339results about "Phase sequence/synchronism indication" patented technology

The invention belongs to the technical field of intelligent substations, and particularly relates to an intelligent nuclear phase method and system for a substation. According to the method, a dynamic priority evaluation model is constructed, multi-source data of four kinds of basic factors including voltage phase difference, environment temperature and humidity, equipment vibration and historical errors are synthesized, and a fuzzy comprehensive evaluation method is utilized to calculate weights and dynamically sort the weights; a multi-port phase scattering model is constructed based on transformer substation topology, impedance mismatch points are analyzed by means of a Smith chart, and dual-stage optimization is implemented; constructing a three-layer decision input set according to the optimization model, designing a fuzzy logic driven adaptive rule engine, dynamically outputting a working condition level and matching a nuclear phase strategy; multi-dimensional quality evaluation, dynamic updating of factor weights and optimization of fuzzy model parameters are carried out by monitoring indexes such as reflection coefficients in real time, abnormal mode recognition and compensation strategy solidification are realized by fusing LSTM and a graph neural network, a self-evolution closed-loop system is formed, and finally, crossing of a nuclear phase process from accurate matching to autonomous evolution is realized.

The invention relates to a method and a system for detecting abnormal electricity consumption of an electric energy meter, and relates to the technical field of electric power detection. According to the method for detecting abnormal power consumption of the electric energy meter, the data of the electric energy meter is collected and analyzed, so that the accuracy of wiring of the electric energy meter can be preliminarily judged through an instrument, the electric quantity needing to be compensated during a fault period is automatically calculated, the manual calculation processing time is shortened, and the field operation and maintenance working efficiency can be greatly improved; the electric quantity calculation method can be immediately corrected by analyzing acquired data of the electric energy meter, finding a wrong wiring condition, so that the device can acquire a real-time power consumption condition and automatically calculate the electric quantity needing to be compensated in a wrong wiring state and in abnormal operation, the operation and maintenance work difficulty of an electric power department is reduced, and the working efficiency is improved. And the efficiency of field operation and the timeliness of electric quantity compensation are improved.

The invention discloses an intelligent distribution network nuclear phase method and system based on GPS clock synchronization, and relates to the field of power system distribution network operation and maintenance. The intelligent distribution network nuclear phase method and system based on GPS clock synchronization comprise a nuclear phase source reference unit, a non-contact nuclear phase terminal and a cloud server system. According to the intelligent distribution network nuclear phase method and system based on GPS clock synchronization, three-phase voltage waveforms are continuously collected through a nuclear phase source reference unit, and reference waves are formed through GPS clock synchronization, time label adding and cloud real-time synchronization; a non-contact phase checking terminal is used for collecting three-phase voltage waveforms of a measuring end, GPS clock synchronization, time label adding and data packaging are carried out and uploaded to a cloud end, then a cloud server system is used for intercepting the voltage waveforms of the same time period through a GPS clock to carry out phase checking and phase difference analysis, and then feedback signals are generated according to the analysis result and a phase difference threshold value. The single-person non-contact operation is realized, the safety is high, the precision is high, and the nuclear phase structure can be stored.

The invention belongs to the technical field of motor control, and particularly relates to a motor three-phase counter electromotive force phase sequence detection circuit and a running direction judgment device. The phase sequence detection circuit comprises a comparison circuit and further comprises a tachogenerator coaxially connected with the motor to be detected, and the output end of the tachogenerator is electrically connected with the input end of the comparison circuit so that the phase sequence of the three-phase counter electromotive force of the motor to be detected can be obtained through the three-phase voltage output by the tachogenerator through the comparison circuit. The three-phase counter electromotive force of the to-be-tested motor is directly detected through the tachogenerator coaxially connected with the to-be-tested motor. The rotor of the tachogenerator rotates along with the rotation of the motor to be tested, and the rotor of the tachogenerator cuts magnetic lines in the operation process, thereby generating the three-phase counter electromotive force of the motor to be tested. The technical problem that in the prior art, when ground voltage detection is not accurate due to external interference, detected counter electromotive force is not accurate, and then the motor control effect is affected is solved.

The invention relates to the field of phasing instruments, in particular to an airborne wireless phase checking and phasing instrument which comprises an unmanned aerial vehicle, a host and a detector (composed of an X detector and a Y detector), a 4.3-inch 65K-color LCD color screen is selected for the host, the phase, frequency, phase sequence, phase checking results and dynamic vector diagram indication can be displayed on the same screen, and a voice prompt module is arranged in the host. The device can be used inside or outside a transformer substation and is not affected by topographic conditions.

The present application relates to a power failure detection method and system for an air conditioning device. The method includes respectively obtaining the main board voltage detection value, transformer voltage detection value, and plug voltage detection value when the air conditioning device is powered on, and performing data cleaning processing to obtain the preprocessed air conditioning operation data. Furthermore, a power phase waveform among the main board, transformer, and power plug of the air conditioning device is drawn, and the power phase sequence balance relationship of the air conditioning device is analyzed. The abnormal power phase sequence is analyzed in combination with the historical fault data of the air conditioning device and the power phase sequence balance relationship. According to the analysis results, a power failure analysis model for analyzing the power failure of the air conditioning device is constructed. The power failure analysis model performs power failure analysis on the power phase data in the power failure state of the air conditioning device to obtain the power failure detection data corresponding to the current power failure phase. The present application has the effect of improving the intelligent degree of power failure detection of the air conditioning device.

The utility model relates to the field of power equipment, in particular to an auxiliary nuclear phase device for a centrally installed switchgear, which comprises a cart, a position adjusting mechanism, a mounting seat and a clamp. The position adjusting mechanism is arranged on the cart, the mounting base is arranged on the position adjusting mechanism, and the position adjusting mechanism is used for adjusting the position of the mounting base in the first direction and / or the second direction; the number of the clamps is multiple, the multiple clamps are arranged on the mounting base, and the clamps are used for clamping an insulating rod; wherein an included angle which is not zero exists between the first direction and the second direction. According to the utility model, a worker does not need to hold the insulating rod by hand for phase checking operation, and the safety is high.

The invention relates to the technical field of power system operation and maintenance, in particular to an intelligent line shaking insulation nuclear phase test system and a test method thereof.An insulation resistance test module adopts a self-adaptive algorithm, the influence of environment temperature and humidity on a test result can be eliminated, and the insulation resistance measurement precision is remarkably improved; a dynamic grounding technology: the induced voltage suppression module adjusts a grounding state and a compensation voltage in real time through the dynamic grounding technology and a voltage compensation algorithm to ensure that a test result is not interfered by the induced voltage; a test neutral period and a quick access technology are optimized: the system can quickly complete access and test in a neutral period from grounding disconnection of a to-be-tested line to equipment access test, and damage to equipment caused by secondary rise of induced voltage is avoided; and real-time monitoring and adjustment: in the test neutral period, the system monitors the line induction voltage in real time, and dynamically adjusts the grounding state and the compensation voltage according to the monitoring result to ensure the equipment safety.

The invention discloses a phase sequence detection method and device for an inverter electric meter, computer equipment and a storage medium, and the method comprises the steps: controlling a first phase of an inverter to operate according to a set power in response to a phase sequence detection request, the first phase comprising at least one of an R phase, an S phase and a T phase, the set power comprises at least one of first set power of the R phase, second set power of the S phase and third set power of the T phase, and the first set power, the second set power and the third set power are different from one another; acquiring electric meter power of a second phase electrically connected with the first phase in the electric meter; the second phase comprises at least one of an R phase, an S phase and a T phase; and determining a phase sequence detection result between the first phase and the second phase according to the set power of the first phase and the electric meter power of the second phase. According to the embodiment of the invention, the three-phase imbalance work of the inverter is controlled to realize automatic detection.

The invention provides a current phase sequence automatic identification method and system, and the method comprises the steps: collecting a three-phase current signal, preprocessing the three-phase current signal, and inputting the preprocessed three-phase current signal to a spatial-temporal feature extraction model; the model extracts the depth time sequence features of each phase through a plurality of parallel one-dimensional convolutional neural networks, and fuses the depth time sequence features by using an attention mechanism to capture the dynamic relevance between the phases and generate a space-time fusion feature vector; inputting the space-time fusion feature vector into a pre-trained generative adversarial network, and calculating a deviation degree between the space-time fusion feature vector and a normal state to obtain an abnormal score; and if the abnormal score exceeds a threshold value, judging that the phase sequence is abnormal, further starting a diagnosis classifier to determine an abnormal type, and finally generating and outputting a phase sequence adjustment control signal corresponding to the type. According to the method, the problems of low recognition accuracy and insufficient intelligence of a traditional method under complex working conditions are solved, and high-robustness monitoring and active closed-loop correction of the phase sequence are realized.

The invention relates to a method for identifying a single-phase earth fault of a power distribution network based on a phase current break variable characteristic, which comprises the following steps of: acquiring a three-phase current signal according to a set theoretical sampling frequency, calculating an effective value of the three-phase current signal, and completing three-phase current power-on judgment when specific conditions are met at the same time; carrying out frequency tracking sampling frequency real-time sampling monitoring on the zero-sequence current, extracting a zero-sequence current break variable difference current curve, and carrying out fault starting condition judgment on the difference current curve; extracting three-phase current fault component waveforms from a fault starting point, and then performing low-pass filtering processing on the waveforms to obtain effective frequency band characteristic waveforms and power frequency component characteristic waveforms; and calculating the fault characteristic quantity, and executing different single-phase grounding fault positioning algorithms according to different types of neutral point grounding systems. According to the method, the single-phase grounding fault of the power distribution network is identified by adopting the technical principle of definite physical rules through phase current and zero sequence current signals.

The disclosure relates to a method for synchronising data of a power transmission line. The method comprises obtaining voltage measurements and current measurements from a local end and a remote end of the power transmission line; obtaining voltage and current phasors of the local end and the remote end using the voltage and current measurements; determining, whether synchronisation of the voltage and current measurements has been lost and determining a synchronisation angle based on the determination of whether synchronisation of the voltage and current measurements has been lost; and synchronising the voltage and current measurements using the synchronisation angle. Furthermore, a corresponding device and computer-readable storage medium are provided.

The invention belongs to the technical field of power grids, and relates to a voltage and current phase sequence recognition device based on single-phase voltage sampling and others, the phase sequence recognition device comprises a device power supply unit, a voltage sampling unit, three current detection units and a data processing unit, the device power supply unit is connected in parallel with the voltage sampling unit, and the three current detection units are connected in parallel with the data processing unit. The voltage sampling unit carries out voltage sampling on any phase line in the three-phase four-wire system power grid, the three current detection units carry out current sampling on each phase line of the three-phase four-wire system power grid, and the data processing unit reconstructs voltage signals of the other two phases according to voltage sampling models and current sampling signals. And identifying the phase sequence of the voltage and the current of the three-phase four-wire system power grid. According to the invention, the phase sequence identification of the three-phase line voltage and the three-phase current can be carried out only by sampling the single-phase voltage signal and the three-phase current signal, and the method has the characteristics of fast phase sequence identification speed and high efficiency, and also has the characteristics of simple installation, convenient use and plug-and-play.

The invention discloses a method and device for monitoring a burning loss hidden danger of metering equipment, and relates to the technical field of power systems. The method comprises the following steps: confirming a monitored electric energy meter corresponding to monitored metering equipment; acquiring data of a monitored electric energy meter to obtain monitored meter data, the monitored meter data including monitored meter voltage data and monitored meter current data; identifying the phase sequence of the voltage data of the monitored meter and / or the current data of the monitored meter to obtain a phase sequence identification result; according to the phase sequence identification result, extracting data corresponding to a target phase sequence from the monitored table data to obtain first phase sequence data; and according to the first phase sequence data, judging whether the metering equipment has a burning loss hidden danger or not. According to the method, the burning loss hidden danger of the metering equipment can be accurately identified, and the occurrence position of the burning loss hidden danger can be positioned.

The invention discloses a method for judging a voltage phase sequence of a high-voltage side of a transformer during grid connection of a low-voltage line of an interconnected power grid. The method comprises the following steps of: setting a maximum value theta m of an absolute value of a phase angle difference of phase voltages of nodes to be connected in parallel of two lines; a phase sequence indicator is used for determining the phase sequence of phase voltages of nodes to be connected in two lines, one line with the phase voltages of the nodes to be connected in the positive phase sequence is set as a line LL1, and the other line is set as a line LL2; the phase sequence of the voltage of the high-voltage side of the transformer connected with the line LL1 is A-B-C; measuring the phase difference delta between the a-phase voltage of the to-be-paralleled node of the line LL2 and the a-phase voltage of the to-be-paralleled node of the line LL1; and the phase sequence of the high-voltage side voltage of the transformer connected with the line LL2 is judged by comparing the angle interval where the phase angle difference delta is located. Detection is only carried out on the low-voltage line side, the phase sequence of the voltage on the high-voltage side of the transformer does not need to be directly detected, and the convenient and safe low-voltage line grid connection condition detection method is provided for electric power system dispatching personnel.

The invention discloses an ultra-high voltage nuclear phase correction method, device and equipment based on multi-source data fusion and a medium, and relates to the technical field of power grids, and the method comprises the steps: firstly obtaining the t-th round of multi-source data and a real phase value of ultra-high voltage equipment; and inputting the multi-source data into the pre-trained neural network model to generate a correction coefficient, correcting a phase value by combining the correction coefficient and the original phase value, and calculating a phase error with a real phase value. If the phase error exceeds the error threshold value and the adjustment frequency does not exceed the adjustment frequency threshold value, adjusting the gain of the acquisition equipment amplifier according to the electric field intensity, and re-acquiring the (t + 1) th round of multi-source data; and outputting a corrected phase value if the phase error reaches the standard. In addition, the correction phase value needs to be rechecked by two persons, and when the deviation exceeds a second threshold value, intelligent contract alarm and frozen combination ring operation are triggered; time deviation and a second phase error can be obtained through the current temperature, and secondary correction is carried out on the original phase value. According to the method, the nuclear phase precision and safety of the ultrahigh-voltage equipment can be improved.

The invention relates to an ammeter phase sequence adjusting method, a computer readable storage medium, a sampling device and a grid-connected power generation system, after an inverter is connected to a grid, if it is determined that reactive current output by the inverter reaches preset reactive current, reactive current increment of the inverter is calculated, and three-phase instantaneous current of a three-phase power grid is obtained; determining a current sampling phase sequence of the electric meter based on the reactive current increment, obtaining a three-phase voltage of the inverter and performing clark conversion to obtain a first voltage component and a second voltage component, determining a voltage sampling phase sequence of the electric meter according to the first voltage component, the second voltage component and the three-phase instantaneous current, and if the current sampling phase sequence or the voltage sampling phase sequence is incorrect, determining that the three-phase instantaneous current is correct. And exchanging the corresponding relationship between the sampling data corresponding to the incorrect current sampling phase sequence or the incorrect voltage sampling phase sequence and the preset assignment data, so that the current sampling phase sequence and the voltage sampling phase sequence are matched with the phase sequence of the signal output to the three-phase power grid by the inverter. The ammeter calculation correctness is improved, and the phase sequence adjustment efficiency is improved.

The application provides a power module test method, system, device and medium. The method is applied to a chip test device, the chip test device includes a probe card, the probe card includes a plurality of phase sequence modules, and each phase sequence module is connected with a drive board. For the plurality of phase sequence modules, when it is detected that a target drive board is powered on, the target drive board reads test configuration information from the phase sequence module, the target drive board generates a first target phase sequence drive voltage based on initial phase sequence voltage information in the test configuration information, when a drive instruction is received, the target drive board generates a drive signal, and based on the drive signal, the first target phase sequence drive voltage is transmitted to the power module under test through the phase sequence module at a target pin to drive the power module under test. Therefore, no matter how the drive board is placed, the phase sequence drive voltage generated by the drive board can be accurately matched to the corresponding phase sequence of the device through the power module under test, manual operation errors are reduced, and test safety is ensured.

The invention relates to a method for generating at least one item of information relating to the balancing of the phases of a power supply input (P), comprising: a. at least for each electrical output (Di), and preferably also for the power supply input (P), a step (E1) of measuring the currents of the various phases using a measuring device (30), in particular a measuring device arranged around the corresponding one or more conductors (34), this measurement being performed, in particular continuously, over a predefined period, the measurements being transmitted to a processing system (40); b. a step (E2) of generating, by the processing system (40), on the basis of the measurements, at least one item of information indicating the phase balancing of the power supply input and / or indicating at least one swap to be performed between two phases of at least one output (Di), wherein this swap serves to improve the phase balance of the power supply input (P).

The present disclosure provides a three-phase power supply phase sequence detection circuit and device. The three-phase power supply phase sequence detection circuit includes: a unidirectional conduction unit; an alarm unit, which is connected in series with the unidirectional conduction unit; a switch unit, which is connected in series with the alarm unit; a voltage stabilization unit, which is grounded after being connected in parallel with the alarm unit and the switch unit; a phase shift unit, which is connected in parallel with the voltage stabilization unit, and the phase shift unit is used to shift the phase of the single-phase power by 60 degrees backward; a triode, which is an NPN type, the base of the triode is connected to the phase shift unit, the emitter of the triode is connected to the control end of the switch unit, and the collector of the triode is connected to the voltage stabilization unit; wherein, when the phase of the single-phase power input by the unidirectional conduction unit lags behind the phase of the single-phase power input by the phase shift unit by 120 degrees, the alarm unit does not send out an alarm message. In a three-phase power supply phase sequence detection circuit and device of the present disclosure, the phase sequence of the three-phase power supply can be quickly judged, thereby effectively improving the installation efficiency of electrical equipment.

The invention belongs to the technical field of phase checking instruments, and particularly relates to a phase checking instrument with a phase checking function for a 10-kilovolt ring main unit switch. Comprising a mobile acquisition device and a handheld nuclear phase host, the mobile acquisition device comprises a mobile chassis, the mobile chassis is provided with a main supporting vertical plate, the main supporting vertical plate is provided with a lifting driving assembly, the lifting driving assembly is connected with a lifting mobile side plate, and the lifting mobile side plate is provided with a telescopic driving assembly. The telescopic driving assembly is connected with a telescopic moving side plate, the telescopic moving side plate is provided with a spacing adjusting assembly, the spacing adjusting assembly is connected with two mounting sleeves, the mounting sleeves are internally connected with acquisition emitters, and the acquisition emitters are used for performing signal acquisition on the ring main unit through acquisition points on the ring main unit; the collected information is wirelessly sent to the handheld nuclear phase host; the ring main unit phase checking device can effectively assist workers in phase checking operation of the ring main unit, labor is saved, operation efficiency is improved, and high efficiency of phase checking operation and accuracy of results are guaranteed.

The embodiment of the invention provides a low-voltage transformer area user phase determination method and device, equipment and a medium. The method comprises the following steps: firstly, acquiring a first power supply radius of a power user in a target low-voltage transformer area and first three-phase voltage data of the power user in a first preset duration; determining a second power supply radius of the at least one three-phase user and third three-phase voltage data corresponding to the at least one single-phase user, and then determining a user proportion value corresponding to a target three-phase user of which the second power supply radius of the at least one three-phase user is greater than a first preset threshold value; and finally, determining the phase of the at least one single-phase user according to the third three-phase voltage data corresponding to the at least one single-phase user, the user proportion value and a second preset threshold. According to the method provided by the invention, the determination of the user phase of the low-voltage transformer area is realized, and the identification efficiency and the identification accuracy of the user phase are improved.

The utility model is suitable for the technical field of phase checking instruments, and provides a portable intelligent phase checking instrument, which comprises an insulating rod and a signal transmitter matched with the phase checking instrument, one end of the signal transmitter is provided with a socket matched with the insulating rod in a threaded manner, and the other end of the signal transmitter is provided with a clamping unit. The clamping unit comprises two pincer handles which are arranged in a crossed mode, two pincer heads installed at the ends of the pincer handles and a driving unit for driving the two pincer handles to rotate in a crossed mode, the two pincer handles are rotationally installed in the signal transmitter through an installation shaft, arc-shaped grooves are symmetrically formed in the two pincer heads, and contact ends are arranged in the arc-shaped grooves. When the driving unit in the clamping unit drives the two clamp handles to rotate crosswise, the driving unit can drive the two clamp heads to clamp the line to be subjected to phase checking and enable the contact end to be in stable contact with the line, so that compared with contact with an electric power line in a contact hook mode in the prior art, the influence of strong wind weather on the detection of the phase checking instrument does not need to be worried, and the detection efficiency is improved. And the use and the operation of the nuclear phase instrument are convenient.

A system for discovering the topology and phases of a power distribution system is provided. For example, a group of meters connected to the power distribution system can process sensor data acquired at the meters and generate descriptors based on the processed data, sending the descriptors to a headend system. The headend system can, after receiving descriptors from the individual meters in the system, group the meters to generate groups by applying a clustering algorithm to the descriptors of these meters. The headend system can also compare the current group with past groups to determine the confidence level of the current group, and assign segment identifiers or phase identifiers, or both, to one or more meters based on the confidence level.

The present invention relates to the technical field of phase sequence detection, and discloses a phase sequence detection and adaptive adjustment method for an energy storage converter. The phase sequence detection method determines whether the phase sequence of the energy storage converter is positive or negative based on the per-unit value of the sampled voltage at a certain moment and the per-unit value of the voltage after a set delay duration. The present invention solves the problems existing in the prior art, such as large computational amount and much occupation of processor resources.

The utility model discloses a pre-debugging detection device before power-on of a power supply distribution unit, which is characterized in that a rectification unit converts single-phase alternating current into direct current, an inversion unit converts the direct current into three-phase four-wire system alternating current and provides the alternating current for the power supply distribution unit to be detected, and when a loop in the power supply distribution unit to be detected is abnormal, the power supply distribution unit is powered on. The inversion unit stops outputting, the phase sequence detection unit detects whether the phase sequence of the main bus in the to-be-detected power distribution unit is correct, and if the phase sequence is correct, the main bus is correctly installed; in the process of supplying power to the main bus of the PDU, if the power-on is abnormal, the inverter unit stops outputting, the detection device performs rapid protection, and bus faults can be checked in a focused manner subsequently; in the process of supplying power to the secondary loop of the PDU, the interlocking installation and wiring correctness of the PDU can be tested. Compared with detection after normal power-on of the PDU, the detection efficiency can be improved, the probability of short circuit occurrence is reduced, and the risk that the PDU is damaged is reduced; in addition, the device is portable, small in size and light in weight.

The present invention belongs to the technical field of smart substations, and specifically relates to a method and system for smart phase checking in substations. The method constructs a dynamic priority evaluation model, integrates multi-source data of four basic factors: voltage phase difference, ambient temperature and humidity, equipment vibration, and historical error, and uses a fuzzy comprehensive evaluation method to calculate weights and dynamically sort them. A multi-port phase scattering model is constructed based on the substation topology, and impedance mismatch points are analyzed with the help of a Smith chart to implement two-stage optimization. A three-layer decision input set is constructed based on the optimization model, and a fuzzy logic-driven adaptive rule engine is designed to dynamically output the operating condition level and match the phase checking strategy. Multi-dimensional quality assessment is performed through real-time monitoring of indicators such as reflection coefficient, dynamically updating factor weights, optimizing fuzzy model parameters, and integrating LSTM and graph neural networks to realize abnormal pattern recognition and compensation strategy solidification, forming a self-evolving closed-loop system, and ultimately achieving a transition from precise matching to autonomous evolution in the phase checking process.

The utility model provides a non-contact current nuclear phase device, which relates to the technical field of electric power detection and comprises a three-phase cable, a coil array, a signal receiving and processing device and an upper computer. The coil array, the signal receiving and processing device and the upper computer are electrically connected in sequence, and the coil array is arranged between the signal receiving and processing device and the three-phase cable. According to the utility model, the coil array is arranged between the signal receiving and processing device and the three-phase cable, so that the sensor is prevented from being too close to the cable, the measurement condition is looser, and the installation safety of the measurement device is better guaranteed; each coil group in the coil array is provided with two magnetic core-containing coils of which the sensitive directions are perpendicular to each other, interference signals can be better eliminated, each magnetic core-containing coil contains a manganese-zinc magnetic core, the sensitivity of the coils is enhanced, smaller current can be measured, longer-distance measurement can be realized, and the installation of the measuring device is more convenient.

To provide a phase detector jig for electrically connecting a phase detector to a measurement target when measuring phase rotation of the measurement target using the phase detector, which can be easily adapted to measurement targets of various forms and enables safe and quick measurement.SOLUTION: A phase detector jig comprises a plurality of types of measurement target contact heads 1 composed of a plug-in type head to be inserted into a plurality of types of outlets and a contact-type head that can be brought into contact with terminals and conductor parts, and an adapter 2 that can be connected to a phase detector 50, where one of the plurality of types of measurement target contact heads 1 can be freely connected to and disconnected from the adapter 2.SELECTED DRAWING: Figure 1

The utility model discloses a three-phase voltage, frequency and phase sequence detection circuit, and belongs to the technical field of electric power detection. The three-phase voltage, frequency and phase sequence detection circuit comprises an MCU control unit, an A-phase detection circuit, a B-phase detection circuit and a C-phase detection circuit, wherein the A-phase detection circuit, the B-phase detection circuit and the C-phase detection circuit have the same structure. Each detection circuit comprises a voltage sampling circuit and a frequency detection circuit. According to the utility model, the operational amplifier is used for scaling down the input voltage, and the input voltage is skillfully raised to a range which can be accurately sampled by the MCU, compared with a traditional transformer detection method, the size and the weight are greatly reduced, the waveform distortion is extremely small, the characteristics of an original voltage signal are accurately reflected, and the detection precision is greatly improved. The effects of small size, light weight, low cost and high detection precision can be simultaneously achieved.