Simulation model and simulation method for whole operation process of AIS disconnecting switch

Abstract

The invention discloses a simulation model and a simulation method for the whole operation process of an AI disconnecting switch, and the model comprises the steps: connecting the disconnecting switch with an arc resistor and an arc inductor to form a series branch, and then connecting the disconnecting switch with a fracture capacitor to form a parallel branch, which is used for simulating the arc breakdown characteristics of a switch gap in the operation process of the disconnecting switch; the re-arcing module is used for judging whether voltage across the gap of the disconnecting switch breaks down or not and outputting a re-arcing signal; the arc quenching module is used for acquiring a current signal of the series branch, judging whether the current signal meets an arc quenching criterion or not, and outputting an arc quenching signal; the arc-extinguishing ending module is used for judging whether the current signal meets an arc-extinguishing ending criterion or not and outputting an arc-extinguishing signal; the switch control module is used for controlling on and off of the isolating switch; the arc resistance control module is used for controlling the resistance change of the arc resistor based on the reignition arc signal, the arc quenching signal and the arc quenching ending signal; and the timing module is used for recording the gap breakdown time of the disconnecting switch and the starting time and the ending time of the arc quenching stage.

Description

Technical Field

[0001] The present invention relates to the field of simulation technology, and more specifically, to a simulation model and a simulation method for the entire operation process of an AIS disconnector. Background Art

[0002] In the power system, since the disconnector has no arc extinguishing device and the switch action speed is slow, the disconnector will produce dozens or even hundreds of gap breakdowns during the process of opening and closing small capacitance currents, that is, repeated arcing and arc extinguishing transient processes occur between the contacts of the disconnector. In this process, the switch gap will undergo multiple re-breakdowns, and the generated voltage steep waves and traveling waves will propagate back and forth in the substation equipment and busbars, resulting in complex refraction, reflection and superposition, thus forming high-amplitude, high-steepness, and high-frequency very fast transient overvoltage (VFTO) and very fast transient current (VFTC). Since it is difficult to measure VFTO and VFTC on site, the main research method for VFTO and VFTC is to conduct simulation calculations. At present, there are seven arc models that are widely used, including fixed resistance model, exponential model, hyperbolic resistance model, black box model, segmented arc model, dynamic arc model, and multiple restrike model.

[0003] The article "Simulation and Characteristic Analysis of VFTO and VFTC Based on Dynamic Restirritation Model" established a multiple restirritation model based on the dynamic model. The model establishes the reignition criterion and the arc extinction criterion. When the voltage difference between the contacts of the disconnector is greater than the dielectric breakdown voltage, the gap breaks down, the arc reignites, and when the arc current passes through zero to meet the arc extinction criterion, the arc is extinguished, and the transient process ends. At the same time, the multiple restirritation model considers the cumulative effect of residual voltage on the VFTO characteristics, as well as the influence of the operating speed of the disconnector and the wave impedance of the disconnector guide rod on VFTO, solving the problem of arc continuity, and has obvious advantages over the single arc. However, the entire operation process of the disconnector is not always in a transient state, but the model does not consider the steady-state non-breakdown stage during the operation of the disconnector, but simply includes the steady-state non-breakdown stage in the arc extinction stage, and uses the "or" logic to control the switch state for the reignition signal and the arc extinction signal in the switch control part, resulting in the designed disconnector always being in a closed state during the operation process, which is inconsistent with the actual situation. There are problems in the logic design when recording the breakdown and arc extinction moments, and the arc resistance control module is brought in, resulting in the arc resistance value not being consistent with the actual value. In summary, the program design of the model is not logically rigorous, and the consideration is not comprehensive enough when calculating the arc resistance. The model needs to be corrected and improved.

[0004] Through a comprehensive comparative analysis of the development of the disconnector operation transient model over the years, the current simulation model results cannot simulate the actual VFTO waveform well, and the accuracy needs to be further improved. Therefore, a simulation model and simulation method for the entire process of AIS disconnector operation is needed. Summary of the invention

[0005] Aiming at the technical problem that the arc resistance model of the current open type switchgear (Air Insulated Switchgear, AIS) disconnector cannot reflect the complete change of arc resistance from the pre-breakdown stage to the arc extinction stage during multiple reignition and arc extinction processes. The present invention provides a simulation model of the whole operation process of the AIS disconnector and a modeling method thereof. On the basis of the original dynamic arc model, the influence of the resistance change of the disconnector arc resistance at each stage, the dynamic inductance and the fracture capacitance on the simulation calculation are further considered, and improvements are made in combination with the shortcomings of the existing simulation model, thereby further improving the accuracy of the simulation model of the disconnector operation process.

[0006] From the perspective of existing research progress, establishing an accurate equivalent simulation model for isolating switch operation and obtaining the relevant characteristics of ultra-fast transient processes are the main means of studying such problems at present. However, the various equivalent simulation models currently proposed do not fully consider the structure and operating characteristics of the isolating switch, resulting in large differences between the simulation results and the measured results, and the existing research lacks a comprehensive statistical analysis of the relevant parameters of the ultra-fast transient process, making it difficult to provide basic data for the electromagnetic protection research of the equipment. To this end, the present invention fully considers the influence of the arc resistance and capacitance and inductance characteristics of the isolating switch on the model, and establishes a high-precision simulation model of the entire process of the isolating switch. Based on the improvement ideas of the model, the arc resistance stages are divided more finely, and the influence of the load side recovery voltage, the isolating switch's own structure, and the arc resistance, capacitance, and inductance on the model are fully considered. In conjunction with modules such as restrike, arc extinguishing, and arc resistance control, a simulation model and simulation method for the entire operation process of the AIS isolating switch are established to solve the problem of how to simulate the operation process of the isolating switch.

[0007] In order to solve the above problems, according to one aspect of the present invention, a simulation model of the whole operation process of an AIS disconnector is provided, wherein the model comprises: a disconnector, an arc resistance, an arc inductance, a break capacitance, an arc restrike module, an arc extinguishing module, an arc extinguishing end module, a switch control module, an arc resistance control module and a timing module; wherein,

[0008] The isolating switch is connected with the arc resistor and the arc inductor to form a series branch, and then connected with the break capacitor to form a parallel branch, which is used to simulate the arc breakdown characteristics of the switch gap during the operation of the isolating switch;

[0009] The restrike module is used to determine whether the voltage across the gap exceeds a preset tolerance value and breaks down during the opening and closing process of the isolating switch, and output a restrike signal to the switch control module and the arc resistance control module;

[0010] The arc extinguishing module is used to obtain the current signal of the isolating switch and the arc resistance series branch, determine whether the arc extinguishing criterion is met, and output the arc extinguishing signal to the switch control module and the arc resistance control module;

[0011] The arc extinction termination module is used to obtain the current signal of the isolating switch and the arc resistance series branch, determine whether the arc extinction termination criterion is met, and output the arc extinction signal to the switch control module and the arc resistance control module;

[0012] The switch control module is used to control the closing and opening of the disconnecting switch based on the restrike signal and the arc extinction end signal;

[0013] The arc resistance control module is used to control the resistance change of the arc resistor based on the restrike signal, the arc extinction signal and the arc extinction end signal;

[0014] The timing module is used to record the gap breakdown moment of the disconnector, the start moment and the end moment of the arc extinction phase.

[0015] Preferably, the input port IN of the switch module is connected to the power supply side of the simulation circuit, and the output port OUT is connected to the load side of the simulation circuit; the node voltage of the isolation switch is obtained by using a node voltage measuring element, and the current flowing through the isolation switch is obtained by a branch current measuring element.

[0016] Preferably, the switch control module uses input ports ST_B and ST_E to respectively receive the reignition signal and arc extinction end signal issued by the reignition module and the arc extinction end module, and outputs the isolating switch state signal OUT_ST to the isolating switch through the output port to control the opening and closing of the isolating switch, and at the same time returns the state of the isolating switch to the reignition module and the arc extinction end module.

[0017] Preferably, the arc resistance control module uses input ports RB and RE to receive the reignition signal and the arc extinction signal issued by the reignition module and the arc extinction module, uses input ports RTb and RTe to receive the gap breakdown time, the start time and the end time of the arc extinction stage recorded by the timing module, uses input port It to receive the current flowing through the isolating switch, and transmits the arc value of each stage to the arc resistor in real time and dynamically through the output signal OUT_Ra.

[0018] Preferably, the restrike module uses input ports IN_U1 and IN_U2 to receive voltage signals at both ends of the main circuit composed of the isolating switch and the arc resistance, arc inductance and break capacitance; calculates and outputs the gap breakdown voltage under the set simulation step; and outputs the restrike signal to the switch control module and the arc resistance control module by comparing the voltage difference at both ends with the size of the gap breakdown voltage.

[0019] According to another aspect of the present invention, a method for simulating the entire operation process of an AIS disconnector is provided, the method comprising:

[0020] The restrike module receives the voltage signals U1 and U2 at both ends of the disconnector. When |U1-U2|≥U b When the isolating switch gap is broken down, the gap enters the arc starting and arc burning stage. At this time, the restrike signal is output to the switch control module and the arc resistance control module. The switch control module receives the restrike signal and controls the switch to close. The arc resistance control module outputs a control signal R based on the received restrike signal. a (t) Control arc resistance to start changing; if not satisfied, continue to restrike judgment; where U b is the gap breakdown voltage;

[0021] The arc extinguishing module receives the current signals I in the branches one by one simulation step length in turn. t and I (t-Δt) , if I t ×I (t-Δt) <0 and |I t -I (t-Δt )|<K, it enters the arc extinction stage, and the arc extinction signal OUT_Q will be transmitted to the switch control module and the arc resistance control module. At this time, the switch continues to remain closed, and the arc resistance is based on the output value R of the arc resistance control module. g (t) starts to rise, simulating the arc extinction stage of the arc; if the above conditions are not met, the simulation step size is progressive and the above judgment is repeated; when the current signal It is less than the fixed value IK, the arc extinction stage ends, and the arc extinction end module outputs the signal OUT_E to the switch control module to control the disconnection switch to be disconnected until the next breakdown. The arc resistance value at this moment is the resistance value at the end of the arc extinction, completing the single breakdown process;

[0022] The switch control module calculates the switch gap D under the current simulation step according to the initial parameters set in step 1. If the disconnect switch operation is completed, the state of the disconnect switch and the value of the arc resistance are adjusted; if the disconnect switch operation is not completed, the above steps are repeated.

[0023] Preferably, the breakdown voltage U b The expression is:

[0024] When the isolating switch is closed:

[0025] u b (t) = E0(D0-vt)

[0026] When the isolating switch is open:

[0027] u b (t) = E0vt

[0028] Wherein, E0 is the breakdown voltage per unit length of the disconnector contact gap; D0 is the disconnector gap distance; v is the operating speed of the disconnector; and t represents time.

[0029] Preferably, the control signal R output by the arc resistance control module is a (t), including:

[0030]

[0031] Among them, R i is the arc-extinguishing resistance at the end of the previous restrike module, and R is taken at the first breakdown i =R0; z0 is the sum of the wave impedance of the line at both ends of the isolating switch and the wave impedance of the isolating switch guide rod; t δ is the breakdown delay; r0 is the arc resistance in the steady-state arcing stage.

[0032] Preferably, the output value R of the arc resistance control module is g (t), including:

[0033]

[0034] Where g is the arc conductance; u h is the instantaneous value of the arc voltage; i h is the instantaneous value of the arc current; P s (g) is the arc heat dissipation power, τ(g) is the insulation recovery time constant; τ, p, α and β are all constants.

[0035] Preferably, the isolating switch gap D comprises:

[0036] When the disconnector is closed: D(t) = D0-vt

[0037] When the isolating switch is open: D(t) = vt

[0038] Wherein, D0 is the gap distance of the disconnector; v is the operating speed of the disconnector; and t represents time.

[0039] The present invention provides a simulation model and simulation method for the whole process of AIS disconnector operation, wherein the model comprises: a switch module, an arc restrike module, an arc extinguishing module, an arc extinguishing end module, a switch control module, an arc resistance control module and a timing module; the present invention fully considers the influence of load side recovery voltage, the structure of the disconnector itself, and arc resistance, capacitance and inductance on the model, and utilizes the system of the present invention to realize accurate simulation of the breakdown of the break gap, arc extinguishing and restrike of the whole process of disconnector operation, thereby realizing the simulation of the whole process of complete disconnector operation; the simulated macro pulse waveform has high similarity with the measured waveform and conforms to the random characteristics; the waveform parameters such as the rise time, maximum peak value and duration of the simulated waveform are not much different from the measured data. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0041] Figure 1 1 is a structural schematic diagram of an AIS disconnector operation whole process simulation model 100 according to an embodiment of the present invention;

[0042] Figure 2 is a schematic diagram of a switch module according to an embodiment of the present invention;

[0043] Figure 3 is a schematic diagram of a restrike module according to an embodiment of the present invention;

[0044] Figure 4 A schematic diagram of an arc extinguishing module and an arc extinguishing termination module according to an embodiment of the present invention;

[0045] Figure 5 is a schematic diagram of a switch control module according to an embodiment of the present invention;

[0046] Figure 6 is a schematic diagram of an arc resistance control module according to an embodiment of the present invention;

[0047] Figure 7 A simulation flow chart according to an embodiment of the present invention;

[0048] Figure 8 A schematic diagram of module interaction according to an embodiment of the present invention;

[0049] Fig. 9 A macro pulse waveform diagram of VFTO measured based on data provided in an embodiment of the present invention;

[0050] Fig.10 A VFTO macro waveform diagram of a simulation model and a dynamic restrike model according to an embodiment of the present invention;

[0051] Fig.11 A macro pulse waveform diagram of VFTC is measured based on the data provided by the embodiment of the present invention;

[0052] Fig.12 A VFTC macro waveform diagram of a simulation model and a dynamic restrike model according to an embodiment of the present invention; DETAILED DESCRIPTION

[0053] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0054] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0055] Figure 1 FIG. 1 is a schematic diagram of the structure of the AIS disconnector operation whole process simulation model 100 according to an embodiment of the present invention. Figure 1 As shown, the simulation model of the whole process of the AIS disconnector operation provided by the embodiment of the present invention fully considers the influence of the load side recovery voltage, the structure of the disconnector itself, and the arc resistance, capacitance, and inductance on the model. The system of the present invention is used to realize the accurate simulation of the break gap breakdown, arc extinguishing and restrike of the whole process of the disconnector operation, and realizes the simulation of the whole process of the complete disconnector operation; the simulated macro pulse waveform is highly similar to the measured waveform and conforms to the random characteristics; the rise time, maximum peak value, duration and other waveform parameters of the simulated waveform are not much different from the measured data. The present invention realizes the disconnector 101, arc resistance 102, arc inductance 103, break capacitance 104, restrike module 105, arc extinguishing module 106, arc extinguishing end module 107, switch control module 108, arc resistance control module 109 and timing module 110.

[0056] Preferably, the isolating switch 101 is connected with the arc resistor 102 and the arc inductor 103 to form a series branch, and then connected with the break capacitor 104 to form a parallel branch, so as to simulate the arc breakdown characteristics of the switch gap during the operation of the isolating switch.

[0057] Preferably, the input port IN of the switch module 101 is connected to the power supply side of the simulation circuit, and the output port OUT is connected to the load side of the simulation circuit; the node voltage of the isolation switch is obtained by using a node voltage measuring element, and the current flowing through the isolation switch is obtained by a branch current measuring element.

[0058] In the present invention, the whole process simulation model of AIS disconnector operation includes: switch module, arc reignition module, arc extinguishing module, arc extinguishing end module, switch control module, arc resistance control module and timing module. The above modules are all composed of components in the simulation software ATP-EMTP.

[0059] Combination Figure 2 As shown, in the present invention, the isolating switch is connected with the arc resistor and the arc inductor to form a series branch, and is connected with the break capacitor to form a parallel branch, which is used to simulate the arc breakdown characteristics of the switch gap during the operation of the isolating switch. The input port IN of the isolating switch connected with the arc resistor and the arc inductor to form a series branch is connected to the power supply side of the simulation circuit, and the output port OUT is connected to the load side of the simulation circuit. U1, U2 and It are the voltage and branch current at both ends of the branch respectively. The node voltage measuring element is used to obtain the node voltage of the isolating switch, and the current flowing through the isolating switch is obtained through the branch current measuring element; and the measured voltage signal and current signal are transmitted to other modules.

[0060] Preferably, the restrike module 105 is used to determine whether the voltage across the gap exceeds a preset tolerance value and breaks down during the opening and closing process of the isolating switch, and output a restrike signal to the switch control module and the arc resistance control module.

[0061] Preferably, the restrike module 105 receives the voltage signals at both ends of the main circuit consisting of the isolating switch and the arc resistance, arc inductance and break capacitance by using input ports IN_U1 and IN_U2; calculates and outputs the gap breakdown voltage under the set simulation step size; and outputs the restrike signal to the switch control module and the arc resistance control module by comparing the voltage difference at both ends with the size of the gap breakdown voltage.

[0062] In the present invention, the restrike module is used to determine whether the voltage across the gap exceeds the tolerance value and breaks down during the opening and closing process of the isolating switch. It interacts with the arc extinguishing module to control the on and off of the entire circuit, and outputs the restrike signal to the switch control module and the arc resistance control module. Figure 3 As shown, in the present invention, the input port IN_U1 and the output port IN_U2 of the arc restrike module are used to receive the voltage signals at both ends of the main circuit composed of the isolating switch and the arc resistance, arc inductance and break capacitance; calculate and output the gap breakdown voltage under the set simulation step; and output the restrike signal to the switch control module and the arc resistance control module by comparing the voltage difference at both ends with the size of the gap breakdown voltage.

[0063] Preferably, the arc extinguishing module 106 is used to obtain the current signal of the series branch of the isolating switch and the arc resistor, determine whether the arc extinguishing criterion is met, and output the arc extinguishing signal to the switch control module and the arc resistor control module.

[0064] Preferably, the arc extinction termination module 107 is used to obtain the current signal of the disconnector and the arc resistor series branch, determine whether the arc extinction termination criterion is met, and output the arc extinction signal to the switch control module and the arc resistance control module.

[0065] In the present invention, the arc extinction module and the arc extinction termination module are used to obtain the current signal of the isolating switch and the arc resistor series branch, determine whether the arc extinction criterion and the arc extinction termination criterion are met through certain logical operations, and output the arc extinction signal and the arc extinction termination signal to the switch control module and the arc resistor control module. Figure 4 As shown, in the present invention, the port IN_It of the arc extinction module and the arc extinction end module receives the current signal It of the switch module, determines whether the current state reaches the arc extinction condition or the arc extinction end condition through logical operation, and outputs the arc extinction signal and the arc extinction end signal to the switch control module and the arc resistance control module.

[0066] Preferably, the switch control module 108 is used to control the closing and opening of the disconnecting switch based on the restrike signal and the arc extinction end signal.

[0067] Preferably, the switch control module 108 uses input ports ST_B and ST_E to receive the reignition signal and arc extinction end signal issued by the reignition module and the arc extinction end module respectively, and outputs the isolating switch state signal OUT_ST to the isolating switch through the output port to control the opening and closing of the isolating switch, and at the same time returns the state of the isolating switch to the reignition module and the arc extinction end module.

[0068] In the present invention, the switch control module is used to receive the reignition signal and the arc extinction end signal sent by the reignition module and the arc extinction module, and achieve the purpose of controlling the switch state through certain logical operations. Figure 5 As shown, in the present invention, the input ports ST_B and ST_E of the switch control module are respectively used to receive the reignition or arc extinction end signals issued by the reignition module and the arc extinction end module, and output the isolating switch state signal OUT_ST to control the opening and closing of the isolating switch through certain logical operations, and at the same time return the state of the isolating switch to the reignition module and the arc extinction module.

[0069] Preferably, the arc resistance control module 109 is used to control the resistance change of the arc resistor based on the restrike signal, the arc extinction signal and the arc extinction end signal.

[0070] Preferably, the arc resistance control module 109 uses input ports RB and RE to receive the reignition signal and the arc extinction signal issued by the reignition module and the arc extinction module, uses input ports RTb and RTe to receive the gap breakdown time, the start time and the end time of the arc extinction stage recorded by the timing module, uses input port It to receive the current flowing through the isolating switch, and transmits the arc value of each stage to the arc resistance in real time and dynamically through the output signal OUT_Ra.

[0071] In the present invention, the arc resistance control module is used to receive the restrike signal sent by the restrike module and the arc extinction end signal sent by the arc extinction module and the arc extinction end module, and control the resistance change of the arc resistor through certain logical operations. Figure 6 As shown, in the present invention, ports RB and RE of the arc resistance control module are used to receive the reignition or arc extinction signals sent by the reignition module and the arc extinction module, ports RTb and RTe are used to receive the gap breakdown moment, the start and end time of the arc extinction phase recorded by the timing module, and RI is used to receive the current flowing through the disconnector, so as to control the calculation process of the custom component MODELS_Ra in the module, and the output signal OUT_Ra dynamically transmits the arc value of each stage to the arc resistance in real time.

[0072] Preferably, the timing module 110 is used to record the gap breakdown moment of the disconnector, and the start moment and end moment of the arc extinction phase.

[0073] In the present invention, simulation is performed based on the simulation model of the entire operation process of the AIS disconnector as described above. During the simulation process, the simulation calculation uses the time step Δt as the calculation interval, and uses the circuit state quantity calculated at the time t-Δt to solve the circuit state at the time t. In the algorithm design of multiple reignition calculations, a conditional loop structure is used. The simulation main circuit is built to realize the simulation of the actual line, and the multiple reignition processes of the disconnector are realized by establishing a switch control module, an arc resistance control module, an arc reignition module, an arc extinguishing module, an arc extinguishing end module, a timing module, and designing the corresponding logical judgment relationship between them.

[0074] The AIS isolating switch operation whole process simulation method provided by the embodiment of the present invention includes:

[0075] Step 1: Set the original parameters of each module in the simulation model.

[0076] Step 2: Set the simulation step size and simulation step time

[0077] In the present invention, since the frequency of electromagnetic interference generated during the operation of the isolating switch is as high as tens of MHz, the simulation step time is Generally, the value is less than 10 -8 s.

[0078] Step 3: The restrike module receives the voltage signals U1 and U2 at both ends of the disconnector. When |U1-U2|≥U b When the isolating switch gap is broken down, the gap enters the arc starting and arc burning stage. At this time, the restrike signal is output to the switch control module and the arc resistance control module. The switch control module receives the restrike signal and controls the switch to close. The arc resistance control module outputs a control signal R based on the received restrike signal. a (t) Control arc resistance to start changing; if not satisfied, continue to restrike judgment; where U b is the gap breakdown voltage.

[0079] Preferably, the breakdown voltage U b The expression is:

[0080] When the isolating switch is closed:

[0081] u b (t) = E0(D0-vt)

[0082] When the isolating switch is open:

[0083] u b (t) = E0vt

[0084] Wherein, E0 is the breakdown voltage per unit length of the disconnector contact gap; D0 is the disconnector gap distance; v is the operating speed of the disconnector; and t represents time.

[0085] Preferably, the control signal R output by the arc resistance control module is a (t), including:

[0086]

[0087] Among them, R i is the arc-extinguishing resistance at the end of the previous restrike module, and R is taken at the first breakdown i =R0; z0 is the sum of the wave impedance of the line at both ends of the isolating switch and the wave impedance of the isolating switch guide rod; t δ is the breakdown delay; r0 is the arc resistance in the steady-state arcing stage.

[0088] In the present invention, R i =R0=10 12 Ω;t δ is the breakdown delay, and its value range in AIS is 37.7ns~139.6ns; r0 is the arc resistance in the steady-state arcing stage, and its value is generally in the range of 0.5Ω~5.0Ω.

[0089] Step 4: The arc extinguishing module receives the current signals I in the branches one simulation step apart in sequence. t and I (t-Δt) , if I t ×I (t-Δt) <0 and |I t -I (t-Δt) |<K, it enters the arc extinction stage, and the arc extinction signal OUT_Q will be transmitted to the switch control module and the arc resistance control module. At this time, the switch continues to remain closed, and the arc resistance is based on the output value R of the arc resistance control module. g (t) starts to rise, simulating the arc extinction stage; if the above conditions are not met, the simulation step size is increased and the above judgment is repeated; when the current signal It is less than the fixed value IK, the arc extinction stage ends, and the arc extinction end module outputs the signal OUT_E to the switch control module to control the disconnection of the isolating switch until the next breakdown. The arc resistance at this moment is the resistance at the end of the arc extinction, completing the single breakdown process.

[0090] Preferably, the output value R of the arc resistance control module is g (t), including:

[0091]

[0092] Where g is the arc conductance; u h is the instantaneous value of the arc voltage; i h is the instantaneous value of the arc current; P s (g) is the arc heat dissipation power, τ(g) is the insulation recovery time constant; τ, p, α and β are all constants.

[0093] In the present invention, according to experience, it can be set as follows: τ = 1.5 × 10 -6 , p = 4 × 10 6 , α=0.17 and β=0.68.

[0094] Step 5: The switch control module calculates the switch gap D under the current simulation step according to the initial parameters set in step 1. If the isolating switch operation is completed, the state of the isolating switch and the value of the arc resistance are adjusted; if the isolating switch operation is not completed, steps 3 and 4 are repeated.

[0095] Preferably, the isolating switch gap D comprises:

[0096] When the disconnector is closed: D(t) = D0-vt

[0097] When the isolating switch is open: D(t) = vt

[0098] Wherein, D0 is the gap distance of the disconnector; v is the operating speed of the disconnector; and t represents time.

[0099] In the present invention, the relationship between the switch gap D and whether the switch operation is completed is as follows: when the switch gap is 0, it means that the closing operation is completed, and when the switch gap is D0, it means that the opening operation is completed.

[0100] In the simulation process of the present invention, the simulation process is as follows: Figure 7 As shown in the figure, the restrike criterion is used to determine whether the gap is broken, and the arc extinction criterion is used to determine whether the current is zero-crossing. Figure 8 shown.

[0101] In order to verify the accuracy of the whole process simulation model of the isolating switch proposed in the present invention, a 110kV isolating switch opening and closing capacitive small current test platform was built according to the actual line parameters, so as to simulate the actual opening and closing process of the isolating switch of the operating line and the capacitive small current load process, and provide a data basis for the accuracy verification of the model. The macro pulses of VFTO and VFTC were measured. Fig. 9 , Fig.11 At the same time, according to the experimental principle, a corresponding simulation main circuit was built in the simulation software, and the VFTO and VFTC macro waveforms of the model provided by the present invention were obtained through simulation as shown in FIG. Fig.10 , 12 As shown. Fig. 9 , 10 as well as Fig.11 , 12 It can be seen that the model provided by the present invention has undergone multiple re-breakdowns during the simulation process. The comparison results with the experiment show that the transient voltage waveform of the isolating switch operation obtained by simulation is similar to the development trend of the experimental waveform, which proves the effectiveness of the isolating switch operation full process modeling method of the present invention, which can better reflect the simulation of the switch gap arc reignition and extinction phenomenon.

[0102] The test system is at a voltage level of 110kV, and the reference value selected in the calculation is:

[0103]

[0104] The VFTO and VFTC waveforms of a transient process of a disconnector closing operation obtained in the test are as follows: Fig. 9 , Fig.11 As shown, the maximum amplitude of VFTO is 118.67kV (about 1.32pu), and the maximum amplitude of VFTC is 1223.95A.

[0105] The VFTO and VFTC waveforms of the transient process of the disconnector operation obtained by the simulation of the model of the present invention are similar to the development trend of the test waveform, and the transient voltage waveform is also "step" shaped, but the amplitude of the simulation result is higher, the maximum overvoltage amplitude is 127.43kV (about 1.41pu), and the maximum overcurrent peak value is 1232.49A, which are slightly larger than the maximum voltage and current peak values ​​obtained in the test, with errors of 6.8% and 6.9% respectively.

[0106] The simulation model and simulation method of the whole process of operation of the AIS disconnector of the present invention, on the basis of the existing dynamic arc model and multiple restrike model of the disconnector, re-adjust and define the original parameters, and further consider the influence of the wave impedance of the disconnector guide rod on the simulation calculation. Combined with the characteristics of the simulation calculation, the original dynamic arc model is modified to ensure the continuity of the arc resistance during the switch operation, and the influence of the arc inductance and the disconnector break capacitance on the arc model is further considered. At the same time, according to the gas dielectric theory and the energy balance theory, the arc reignition criterion and the arc extinction criterion are established respectively, and the corresponding reignition arc module and the arc extinction module are established. By combining with the modified dynamic arc model, a dynamic restrike arc resistance model is formed. The simulation model and simulation method of the whole process of operation of the AIS disconnector provided by the present invention realize the simulation of the arc reignition and extinction phenomenon of the switch gap. The overall waveform of the VFTO and VFTC simulation results and the transient attenuation waveform of a single pulse are roughly consistent with the measured waveform, and the characteristic parameters of the simulation waveform are not much different from the measured waveform, which can prove the correctness of the modeling method provided by the present invention.

[0107] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0108] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of said means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A simulation model of the whole process of AIS disconnector operation, characterized in that: The model includes: an isolating switch, an arc resistance, an arc inductance, a break capacitance, an arc restrike module, an arc extinguishing module, an arc extinguishing end module, a switch control module, an arc resistance control module and a timing module; wherein, The isolating switch is connected with the arc resistor and the arc inductor to form a series branch, and then connected with the break capacitor to form a parallel branch, which is used to simulate the arc breakdown characteristics of the switch gap during the operation of the isolating switch; The restrike module is used to determine whether the voltage across the gap exceeds a preset tolerance value and breaks down during the opening and closing process of the isolating switch, and output a restrike signal to the switch control module and the arc resistance control module; The arc extinguishing module is used to obtain the current signal of the isolating switch and the arc resistance series branch, determine whether the arc extinguishing criterion is met, and output the arc extinguishing signal to the switch control module and the arc resistance control module; The arc extinction termination module is used to obtain the current signal of the isolating switch and the arc resistance series branch, determine whether the arc extinction termination criterion is met, and output the arc extinction signal to the switch control module and the arc resistance control module; The switch control module is used to control the closing and opening of the disconnecting switch based on the restrike signal and the arc extinction end signal; The arc resistance control module is used to control the resistance change of the arc resistor based on the restrike signal, the arc extinction signal and the arc extinction end signal; The timing module is used to record the gap breakdown moment of the disconnector, the start moment and the end moment of the arc extinction phase.

2. The simulation model according to claim 1, characterized in that: The input port IN of the switch module is connected to the power supply side of the simulation circuit, and the output port OUT is connected to the load side of the simulation circuit; the node voltage of the isolation switch is obtained by using the node voltage measuring element, and the current flowing through the isolation switch is obtained by the branch current measuring element.

3. The simulation model according to claim 1, characterized in that: The switch control module uses input ports ST_B and ST_E to receive the reignition signal and arc extinction end signal issued by the reignition module and the arc extinction end module respectively, and outputs the isolation switch state signal OUT_ST to the isolation switch through the output port to control the opening and closing of the isolation switch, and at the same time returns the state of the isolation switch to the reignition module and the arc extinction end module.

4. The simulation model according to claim 1, characterized in that: The arc resistance control module uses input ports RB and RE to receive the reignition signal and the arc extinction signal sent by the reignition module and the arc extinction module, uses input ports RTb and RTe to receive the gap breakdown time, the start time and the end time of the arc extinction stage recorded by the timing module, uses input port It to receive the current flowing through the disconnector, and transmits the arc value of each stage to the arc resistor in real time and dynamically through the output signal OUT_Ra.

5. The simulation model according to claim 1, characterized in that: The restrike module receives voltage signals at both ends of the main circuit consisting of the isolating switch and the arc resistance, arc inductance and break capacitance by using input ports IN_U1 and IN_U2; calculates and outputs the gap breakdown voltage under the set simulation step size; and outputs the restrike signal to the switch control module and the arc resistance control module by comparing the voltage difference at both ends with the gap breakdown voltage.

6. A method for simulating the entire operation process of an isolating switch, characterized in that: The method comprises: The restrike module receives the voltage signals U1 and U2 at both ends of the disconnector. When |U1-U2|≥U b When the isolating switch gap is broken down, the gap enters the arc starting and arc burning stage. At this time, the restrike signal is output to the switch control module and the arc resistance control module. The switch control module receives the restrike signal and controls the switch to close. The arc resistance control module outputs a control signal R based on the received restrike signal. a (t) Control arc resistance to start changing; if not satisfied, continue to restrike judgment; where U b is the gap breakdown voltage; The arc extinguishing module receives the current signals I in the branches one by one simulation step length in turn. t and I (t-Δt) , if I t ×I (t-Δt) <0 and |I t -I (t-Δt )|<K, it enters the arc extinction stage, and the arc extinction signal OUT_Q will be transmitted to the switch control module and the arc resistance control module. At this time, the switch continues to remain closed, and the arc resistance is based on the output value R of the arc resistance control module. g (t) starts to rise, simulating the arc extinction stage of the arc; if the above conditions are not met, the simulation step size is progressive and the above judgment is repeated; when the current signal It is less than the fixed value IK, the arc extinction stage ends, and the arc extinction end module outputs the signal OUT_E to the switch control module to control the disconnection switch to be disconnected until the next breakdown. The arc resistance value at this moment is the resistance value at the end of the arc extinction, completing the single breakdown process; The switch control module calculates the switch gap D under the current simulation step according to the original parameters of each module in the preset simulation model. If the isolating switch operation is completed, the state of the isolating switch and the value of the arc resistance are adjusted; if the isolating switch operation is not completed, the above process is repeated.

7. The method according to claim 6, characterized in that The breakdown voltage U b The expression is: When the isolating switch is closed: u b (t)=E0(D0-vt) When the isolating switch is open: u b (t)=E0vt Wherein, E0 is the breakdown voltage per unit length of the disconnector contact gap; D0 is the disconnector gap distance; v is the operating speed of the disconnector; and t represents time.

8. The method according to claim 6, characterized in that The arc resistance control module outputs a control signal R a (t), including: Among them, R i is the arc-extinguishing resistance at the end of the previous restrike module, and R is taken at the first breakdown i =R0; z0 is the sum of the wave impedance of the line at both ends of the isolating switch and the wave impedance of the isolating switch guide rod; t δ is the breakdown delay; r0 is the arc resistance in the steady-state arcing stage.

9. The method according to claim 6, characterized in that The output value R of the arc resistance control module g (t), including: Where g is the arc conductance; u h is the instantaneous value of the arc voltage; i h is the instantaneous value of the arc current; P s (g) is the arc heat dissipation power, τ(g) is the insulation recovery time constant; τ, p, α and β are all constants.

10. The method according to claim 6, characterized in that Disconnector gap D, including: When the disconnector is closed: D(t) = D0-vt When the isolating switch is open: D(t) = vt Wherein, D0 is the gap distance of the disconnector; v is the operating speed of the disconnector; and t represents time.

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