TW201807650A - Method and graphical man-machine interface having sheath induced voltages and sheath circulating currents for calculation of transmission and distribution lines - Google Patents

Abstract

The present invention relates to a method and a graphical man-machine interface having sheath induced voltages and sheath circulating currents for calculation of transmission and distribution lines. The graphical man-machine interface includes a display screen and a window shown on the display screen, wherein the window further includes a calculating parameter input region for users to input load currents, types, length and grounding ways of cables, a cable alignment setting region for users to input assignment methods, spacing and length settings and a calculation result display region for manifesting calculated results according to relevant conditions input by users, including drawing lumps of an induced voltage distribution diagram, an induced voltage vector diagram and a circulating current vector diagram, showing terminal induced voltages, highest induced voltages and induced voltage lumps of phase angles thereof, showing circulating currents and circulating current lumps of phase angles thereof, and further showing three-phase circulating currents, sheath circulating current lumps of phase angles and sheath impedance lumps. As a result, maintenance workers may simply carry out all necessary input of parameters and display various results without delay via the graphical man-machine interface, as the case may be. Maintenance workers may further control all operations of the line system using skills as needed and enable to duly find out weakness or abnormalities of the system to take necessary measures in a real-time manner to avoid accidents or undesired events result from the line system.

Description

Graphical human-machine interface and method for calculating drape induced voltage and circulating current of transmission and distribution lines

The invention relates to a graphical human-machine interface and method for calculating the overlying induced voltage and circulating current of the transmission and distribution lines, in particular to developing a graphical program, the program interface is available for the user to actually In the case, the input of the necessary parameters is briefly completed, and the graphical human-machine interface and method of the induced voltage and the covered circulating current calculation result are quickly displayed.

In recent years, with the continuous advancement of power technology and urban development, the 69kV, 161kV transmission-grade underground cable power supply system has been generally planned in science parks, industrial areas and metropolitan areas. The use of the underground cable power supply system can greatly reduce the impact of external environments such as lightning strikes, salt spray, typhoons and external forces, thus providing higher power supply reliability and power quality. However, underground cable-to-ground charging capacitors are larger than overhead lines, so new operational issues have emerged, including harmonic resonance, switching surge, ground fault transfer, and protection coordination. For the specifications or ratings of underground cable systems, including voltage and current ratings, insulation endurance, test methods, cable routing, cable connector handling, and Cable Covering Protection Unit (CCPU), etc. It is regulated by relevant regulations or standards, such as domestic house, outdoor line device rules and transmission engineering operation manual, Insulated Power Cable Engineering Association (IPCEA) and its national standard (ANSI/IEEE).

The transmission underground cable is usually built with a single-core cable with a shielded copper wire. When the cable-shielded copper wire is grounded at one end, the other ungrounded open end of the cable will be induced by the electromagnetic effect of the conductor current. Voltage, and this induced voltage must be limited below the safety tolerance to ensure the safety of maintenance personnel. However, if the cable-shielded copper wire ends are grounded, although no induced voltage is generated, the shielded copper wire will form a closed loop and generate a circulating current, which will cause loop loss and heat generation, which may reduce the cable power transmission capacity and speed up. The cable covers the aging speed. When the lengths of the sections of the local lower cable are not equal in length, regardless of the arrangement, the longer the length of the cable section, the larger the induced voltage value and the circulating current value of the shielded copper wire. However, when the copper plate in the cable covering protection device is staggered in the wrong direction, the maximum induced voltage of the shielded copper wire is greatly increased. Therefore, the correct grounding direction of the copper plate of the cable covering protection device is caused by the correct value of the shielded copper wire. The impact. It can be seen from this that the arrangement of the cable system, the length of the section, and the correctness of the cable covering protection device all affect the induced induced voltage and the circulating current.

At present, the underground cable in Taiwan is mainly composed of paper-filled cable and Cross-Linked Polyethylene (XLPE) single-core shielding cable. The single-core shielding cable is subjected to high-voltage conductor, shielding conductor and grounding. The influence of the flux linkage between the two causes an induced voltage on the grounding conductor of the shielding layer, and generates a circulating current on the grounded shielding conductor of the double-ended three-phase connection; if a single-point grounding is used at the shielding layer conductor, the circulating current value can be eliminated. However, the length of the cable section is one of the influencing factors of the induced voltage, and the amplitude of the induced voltage at the open end of the shielding layer conductor is regulated by regulations. In the case where the length of the cable section is limited, the three-phase cable system can adopt a shielding conductor. Staggered connection and grounding technology to ensure the safety of the work environment and improve transmission efficiency.

At present, the layout design of underground transmission lines can be divided into single return lines, double return lines and four return lines. Among them, the cable routing mode of the single loop system can be divided into a triangle arrangement, a right angle arrangement, a three-phase parallel arrangement (vertical arrangement) and a complex conductor, as shown in the first figure. As for the layout mode of the double loop system, there are three ways of positive phase sequence arrangement, reverse phase sequence arrangement and right angle arrangement, as shown in the second figure. The layout of the four-loop system can be divided into four tube bottoms, five tube bottoms, eight tube bottoms, and square arrays, as shown in the third figure.

When the single-loop cable system adopts the triangular arrangement, the maximum induced voltage of the shielded copper wire obtained is lower than that of the right-angled arrangement. Therefore, it can be known that the single-loop triangle arrangement should be excellent under normal operating conditions. Arranged at right angles. When the underground cable is vertically aligned in the positive phase sequence of the double-circuit cable system, the maximum induced voltage of the shielded copper wire is much higher than when the cable double-circuit line is arranged in the reverse phase sequence. When the length of the shielded copper wire in each section of the local cable is not equal, the longer the interval length, the longer the length of the shielded copper wire will increase the value of the induced voltage and the circulating current.

Therefore, the design and planning of underground cable layout methods are often affected by factors such as actual terrain changes and cable power transmission capacity, resulting in differences in the arrangement and length of each section of the cable, plus the cable of each arrangement. The results of the calculation of the circulating current and the induced voltage of the cable will also be affected. Therefore, only the planned and properly designed cable layout will help ensure that the cable is covered with circulating current and The induced voltage amplitude meets the specification limits, which in turn improves the performance of the cable system.

The metal of a single-core cable is covered. Due to the electromagnetic effect of the alternating current of the conductor, the electromotive force induced on the coating is called Sheath Induced Voltage. The magnitude of this voltage is related to the conductor load current, cable length and cable. The line arrangement is related. Because the over-covered induced voltage threatens human safety, the safety induced voltage of 69kV and 161kV underground cables is only allowed to be below 65V. In addition, the cable coating is short-circuited due to multi-point grounding, which will generate a blanket current (Sheath Circulating Current), resulting in loss of the covered circuit. Therefore, many kinds of grounding methods have been developed to reduce or prevent coating loss, such as single-ended grounding, direct Ground, staggered ground, impedance ground, transformer ground, non-linear resistor ground.

As shown in the fourth figure, the three single-core cables are connected to one end of the connection, and then grounded together, while the other end is not grounded. This is called Single Point Bonding. In order to avoid the line fault current flowing into the adjacent pipeline, such as telecommunications, gas and tap water, causing interference or accident, the single-ended grounding system usually needs to be provided with an auxiliary grounding wire parallel to the line. The value of the covered voltage of the single-ended ground will increase with the distance from the grounding point, as shown in the fifth figure. Therefore, single-ended grounding is only suitable for short-distance lines. If the line is too long, the induced voltage will be too high. In addition to possibly exceeding the standard 65V, it will also endanger the staff. In view of this, for long-distance lines, the cable line can be divided into several sections, that is, the cable covering of each section is isolated by the insulation connection, and then the single-ended grounding is applied to each section, that is, as the sixth As shown in the figure, the common connection system is used for the cable connection in general, and the metal coating on both sides of the connection is kept continuous, while the insulation connection is mainly used for the single-core cable, which will be connected to both sides of the cable. The metal coating is insulated to prevent it from communicating with each other, which helps to reduce the coating potential and the coating loss.

The terminal 匣 and the middle 匣 of the three-phase cable line are connected together and then grounded, which is called Solid Bonding, also known as multi-point grounding, as shown in the seventh figure. When the cable is covered with multi-point grounding method, the induced voltage of the cable coating can be completely eliminated, as shown in the eighth figure, but the circuit is directly short-circuited to form a short circuit, which will generate a covered circulating current (Sheath Circulating). Current), causing loop loss and reducing the current capacity of the cable. At this time, the high temperature generated by the cable coating loss of electrical energy may also accelerate the aging of the insulator and shorten the cable life. Generally, the smaller the spacing between the cables, the smaller the induced voltage of the coating will be, so as to help reduce the danger caused by the high voltage. However, if the spacing is too small, the circulating circulating current will become larger, resulting in an increase in cable loss.

Cross Bonding is to ground the cable line in groups of three consecutive manholes, as shown in Figure 9, where the first person hole (M1) uses the normal joint, which will The three-phase coatings are connected together for direct grounding, and the second personal hole (M2) and the third personal hole (M3) use Insulation Joint to shift the three-phase sequence of the coating, thereby effectively The covered induced voltage is lowered, and the induced induced voltage is as shown in the tenth figure.

At present, the 161kV single-core cable line of Taiwan Power Company adopts the staggered grounding method, and when the staggered grounding is adopted, the XB cable covering protection device is installed at the insulation connection inside the manhole, such as the eleventh. The figure shows the induced voltage that helps prevent circuit faults and helps reduce the occurrence of electrical shocks.

The construction of the cable covering protection device and the cable terminal and the design of the cable grounding method are correct, which will affect the operation efficiency of the cable system, especially when the newly increased electricity users are integrated into the system, the loop underground cable structure will be changed. At this time, if the designer neglects the importance of the underground cable grounding system, there is a possibility that the gas-sealed cable terminal 匣 and the cable covering protection device are damaged. In addition, the cable covering protection device is in the underground pipeline or culvert, which is easy to damage the cable covering protection device due to the wet water in the pipeline. Therefore, it is an important work item to regularly measure the induced voltage and circulating current of the underground cable and the equipment related to maintenance cable. It is possible to detect system failures early and take appropriate measures to prevent cable line accidents, thereby improving the overall operating efficiency of the system.

The main object of the present invention is to provide a graphical human-machine interface and method for calculating the overlying induced voltage and circulating current of the transmission and distribution lines, and to establish an underground cable inductive voltage and circulating current calculation and measurement technology, and provide The operation and maintenance personnel master the skills required for the operation of the cable system, timely identify the weaknesses and abnormal conditions of the system, and take appropriate measures to prevent the occurrence of cable line accidents.

The object and effect of the present invention are achieved by the following techniques:

A graphical human-machine interface for calculating a coating induced voltage and a circulating current of a transmission and distribution line includes a display screen, the display screen displaying a window, the window including a calculation parameter input area and a cable arrangement setting Zone and calculation result display area; where:

The calculation parameter input area is used by the user to input the relevant parameters of the load current, the cable type, the resistance and the inductive coupling coefficient of the cable;

The cable arrangement setting area is a parameter for the user to input the arrangement manner of the cable, the spacing setting and the length setting;

The calculation result display area displays the result obtained by calculating the relevant parameters input by the user, and includes drawing the induced voltage distribution map, the induced voltage vector map, the drawing block of the circulating current vector map, and the display terminal induced voltage and The maximum induced voltage is the magnitude of the induced voltage block with the phase angle, the circulating current block showing the magnitude of the circulating current and the phase angle, the three-phase circulating current and the block showing the three-phase circulating current and the magnitude and phase angle, and the display Overlying the impedance block.

The graphical human interface as described above, wherein the calculation parameter input area includes a load current parameter input port, a cable type parameter input port, a resistance parameter setting input port, a coupling coefficient correction input port, a start calculation button, and an end program. button.

The graphical human-machine interface as described above, wherein the load current parameter input port comprises four return line input fields, and the four return line input fields are R-S-T, U-V-W, A-B-C and X-Y-Z, and a total of 12 fields that can be input.

The graphical human-machine interface as described above, wherein the cable type parameter input port comprises an oil-filled cable 161kV 3000MCM menu, an oil-filled cable 161kV 4000MCM menu, an XLPE cable 69kV 500mm ² menu, an XLPE cable 69kV 1000mm ² menu, XLPE cable 69kV 1600mm ² menu, XLPE cable 161kV 1600mm ² menu and XLPE cable 161kV 2000mm ² menu, each menu has built-in cable with corresponding operating system rated running current.

The graphical human interface as described above, wherein the cable type parameter input port further includes a further (self-input cable parameter) menu for the user to input the cable parameters, the cable parameters including the cable The average radius of the coating (mm), the shielding layer coating resistance (ohm / km).

The graphical human-machine interface as described above, wherein the resistance parameter setting input includes a ground resistance input field, a ground resistivity input field, and a connection resistance input field, and the connection resistance input field has a R phase Three phases of S phase and T phase.

The graphical human-machine interface as described above, wherein the coupling coefficient correction input includes a self-inductance coupling coefficient correction field and a mutual inductance coupling coefficient correction field.

The graphical human-machine interface as described above, wherein the cable arrangement setting area comprises a first segment input port, a second segment input port and a third segment input port, and each segment comprises three portions. The field selection field, the spacing setting field and the length setting field are respectively arranged for the arrangement.

The graphical human-machine interface as described above, wherein the first segment input port, the second segment input port, and the third segment input port further comprise an arrangement schematic field for respectively when used After selecting the cable arrangement mode in the arrangement selection field, the corresponding arrangement of the selected cable arrangement manner is displayed in the arrangement schematic field; the spacing setting field is the distance between the cables The length setting field needs to input the length of each segment of the cable.

The graphical human-machine interface as described above, wherein the calculation result display area comprises a drawing block, an induced voltage block, a circulating current block, a three-phase circulating current and a block, and a covered impedance block.

The graphical human-machine interface as described above, wherein the drawing block can draw an induced voltage distribution map, an induced voltage phasor diagram, and a circulating current phasor diagram.

The graphical human-machine interface as described above, wherein the drawing block comprises a graphic window, a drawing menu, a storage menu and a storage name field, and the graphic to be drawn is selected by the drawing menu of the pull-down type, and is used by the user. The storage menu is used to determine whether to save the drawn graphic, and the storage name is input by the user in the storage name field during storage.

The graphical human-machine interface as described above, wherein the induced voltage block comprises a terminal induced voltage field and a maximum induced voltage field, and the induced voltage of each phase simultaneously displays the size and the phase angle.

The graphical human interface as described above, wherein the circulating current block includes a circulating current field that displays the magnitude of the circulating current and the phase angle.

The graphical human interface as described above, wherein the three-phase circulating current and the block include a size field and a phase angle field that display a sum of circulating currents.

The patterned human-machine interface as described above, wherein the covered impedance block is an impedance generated by a self-inductance, an internal resistance, and a connection resistance of the cable coating layer, including an impedance field and a phase angle field.

A method for calculating a coating induced voltage and a circulating current of a transmission and distribution line, comprising the steps of:

Step 1: Select the cable type;

Step 2: Determine the cable arrangement, spacing and length of each segment;

Step 3: Input the load current;

Step 4: Start calculation and observe the calculation result; when the calculation result approximates the measured 數 value, it means that the program can correctly evaluate the induced voltage of the cable. At this time, the input system can be stored and recorded, and then the underground line is recorded. When the maintenance test is carried out, the system can be applied to calculate the induced voltage and the circulating current; if the calculated result is very different from the measured value, then step 5 is continued;

Step 5: Correct the calculation parameters; correct the grounding resistance, the earth resistivity and the input value of the connection resistance, and the inductance self-inductance coupling coefficient and the inductance mutual inductance coupling coefficient, and then recalculate in step 4.

Accordingly, the present invention can be used by the maintenance personnel to briefly complete the necessary parameter input according to the actual situation on the site, and quickly display the results, and provide the maintenance personnel with the skills required to master the operation state of the line system, and timely discover the system. Weaknesses and abnormal conditions, and timely take countermeasures to prevent line accidents.

For a more complete and clear disclosure of the technical content, the purpose of the invention and the effects thereof achieved by the present invention, it is explained in detail below, and please refer to the drawings and drawings:

The graphical human-machine interface for calculating the overlying induced voltage and circulating current of the transmission and distribution lines of the present invention is mainly for providing the user to input the necessary parameters according to the actual situation on the site under the condition of the staggered grounded cable system. After that, a graphical human-machine interface that can quickly display the calculation results of related data such as induced voltage and circulating current.

As shown in Figure 12, there is a staggered grounded cable system. The twelfth figure (a) is a schematic diagram of the cable staggered ground transposition, which is composed of four manholes and three sections, in the figure M ₁ M ₂ , M ₃ , M ₄ represent the manhole number, l ₁ , l ₂ and l ₃ represent the length of each section, and D _RS , D _ST and D _RT are respectively the three-phase cable spacing. Figure 12 (b) is the cable-coated equivalent circuit, in which R ₁ and R ₄ are grounding point connection resistors, R ₂ and R ₃ are connected 匣 connection resistances, R _{e1 ,} R _e2 are grounding resistors, Z ₁ , Z ₂ , Z ₃ represent the interval , , Covered impedance, E _R1R2 , E _S1S2 , E _T1T2 are intervals Induced voltage caused by the load _{current, E R2R3, E S2S3, E} T2T3 sections respectively The induced voltage caused by the load current, E _R3R4 , E _S3S4 , E _T3T4 are intervals The induced voltage caused by the load current, I _rsh , I _ssh , and I _tsh are respectively the three-phase covered circulating current of the cable.

The invention performs the calculation method of each parameter in the twelfth figure (b) based on the cable coating equivalent circuit of the twelfth figure (b).

<inductance coefficient>

There are different calculation formulas depending on the number of different loops and the arrangement of different cables.

<<Inductance system calculation method of single loop system>>

The calculation of the single-loop system is based on the thirteenth figure. In the figure, D _RS , D _ST and D _RT represent the distance between the three-phase conductors respectively. I _R , I _S and I _T are the load currents of the three-phase cable respectively. Self-coupling inductance system:

............................(1)

The inductance system of the R phase and the S phase and T phase sensing is:

.....................................(2)

The inductance system of the S phase and the R phase and T phase sensing is:

.....................................(3)

The inductance system of the T phase and the R phase and S phase sensing each other is:

.....................................(4)

Where r _s is the average radius of the shielded copper wire of the cable, which varies according to the transmission grade of the cable and the cable material. For details, please refer to Tables 1 to 3. When D _e represents the shielding layer with the earth as the loop, the skin depth of this loop can be obtained by the following formula:

.............................................(5)

Where σ represents the resistivity of the earth (Ω‧m); f represents the frequency (60Hz).

The calculation formula of the single-loop system inductance system is summarized in Table 4. The arrangement and spacing of the single-loop cables used in the program of the present invention are listed in Table 5. If the results of Table 5 are substituted into (1) ~ ( 4), you can find the self-inductance system and mutual inductance system of the single-loop system.

Table 1 Specifications of 161kV oil-filled cable

Table 2 Specifications of 69kV twisted polyethylene cable

Table 3 Specifications of 161kV twisted polyethylene cable

Table 4 Single loop system inductance system 數 calculation use 參數

Table 5 Single loop system arrangement and cable spacing

<<Inductance system calculation method for single-loop complex conductor system>>

The calculation of the single-loop complex conductor system is based on the fourteenth figure. In the figure, D _RS , D _ST , D _RT , D _{RR '} , D _{RS '} , D _{RT '} , D _{SR '} , D _{SS '} , D _ST , D _TR' , D _TS' , D _TT' represent the distance between the six conductors, I _R , I _S , I _T are the load currents of the three-phase cable respectively, and the three-phase self-coupling inductance system is not due to the return line. The changes are the same as those in (1), and the calculation of the mutual inductance of the single-circuit complex conductor cable is as follows.

The mutual inductance inductance system of R phase and other phases is: ......................................(6)

The mutual inductance system of the S phase and other phases is: ......................................(7)

The mutual inductance system of the T phase and other phases is: ............................................(8)

Where r _s and D _{e are} all the same as single-line, as shown in Tables 1 to 3 and (5); and the calculation formula of the single-loop complex conductor system inductance system is summarized in Table 6, and is graphically represented in the present invention. The arrangement and spacing of the single-loop composite conductors used in the interface are listed in Table 7. The results of Table 7 are substituted into (6) to (8), respectively, and the self-inductance system and mutual inductance system of the single-loop system can be obtained.

Table 6 Single-loop single conductor complex conductor system inductance system 數 calculation use 參數

Table 7 Single-loop complex conductor system arrangement and cable spacing

<<Inductance system calculation method of double loop system>>

The calculation of the double loop system is based on the fifteenth figure. In the figure, D _RS , D _ST , D _RT , D _RU , D _RV , D _RW , D _SU , D _SV , D _SW , D _TU , D _TV , D _TW Representing the distance between the six conductors, I _R , I _S , I _T , I _U , I _V , I _W are the load currents of the three-phase cable respectively. The calculation method of the cable mutual inductance system of each loop system is as described above. The inductance values of the respective loops are arranged in Table 8, and the distance between the conductors is summarized in Tables 9 to 10.

Table 8 Double loop system inductance system 數 calculation use 參數

Table 9 Double loop system arrangement and cable spacing

Table 10 Double loop system arrangement and cable spacing (continued)

<<Cables of the four-loop system for the calculation of the inductive reactance>>

Figure 16 is a schematic diagram of a four-circuit system, where D _RS , D _ST , and D _RT are the distances between the three phase conductors of the R phase, the S phase, and the T phase, respectively, and D _RU , D _RV , D _RW , D _RA , D _RB , D _RC , D _RX , D _RY , D _RZ , D _SU , D _SV , D _SW , D _SA , D _SB , D _SC , D _SX , D _SY , D _SZ , D _TU , D _TV , D _TW , D _TA , D _TB , D _TC , D _TX , D _TY and D _TZ are the distances between the three conductors of the R phase, the S phase and the T phase and the other return conductors, respectively, and the inductance of the four loop system is The spacing from the conductors is organized in Table XI and Tables 12 to 14.

Table 11 four-circuit system inductance system 數 calculation use 參數

Table 12 four-line system arrangement and cable spacing -1

Table 13 Four-loop system arrangement and cable spacing-2

Table 14 Four-loop system arrangement and cable spacing -3

<induced voltage>

The invention takes the staggered grounding system of the twelfth figure as an example, and derives the calculation formula of the induced voltage of different return turns.

<<Induction voltage calculation method of single loop system>>

The single-circuit system induced voltage is generated by three-phase load current induction. As shown in Figure 17, M ₁ , M ₂ , M ₃ and M ₄ represent the manhole number, I _R , I _S and I _T are respectively The load current of the three-phase cable, , and It represents the length of each section, and the induced voltage is divided into three sections. The calculation formula is as follows:

The induced voltage generated by the first segment M ₁ to M ₂ manhole interval:

..........(9)

The induced voltage generated by the second section M ₂ to M ₃ manhole interval:

.........(10)

The induced voltage generated by the third segment M ₃ to M ₄ manhole interval:

.........(11)

Where E _R1R2 , E _S1S2 , and E _T1T2 are intervals The three-phase induction _{voltage, E R2R3, E S2S3, E} T2T3 sections respectively The three-phase induced voltage, E _R3R4 , E _S3S4 , E _T3T4 are intervals The three-phase induced voltage, k _L is a self-coupling correction system, k _M is a mutual coupling correction system, L _RR , L _SS and L _TT represent a three-phase self-coupling inductance system; M _RS , M _ST and M _RT Represents an inductive system in which three phases are coated with each other. As for the calculation method of the inductance system, please refer to Table 4.

<<Induction voltage calculation method for single-loop complex conductor system>>

The induced voltage of the single-loop complex conductor system is generated by three-phase load current induction. As shown in Figure 18, the induced voltage can be divided into three sections. The calculation formula is as follows:

The induced voltage generated by the first segment M ₁ to M ₂ manhole interval is:

..........(12)

The induced voltage generated by the second section M ₂ to M ₃ manhole section is:

..........(13)

The induced voltage generated by the third segment M ₃ to M ₄ manhole interval is:

..........(14)

Where E _R1R2 , E _S1S2 , and E _T1T2 are intervals The three-phase induction _{voltage, E R2R3, E S2S3, E} T2T3 sections respectively The three-phase induced voltage, E _R3R4 , E _S3S4 , E _T3T4 are intervals The three-phase induced voltage, k _L is a self-coupling correction system, k _M is a mutual coupling correction system, L _RR , L _SS and L _TT represent a three-phase self-coupling inductance system; M _RS , M _ST and M _RT Represents an inductive system in which three phases are coated with each other. The calculation method of the inductance system can be referred to Table 6.

<<Induction voltage calculation method of double loop system>>

The double-circuit system is shown in Figure 19. The induced voltage of the system can also be calculated by using the mutual inductance and self-inductance with the three-phase load current. The calculation formula is as follows:

The induced voltage generated by the first segment M ₁ to M ₂ manhole interval is:

..........(15)

The induced voltage generated by the second section M ₂ to M ₃ manhole section is:

..........(16)

The induced voltage generated by the third segment M ₃ to M ₄ manhole interval is:

..........(17)

Where E _R1R2 , E _S1S2 , and E _T1T2 are intervals Within the three-phase induction _{voltage, E R2R3, E S2S3, E} T2T3 sections respectively The three-phase induced voltage inside, E _R3R4 , E _S3S4 , E _T3T4 are intervals The three-phase induced voltage, k _L is the self-coupling correction system, k _M is the mutual coupling correction system, L _RR , L _SS and L _TT represent the three-phase self-coupling inductance system; M _RS , M _ST and M _RT Represents an inductive system in which three phases are coated with each other. The calculation method of the inductance system can be referred to Table 8.

<<Induction voltage calculation method of four loop system>>

Figure 20 shows the staggered grounding diagram of the four-circuit system. It can be seen from the figure that the mutual inductance on the four return lines will affect the induced voltage, and the calculation formula is as follows:

The induced voltage generated by the first segment M ₁ to M ₂ manhole interval is:

..........(18)

The induced voltage generated by the second section M ₂ to M ₃ manhole section is:

........(19)

The induced voltage generated by the third segment M ₃ to M ₄ manhole interval is:

.........(20)

Where E _R1R2 , E _S1S2 , and E _T1T2 are intervals The three-phase induction _{voltage, E R2R3, E S2S3, E} T2T3 sections respectively The three-phase induced voltage, E _R3R4 , E _S3S4 , E _T3T4 are intervals The three-phase induced voltage, k _L is the self-coupling correction system, k _M is the mutual coupling correction system, L _RR , L _SS and L _TT represent the three-phase self-coupling inductance system; M _RS , M _ST and M _RT represent The three-phase is covered by an inductive system that senses each other. The calculation method of the inductance system can be referred to Table 11.

<covered circulating current>

The coated circulating current can be calculated by the relationship between the cable induced voltage and the covered impedance, and the calculation method adopted by the present invention simplifies the circuit of the twelfth figure, as shown in FIG.

In the twenty-first figure, R _e1 and R _e2 are grounding electric groups, R ₁ and R ₄ are grounding point splicing resistors, R ₂ and R ₃ are splicing splicing resistors, and the splicing resistance of the grounding point of the present invention is connected to the splicing resistor The splicing resistors are added together and collectively referred to as the splicing resistor R , ie .

In the twenty-first figure, E _R1R2 , E _S1S2 , and E _T1T2 are intervals respectively Induced voltage caused by the load _{current, E R2R3, E S2S3, E} T2T3 sections respectively The induced voltage caused by the load current, E _R3R4 , E _S3S4 , E _T3T4 are intervals The induced voltage caused by the load current.

Covering each of the R-phase induced voltage E of the first section of _R1R2, E _S3S4 E _T2T3 section of a second, and a third section consisting of, i.e., R-phase of the induced voltages E _R can be expressed as follows:

.............................................(twenty one)

S phase voltages are induced by a coating of a first section of the E _S1S2, E _T3T4 E _R2R3 section of a second, and a third section consisting of, i.e. R E _S phase of the induced voltage can be expressed as follows:

.............................................(twenty two)

The induced induced voltage of the R phase is composed of E _T1T2 of the first segment, E _{S2S3 of the} second segment, and E _{R3R4 of} the third segment, that is, the induced voltage E _{T of the} R phase can be expressed as follows:

.............................................(twenty three)

In the twenty-first figure, Z ₁ , Z ₂ and Z ₃ represent intervals respectively. , , The coverage impedance is calculated as follows.

Coverage impedance produced by the first section of M ₁ to M ₂ manhole cable:

.................................................. (twenty four)

The coating impedance produced by the second section of the M ₂ to M ₃ manhole cable:

.................................................. (25)

Coverage impedance produced by the third section of the M ₃ to M ₄ manhole cable:

.................................................. (26)

Where R _S represents the shielding layer covering resistance, and its value varies depending on the cable transmission level and cable specifications, as shown in Tables 1 to 3. X _S stands for the shielding layer's inductive reactance, which is due to the different cable spacings in the arrangement. The calculation formula is as follows:

.....................................(27)

Where r _s is the average radius of the shielded copper wire of the cable, and its depreciation can be referred to Tables 1 to 3, and D _RS , D _ST and D _RT respectively represent the distance between the three-phase conductors.

In the cable arrangement method used in the present invention, the method for covering the inductive reactance can be divided into four turns, and the first one is a right-angled arrangement type, and the shielding layer is covered by the inductive resistance calculation formula and the right-angled type is arranged in Table 10. The fifth one is the positive triangle arrangement, the arrangement of the shadow layer and the other positive triangles are listed in Table 16; the third is the three-phase parallel type, the shielding layer The arrangement of the covered inductive reactance formula and the remaining three-phase parallel type is detailed in Table 17; the fourth is the isosceles triangular shape, and the shielding layer of the 類 type is covered by the inductive calculation formula and the arrangement of the remaining isosceles triangles. It is detailed in Table 18.

Table 15: Right-angled 類 type and its shielding layer coating inductive reactance calculation

Table 16: Positive triangle arrangement 類 type and its shielding layer coating inductive reactance calculation

Table 17: Three-phase parallel 類 type and its shielding layer

Table 18: Isosceles triangle arrangement 類 type and its shielding layer coating inductive reactance calculation

The simplified circuit of the equivalent circuit is covered by the cable of the twenty-first figure. The circuit analysis method of the circuit can be used to solve the current branches in the circuit. The equations of each mesh are as follows:

...................................(28)

The relationship between the three-phase covered circulating current and each mesh current is:

.................................................. .............(29)

Therefore, from the above six formulas, the coated circulating current can be obtained as follows:

.........................(30)

.........................(31)

........................(32)

The graphical human-machine interface of the present invention is further described below. The graphical human-machine interface of the present invention displays a window on a display screen, and the window includes: a calculation parameter input area (1) and a cable arrangement setting area (2). ) and the calculation result display area (3) (as shown in the twenty-second figure).

Please also refer to the twenty-third figure. The calculation parameter input area (1) includes load current parameter input 埠 (11), cable type parameter input 埠 (12), resistance parameter setting input 埠 (13), coupling coefficient correction input 埠 (14), start calculation button ( 15) and the end program button (16), the load current parameter input 埠 (11), cable type parameter input 埠 (12), resistance parameter setting input 埠 (13) and coupling coefficient correction input 埠 (14) are for use. Enter the load current, cable type, length and resistance of the cable, and the parameters of the self-inductance and mutual inductance coupling correction coefficient. Start the calculation button (15) and the end program button (16) to control the parameter calculation timing and the end of the interface respectively. Service timing; due to different load currents, cable type, length and resistance will affect the calculation results of induced voltage and circulating current, so the user must calculate according to the actual cable structure input parameters.

Figure 24 shows the interface diagram of the load current parameter input 埠(11), which includes four return input fields (111). The four return input fields (111) are RST, UVW, ABC and XYZ, for a total of 12 The fields that can be input, and the currents of all fields are in amps. The initial preset value is 0. If the underground cable structure to be calculated by the user is a single loop, only the RST return current must be input. The current field input of the remaining three loops remains at 0; in the case of the two loop structure, the current of the RST and UVW loops must be input, and for the four loop structure, all fields must be input.

The twenty-fifth figure shows the interface diagram of the cable type parameter input 埠 (12). Since different cable types will affect the induced voltage, the user must understand the actual cable type and use the pull-down menu to select . In the cable type parameter input 埠(12) of the present invention, there are seven common cable types and specification menus for the user to select: oil-filled cable 161kV 3000MCM menu (121) and oil-filled cable 161kV 4000MCM menu ( 122) and XLPE cable 69kV 500mm ² menu (123), XLPE cable 69kV 1000mm ² menu (124), XLPE cable 69kV 1600mm ² menu (125), XLPE cable 161kV 1600mm ² menu (126) and XLPE cable 161kV 2000mm ² menu (127), and cable type parameter input 埠 (12) The preset cable type is 161kV 3000MCM for oil-filled cable. When the cable type is selected, the cable will be automatically displayed under each menu. Rated operating current; if the user finds that the line cable specification to be calculated is not in the above menu, you can select the "Other (self-input cable parameter)" menu (128) and enter the cable parameters yourself. The cable parameters include Cable coating average radius (mm), shielding layer coating resistance (ohm / km), as shown in Figure 26.

Figure 27 is a schematic diagram of the interface of the resistance parameter setting input 埠 (13), which includes a grounding resistance input field (131), a ground resistivity input field (132), and a connection resistance input field (133); The grounding resistance is the _{e e1} and R _e2 in the equivalent circuit diagram of the cable covering in the twelfth figure (b). The value is recommended to be 5-15. , the program default value is 10 And the earth resistivity is used to calculate the skin depth of the cable grounding circuit. This value will vary due to different soil environments. The value is recommended to be set to 10~350 (Ω‧m), and the program preset value is 250. (Ω‧m); Finally, the wire connection resistance value is generated by the grounding of both ends of the cable and the connection of the cable covering protection device. Generally, the value is recommended to be set from 0.0001 to 0.01. The connection resistance input field (133) has three fields of R phase, S phase and T phase, and the preset three fields have a value of 0.0012. .

The coupling coefficient correction input 埠(14) includes a self-inductance coupling coefficient correction field (141) and a mutual inductance coupling coefficient correction field (142), and the calculation of the self-inductance system is affected by the average radius of the cable shielding copper wire and the cable material, so when the cable When the line is aged due to long-term operation, and the structure and characteristics of the junction are changed, the calculation accuracy of the self-inductance value will be affected. Therefore, the system is introduced into the system for correction, so as to remove the calculation error caused by the phenomenon; mutual inductance The calculation is mainly affected by the enthalpy factors, which are the conductor spacing and the environment where the cable is located, that is, the calculation of the value is susceptible to the cable conductor arrangement and terrain structure change, and the impact is difficult to be evaluated and analyzed in the actual line test. Only by calculating the data obtained from the cable structure measurement, an error may occur, so the present invention introduces a mutual inductance coupling correction system and corrects the error caused by the phenomenon.

Please refer to the twenty-eighth figure below. The cable arrangement setting area (2) is a parameter for the user to input the arrangement, the distance setting and the length setting of the cable; and includes a first input 埠 (21), a second input 埠 (22) and a third input.埠(23) and other three sections are set, and each section has three sections. As shown in the twenty-ninth figure, the selection fields (211), (221), and (231) are respectively arranged. , spacing setting fields (212), (222), (232) and length setting fields (213), (223), (233); wherein, the arrangement selection fields (211), (221), (231 The selection is based on the "New Underground Transmission Line Management Buried Depth and Configuration Design Guidelines" compiled by the Taiwan Power Company. The program developed by the present invention has 26 different arrangements to choose from. Arrangement, each segment is arranged in a right-angled RST format, and the first segment input 埠 (21), the second segment input 埠 (22) and the third segment input 埠 (23) further comprise an arrangement schematic field respectively (214), (224), (234), after the user selects the cable arrangement in the arrangement selection fields (211), (221), (231) The layout diagrams (214), (224), and (234) correspondingly display the pattern of the selected cable arrangement; the spacing setting fields (212), (222), and (232) are separated by cables. The distance is the distance D between the arrangement diagrams, the unit is mm, the program presets each section is 310mm; the length setting fields (213), (223), (233) need to input the cable of each section. The length is in kilometers and the program is preset to 0.25km.

Please refer to the thirty-first figure together. The calculation result display area (3) is divided into five display blocks, including a drawing block (31), an induced voltage block (32), a circulating current block (33), a three-phase circulating current, and a block (34). ) and covered impedance block (35). It is used to display the relevant data results obtained after calculation based on the relevant parameters input by the user.

The drawing block (31) is mainly used to display the drawing of various calculation results. The program can draw three kinds of graphics, which are the induced voltage distribution map (refer to the 31st map) and the induced voltage phasor diagram (see the third Figure 12) and the circulating current phasor diagram (refer to Figure 33); wherein the drawing block (31) includes a graphics window (311), a drawing menu (312), a storage menu (313), and a storage name field. (314), selecting a graphic to be drawn (such as an induced voltage distribution map, an induced voltage phasor diagram, or a circulating current phasor diagram) through a pull-down drawing menu (312), and is determined by the user via the storage menu (313). Whether to save the drawn graphic, the user inputs the storage name in the storage name field (314) during storage.

Figure 31 shows a graph showing the distribution of the induced induced voltage in the graph window (311) for displaying the trend of the induced induced voltage. The horizontal axis in the figure is the cable length in km, which is The grounding end of a section of cable is 0km, and the vertical axis is the magnitude of the induced voltage in volts. After each calculation, three induced voltage distribution curves are drawn, which represent R phase, S phase and T phase respectively. The induced voltage changes.

Figure 32 shows the induced voltage phasor diagram in the graph window (311). The horizontal axis of the graph represents the real part of the induced voltage, and the vertical axis represents the imaginary part, which is calculated due to the induced voltage in the staggered grounding model. It is divided into three segments, and the terminal induced voltage generated by each phase will be the phasor sum of the three-stage induced voltage. In this figure, the thinner dotted line is the induced voltage phasor generated by each segment, and the thicker phase The amount is the sum of the voltage phasors induced by each segment, that is, the terminal induced voltage of each phase. Using this graph, the relative relationship between the induced voltages of the phases can be observed.

Figure 33 shows the phasor diagram of the three-phase covered circulating current in the graphical window (311). This phasor diagram is similar to the induced voltage phasor diagram, but the calculation of the circulating current is only related to the terminal induced voltage of each phase. Relatedly, the circulating current of each phase has no segmental phasor and only has a single phasor.

The induced voltage block (32) is mainly divided into a terminal induced voltage field (321) and a maximum induced voltage field (322), and the induced voltage of each phase simultaneously displays the size and the phase angle, the former unit is volt, and the latter unit is watt. The terminal induced voltage is the induced voltage at the end of the cable, and the maximum induced voltage is the maximum voltage induced by the phase cable, and the voltage is only displayed in numerical value, as shown in Figure 34.

The circulating current block (33) is quite similar to the induced voltage block (32), and also includes a circulating current field (331) showing the magnitude of the circulating current and the phase angle, but the circulating current has no maximum value and the terminal value, such as Figure 35 shows.

Figure 36 shows the three-phase circulating current and block (34) and the covered impedance block (35). The three-phase circulating current and block (34) include the display circulating current and size field (341) and phase. The angle field (342) is the final circulating current value; the coated impedance block (35) shows the impedance of the cable coating self-inductance, internal resistance and connection resistance, including the impedance field (351) and The phase angle field (352), the impedance field (351) size value is in ohms, and the phase angle field (352) phase angle value is in degrees.

Please refer to the thirty-seventh figure for the flow of the steps of the present invention, including:

Step 1: Select the cable type

Enter the oil-filled cable in the 埠(12) through the cable type parameter 161kV 3000MCM menu (121), oil-filled cable 161kV 4000MCM menu (122), XLPE cable 69kV 500mm ² menu (123), XLPE cable 69kV 1000mm ² menu (124), XLPE cable 69kV 1600mm ² menu (125), XLPE cable 161kV 1600mm ² menu (126) and XLPE cable 161kV 2000mm ² menu (127) select the cable type used, or select "other (Enter the cable parameters yourself) menu (128) Enter the cable parameters used by yourself.

Step 2: Determine the cable arrangement, spacing and length of each segment

The selection field (211) is provided by the arrangement of the first segment input 埠 (21), the second segment input 埠 (22) and the third segment input 埠 (23) of the cable arrangement setting area (2), ( 221), (231), spacing setting fields (212), (222), (232) and length setting fields (213), (223), (233) for each segment of the cable arrangement, spacing and The length of each segment is set; at the same time, when the user selects the cable arrangement mode in the arrangement selection fields (211), (221), (231), the layout mode fields (214), (224), (234) The picture corresponding to the arrangement of the selected cables will be displayed.

Step 3: Input load current

The load current parameter is input through the four return input fields (111) of the load current parameter input 埠(11)--RST, UVW, ABC and XYZ; the required input is determined by the segments set in step two. The arrangement of the ruins determines that if there is no arrangement above the 兩 return line in the three-segment cable arrangement, only the current clamp of RST must be input; and if the highest return line 三 is arranged in the 兩 return line arrangement, only the three-segment cable is arranged. It is necessary to input the load current clamps of RST and UVW. In this case, if the highest return line is arranged in a four-line arrangement, all load current clamps must be input with a threshold value; that is, if the user wants to calculate the underground cable If the structure is a single loop, only the RST loop current needs to be input, and the current field inputs of the remaining three loops remain at 0; similarly, in the case of the two loop structures, the current of the RST and UVW loops must be input, and if it is a four-loop structure , all fields must be entered.

Step 4: Start calculating and observing the calculation results

After the above setting steps are completed, the calculation can be performed by pressing the start calculation button (15), and the result of the calculation will be displayed through the calculation result display area (3), and the calculation result display area (3) is divided into five display blocks. The method includes a drawing block (31), an induced voltage block (32), a circulating current block (33), a three-phase circulating current and a block (34), and a covered impedance block (35). The drawing block (31) is mainly used to display the induced voltage distribution map (see Figure 31), the induced voltage phasor diagram (see Figure 32), and the circulating current phasor diagram (see Figure 33). The induced voltage block (32) is mainly divided into a terminal induced voltage field (321) and a maximum induced voltage field (322), and the induced voltage of each phase simultaneously displays the size and phase angle; the circulating current block (33) includes A circulating current field (331) showing the magnitude and phase angle of the circulating current; the three-phase circulating current and the block (34) include a size field (341) and a phase angle field (342) indicating the sum of the circulating currents, that is, The final circulating current value; the coated impedance block (35) is the impedance generated by the cable coating self-inductance, internal resistance and connection resistance, including the impedance field (351) and the phase angle field (352).

When the calculation result approximates the measured 數 value, the display program can correctly evaluate the induced voltage of the cable without any correction step. At this time, the input system can be stored and recorded, and then the underground line is subjected to the maintenance test. , the system can be applied to calculate the induced voltage and the circulating current; if the calculated result is very different from the measured value, then step 5 is continued;

Step 5: Correct the calculation parameters

When there is a difference between the calculated result and the measured one, it may be that the inductive coupling situation of the calculation is different from the actual situation, or the grounding resistance and the connection resistance are affected. At this time, the grounding resistance input field in the input 埠(13) is set by the resistance parameter. (131), earth resistivity input field (132) and connection resistance input field (133), and self-inductance coupling coefficient correction field (141) of coupling coefficient correction input 埠 (14), mutual inductance coupling coefficient correction field (142) Re-enter each correction factor for correction, and set and adjust according to the recommended values on the interface. After setting, click the start calculation button (15) and return to step 4 to recalculate.

Finally, if the user wants to save the graphic drawn by the program in the graphic window (311), select "Yes" in the save menu (313) and enter the file in the storage name field (314). The name, such as the thirty-eighth figure, is followed by pressing the start calculation button (15) to save the drawing as a JPEG image file.

The above is only a part of the embodiments of the present invention, and is not intended to limit the present invention. It is intended to be included in the scope of the present invention.

In summary, the embodiments of the present invention can achieve the expected use efficiency, and the specific technical means disclosed therein have not been seen in similar products, nor have they been disclosed before the application, and have completely complied with the patent law. The regulations and requirements, the application for invention patents in accordance with the law, and the application for review, and the grant of patents, are truly sensible.

(1) ‧‧‧ Calculation parameter input area

(11)‧‧‧Load current parameter input埠

(111) ‧‧‧ four return input fields

(12)‧‧‧ Cable type parameter input埠

(13)‧‧‧Resistance parameter setting input埠

(131)‧‧‧ Grounding resistance input field

(132)‧‧‧ Earth Resistivity Input Field

(133)‧‧‧Connected resistance input field

(14)‧‧‧Coupling coefficient correction input埠

(141)‧‧‧Self-inductive coupling coefficient correction field

(142) ‧‧‧ Mutual Coupling Coefficient Correction Field

(15) ‧‧‧Start calculation button

(16) ‧‧‧End program button

(2) ‧‧‧ Cable arrangement area

(211), (221), (231) ‧‧‧Arrangement selection field

(212), (222), (232) ‧‧‧ spacing setting field

(213), (223), (233) ‧‧‧ Length setting field

(214), (224), (234) ‧ ‧ Layout diagrams

(21)‧‧‧First paragraph input埠

(22)‧‧‧Second paragraph input埠

(23) ‧ ‧ third paragraph input 埠

(3) ‧‧‧ Calculation result display area

(31)‧‧‧Drawing blocks

(311)‧‧‧Graphic window

(312)‧‧‧ Drawing menu

(313)‧‧‧Storage menu

(314) ‧‧‧Storage Name Field

(32)‧‧‧Induced voltage block

(321)‧‧‧ Terminal induced voltage field

(322)‧‧‧Maximum induced voltage field

(33) ‧ ‧ Circulating current block

(331)‧‧‧Circular current field

(34)‧‧‧Three-phase circulating current and block

(341)‧‧‧Circular current and size fields

(342)‧‧‧Circular current and phase angle fields

(35) ‧‧‧covered impedance block

(351)‧‧‧ Impedance field

(352)‧‧‧ phase angle field

The first picture: the cable routing mode of the single-loop system; (a) single-line triangle arrangement; (b) single-line parallel angle arrangement; (c) single-loop three-phase parallel; (d) single-loop complex conductor normal phase sequence; (e) Single-loop complex conductor reverse phase sequence

The second figure: the cable layout mode of the double loop system; (a) the normal sequence of the double loops; (b) the reverse phase sequence of the double loops; (c) the double loops arranged at right angles

The third figure: the cable layout mode of the four-loop system; (a) four-line 2 tube bottom arrangement; (b) four-line line 5 tube bottom arrangement; (c) four-line line 8 tube bottom arrangement; (d) four-line square shape Arrangement 1; (e) four-line square arrangement 2

Figure 4: Single-ended grounding of the cable

Figure 5: Schematic diagram of the induced voltage distribution of the single-ended grounding coating of the cable

Figure 6: Schematic diagram of single-ended grounding of long-distance 離 cable; Y stands for ordinary connection Z, Z stands for insulation connection 匣

Figure 7: Schematic diagram of direct cable grounding; Y stands for normal connection, I represents circulating current

Figure 8: Schematic diagram of the induced voltage distribution of the direct grounding coating of the cable

Figure IX: Schematic diagram of cable staggered grounding; Y stands for normal connection, Z stands for insulation connection匣

Figure 10: Schematic diagram of the induced voltage distribution of the cable staggered grounding coating

Figure 11: Schematic diagram of cable protection device with staggered grounding; XB stands for cable covering protection device

Twelfth figure: (a) schematic diagram of cable staggered ground transposition; (b) cable covered equivalent circuit diagram

Figure 13: Schematic diagram of the distance between the three-phase conductors of a single loop system and the load current

Figure 14: Schematic diagram of the distance between the three-phase conductor of the single-circuit complex conductor system and the load current

Figure 15: Schematic diagram of the distance between the three-phase conductors of the double-circuit system and the load current

Figure 16: Schematic diagram of the distance between the three-phase conductor of the four-circuit system and the load current

Figure 17: Schematic diagram of the staggered grounding of the single loop system of the present invention

Figure 18: Schematic diagram of the staggered grounding of the single-circuit complex conductor system of the present invention

Figure 19: Schematic diagram of staggered grounding of the double loop system of the present invention

Figure 20: Schematic diagram of staggered grounding of the four-circuit system of the present invention

Twenty-first diagram: (a) an equivalent circuit diagram of the cable coating of the present invention; (b) a simplified diagram of the equivalent circuit of the cable coating of the present invention

Figure 22: Schematic diagram of the graphical human-machine interface of the present invention

Twenty-third figure: Schematic diagram of the calculation parameter input area of the graphical human-machine interface of the present invention

Figure 24: Enlarged schematic diagram of load current parameter input 图形 of the graphical human-machine interface of the present invention

Figure 25: Enlarged schematic diagram of cable type parameter input 图形 of the graphical human-machine interface of the present invention (1)

Figure 26: Enlarged schematic diagram of cable type parameter input 图形 of the graphical human-machine interface of the present invention (2)

Twenty-seventh drawing: an enlarged view of the resistance parameter setting input port of the graphical human-machine interface of the present invention

Figure 28: Schematic diagram of the cable arrangement setting area of the graphical human-machine interface of the present invention

Twenty-ninth drawing: enlarged schematic view of the cable arrangement setting area of the graphical human-machine interface of the present invention

Thirty-fifth: Schematic diagram of the calculation result display area of the graphical human-machine interface of the present invention

Figure 31: An enlarged view showing the distribution of induced voltages in the drawing block of the graphical human-machine interface of the present invention

Figure 32: An enlarged view showing the phasor of the induced voltage in the drawing block of the graphical human-machine interface of the present invention

Thirty-third figure: an enlarged view showing the phasor of the circulating current in the drawing block of the graphical human-machine interface of the present invention

Figure 34: An enlarged view of the induced voltage block of the graphical human-machine interface of the present invention in the display calculation result

The thirty-fifth figure: an enlarged view of the calculation result of the circulating current block of the graphical human-machine interface of the present invention

Figure 36: A schematic diagram of the graphical human-machine interface of the present invention showing the calculation results of the three-phase circulating current and the coated impedance

Figure 37: Flow chart of the steps of the method for calculating the overlying induced voltage and circulating current of the transmission and distribution lines of the present invention

The thirty-eighth figure: an enlarged schematic diagram of the graphical human-machine interface of the present invention in the display storage calculation result

Claims (10)

A graphical human-machine interface for calculating a coating induced voltage and a circulating current of a transmission and distribution line includes a display screen, the display screen displaying a window, the window including a calculation parameter input area and a cable arrangement setting And a calculation result display area; wherein: the calculation parameter input area is a parameter related to a load current, a cable type, a resistance and an inductive coupling coefficient of the user input cable; the cable arrangement setting area is provided for the user Input parameter arrangement, spacing setting and length setting parameters; the calculation result display area displays the result obtained by calculating the relevant parameters input by the user, including drawing the induced voltage distribution map and the induced voltage vector diagram a drawing block of the circulating current vector diagram, an induced voltage block showing the magnitude of the induced voltage and the maximum induced voltage of the terminal and the phase angle, a circulating current block showing the magnitude of the circulating current and the phase angle, and a three-phase circulating current and Three-phase circulating current and block of size and phase angle and display of the covered impedance block. The graphical human-machine interface according to claim 1, wherein the calculation parameter input area comprises a load current parameter input port, a cable type parameter input port, a resistance parameter setting input port, a coupling coefficient correction input port, Start the calculation button and the end program button. The graphical human-machine interface according to claim 2, wherein the load current parameter input port comprises four return input fields, and the four return input fields are RST, UVW, ABC and XYZ, for a total of 12 Fields that can be entered. The graphical human-machine interface according to claim 2, wherein the cable type parameter input includes an oil-filled cable 161kV 3000MCM menu, an oil-filled cable 161kV 4000MCM menu, and an XLPE cable 69kV 500mm ² menu. XLPE cable 69kV 1000mm ² menu, XLPE cable 69kV 1600mm ² menu, XLPE cable 161kV 1600mm ² menu and XLPE cable 161kV 2000mm ² menu, each menu has built-in cable for the corresponding menu. The graphical human-machine interface according to claim 2, wherein the cable type parameter input port further includes an other (self-input cable parameter) menu for the user to input the cable parameter. The cable parameters include the average radius of the cable coating (mm) and the shielding layer coating resistance (ohm/km). The graphical human-machine interface according to claim 2, wherein the resistance parameter setting input includes a ground resistance input field, a ground resistivity input field, and a connection resistance input field, and the connection resistance The input fields have three fields of R phase, S phase and T phase. The graphical human-machine interface according to claim 2, wherein the coupling coefficient correction input includes a self-inductance coupling coefficient correction field and a mutual inductance coupling coefficient correction field. The graphical human-machine interface of claim 1, wherein the cable arrangement setting area comprises a first input port, a second input port, and a third segment input port, and each segment is There are three parts, which are an arrangement selection field, a spacing setting field and a length setting field; the first segment input port, the second segment input port and the third segment input port are further respectively separated Include an arrangement schematic field for displaying a pattern of the selected cable arrangement in the arrangement schematic field after the user selects the cable arrangement in the arrangement selection field; The spacing setting field is the distance between the cables; the length setting field needs to input the length of each cable. The graphical human-machine interface according to claim 1, wherein the calculation result display area comprises a drawing block, an induced voltage block, a circulating current block, a three-phase circulating current and a block, and a covered impedance region. The drawing block may draw an induced voltage distribution map, an induced voltage phasor diagram, and a circulating current phasor diagram; the drawing block includes a graphics window, a drawing menu, a storage menu, and a storage name field, through a pull-down type The drawing menu selects a graphic to be drawn, and the user determines, by the storage menu, whether to save the drawn graphic, and the storage name is input by the user in the storage name field during storage; The induced voltage block includes a terminal induced voltage field and a maximum induced voltage field, and the induced voltage of each phase simultaneously displays the size and the phase angle; the circulating current block includes a circulating current bar that displays the magnitude and phase angle of the circulating current. The three-phase circulating current and the block include a size field and a phase angle field indicating a sum of the final three-phase circulating current; the covered impedance block display The impedance of the cable coating self-inductance, internal resistance and connection resistance, including impedance field and phase angle field. A method for calculating a coating induced voltage and a circulating current of a transmission and distribution line, comprising the following steps: Step 1: selecting a cable type; Step 2: determining a cable arrangement, a spacing, and lengths of the segments; Step 3: inputting a load Current; Step 4: Start calculation and observe the calculation result; when the calculation result approximates the measured value, it means that the program can correctly evaluate the induced voltage of the cable. At this time, the input system can be stored and recorded. When the underground line is in maintenance test, the system can be used to calculate the induced voltage and circulating current; if the difference between the calculated result and the measured value is very large, then proceed to step 5; Step 5: Correct the calculation parameters; Correct the grounding resistance, earth resistivity and connection The input value of the resistor, as well as the inductance self-inductance coupling coefficient and the inductance mutual inductance coupling coefficient, are then recalculated in step 4.