the inner wall of the ceramic insulating tube 141 and degrading the insulation performance.

[0030]

[0029] The breaker section 40 composed of the solid-insulated switch shown in FIG. 3 mainly includes components such as an epoxy insulator housing 127 formed of a polymer, a vacuum valve 122 attached by molding inside the polymer epoxy insulator housing 127, an insulating rod 126 connecting the vacuum interrupter to an operating device (not shown), a primary conductor 121 for electrical connection to the power supply side, a secondary conductor 120 for electrical connection and connection to the load side, a wound current transformer 125 for measuring the load current, a primary voltage detection sensor 123 and a secondary voltage detection sensor 124 for voltage detection. The opening and closing operation of the solid-insulated switch is performed by manual operation using a manual operation handle and electrical motor-driven operation using a motor. However, the clockwise or counterclockwise rotational power generated by the electric or manual operation is transmitted to a power transmission device (not shown) via a drive shaft (not shown), and the power transmission device converts the clockwise or counterclockwise rotational power into a vertical opening and closing driving force and transmits it to the insulating rod 246, whereby the lower switch main contacts are driven to perform the opening and closing operation.

[0031] Since the power system is configured in three-phase alternating current so as to efficiently supply electrical energy, all electrical equipment such as switchgear and general switches used in the system is configured in a three-phase form. Generally, the power switch used in the power system operates the movable electrode 35 in a lump for three phases by one operating device in an external control panel to perform the opening and closing operation. The main elements of the operating characteristics for evaluating the performance of the power switch are the opening and closing times of each phase of the power switch, the three-pole non-simultaneous opening and closing time, the stroke, the operating speed, and the like.

[0032] A power switch that is opened and closed (Open / Close) on-site or remotely via communication means must complete the opening and closing operation within a specified opening and closing time when an opening and closing operation signal is given, and at the same time, it must not exceed the three-pole non-simultaneous opening and closing time specified in the standard. The three-pole non-simultaneous opening and closing time of a power switch refers to the difference in the operating times of each phase of the power switch when the power switch is operated in three phases together, which is caused by the length of the link of each phase, and the assembly tolerances that occur when assembling the components of mechanical operators such as levers, shafts, and rods, as well as electrical and mechanical defects during operation. If the difference in the opening and closing times between each phase is large, the power switch may become inoperable (interruptible), so continuous real-time state monitoring and diagnosis for this are required.

[0033] When conducting development tests before applying the power switch to the power system, the lower and upper limits of the magnitude of the control power are determined, and the operating characteristics such as the opening and closing time of each phase, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed are measured to verify the performance in advance. However, since it is continuously used after system application, it is difficult to diagnose the operating characteristics caused by electrical and mechanical defects occurring during operation during operation. As a complementary measure for this, currently, in the Korea Electric Power Corporation, in accordance with the operation guidelines, the maintenance of the power switch is carried out by measuring the operating characteristics in the operating stop state without voltage applied according to the short-term, medium-term, and long-term inspection schedules.

[0034] When the wear of the main contacts increases due to long-term use of the power switch, the insulation performance of the switch decreases and the operating characteristics change. The heat generation from the charging conductor part increases due to the increase in the main circuit resistance, which has an adverse effect on the physical and chemical basic characteristics of the surrounding insulators. In addition, it causes a state of insufficient contact pressure between the contacts. If the electrodes are detached from the normal position due to the electromagnetic force generated during large current conduction, it will lead to a major electrical accident. Therefore, not only inspection during a power outage state but also the application of a technology that can monitor and diagnose the state of the operating characteristics during the opening and closing of the power switch in real time during the operating period with voltage applied is required.

[0035] As shown in FIG. 4, the operating characteristic monitoring system for the power switch according to the present invention measures and calculates operating characteristics such as the opening and closing time of each phase of the power switch, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed in real time during pressurized operation. When the measured value deviates from a predetermined safe range, a control signal for alarm or locking is output, so that an alarm sound is output to the outside by the alarm means, enabling the administrator to take appropriate measures, or the operation of the power switch is automatically stopped by the locking means, thereby preventing serious accidents caused by electrical and mechanical abnormalities of the power switch.

[0036] The capacitance-type electrode sensor unit for the operating characteristic monitoring system of the power switch is installed in the form of an electrode sensor including an electrode impregnated inside the insulator of the insulating partition spacer 80 of the switch within the power switch, or installed in the form of an electrode sensor module having a separable and detachable structural feature outside the insulating partition spacer. It is composed of a composite circuit of capacitances C1 and C2 sequentially formed between the main conductor of the power switch and the electrode sensor, and between the electrode sensor and the housing. When the movable electrode 35 changes its spatial position according to a control command, the operating characteristics of each phase of the power switch during operation, such as the opening and closing time, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed, can be monitored in real time using the characteristic that the voltage induced by the capacitance-type electrode sensor varies.

[0037] As shown in FIGS. 5A, 5B, and 5C, the internal electrode sensor impregnated inside the insulator for monitoring and diagnosing the operating characteristics of the power switch is configured in various forms according to the type and structure of the power switch.

[0038] As shown in Fig. 5A, in an operating characteristic monitoring system for a power switch such as a phase-separated gas-insulated switchgear, the electrode sensor for a three-terminal switch is installed for each phase in the form of an annular or rectangular conductor inside the single-phase insulation partition spacer 80 between the three-terminal switch section 30 and the circuit breaker section 40. The electrode sensor for the circuit breaker is installed for each phase in the form of an annular or rectangular conductor inside the single-phase insulation partition spacer 80 between the circuit breaker section 40 and the cable connection section 50. As shown in Fig. 5B, in an operating characteristic monitoring system for a power switch such as a three-phase integrated gas-insulated switchgear, the electrode sensors are arranged in a structure in which three annular or rectangular conductors are collectively configured inside one three-phase insulation partition spacer 80 between the three-terminal switch section 30 and the circuit breaker section 40 and between the circuit breaker section 40 and the cable connection section 50, respectively. As shown in Fig. 5C, in an operating characteristic monitoring system for a power switch such as a solid-insulated switchgear, the electrode sensor is installed in the form of an annular or rectangular conductor inside the external epoxy insulation housing 127 impregnating the switching section (vacuum interrupter and blade-type contact) electrically connected to the primary side lead-in section 121 of the switchgear.

[0039] In an operating characteristic monitoring system for a power switch such as a phase-separated gas-insulated switchgear, as shown in Fig. 6A, one of the embedded fittings (nut type) of the conventional insulation partition spacer 80 may be subjected to insulation treatment and directly used as a capacitance-type electrode sensor. As shown in Fig. 6B, one impregnated and insulated pin-type electrode may be added between the embedded fittings (nut type) of the insulation partition spacer and used as a capacitance-type electrode sensor. Similarly, in an operating characteristic monitoring system for a power switch such as a three-phase integrated gas-insulated switchgear, three of the embedded fittings (nut type) of the insulation partition spacer adjacent to the main conductor of each phase may be subjected to insulation treatment and directly used as the capacitance-type electrode sensors for each phase. Three impregnated and insulated pin-type electrodes may be added between the embedded fittings (nut type) of the insulation partition spacer and used as the capacitance-type electrode sensors for each phase.

[0040] As shown in FIGS. 7A and 7B, the separable and detachable electrode sensor module unit for monitoring and diagnosing the operating characteristics of a power switch can install the electrode sensors of each phase in a ring structure that can be detached and attached outside the insulating partition spacer without changing the structure of the power switch. Therefore, it has a structural feature that it can be easily installed and applied not only to newly applied switching devices but also to conventional switching devices.

[0041] The operating characteristic monitoring system of the power switch according to the present invention includes a capacitance type electrode sensor for voltage detection and an electrode sensor module configured in various forms according to the type of the power switch as described above, and is respectively connected to the electrode sensors, converts and calculates the signals input from the electrode sensors into digital signals, and simultaneously calculates, diagnoses, and displays the opening and closing times of each phase of the power switch, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed. When the calculated output value deviates from a predetermined operating characteristic limit range, it includes monitoring means for outputting a control signal for alarm or locking. Therefore, the power switch can be replaced and maintained at an appropriate time, and accidents of the power system and power equipment can be prevented in advance, and the operation reliability of the system can be ensured.

[0042] FIGS. 8A, 8B, and 8C are diagrams showing the potential distribution diagram of the three-terminal switch part of the gas-insulated switchgear by the Finite Element Method and the induced voltage of the electrode sensor according to the present invention. When the three-terminal switch of the gas-insulated switchgear is in the open (DS / ES Open) state (FIG. 8A), the circuit breaker closed (DS Close) state (FIG. 8B), and the earthing switch closed (ES Close) state (FIG. 8C), respectively. It is confirmed that the voltages induced by the capacitance type electrode sensor are different according to the spatial position change of the movable electrode due to the operation of the switch. Let the induced voltage when the three-terminal switch is in the open state be V OPEN , the induced voltage when the circuit breaker is in the closed state be V DSCL , and the induced voltage when the earthing switch is in the closed state be V ESCL . Then, as shown in the figure, V DSCL = 19.03%[V], V OPEN = 3.44%[V], V ESCL=0.00%[V]. V DSCL , V OPEN , V ESCL The values of V are illustrative and are not necessarily limited to these. DSCL >V OPEN >V ESCL It has been confirmed that the opening and closing time of the three-terminal switch can be measured from the change in the induced voltage of the electrode sensor that occurs in response to the change in the internal capacitance due to the positional movement of the movable electrode.

[0043] FIG. 9A is a diagram showing the basic concept of measuring the opening and closing times of each phase using changes in the induced voltage of a capacitance-type electrode sensor that appear when the three-terminal switch unit of the gas-insulated switchgear according to the present invention performs the disconnector closing, disconnector opening, and earthing switch closing operations, and FIG. 9B is a diagram showing the concept of measuring the three-pole non-simultaneous opening and closing times during the closing operation and the three-pole non-simultaneous opening and closing times during the opening operation by the operation of the three-terminal switch unit of the gas-insulated switchgear.

[0044] When the three-terminal switch of the gas-insulated switchgear is in the open state (DS / ES Open), if a disconnector close command is transmitted by the control switch, the operating motor is driven, and a force is transmitted to the movable electrode 35 via the external link interconnected to move the movable electrode of the power switch from the open position to the disconnector close position. Here, the operating current of the operating motor of the power switch changes until the operation of the movable electrode 35 is completed, as shown in Figure 9A. When the position of the movable electrode changes, the values of the capacitance C1 between the pressurized bus bar 21 and the electrode sensor and the capacitance C2 between the electrode sensor and the earthed housing change, and the voltage induced in the electrode sensor is V, which is the voltage of the electrode sensor in the open position. OPEN When the disconnector closing operation is completed, the voltage induced in the electrode sensor reaches a voltage value V DSCL When the power switch in the disconnector closed position receives a disconnector open command, it goes through the same electrical and mechanical operation process. Here, the voltage induced in the electrode sensor is V, which is the opposite of when the disconnector is closed. DSCL Value to V OPENIt changes in a form that decreases in value and finally converges to a constant value. Also, the closing and opening operations of the earthing switch are performed through the same process as described above. However, the induced voltage of the electrode sensor during the closing operation of the earthing switch is V OPEN to V ESCL (=0V) and decreases. The induced voltage during the opening operation of the earthing switch is V ESCL to V OPEN and shows an upward change.

[0045] As shown in FIG. 9A, the operation characteristic monitoring system of the three-terminal switch of the gas-insulated switchgear, which is an application example of the present invention, can measure the opening and closing times of each phase in real time from the change in the induced voltage of the electrode sensor installed in each phase during the pressurized operation. Also, as shown in FIG. 9B, by comparing and analyzing the opening and closing time differences of each phase, the three-pole non-simultaneous opening and closing time during the opening and closing operations of the three-terminal switch can also be calculated and diagnosed. In the operation characteristic monitoring system of the three-terminal switch according to the present invention, by comparing the operation characteristic data collected in real time with the reference operation characteristic data in the normal state, the electrical and mechanical abnormal states of the three-terminal switch of the power switch are always monitored and diagnosed, so that maintenance measures can be taken preemptively.

[0046] Figures 10A and 10B are diagrams showing the potential distribution diagram of the circuit breaker section of a gas-insulated switchgear using a vacuum interrupter and the induced voltage of the electrode sensor according to the present invention by the Finite Element Method. In the circuit breaker closed (CB Close) and open (CB Open) states of the gas-insulated switchgear respectively, the voltage induced by the capacitance-type electrode sensor according to the spatial position change of the movable electrode 35 due to the operation of the circuit breaker is such that the induced voltage of the electrode sensor at the circuit breaker closed position (19.19% [V]) is larger than the induced voltage at the open position (2.46% [V]). The induced voltage of the electrode sensor at the circuit breaker closed position (19.19% [V]) and the induced voltage at the open position (2.46% [V]) are exemplary and not necessarily limited to these values. Similar to the application to the 3-terminal circuit breaker section of the gas-insulated switchgear, the opening and closing times of each phase and the 3-pole non-simultaneous opening and closing time during the opening and closing operation of the circuit breaker can be measured from the change in the induced voltage of the electrode sensor, and real-time online measurement and diagnosis of the stroke and operating speed are also possible.

[0047] Figure 11A is a diagram showing the change in the induced voltage of the capacitance-type electrode sensor when the distance between the fixed contact and the movable contact of the circuit breaker of the gas-insulated switchgear according to the present invention changes by 1 mm at a time when the circuit breaker operates from the closed state to the open state.

[0048] Figure 11B is a diagram showing the concept of measuring the operating stroke of a circuit breaker based on the change in the induced voltage of the electrode sensor in Figure 11A, and is a diagram estimated considering the electrical and mechanical characteristics of the operating device according to the time change when the circuit breaker of the gas-insulated switchgear receives an operation command and completes the opening / closing operation. For a circuit breaker using an operating device of the spring charging method mainly used in the distribution voltage class in Korea, when the control power supply is supplied, the input spring is compressed by a cam and a crank connected to the motor. Here, when a closing command is given, the closing coil operates by the excitation of the closing coil, the compression of the input spring is released, the operating shaft rotates by the operation of a roller connected to the operating shaft, and a rapid closing operation is performed. During the closing operation, the opening spring is simultaneously compressed, and after the operation, the contact pressure of the circuit breaker is maintained by a wipe spring mechanically connected to the operating shaft. In the opening operation, when an opening command is given, the rod operates by the excitation of the opening coil, the operating shaft rotates by the restoring force of the opening spring and the wipe spring, and the circuit breaker performs a rapid opening operation in an extremely short time. As shown by the stroke curve in Figure 11B, there is a time delay when the coil is excited and the opening / closing operation is performed, and there is a time required for the force of the cam, lever, shaft, rod, etc. constituting the operating device to be transmitted. Therefore, at the initial stage of the opening / closing operation, a time delay phenomenon occurs in the force transmission, and due to the influence of various springs used in the mechanical operating device and the contact repulsive force, mechanical vibration occurs during the opening / closing operation, and the contact interval fluctuates. Therefore, the stroke curve using the induced voltage also exhibits a vibrating aspect. By utilizing the digital data of the opening / closing time and the stroke curve of each phase obtained as described above based on the circuit breaker contact interval that has already been pre-input, the opening / closing average speed and the initial speed of the circuit breaker of the gas-insulated switchgear can be monitored, diagnosed, and displayed in real time.

[0049] By using the above method, the operational characteristics monitoring system for power switches according to the present invention can be expanded and applied to all power switches that use a method of opening and closing by a structure in which contacts are separated and moved, such as switchgear and general switches, such as circuit breakers, load switches, automatic transfer switches, automatic fault section switches, automatic load transfer switches, and disconnectors.

[0050] As shown in FIG. 12 , the integrated monitoring means 200 includes an input conversion unit 230 that converts signals input from a secondary-side reference voltage of a potential transformer (PT) and a voltage detection capacitance-type electrode sensor into voltage values, an A / D converter 240 that converts the voltage value received from the input conversion unit 230 into a digital signal, a central arithmetic and control unit 250 that is connected to the A / D converter 240 and calculates and diagnoses operating characteristics such as the opening and closing time of each phase of the power switchgear, the three-pole non-simultaneous opening and closing time, stroke, and operating speed based on the digital signal input via the A / D converter 240, and a central arithmetic and control unit 250 that is connected to the central arithmetic and control unit 250. The system includes a control signal generating unit 260 that outputs a control signal for issuing an alarm or locking when the operating characteristic value of the power switch diagnosed by the central processing control unit 250 deviates from a predetermined safety range, a display unit 270 that is connected to the central processing control unit 250 and digitally displays the open / closed state of each power switch calculated and diagnosed by the central processing control unit 250, a key input unit 280 that is connected to the central processing control unit 250 and enables setting of an operation mode or a safety range, and a power supply unit 290 that supplies power required for operation from an external power source 400.

[0051] An A / D converter 240 is connected to the input conversion unit 230, and the A / D converter 240 converts the voltage value received from the input conversion unit 230 into a digital signal and transmits it to a central processing control unit 250 which functions as a digital processing unit.

[0052] The central arithmetic control unit 250 connected to the A / D converter 240 is a kind of central arithmetic processing unit that calculates and diagnoses the operating characteristic values of the power switches of each phase based on the digital signals input via the A / D converter 240, and transmits them to the display unit 270. When the calculated operating characteristic values deviate from a predetermined safe range, the signal is supplied to the control signal generation unit 260, and the operating mode or the safe operating characteristic value range is set in advance according to the input signal from the key input unit 280. It is formed in the shape of a printed circuit board with a predetermined circuit printed thereon or a chip with a predetermined circuit integrated therein.

[0053] When the operating characteristic values calculated and diagnosed by the central arithmetic control unit 250 deviate from a predetermined safe range due to electrical or mechanical defects, the control signal generation unit 260 connected to the central arithmetic control unit 250 outputs a control signal for alarm or locking. By using a predetermined alarm means (not shown) connected to the control signal generation unit 260, an alarm sound is output to the outside to prompt the administrator to take appropriate measures, or the operation of the power switch is automatically cut off by using a predetermined locking means (not shown) connected to the control signal generation unit 260.

[0054] The control signal generation unit 260 is installed on the back of the integrated monitoring means 200 and includes a control signal output terminal for outputting a control signal for alarm or locking. The above-mentioned alarm means and locking means are electrically connected to the control signal output terminal.

[0055] The display unit 270 connected to the central arithmetic control unit 250 digitally displays the operating characteristic values of the power switches of each phase calculated and diagnosed by the central arithmetic control unit 250. It includes a panel that displays the operating characteristics such as the opening and closing time of each phase of the power switch, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed in digital values and graphs, a safety range display window that continuously displays the safe range and the upper and lower danger ranges, and two operating display lamps (not shown) installed on the front side of the integrated monitoring means 200 that respectively display whether to output a control signal for alarm or locking by the control signal generation unit 260, but is not necessarily limited to this.

[0056] The key input unit 280 connected to the central arithmetic control unit 250 enables settings such as the operation mode and the range of safety operation characteristic values, and includes a mode selection button that enables setting of the operation mode and a safety range setting button that enables setting of the range of safety operation characteristic values, but is not necessarily limited thereto.

[0057] The power supply unit 290 supplies the power necessary for operation from an external power source 400, and includes a power connection terminal (not shown) to which the external power source 400 is connected, as shown in FIG. 8. The external power source 400 is preferably a DC voltage for stable operation of the integrated monitoring means 200.

[0058] The communication module 265 connected to the central arithmetic control unit 250 enables communication with an external computer at a remote location and allows the operation characteristic state of the power switch to be monitored by the external computer at the remote location, and is preferably composed of a known wired communication module such as a modem or a known wireless communication module such as Bluetooth.

[0059] Further, the integrated monitoring means 200 may be sequentially connected between the input conversion unit 230 and the A / D converter 240, and may further include a filter unit 210 that removes noise from the voltage value output from the input conversion unit 230, and a linear processing unit 220 that linearizes the voltage value that has passed through the filter unit 210 and supplies it to the A / D converter 240.

[0060] Since abnormal voltages may be included in the power switch operated with a high voltage applied due to a magnetic field and switching surges, the filter unit 210 is installed to remove them, and the filter unit 210 is preferably composed of a low pass filter.

Claims

1. In a power switch, a capacitive electrode sensor that is installed outside the primary conductor and detects the electrostatic voltage induced during the opening and closing operation of the main contacts of the power switch, and integrated monitoring means that diagnoses the operating characteristics for each phase based on the electrostatic voltage input from the capacitive electrode sensor and outputs a control signal for alarm or locking when deviating from a predetermined operating characteristic safety range. An operating characteristic monitoring system for a power switch.

2. When the main contacts of the power switch open and close, the voltage induced in the electrode sensor changes according to the voltage division characteristics generated by the variation of the relative internal capacitance of the electrode sensor of the power switch. The operating characteristic monitoring system for a power switch according to Claim 1.

3. The capacitive electrode sensor is composed of a synthetic circuit of capacitances (C1, C2) that are sequentially electrically formed between the primary conductor and the electrode sensor and between the electrode sensor and the ground electrode. The operating characteristic monitoring system for a power switch according to Claim 1.

4. The capacitive electrode sensor is a non-contact type, and is configured in the form of circular, rectangular, and pin-type electrode sensors impregnated inside an insulator in the internal space of the insulating partition spacer between the breaker section and the three-terminal switch section and between the three-terminal switch section and the bus section, or is configured in the form of circular, rectangular, and pin-type electrode sensors inside and outside the epoxy insulator housing of the breaker section, or is configured in the form of a separable and detachable electrode sensor module outside the insulating partition spacer and the insulator. The operating characteristic monitoring system for a power switch according to Claim 1.

5. The operating characteristics diagnosed based on the capacitive electrode sensor include the opening and closing time of each phase of the power switch, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed. The operating characteristic monitoring system for a power switch according to Claim 1.

6. The integrated monitoring means is characterized in that it receives operation and control signals including the secondary voltage of an instrument transformer (PT), the control power supply, the coil current, the motor current, and the auxiliary contact signal of the power switch from the operation control panel. The operating characteristic monitoring system for a power switch according to Claim 1.

7. The integrated monitoring means A potential transformer (PT) and an input conversion unit that converts a signal input from an electrode sensor into a voltage value, an A / D converter connected to the input conversion unit that converts the voltage value received from the input conversion unit into a digital signal, a central arithmetic control unit connected to the A / D converter that diagnoses the opening and closing operations of the switching devices of each phase based on the digital signal input via the A / D converter, a control signal generation unit connected to the central arithmetic control unit that outputs a control signal for alarm or locking when the opening and closing state of the switching device diagnosed by the central arithmetic control unit deviates from a predetermined safe range, a display unit connected to the central arithmetic control unit that digitally displays the opening and closing state of the switching device diagnosed by the central arithmetic control unit, a key input unit connected to the central arithmetic control unit that sets an operating mode or a safe vacuum degree range, characterized in that it includes a power supply unit provided within the integrated monitoring means that supplies power necessary for the operation of the integrated monitoring means from an external power source. The operating characteristic monitoring system for a power switch according to claim 1.

8. The integrated monitoring means is further connected to the central arithmetic control unit and includes a communication module that enables communication with an external computer at a remote location and allows the operating characteristics including the opening and closing time of each phase of the power switch, the three-pole non-simultaneous opening and closing time, the stroke, and the operating speed to be monitored by the external computer at the remote location. The operating characteristic monitoring system for a power switch according to claim 7.

9. The power switch has an opening and closing method using contacts and includes a gas-insulated switchgear, a solid-insulated switchgear, a circuit breaker, a load switch, an automatic transfer switch, an automatic fault section switch, an automatic load transfer switch, a grounding switch, a circuit breaker. The operating characteristic monitoring system for a power switch according to claim 1.

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