Rapid and automatic phase checking method for high and low voltage cables

Abstract

The invention relates to a high and low voltage cable rapid automatic phase checking method, which comprises the following steps that: host equipment simultaneously applies a voltage signal as an initial signal to a three-phase cable, slave equipment indicates that the slave equipment is synchronized with the host equipment after receiving the initial signal, and then the host equipment applies a high voltage to an A phase of the three-phase cable and applies a low voltage to a B phase and a C phase of the three-phase cable; the slave equipment receives the high-voltage signal, judges the high-voltage signal, marks the cable receiving the high-voltage signal as an A-phase sequence and displays the A-phase sequence; the host equipment applies high voltage to the B phase of the three-phase cable and applies low voltage to the A phase and the C phase of the three-phase cable, and the slave equipment receives a high voltage signal for judgment, marks the cable receiving the high voltage signal as a B phase sequence and displays the B phase sequence; the host device applies high voltage to the C phase of the three-phase cable and applies low voltage to the A phase and the B phase of the three-phase cable, and the slave device receives a high voltage signal for judgment, marks the cable receiving the high voltage signal as a C phase sequence and displays the C phase sequence. According to the invention, the phase checking of the cable can be rapidly, effectively and accurately realized.

Description

Technical Field

[0001] The invention relates to the technical field of power debugging and power testing, in particular to a fast automatic phase checking method for high and low voltage cables. Background Art

[0002] With the continuous improvement of my country's comprehensive national strength, the further acceleration of urbanization, and the continuous improvement of infrastructure construction, electricity is increasingly used in people's daily lives, and the proportion of high-voltage cable lines in power transmission lines is increasing. Whether in the main grid substation or the distribution network line, before the cable terminal head is made and connected, or when the cable intermediate joint is made, connected to the ring network cabinet, branch box or tower, and before the cable construction is completed and the power is delivered to the user, the cable phase sequence must be checked. This is very important for the later operation of the cable, so as to avoid short circuits caused by inconsistent phase sequence after being put into operation, damage to equipment, and accidents. At present, after the cable is laid, when the two ends of A, B, and C are checked, the megohmmeter is mainly used to check the phase sequence. At one end of the cable, the A, B, and C phases are calibrated and the shielding wire is grounded. At the other end, a short-circuit wire is used to short-circuit one phase conductor with the shielding wire, and the other two phases are open. At this time, the megohmmeter is used to boost the voltage of the three cables respectively. The phase that cannot be boosted is phase A. Repeat the remaining two phases, and then the A, B, and C phases can be checked. The traditional method uses a megohmmeter, which requires nine voltage boosts and replacement of short-circuit wires. Special personnel are required at both ends of the cable to coordinate, making the operation complicated and wasting human resources, resulting in low efficiency. Summary of the invention

[0003] To this end, the technical problem to be solved by the present invention is to overcome the problem in the prior art that when checking the phase sequence of a cable, the operation is complicated and manual cooperation is required at both ends, resulting in low efficiency.

[0004] In order to solve the above technical problems, the present invention provides a method for rapid automatic phase checking of high and low voltage cables, comprising:

[0005] The host device controls the voltage signal and applies the voltage signal to the A, B, and C phases of the three-phase cable respectively. The slave device receives the voltage signal transmitted by the three-phase cable and analyzes the timing to determine the phase sequence of the three-phase cable. Specifically:

[0006] When the host device simultaneously applies voltage signals to the three-phase cables as a start signal, the slave device receives the start signal, indicating that it has synchronized with the host device, and then executes the following steps in sequence:

[0007] The host device applies a high voltage to phase A of the three-phase cable and a low voltage to phases B and C. The slave device receives the high voltage signal for judgment and marks the cable that receives the high voltage signal as phase A and displays it;

[0008] The host device applies a high voltage to the B phase of the three-phase cable and a low voltage to the A and C phases. The slave device receives the high voltage signal for judgment and marks the cable that receives the high voltage signal as the B phase sequence and displays it;

[0009] The host device applies a high voltage to the C phase of the three-phase cable and a low voltage to the A and B phases. The slave device receives the high voltage signal for judgment and marks the cable that receives the high voltage signal as the C phase sequence and displays it;

[0010] The high voltage ranges from 9V to 12V, and the low voltage ranges from 0V to 1V.

[0011] In one embodiment of the present invention, the phase sequence of the three-phase cable of which the A, B and C phases have been determined is checked, specifically:

[0012] The host device applies low voltage to phase A of the three-phase cable, and applies low voltage to phases B and C. The slave device receives the low voltage signal and determines whether it is consistent with the previously marked phase A.

[0013] The host device applies a low voltage to the B phase of the three-phase cable, and applies a low voltage to the A and C phases. The slave device receives the low voltage signal and determines whether it is consistent with the previously marked B phase;

[0014] The host device applies a low voltage to the C phase of the three-phase cable, and applies a low voltage to the A and B phases. The slave device receives the low voltage signal and determines whether it is consistent with the previously marked C phase;

[0015] If the phase sequence check is consistent, the determination ends; if the phase sequence check is inconsistent, the phase sequence of the three-phase cable is re-determined.

[0016] In one embodiment of the present invention, the host device includes a first main control module, a first core phase module, and a first battery power supply module. The first main control module is connected to the first core phase module and the first battery power supply module, respectively. The first main control module is used to control the first core phase module to apply the voltage signal provided by the first battery power supply module to the A, B, and C phases of the three-phase cable, respectively.

[0017] In one embodiment of the present invention, the first core phase module is a MOS tube, and the first main control module adopts an STM32 series control chip.

[0018] In one embodiment of the present invention, the high voltage signal received by the slave device is corrected, and the formula is:

[0019] V out1 =V in -V f1 -V m ;

[0020] Among them, Vout1 Indicates the output high level voltage, V in Represents the input voltage of the first battery power module, V f1 represents the voltage drop of the first Schottky diode, which is located in the first battery power supply module; V m Indicates the voltage drop of MOS tube;

[0021] Where n is the ideal factor; V t is the thermal voltage, which is 25mV at room temperature; I is the current through the first Schottky diode, I S is the saturation current;

[0022] V m =I d ×R d , where I d is the current flowing through the MOS tube, R d is the on-resistance of the MOS tube.

[0023] In one embodiment of the present invention, the low voltage signal received by the slave device is corrected, and the formula is:

[0024] V out2 =V f2 ;

[0025] Among them, V out2 Indicates the output low level voltage, V f2 Indicates the clamping voltage of the second Schottky diode, which is located in the MOS tube;

[0026] Where n is the ideal factor; V t is the thermal voltage, which is 25mV at room temperature; I is the current through the second Schottky diode, I S is the saturation current.

[0027] In one embodiment of the present invention, the host device also includes a first display module, which is connected to the first main control module. The first display module includes a first display screen and a first indicator light. The first display screen is used to display the phases of the three-phase cable, and the first indicator light is used to emit lights of corresponding colors of A, B, and C.

[0028] In one embodiment of the present invention, the slave device includes a second main control module and a second phase checking module. The second main control module is connected to the second phase checking module. The second main control module is used to perform voltage timing analysis on the voltage signal collected by the second phase checking module to determine the cable phase.

[0029] In one embodiment of the present invention, the second core module is an ADC data acquisition chip, and the second main control module adopts an STM32 series control chip.

[0030] In one embodiment of the present invention, the slave device also includes a second display module, which is connected to the second main control module. The second display module includes a second display screen and a second indicator light. The second display screen is used to display the phases of the three-phase cable, and the second indicator light is used to emit lights of corresponding colors of A, B, and C.

[0031] The above technical solution of the present invention has the following advantages compared with the prior art:

[0032] The high and low voltage cable rapid automatic phase checking method of the present invention reduces the number of cable phase checking operators. Only one person is needed to complete the work during phase checking. Compared with the traditional method, at least two construction operators who cooperate with phase checking can be reduced, which can effectively save labor costs. The cable phase checking device has a simple structure, convenient and fast wiring, easy operation, and reduced manufacturing costs.

[0033] The present invention improves the accuracy and work efficiency of phase checking, and avoids the problem of inconsistent phase sequence at both ends of the cable caused by unclear communication and confirmation between workers at both ends of the cable when using communication equipment for communication in a noisy construction environment with poor signal. The present invention does not require an external power supply, is not affected by the construction area environment, has good stability in maintenance and construction operations, is simple and convenient to operate, improves construction efficiency, has high accuracy, high safety, and avoids the occurrence of equipment safety and quality accidents;

[0034] Since the high level value or low level value provided by the host device is often different from the high level value or low level value received by the slave device, in order to reduce this influence and reduce the misjudgment of the staff, the present invention optimizes the high level value and low level value received by the slave device;

[0035] The present invention can play an important role in the electrical construction, high-voltage cable head production and electrical test construction process, and provides an efficient and convenient method for cable phase core construction. The present invention is suitable for non-energized cable phase core, suitable for all high-voltage cable non-voltage phase core construction, and can be widely promoted and applied in the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0037] Figure 1 is a flow chart of a method for rapid automatic phase checking of high and low voltage cables in an embodiment of the present invention;

[0038] Figure 2Schematic diagram of correct phase color of the cable in the embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of incorrect phase color of a cable in an embodiment of the present invention;

[0040] Figure 4 Schematic diagram of the structure of the cable phase core device in an embodiment of the present invention;

[0041] Figure 5 It is a timing analysis diagram of the master and slave devices in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0043] Embodiment 1

[0044] Reference Figure 1 As shown, the present invention relates to a method for rapid automatic phase checking of high and low voltage cables, comprising: a host device controls the voltage signal provided by a power supply through a MOS tube, and applies the voltage signal to three-phase cables A, B, and C respectively; a slave device receives the voltage signal transmitted by the three-phase cable, and analyzes the timing to determine the phase sequence of the three-phase cable. Specifically, when the host device simultaneously applies a voltage signal to the three-phase cable as a start signal, after the slave receives the start signal, it indicates that it has synchronized with the host device and begins to record the voltage timing received thereafter. The host device applies a high voltage to phase A, and phases B and C are grounded. The slave device receives the voltage signal, and after analysis, marks the cable that receives the high voltage signal as phase sequence A and displays it and lights a yellow light. Similarly, high voltages are applied to phases B and C respectively, and the phase sequence of phases B and C is marked to complete the phase checking. Please refer to Figure 2 For the correct cable color, refer to Figure 3 , which indicates the cable has the wrong phase color.

[0045] The following is a detailed introduction to this embodiment:

[0046] This embodiment uses a cable phase checking device to implement a fast and automatic phase checking method for high and low voltage cables. The cable phase checking device can be found in Figure 4 , specifically including host devices and slave devices.

[0047] (1) The host device of this embodiment includes a first main control module, a first phase detection module, a first battery power supply module, a first display module, an audible and visual alarm module, four yellow, green, red and black terminal blocks and matching test lines. The first main control module is connected to the first phase detection module, the first battery power supply module, the first display module and the audible and visual alarm module respectively. The first main control module adopts the mainstream STM32 series control chip; the first phase check module adopts MOS tube, which is connected to the yellow, green, red and black ends of the cable through four yellow, green, red and black terminals; the first main control module is used to control the MOS tube to apply the voltage signal provided by the first battery power supply module to the A, B and C phases of the three-phase cable respectively, the first display module includes a first display screen and a first indicator light, the first display screen is used to display the phase difference of the three-phase cable, and the first indicator light is used to emit lights of corresponding colors of A, B and C (A, B and C phases correspond to yellow, green and red respectively), and the double display of cable phase difference can effectively deepen the interaction; after completing the cable phase check, the sound and light alarm module emits a "beep beep" sound to prompt that the phase check is completed, or emits different lengths of beep sounds to alarm that the phase check is wrong, and the first battery power supply module supplies power to the host device and outputs a voltage signal. The high voltage range is 9V-12V, and the low voltage range is 0V-1V.

[0048] (2) The slave device of this embodiment includes a second main control module, a second core phase module, a second battery power supply module, a second display module, four yellow, green, red and black terminals and matching test lines. The second main control module is connected to the second core phase module, the second battery power supply module and the second display module respectively. The second main control module adopts the mainstream STM32 series control chip; the second core phase module adopts a high-speed and high-precision ADC data acquisition chip (model ADS1256), the ADC data acquisition chip is connected to the black end of the cable through the black terminal, and the remaining three terminals (yellow, green and red terminals) are randomly connected to the yellow, green and red ends of the cable; the second display module includes a second display screen and a second indicator light, the second display screen is used to display the phase difference of the three-phase cable, and the second indicator light is used to emit lights of corresponding colors of A, B and C. The dual display of the cable phase difference can effectively deepen the interaction; the second main control module determines the cable phase difference by analyzing the voltage timing, and the second battery power supply module supplies power to the slave device.

[0049] The following is a detailed introduction to the cable phase core principle of this embodiment:

[0050] When checking the phase of the cable, the A, B, and C phase sequence is determined at one end, and the other end is used to check whether the three-phase sequence is consistent. In the cable phase checking device of this embodiment, the A, B, and C phase sequence is determined by default at the first end of the cable and connected to the host device (specifically connected to the MOS tube), and the slave device is connected at the end of the cable (specifically connected to the ADC data acquisition chip) to analyze and determine the phase sequence. Figure 4The host device is connected to the cable as shown. When in use, connect the yellow, green and red terminals of the host device to the A, B and C terminals of the cable, and connect the black terminal to the grounding copper braid of the copper shielding layer of the cable. At this time, the host device is connected.

[0051] Combination Figure 4 The connection between the slave device and the cable is shown as follows. When in use, connect the yellow, green and red terminals of the slave device to the three phases at the end of the cable at will, and connect the black terminal to the grounding copper braid of the copper shielding layer of the cable. At this time, the wiring of the slave device is completed.

[0052] See also Figure 5 , when the host device and the slave device are connected, the host device is turned on, the first main control module controls the first core phase module (MOS tube) to control the voltage signal output, and when the slave device is turned on, the second main control module analyzes the voltage signal collected by the ADC data acquisition module. When the sequence is a high-level signal (can also be set to a low-level signal), it is judged as the acquisition start signal. The next moment, the host device will apply a high-level signal to phase A, and a low-level signal to phases B and C. The slave device analyzes and determines that the high-level signal is calibrated as phase A, and displays the yellow light and the word A phase on its respective display module. Similarly, the next moment, the host device will apply a high-level signal to phase B, and a low-level signal to phases A and C. The slave device analyzes and determines that the high-level signal is calibrated as phase B, and displays the green light and the word B phase on its respective display module. The next moment, the host device will apply a high-level signal to phase C, and a low-level signal to phases A and B. The slave device analyzes and determines that the high-level signal is calibrated as phase C, and displays the red light and the word C phase on its respective display module. So far, the phase sequence judgment has been completed, but in order to further improve the accuracy of the phase sequence judgment, this embodiment needs to perform a phase sequence check, which includes: at the next moment, the host device will apply a low-level signal to phase A, and high-level signals to phases B and C. The slave device receives the signal and determines whether it is consistent with the previously calibrated phase A. Figure 5 The master and slave devices perform timing analysis and check phases B and C. When the check is correct, in order to promptly remind the staff that the phase sequence determination is completed, the slave device receives a termination signal (set as a low-level signal in this embodiment) sent by the host device, and the sound and light alarm module sends a sound and light alarm to indicate that the phase sequence determination is completed.

[0053] It is worth mentioning that since the high level value or low level value provided by the host device is often different from the high level value or low level value received by the slave device, this is because the level is affected by the electronic components in the device during the transmission process. In order to reduce this influence and reduce the misjudgment of the staff, this embodiment optimizes the high level value and low level value received by the slave device. The formula is as follows:

[0054] (1) The optimized high-level formula is:

[0055] V out1 =V in -V f -V m ;

[0056] Among them, V out1 Indicates the output high level voltage, V in Represents the input voltage of the first battery power module, V f represents the voltage drop of the Schottky diode, which is located in the first battery-powered module; V m Indicates the voltage drop of MOS tube.

[0057] Where n is the ideal factor, usually 1 to 2; V t is the thermal voltage, which is 25mV at room temperature; I is the current through the Schottky diode, I S is the saturation current.

[0058] V m =I d ×R d , where I d is the current flowing through the MOS tube, R d is the on-resistance of the MOS tube.

[0059] After optimization calculation, V out1 The output voltage needs to be above 9V to be considered a high level value.

[0060] (2) The optimized low-level formula is:

[0061] V out2 =V f ;

[0062] Among them, V out2 Indicates the output low level voltage, V f represents the Schottky diode clamping voltage, the Schottky diode is located in the first battery power module, Where n is the ideal factor, usually 1 to 2; V t is the thermal voltage, which is 25mV at room temperature; I is the current through the Schottky diode, I S is the saturation current.

[0063] After optimization calculation, V out2 The output voltage needs to be below 1V to be considered a low level value.

[0064] It is worth mentioning that the traditional megohmmeter needs to be boosted to 2500V for phase checking. The method of this embodiment has a maximum voltage of only 12V, which meets the safety voltage for the human body.

[0065] It can be seen that the cable phase checking device and phase sequence determination method adopted by the present invention reduce the number of cable phase checking operators. Only one person is needed to complete the work when performing phase checking. Compared with the traditional method, at least two construction personnel who cooperate with phase checking can be reduced, which can effectively save labor costs. The cable phase checking device has a simple structure, convenient and fast wiring, easy operation, and reduced production costs. The present invention improves the accuracy and work efficiency of phase checking, avoids the problem of unclear communication and confirmation between the construction personnel at both ends of the cable, resulting in inconsistent phase sequence at both ends of the cable, caused by the use of communication equipment for communication in a noisy construction environment with poor signals. The present invention does not require an external power supply, is not affected by the construction area environment, has good stability in maintenance and construction operations, is simple and convenient to operate, improves construction efficiency and has high accuracy and high safety, and avoids the occurrence of equipment safety and quality accidents.

[0066] The present invention can play an important role in the electrical construction, high-voltage cable head production and electrical test construction process, and provides an efficient and convenient method for cable phase core construction. The present invention is suitable for non-energized cable phase cores and non-voltage phase core construction of all high-voltage cables, and can be widely promoted and applied in the industry.

[0067] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0068] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for rapid automatic phase checking of high and low voltage cables, characterized in that: include: The host device controls the voltage signal and applies the voltage signal to the A, B, and C phases of the three-phase cable respectively. The slave device receives the voltage signal transmitted by the three-phase cable and analyzes the timing to determine the phase sequence of the three-phase cable. Specifically: When the host device simultaneously applies voltage signals to the three-phase cables as a start signal, the slave device receives the start signal, indicating that it has synchronized with the host device, and then executes the following steps in sequence: The host device applies a high voltage to phase A of the three-phase cable and a low voltage to phases B and C. The slave device receives the high voltage signal for judgment and marks the cable that receives the high voltage signal as phase A and displays it; The host device applies a high voltage to the B phase of the three-phase cable and a low voltage to the A and C phases. The slave device receives the high voltage signal for judgment and marks the cable that receives the high voltage signal as the B phase sequence and displays it; The host device applies a high voltage to the C phase of the three-phase cable and a low voltage to the A and B phases. The slave device receives the high voltage signal for judgment and marks the cable that receives the high voltage signal as the C phase sequence and displays it; The high voltage ranges from 9V to 12V, and the low voltage ranges from 0V to 1V.

2. The method for rapid automatic phase checking of high and low voltage cables according to claim 1 is characterized in that: It also includes checking the phase sequence of the three-phase cable whose A, B, and C phases have been determined, specifically: The host device applies low voltage to phase A of the three-phase cable, and applies low voltage to phases B and C. The slave device receives the low voltage signal and determines whether it is consistent with the previously marked phase A. The host device applies a low voltage to the B phase of the three-phase cable, and applies a low voltage to the A and C phases. The slave device receives the low voltage signal and determines whether it is consistent with the previously marked B phase; The host device applies a low voltage to the C phase of the three-phase cable, and applies a low voltage to the A and B phases. The slave device receives the low voltage signal and determines whether it is consistent with the previously marked C phase; If the phase sequence check is consistent, the determination ends; If the phase sequence check is inconsistent, re-determine the phase sequence of the three-phase cable.

3. The method for rapid automatic phase checking of high and low voltage cables according to claim 2 is characterized in that: The host device includes a first main control module, a first core phase module, and a first battery power supply module. The first main control module is connected to the first core phase module and the first battery power supply module respectively. The first main control module is used to control the first core phase module to apply the voltage signal provided by the first battery power supply module to the A, B, and C phases of the three-phase cable respectively.

4. The method for rapid automatic phase checking of high and low voltage cables according to claim 3 is characterized in that: The first core phase module is a MOS tube, and the first main control module adopts an STM32 series control chip.

5. The method for rapid automatic phase checking of high and low voltage cables according to claim 4 is characterized in that: It also includes correction for the slave device receiving high voltage signals, the formula is: V out1 =V in -V f1 -V m ; Among them, V out1 Indicates the output high level voltage, V in Represents the input voltage of the first battery power module, V f1 represents the voltage drop of the first Schottky diode, which is located in the first battery power supply module; V m Indicates the voltage drop of MOS tube; Where n is the ideal factor; V t is the thermal voltage, which is 25mV at room temperature; I is the current through the first Schottky diode, I S is the saturation current; V m =I d ×R d , where I d is the current flowing through the MOS tube, R d is the on-resistance of the MOS tube.

6. The method for rapid automatic phase checking of high and low voltage cables according to claim 4 is characterized in that: It also includes correction for the low voltage signal received by the slave device, the formula is: V out2 =V f2 ; Among them, V out2 Indicates the output low level voltage, V f2 Indicates the clamping voltage of the second Schottky diode, which is located in the MOS tube; Where n is the ideal factor; V t is the thermal voltage, which is 25mV at room temperature; I is the current through the second Schottky diode, I S is the saturation current.

7. The method for rapid automatic phase checking of high and low voltage cables according to claim 3 is characterized in that: The host device also includes a first display module, which is connected to the first main control module. The first display module includes a first display screen and a first indicator light. The first display screen is used to display the phases of the three-phase cable, and the first indicator light is used to emit lights of corresponding colors A, B, and C.

8. The method for rapid automatic phase checking of high and low voltage cables according to claim 1 is characterized in that: The slave device includes a second main control module and a second phase checking module. The second main control module is connected to the second phase checking module. The second main control module is used to perform voltage timing analysis on the voltage signal collected by the second phase checking module to determine the cable phase.

9. The method for rapid automatic phase checking of high and low voltage cables according to claim 8 is characterized in that: The second core module is an ADC data acquisition chip, and the second main control module adopts an STM32 series control chip.

10. The method for rapid automatic phase checking of high and low voltage cables according to claim 8 is characterized in that: The slave device also includes a second display module, which is connected to the second main control module. The second display module includes a second display screen and a second indicator light. The second display screen is used to display the phases of the three-phase cable, and the second indicator light is used to emit lights of corresponding colors A, B, and C.

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