CN114355243A - Unreliable grounding detector for judging direct current system based on amplitude-to-amplitude phase comparison and control method - Google Patents
Unreliable grounding detector for judging direct current system based on amplitude-to-amplitude phase comparison and control method Download PDFInfo
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Abstract
The application discloses direct current system unreliable grounding detector is control method based on amplitude-to-amplitude ratio phase judgment, wherein the detector includes: the direct current detection module is used for detecting a direct current signal; the alternating current detection module is used for detecting an alternating current signal; the digital-to-analog conversion module is respectively connected with the direct current detection module and the alternating current detection module and is used for converting the direct current electric signal and the alternating current electric signal into digital signals; and the processor module is connected with the digital-to-analog conversion module and is used for analyzing the digital signals. According to the method and the device, whether the direct current system is in unreliable grounding or not is judged based on the amplitude-to-amplitude ratio phase of the alternating current and the direct current, the unreliable grounding fault is intelligently analyzed and detected, the fault detection efficiency is improved, and the safe operation of the direct current system is guaranteed.
Description
Technical Field
The application relates to the field of electronic circuits, in particular to a direct current system unreliable grounding detector based on amplitude-to-amplitude phase comparison judgment and a control method.
Background
In an electric power network, a direct current system is used as a power supply system in various electric power apparatuses. In order to avoid ground faults forming a fault loop, which leads to protection malfunction or operation failure, it is often necessary to set the dc system as a non-grounded system. However, in actual production operation, an unreliable ground fault may occur in the non-grounded direct current system, which affects the normal operation of equipment and power networks. Therefore, in order to timely detect whether the dc system has an unreliable ground fault, an insulation detection device detection system is often provided in related applications to detect whether the dc system has a fault.
The response time from the detection of the direct-current ground fault by the related insulation detection device to the alarm and the line selection is long, and the duration time of the unreliable ground fault is short, so that the related insulation detection device cannot detect the unreliable ground fault in time, and the operation safety of the power network is influenced.
Therefore, the above technical problems of the related art need to be solved.
Disclosure of Invention
The present application is directed to solving one of the technical problems in the related art. Therefore, the embodiment of the application provides the unreliable grounding detector for judging the unreliable grounding fault of the direct current system based on the amplitude-to-amplitude ratio and the control method, the unreliable grounding fault can be intelligently analyzed and detected, and the safe operation of the direct current system is guaranteed.
According to an aspect of the embodiments of the present application, there is provided a detector for determining unreliable ground of a dc system based on amplitude-to-amplitude ratio, including:
the direct current detection module is used for detecting a direct current signal;
the alternating current detection module is used for detecting an alternating current signal;
the digital-to-analog conversion module is respectively connected with the direct current detection module and the alternating current detection module and is used for converting the direct current electric signal and the alternating current electric signal into digital signals;
the processor module is connected with the digital-to-analog conversion module and is used for analyzing the digital signals;
the direct current detection module transmits the detected direct current signal to the digital-to-analog conversion module, the alternating current detection module transmits the detected alternating current signal to the digital-to-analog conversion module, the digital-to-analog conversion module converts the direct current signal and the alternating current signal into digital signals, the digital-to-analog conversion module transmits the digital signals to the processor module, and the processor module analyzes the digital signals and judges whether a direct current system is unreliable in ground.
In one embodiment, the processor module analyzes the digital signal, including:
the processor module samples the digital signals by a preset number within a preset time to obtain a preset number of sampling points;
and obtaining a complete direct current signal variation waveform and an alternating current signal variation waveform according to the sampling point, and determining that the direct current system is unreliable in grounding if the direct current signal variation waveform and the alternating current signal variation waveform exist in the same period at the same time.
In one embodiment, the dc detection module detects a dc signal, including:
the direct current detection module samples the direct current system according to a preset sampling period to obtain a direct current sampling signal;
and the direct current detection module is used for detecting the direct current change value of the direct current sampling signal.
In one embodiment, the dc detection module detects a dc current variation value of the dc sampling signal, including:
and the direct current detection module subtracts the stable value of the direct current sampling signal from the peak value of the direct current sampling signal to obtain the direct current change value.
In one embodiment, the ac detection module detects an ac signal, including:
the alternating current detection module samples the alternating current system according to a preset sampling period to obtain an alternating current sampling signal;
and the alternating current detection module is used for detecting the alternating current change value of the alternating current sampling signal.
In one embodiment, the ac detection module detects an ac current variation value of the ac sampling signal, including:
and the alternating current detection module subtracts the stable value of the alternating current sampling signal from the peak value of the alternating current sampling signal to obtain the alternating current change value.
In one embodiment, the detector further comprises:
the display module is connected with the processor module and used for displaying whether the direct current system is unreliable in grounding;
and the prompting module is connected with the processor module and is used for prompting when the direct current system is not reliably grounded.
According to an aspect of the embodiments of the present application, there is provided a control method for determining an unreliable ground fault detector of a dc system based on a amplitude-to-amplitude ratio phase, where the control method is used to control the unreliable ground fault detector of the dc system based on the amplitude-to-amplitude ratio phase described in the foregoing embodiments, the control method includes:
acquiring a direct current signal and an alternating current signal of a direct current system;
converting the direct current signal and the alternating current signal into digital signals;
and analyzing the digital signal to judge whether the direct current system is unreliable in grounding.
In one embodiment, the analyzing the digital signal to determine whether the dc system is not reliably grounded includes:
sampling the digital signals by a preset number within a preset time to obtain a preset number of sampling points;
and obtaining a complete direct current signal variation waveform and an alternating current signal variation waveform according to the sampling point, and determining that the direct current system is unreliable in grounding if the direct current signal variation waveform and the alternating current signal variation waveform exist in the same period at the same time.
The method for upgrading the elevator master control program provided by the embodiment of the application has the beneficial effects that: according to the method and the device, whether the direct current system is in unreliable grounding or not is judged based on the amplitude-to-amplitude ratio phase of the alternating current and the direct current, the unreliable grounding fault is intelligently analyzed and detected, the fault detection efficiency is improved, and the safe operation of the direct current system is guaranteed.
Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic diagram of an experimental non-reliable ground circuit provided in an embodiment of the present application;
FIG. 2 is a waveform variation diagram of an unreliable ground test provided by an embodiment of the present application;
fig. 3 is a schematic structural diagram of a detector for determining unreliable grounding of a dc system based on amplitude-to-amplitude ratio and phase-to-phase ratio according to an embodiment of the present disclosure;
fig. 4 is a flowchart of a method for determining unreliable ground fault detector control of a dc system based on amplitude-to-amplitude ratio phase according to an embodiment of the present application;
fig. 5 is another flowchart of a method for determining unreliable ground fault detector control of a dc system based on amplitude-to-amplitude ratio and phase-to-phase ratio according to an embodiment of the present disclosure.
Detailed Description
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "first," "second," "third," and "fourth," etc. in the description and claims of this application and the accompanying drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
In an electric power network, a direct current system is used as a power supply system in various electric power apparatuses. In order to avoid ground faults forming a fault loop, which leads to protection malfunction or operation failure, it is often necessary to set the dc system as a non-grounded system. However, in actual production operation, an unreliable ground fault may occur in the non-grounded direct current system, which affects the normal operation of equipment and power networks. Therefore, in order to timely detect whether the dc system has an unreliable ground fault, an insulation detection device detection system is often provided in related applications to detect whether the dc system has a fault.
The response time from the detection of the direct-current ground fault by the related insulation detection device to the alarm and the line selection is long, and the duration time of the unreliable ground fault is short, so that the related insulation detection device cannot detect the unreliable ground fault in time, and the operation safety of the power network is influenced.
In order to solve the problems, the application provides a direct current system unreliable grounding detector based on amplitude-to-amplitude ratio phase judgment and a control method.
First, the present specification introduces an experimental process for determining unreliable grounding of a dc system based on amplitude-to-amplitude ratio, which is specifically as follows:
fig. 1 is a circuit diagram of an experiment for non-reliable grounding according to an embodiment of the present disclosure, as shown in fig. 1, C1 and C2 are capacitances to ground of a dc system, RL simulates a feeder load, R0 is a ground resistance, and switching on and off of a switch k simulates generation and disappearance of non-reliable grounding of dc, and current change of a grounding generation feeder is monitored by using two types of CTs, namely a dc leakage current sensor CT1 and an ac current sensor CT2, and a change of a voltage to ground of a positive bus is observed by using an oscilloscope.
In the related technology, whether a direct current unreliable grounding fault occurs is judged according to characteristic quantity of alternating current and direct current changes of a feeder line, but when direct current unreliable grounding occurs, direct current leakage current of a grounding branch circuit can have obvious changes, and large current changes can also exist due to charging and discharging of a capacitor. The characteristic quantity change caused by the branch capacitance of the feeder line is detected by adopting a mode of resistance-capacitance phase difference and curve change direction, and the characteristic quantity change caused by the direct current non-grounded fault or the characteristic quantity change of the capacitive feeder line is judged and distinguished according to the resistance-capacitance phase difference, and then the characteristic quantity change of the system bus line to the ground voltage change is combined for confirmation and judgment, so that the phenomenon of misjudgment is avoided.
Fig. 2 is a waveform diagram of an unreliable grounding test provided by an embodiment of the present application, and as shown in fig. 2, it can be seen that when a direct current unreliable grounding occurs, the voltage to ground of the positive bus gradually decreases until it is stable due to the system capacitors C1 and C2, and the stable voltage value is determined by the balance bridge resistor and the grounding resistor R0 in the dc system insulation monitoring device. Due to the system capacitor, when the system capacitor is fully charged, the electric energy is released, the direct current reaches the maximum value instantly, and along with the reduction of the electric energy of the capacitor, the change current I detected by the direct current leakage current CT1 has a process of gradually reducing to be stable after the maximum value suddenly changes, the current change value is delta I, and a small reverse pulse is generated immediately after a positive pulse is detected by the alternating current CT2 in the same time period.
When the direct current unreliable grounding is finished, the voltage to ground of the positive bus has a charging process due to the action of the system capacitors C1 and C2, the voltage to ground of the positive bus cannot suddenly change to a normal voltage value immediately, and the voltage gradually rises until the voltage is stable. When the direct current unreliable grounding happens to the system capacitor, the electric energy is released completely, the positive and negative pole currents of the grounding branch are mutually offset, the direct current leakage current is equal to 0, and the alternating current CT2 can detect a small reverse pulse.
Therefore, it is necessary to determine whether or not dc unreliable occurs by determining whether or not the current variation waveform of the dc leakage current CT1 or the ac CT2 is present simultaneously in the same sampling period and whether or not the dc variation value reaches Δ I.
Next, a principle for judging the unreliability of the dc system based on amplitude-to-amplitude phase comparison provided by the present application is derived, specifically as follows:
for the direct current characteristic signal, the complete direct current change waveform can be obtained only by filtering, amplifying and the like the acquired change signal and performing AD conversion.
For the alternating current characteristic signal, amplitude characteristic quantity and phase of a fundamental wave signal of the alternating current characteristic signal are calculated through discrete Fourier transform. Since the fourier principle refers to any continuously measured time sequence or signal, which can be expressed as an infinite superposition of sine wave signals of different frequencies. The fourier transform algorithm created according to this principle uses the directly measured raw signal to calculate the frequency, amplitude and phase of the different sinusoidal signals in the signal in an additive manner. The fast algorithm of discrete Fourier transform is obtained by improving the algorithm of discrete Fourier transform according to the characteristics of odd, even, imaginary and real of discrete Fourier transform.
According to the principle, a sinusoidal pulse analog signal, after being sampled, becomes a digital signal. The digital signal obtained by sampling can be subjected to discrete Fourier transform, and the discrete Fourier transform can extract the frequency spectrum of one signal for frequency spectrum analysis. The following is the calculation formula for the fourier transform to calculate the single harmonic:
in the formula: n denotes the desired harmonicThe wave number (N is 1, which is the fundamental wave quantity obtained), N is the number of sampling points per cycle, k is the sampling sequence number (i.e. the k-th sampling point), ikIs denoted by tkThe sampled value of the moment.
When the fundamental wave quantity is obtained, N is 1, N is 40, k is a positive integer from 1 to 40, the calculation is performed according to the formula for calculating the single harmonic, wherein pi is 3.1415926, the sum of the final calculation result is the cumulative sum calculated for 40 times, and the fundamental wave quantity of the signal is obtained as:
In＝sqrt[(an*an)+(bn*bn)]
therefore, by performing fourier transform on the sampling sequence, the frequency spectrum of the 50Hz alternating current signal can be extracted, and the amplitude characteristic quantity and the phase of the varying current signal can be calculated.
According to the calculation method, the method for judging the amplitude-to-amplitude ratio and the phase-to-phase ratio of the alternating current and the direct current specifically comprises the following steps: and rapidly sampling 40 points in a characteristic signal change period to obtain a complete alternating current and direct current characteristic signal change waveform, and judging that the direct current system has an inaccessible ground fault when the alternating current and direct current characteristic signal change waveforms exist simultaneously in the same period, or judging that no fault exists.
Based on the principle, the application provides a direct current system unreliable grounding detector based on amplitude-to-amplitude ratio phase judgment. As shown in fig. 3, includes:
the direct current detection module is used for detecting a direct current signal;
the alternating current detection module is used for detecting an alternating current signal;
the digital-to-analog conversion module is respectively connected with the direct current detection module and the alternating current detection module and is used for converting the direct current electric signal and the alternating current electric signal into digital signals;
the processor module is connected with the digital-to-analog conversion module and is used for analyzing the digital signals;
in this embodiment, the microprocessor module adopts a high-speed and low-power consumption single-chip processor, and a self-contained FLASH memory is used as a program memory for data processing and analysis of the system; the AC/DC detection module is internally provided with a signal conditioning module which is used for amplifying, filtering and converting the analog signal of the tested AC/DC current and transmitting the analog signal to the digital-to-analog conversion module; the digital-to-analog conversion module adopts a 12-bit switched capacitor successive approximation analog-to-digital converter, has small conversion error and converts an analog signal into a digital signal; the display module is used for displaying the AC/DC characteristic signal; the keyboard is provided with a test key, a zero setting key and a self-correcting key; the prompt module adopts Chinese voice prompt of fixed telephone to prompt whether the fault of unreliable ground exists.
The direct current detection module transmits the detected direct current signal to the digital-to-analog conversion module, the alternating current detection module transmits the detected alternating current signal to the digital-to-analog conversion module, the digital-to-analog conversion module converts the direct current signal and the alternating current signal into digital signals, the digital-to-analog conversion module transmits the digital signals to the processor module, and the processor module analyzes the digital signals and judges whether a direct current system is unreliable in ground.
Optionally, the processor module analyzes the digital signal, including: the processor module samples the digital signals by a preset number within a preset time to obtain a preset number of sampling points; and obtaining a complete direct current signal variation waveform and an alternating current signal variation waveform according to the sampling point, and determining that the direct current system is unreliable in grounding if the direct current signal variation waveform and the alternating current signal variation waveform exist in the same period at the same time.
Optionally, the detecting the dc signal by the dc detecting module includes: the direct current detection module samples the direct current system according to a preset sampling period to obtain a direct current sampling signal; and the direct current detection module is used for detecting the direct current change value of the direct current sampling signal.
In this embodiment, the dc detecting module may further include: and the direct current detection module subtracts the stable value of the direct current sampling signal from the peak value of the direct current sampling signal to obtain the direct current change value. For example, the detected dc current signal is sampled at a speed of 0.5ms by a sampling point from the beginning of sudden change to stabilization, and finally the dc current peak signal is subtracted from the dc current stabilization signal to obtain the dc current change value Δ I, where the time required for this process is the sampling period T.
Optionally, the ac detection module detects an ac signal, including: the alternating current detection module samples the alternating current system according to a preset sampling period to obtain an alternating current sampling signal; and the alternating current detection module is used for detecting the alternating current change value of the alternating current sampling signal.
In this embodiment, the ac detection module may further include: and the alternating current detection module subtracts the stable value of the alternating current sampling signal from the peak value of the alternating current sampling signal to obtain the alternating current change value. For example, while detecting the dc current signal, the ac CT measures the ac current signal, and similarly samples the ac current signal at a speed of 0.5ms by one sampling point, where the number of sampling points is T/0.5, so as to obtain all the ac/dc current signals in the sampling period T.
Optionally, the detector further comprises: the display module is connected with the processor module and used for displaying whether the direct current system is unreliable in grounding; and the prompting module is connected with the processor module and is used for prompting when the direct current system is not reliably grounded.
According to the method and the device, whether the direct current system is in unreliable grounding or not is judged based on the amplitude-to-amplitude ratio phase of the alternating current and the direct current, the unreliable grounding fault is intelligently analyzed and detected, the fault detection efficiency is improved, and the safe operation of the direct current system is guaranteed.
In addition, the present application further provides a control method for determining an unreliable ground fault detector of a dc system based on a amplitude-to-amplitude ratio phase, which is used to control the unreliable ground fault detector of the dc system based on the amplitude-to-amplitude ratio phase according to the foregoing embodiment, as shown in fig. 4, the control method includes:
s401, acquiring a direct current signal and an alternating current signal of a direct current system.
S402, converting the direct current signal and the alternating current signal into digital signals.
And S403, analyzing the digital signal and judging whether the direct current system is unreliable in grounding.
Optionally, the analyzing the digital signal to determine whether the dc system is not reliably grounded includes, as shown in fig. 5:
s501, acquiring a direct current signal and an alternating current signal of a direct current system.
S502, converting the direct current signal and the alternating current signal into digital signals.
S503, sampling the digital signal in a preset amount within a preset time to obtain a preset amount of sampling points.
And S504, obtaining a complete direct current signal variation waveform and an alternating current signal variation waveform according to the sampling points.
And S505, if the direct current signal variation waveform and the alternating current signal variation waveform exist in the same period, determining that the direct current system is not reliably grounded.
In alternative embodiments, the functions/acts noted in the block diagrams may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Furthermore, the embodiments presented and described in the flowcharts of the present application are provided by way of example in order to provide a more thorough understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of larger operations are performed independently.
Furthermore, although the present application is described in the context of functional modules, it should be understood that, unless otherwise stated to the contrary, one or more of the functions and/or features may be integrated in a single physical device and/or software module, or one or more functions and/or features may be implemented in separate physical devices or software modules. It will also be appreciated that a detailed discussion regarding the actual implementation of each module is not necessary for an understanding of the present application. Rather, the actual implementation of the various functional modules in the apparatus disclosed herein will be understood within the ordinary skill of an engineer, given the nature, function, and internal relationship of the modules. Accordingly, those skilled in the art can, using ordinary skill, practice the present application as set forth in the claims without undue experimentation. It is also to be understood that the specific concepts disclosed are merely illustrative of and not intended to limit the scope of the application, which is defined by the appended claims and their full scope of equivalents.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.
It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.
In the foregoing description of the specification, reference to the description of "one embodiment/example," "another embodiment/example," or "certain embodiments/examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: numerous changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.
The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.
Claims (9)
1. Direct current system unreliable ground connection detector is judged based on than amplitude phase, its characterized in that includes:
the direct current detection module is used for detecting a direct current signal;
the alternating current detection module is used for detecting an alternating current signal;
the digital-to-analog conversion module is respectively connected with the direct current detection module and the alternating current detection module and is used for converting the direct current electric signal and the alternating current electric signal into digital signals;
the processor module is connected with the digital-to-analog conversion module and is used for analyzing the digital signals;
the direct current detection module transmits the detected direct current signal to the digital-to-analog conversion module, the alternating current detection module transmits the detected alternating current signal to the digital-to-analog conversion module, the digital-to-analog conversion module converts the direct current signal and the alternating current signal into digital signals, the digital-to-analog conversion module transmits the digital signals to the processor module, and the processor module analyzes the digital signals and judges whether a direct current system is unreliable in ground.
2. The dc system unreliable ground detector based on amplitude-to-amplitude ratio determination of claim 1, wherein said processor module analyzes said digital signal comprising:
the processor module samples the digital signals by a preset number within a preset time to obtain a preset number of sampling points;
and obtaining a complete direct current signal variation waveform and an alternating current signal variation waveform according to the sampling point, and determining that the direct current system is unreliable in grounding if the direct current signal variation waveform and the alternating current signal variation waveform exist in the same period at the same time.
3. The detector of claim 1, wherein the dc detection module detects dc signals and comprises:
the direct current detection module samples the direct current system according to a preset sampling period to obtain a direct current sampling signal;
and the direct current detection module is used for detecting the direct current change value of the direct current sampling signal.
4. The detector of claim 3, wherein the dc detection module detects a dc current variation value of the dc sampling signal, and comprises:
and the direct current detection module subtracts the stable value of the direct current sampling signal from the peak value of the direct current sampling signal to obtain the direct current change value.
5. The detector of claim 1, wherein the ac detection module detects ac signals and comprises:
the alternating current detection module samples the alternating current system according to a preset sampling period to obtain an alternating current sampling signal;
and the alternating current detection module is used for detecting the alternating current change value of the alternating current sampling signal.
6. The detector of claim 5, wherein the AC detection module detects the AC current variation value of the AC sampling signal, and comprises:
and the alternating current detection module subtracts the stable value of the alternating current sampling signal from the peak value of the alternating current sampling signal to obtain the alternating current change value.
7. The detector of claim 1, further comprising:
the display module is connected with the processor module and used for displaying whether the direct current system is unreliable in grounding;
and the prompting module is connected with the processor module and is used for prompting when the direct current system is not reliably grounded.
8. A control method for judging unreliable grounding detector of dc system based on amplitude-to-amplitude ratio phase, which is used for controlling the unreliable grounding detector of dc system based on amplitude-to-amplitude ratio phase according to any one of claims 1 to 7, the control method comprising:
acquiring a direct current signal and an alternating current signal of a direct current system;
converting the direct current signal and the alternating current signal into digital signals;
and analyzing the digital signal to judge whether the direct current system is unreliable in grounding.
9. The method for controlling a dc system unreliable ground detector according to claim 1, wherein said analyzing said digital signal to determine if the dc system is unreliable grounded comprises:
sampling the digital signals by a preset number within a preset time to obtain a preset number of sampling points;
and obtaining a complete direct current signal variation waveform and an alternating current signal variation waveform according to the sampling point, and determining that the direct current system is unreliable in grounding if the direct current signal variation waveform and the alternating current signal variation waveform exist in the same period at the same time.
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