2365results about "Power distribution line transmission" patented technology

The invention relates to the technical field of communication engineering, and discloses a power line carrier and wireless dual-mode fusion optimized communication method, which comprises the following steps of: 1, acquiring signal quality, noise and delay data of a power line and a wireless link in real time, and constructing a prediction model by utilizing historical data; step 2, dynamically adjusting a judgment threshold value of link switching in real time based on the prediction model, and ensuring that switching is triggered only when the signal change exceeds a preset range; step 3, based on the dynamic threshold, combining multiple indexes of signal-to-noise ratio, delay, packet loss rate and network load; according to the method, the necessity of link switching can be more intelligently judged by dynamically adjusting the judgment threshold of link switching and adopting a fuzzy logic decision mechanism, frequent switching during tiny fluctuation of signals is avoided by dynamic threshold adjustment, and a fuzzy logic system integrates multiple factors, so that the decision is finer, and the reliability of link switching is improved. And unnecessary delay and resource waste are reduced, so that the stability of a communication system is improved.

The invention provides an HPLC (High Performance Liquid Chromatography) station area cooperative communication method based on clock synchronization, which comprises the following steps: step 1, multi-dimensional data acquisition and broadcasting: each concentrator periodically acquires clock precision, stability and reliability data, and sends a beacon frame containing a timestamp and a health degree score through a power line carrier broadcasting channel; step 2, dynamically calculating the index distinction degree by using an entropy weight method, adaptively allocating weights, and electing an optimal main CCO in real time; step 3, dual-mode PID cooperative control: the main CCO adopts a dual-mode switching strategy of a dynamic PID algorithm and a chaotic fractional order PID algorithm; 4, monitoring a synchronization state in real time by constructing a clock check network, and optimizing a fault isolation strategy in combination with weighted scoring to realize that the state switching time of the master node and the slave node is less than or equal to 50ms; cooperative communication is realized on the basis of completing synchronization of the concentrators CCO in the whole network. Redundant message transmission is reduced through a dynamic parameter resynchronization mechanism, and the utilization rate of network resources is optimized.

The invention relates to the technical field of communication, in particular to an underground power distribution room communication system and method based on heterogeneous network and multi-modal fusion, and the system comprises a three-dimensional heterogeneous network cooperation module, a cross-modal feature fusion module, a dynamic routing decision engine module, a self-adaptive interference suppression system and a cross-layer cooperation optimization module. The three-dimensional heterogeneous network cooperation module comprises a 4G / 5G wireless communication sub-layer, a power line carrier communication sub-layer and an edge computing management sub-layer; the cross-modal feature fusion module comprises a multi-modal encoder group, a shared feature projection layer, a twin network structure and a cross-modal attention fusion module; and the dynamic routing decision engine module comprises a state space monitoring unit, a routing optimization unit and a millisecond-level path switching strategy. Through the arrangement, the reliability, the real-time performance and the energy efficiency of communication of the underground power distribution room are systematically improved, and a high-robustness communication infrastructure is provided for an intelligent power grid.

The invention relates to the technical field of power line communication, and discloses a frame synchronization method and device for broadband power line communication, and the method comprises the steps: carrying out the symbolization cross-correlation operation of a received signal, and obtaining a cross-correlation result sequence; performing secondary autocorrelation analysis and accumulation processing on the cross-correlation values in the sequence to generate an autocorrelation accumulated value sequence; screening candidate peak positions according to absolute values of the self-correlation accumulated values; defining a synchronous peak analysis window around the candidate peak position, and setting a noise reference window in an area far away from the window; verifying the validity of the candidate peak based on the difference between the autocorrelation accumulated values of the synchronization peak window and the noise reference window; and if the verification is valid, calculating and determining a final synchronization position through a mean value of a plurality of peak value positions in the synchronization peak window. According to the method, the problem of inaccurate synchronization peak positioning under the multipath effect and noise interference in the existing method is solved through the self-correlation accumulation and noise separation mechanism, and the reliability of frame synchronization is improved.

The invention discloses a power line carrier signal synchronization method and device, and belongs to the technical field of power line carrier communication. The method comprises the following steps: under the condition that a signal sequence is received, determining an autocorrelation result based on a known signal sequence; under the condition that the self-correlation result exceeds a dynamic threshold value, determining an effective correlation peak; the dynamic threshold is dynamically updated along with the change trend of the plurality of self-correlation results; and starting signal synchronization under the condition that the effective correlation peak and the historical effective correlation peak form a continuous correlation peak. According to the invention, through combination of cross-correlation and self-correlation, accurate detection of effective correlation peaks is realized, a dynamic threshold and continuity verification mechanism is introduced, the accuracy and robustness of signal synchronization are improved, the synchronization misjudgment rate can be significantly reduced, and the synchronization efficiency is improved.

The invention discloses a method for improving transformer area crosstalk of HPLC (High Performance Liquid Chromatography) and micropower wireless dual-mode communication, which comprises the following steps of: S1, electrifying an acquisition terminal equipment node, and aligning signal acquisition time windows of two communication modes; s2, combining the obtained dual-mode signal parameters with a preset transformer area topology database to generate feature vectors of multi-dimensional features; s3, training to generate a random forest model, inputting feature vectors of multi-dimensional features, dynamically calculating the affiliation weight value of the transformer area, and carrying out nonlinear weighted calculation on the feature vectors; and S4, on the basis of weight comparison and transformer area boundary node processing, correcting measurement errors by combining the transformer area attribution weight value with a preset impedance shielding compensation algorithm, generating a unique transformer area identifier, locking a networking relationship, and executing transformer area attribution judgment. According to the method, the wide coverage advantage of HPLC is reserved, meanwhile, the space attenuation characteristic of wireless communication is used for achieving accurate recognition of the transformer area boundary, and the installation and acquisition stability of the use and acquisition terminal equipment can be improved.

The invention relates to the technical field of intelligent power supplies, in particular to an intelligent power supply for an unattended station. Comprising a multi-source power supply scheduling unit; an intelligent energy storage management unit; a double-link communication unit; the double-link communication unit is used for constructing a multi-redundancy communication link of wired, wireless and power line carriers, and the double-link communication unit is based on link quality data, adopts an automatic switching strategy to guarantee data transmission continuity, preprocesses monitoring data by using an edge side data clustering algorithm, and realizes offline data caching and transmission flow optimization. Through a multi-source energy dynamic scheduling strategy, according to photovoltaic real-time output, commercial power time-of-use electricity price and load electricity demand, power supply paths of photovoltaic, commercial power and a storage battery can be dynamically optimized, the consumption proportion of clean energy is improved, the dependency degree of high-cost commercial power is reduced, a complex energy structure of photovoltaic, commercial power and storage battery multi-energy complementation is effectively adapted, and the energy utilization rate is improved. And power supply flexibility is enhanced.

The invention relates to the technical field of electric power communication, and discloses a district physical topology identification method based on dual-mode communication signal strength, comprising the following steps: S1, building a district network; s2, topology identification is started, self initialization is completed, and necessary environment preparation before topology identification is carried out; s3, adding STA operation participation data one by one until all STA data are added; s4, identification calculation is started, branch calculation is carried out through HPLC signals of neighbor STAs by adopting a mode of selecting a rated threshold value, meter box calculation is carried out through HRF signals of the neighbor STAs, and relevancy ranking is determined; and S5, obtaining a topology result, and ending identification. According to the method, identification of the physical topology of the transformer area can be completed without additional equipment and manual intervention, and the method is safe, convenient and high in practicability. In the recognition process, the method is not affected by load voltage and current changes and the length of a power line, and compared with an existing impedance calculation and time delay calculation scheme, the recognition accuracy is high.

The invention relates to the technical field of carrier communication, and particularly discloses a power line carrier channel simulation method and system based on a dynamic multi-dimensional interference model.The power line carrier channel simulation method based on the dynamic multi-dimensional interference model.The power line carrier channel simulation method based on the dynamic multi-dimensional interference model comprises the steps that a power line noise sample is collected, and characteristic parameters of periodic interference, transient noise and background noise are extracted; classifying and marking according to noise types and corresponding power grid working conditions, and establishing a noise database containing a mapping relation between noise characteristics and working conditions; and based on the noise database, respectively establishing a periodic interference model, a transient noise model and a background noise model, and forming a multi-dimensional noise interference model. According to the power line carrier channel simulation method based on the dynamic multi-dimensional interference model, through multi-dimensional noise modeling and dynamic environment adaptation, the precision, the real-time performance and the scene coverage capability of power line carrier communication simulation are remarkably improved, and the simulation bottleneck in a complex power grid environment in the prior art is solved.

The invention discloses an HPLCamp (High Performance Liquid Chromatography) based on deep learning. The invention discloses an HRF dual-mode communication adaptive coding modulation and anti-noise method. The method comprises the following steps: acquiring an optical radio frequency signal amplitude-phase change rate and synchronously sampling and normalizing; calculating a node amplitude-phase residual error to generate a nonlinear mapping coefficient; monitoring coherent change to solve a drift trend, adjusting a modulation coding optimization scheme, compensating distortion and outputting an anti-noise result. According to the method, the instantaneous amplitude and phase of the optical radio frequency dual-mode signal are extracted, a multi-dimensional amplitude-phase characteristic matrix is formed in combination with time domain synchronization and a normalization template, differential residual modeling and nonlinear mapping coefficient calculation are carried out between impedance nodes, and dynamic compensation of amplitude-phase mismatch and envelope offset is achieved. A drift trend quantity is generated based on coherent offset parameter differentiation, feedback is provided for modulation format and coding strategy optimization, amplitude equalization and phase correction are completed, the signal synchronization degree and amplitude-phase consistency are improved, and the steady-state response and anti-disturbance performance of a transmission link are enhanced.

The invention discloses a network communication dynamic optimization method based on multi-module collaboration, and relates to the technical field of network communication, a dual-mode communication module is deployed at each network node, and the network communication dynamic optimization method comprises the following steps: each network node broadcasts own existence information and power line channel characteristics through an HPLC (High Performance Liquid Chromatography) channel of the dual-mode communication module; each network node scans surrounding wireless networks through an HRF channel of the dual-mode communication module and reports own wireless channel quality information to the gateway; the global state sensing module collects all information and constructs a global network view containing physical topology and a channel quality map. A dual-mode cooperation mechanism, a machine learning prediction model and a dynamic decision strategy can adapt to complex dynamic environments such as power line noise fluctuation and wireless interference change, and communication parameters can be autonomously optimized without manual intervention; and meanwhile, the modular design is convenient to expand to a multi-mode communication scene, and has a wide application prospect.

The invention discloses a power line carrier communication protocol data link layer simulation method, which comprises the following steps of: constructing a physical layer interface simulation module, simulating power line carrier or wireless air interface transmission through TCP socket communication, and creating a high-priority task process to process time slot-level time sequence synchronization for triggering a physical layer transceiving action at a specified time slot; configuring a time sequence synchronization control mechanism, obtaining a timestamp carried by a beacon frame sent by a concentrator, calling a clock synchronization function to align a site local clock with the timestamp when receiving the head of the beacon frame, adding delay compensation before sending data, and delaying and starting a physical layer receiving action to offset IP network transmission delay when receiving the data; a data frame processing flow is realized, a header callback function is controlled through a registration frame to respond to a physical layer state change, TCP message data is cached by using an annular queue, and a physical layer interface simulation module analyzes a message, distributes a memory and processes a load at a specified time slot after time sequence synchronization.

The invention relates to the technical field of intelligent power grid communication, and discloses an HPLC communication-oriented power topology adaptive reconstruction and energy consumption optimization control method, which comprises the following steps of: acquiring HPLC communication characteristic data of power network nodes in real time; constructing a dynamic spatio-temporal topological graph based on the communication feature data and predicting a future topological state; generating a communication power distribution and routing path joint optimization strategy by using a multi-target reinforcement learning algorithm in combination with the predicted future topology state and the real-time energy consumption parameter; verifying the electromagnetic compatibility and protocol compliance of the optimization strategy through a digital twin model, and generating a control instruction which can be executed by equipment; and the transmitting power and the communication route of the HPLC node are dynamically adjusted through the control instruction. According to the method, the communication quality stability and the energy efficiency level are improved, topology dynamic perception, multi-target collaborative optimization and strategy security verification are realized, and efficient and reliable operation of HPLC communication in a complex power grid environment is guaranteed.

The invention relates to the technical field of communication, in particular to a communication method based on a power line carrier communication system adopting OFDM (Orthogonal Frequency Division Multiplexing), which comprises the following steps: S1, a transmitting end performs OFDM modulation on an original data stream to generate an OFDM signal; s2, the transmitting end transmits the OFDM signal to a receiving end through a power line; s3, the receiving end performs analog-to-digital conversion on the received OFDM signal to obtain a digital baseband signal, and the sampling frequency of the analog-to-digital conversion is higher than the sampling frequency during OFDM modulation; s4, the receiving end performs discrete Fourier transform on the digital baseband signal to obtain a frequency domain data symbol; and S5, the receiving end demodulates and decodes the frequency domain data symbol to obtain a received data stream. According to the method, OFDM modulation is carried out on the original data stream, so that the spectrum utilization rate is improved, the capability of resisting the multipath effect is enhanced, and efficient transmission in a complex power line environment is ensured.

The invention relates to a power line network topology estimation method and device and computer equipment. The method comprises the following steps: sending a modulation signal, and receiving a plurality of reflection signals corresponding to the modulation signal; determining a path length set and a current topological structure according to the signal propagation time corresponding to each reflected signal; the signal propagation time is a time difference between the sending time of the modulation signal and the receiving time of the reflection signal; selecting an expansion node from the current topological structure, and updating the current topological structure according to the expansion node and the path length set; the extension nodes are unselected nodes in the current topological structure. According to the topology estimation method, the complexity and cost of system deployment are reduced through a single modem implementation method, the topology structure is updated by analyzing the expansion nodes, dynamic network changes are supported, the applicability of the topology estimation method is improved, and the efficiency of topology network management and maintenance is improved.

The invention provides an alternating current charging pile power line carrier control method, a medium and a system, and belongs to the technical field of alternating current charging piles. Real-time channel characteristic detection is carried out on a charging pile power line to obtain dynamic channel state parameters, forward error correction coding processing is carried out on a charging pile control instruction to obtain a coded carrier data frame, and the coded carrier data frame is sent to the medium; a double-layer coupling game control model is utilized to calculate transmission parameters, coupling optimization of upper and lower game models is realized through a grey wolf optimization game algorithm to obtain an optimal carrier transmission parameter set, and working parameters of a power line carrier transmitter of the charging pile are adjusted according to the optimal parameter set to realize carrier communication. And meanwhile, a comprehensive evaluation index output by the carrier parameter dynamic adjustment function is fed back to the double-layer coupling game control model to form closed-loop iterative optimization, so that the technical problem that carrier communication parameters cannot be adaptively adjusted in real time due to dynamic change of power line channel characteristics along with factors such as load change and switching operation is solved.

Disclosed are a power line communication method and apparatus, comprising: a first device generating a physical layer protocol data unit (PPDU) frame, the PPDU frame comprising a frame control field, a training symbol field, and a load symbol field, the load symbol field being used for modulating and transmitting a load symbol, the training symbol field being used for bearing a training symbol, and the load symbol field being used for receiving the training symbol; the training symbol field is used for channel estimation of multiple input multiple output (MIMO) and extended bandwidth, the frame control field comprises a variable region field, the variable region field comprises a frame identification field and a frequency band field, the frame identification field is used for indicating a frame type of a frame start (SOF) frame included in the PPDU frame, and the frequency band field is used for indicating an available frequency band of a training symbol and a load symbol; and the first device sends the PPDU frame to the second device. According to the embodiment of the invention, through the redefined PPDU frame, the power line communication supports the characteristics of MIMO, large bandwidth and the like, so that the overall network performance is improved.

The invention relates to the technical field of dual-mode communication, and particularly discloses a dual-mode communication distribution method and device based on power line carrier and wireless communication, and the method comprises the steps: receiving a plurality of data communication requests sent by a user terminal, performing embedded coding of each communication event and each demand description in a plurality of data communication requests by using a data analysis and distribution mode based on artificial intelligence, and then performing semantic fusion on each group of coded communication event embedded features and demand description embedded features; weight of power line carrier communication and weight of wireless communication are automatically allocated according to a significant aggregation representation of attention complementation features between respective plurality of data communication request embedding semantic fusion features. According to the invention, the weight between the power line carrier communication and the wireless communication can be dynamically adjusted according to the change of the real-time communication environment and the user demand, and the communication quality is ensured not to be affected.

A power-over-Ethernet (PoE) PD / PSE device comprises a powered device (PD) interface configured to connect to an upstream power sourcing equipment (PSE) and receive input PoE power from the PSE, and a PSE interface configured to connect to a downstream PD and to supply output PoE power to the PD. The PD / PSE also comprises a device power rail to supply operational power to one or more components of the PD / PSE, and a DC-DC converter comprising a multi-output transformer comprising a transformer input, a first transformer output electrically connected to the PSE interface, and a second transformer output electrically connected to the device power rail. The DC-DC converter is configured to receive the input PoE power and, in response, supply the input PoE power to the transformer input, generate the output PoE power at the first transformer output, and generate the operational power at the second transformer output.

The invention discloses an HPLC and HRF multi-node ad hoc network type dual-mode communication system based on a power system, which comprises a concentrator communication module, an electric meter communication node module and a remote monitoring terminal, and is characterized in that the electric meter communication node module comprises a plurality of communication nodes, and a dual-mode communication module is embedded in each communication node; a power line carrier module and a micro-power wireless module are integrated in each dual-mode communication module. The invention relates to the technical field of electric power communication. According to the HPLC and HRF multi-node ad hoc network type dual-mode communication system based on the electric power system, a wireless routing beam pair with the strongest signal can be automatically predicted and selected to establish communication connection with an on-site maintenance mobile terminal, so that the transmitting power of a concentrator communication module is reduced, and the minimum power consumption of data information transmission is ensured; according to the invention, the purpose of enabling the on-site routing transmission to achieve the optimal power consumption by tracking and predicting the on-site mobile terminal in real time is achieved, so that the power communication resources are greatly saved.

The invention relates to the technical field of electric power communication, in particular to a remote control system and method for a multimode communication chip of a middle-high voltage power line, and the system comprises a communication chip module, an edge node module, a central server module and a block chain network module. And the verification module is used for verifying the consistency of the cooperative control instruction and recording equipment state data. Based on a multi-mode converged communication architecture of carrier communication, microwave communication and laser communication, reliable communication in a middle and high voltage power line environment is realized through an intelligent switching and cooperative working mechanism. And the power line channel state, the service requirement and the frequency spectrum use condition can be monitored in real time.

The invention discloses an intelligent monitoring method and system based on dual-mode communication, and relates to the technical field of dual-mode communication, and the method comprises the steps: obtaining basic data information, extracting multi-dimensional signal features to construct a spectrum feature library, and calculating the real-time noise similarity; calculating a cross mode support degree between the double signals according to the multi-dimensional signal features; acquiring propagation characteristics of all nodes in a second range, and generating a secondary anomaly propagation graph; analyzing causal features according to the secondary anomaly propagation graph, determining a causal path, identifying a risk index to obtain a risk index, and predicting a threat level; the noise interference condition is quickly identified, different conditions of the communication problem and the noise interference are effectively distinguished, and the noise identification accuracy is improved; time domain complementarity and space domain collaboration of an HPLC mode and an HRF mode are quantified, a single-mode sensing blind area is eliminated, a feature fusion strategy is dynamically adjusted, and monitoring accuracy is improved.

The invention discloses a power line carrier signal synchronization method and device based on an OFDMA system, and belongs to the technical field of power line carrier communication. The method comprises the following steps: performing cross-correlation processing on a received signal and a reference sequence to obtain a target cross-correlation result, and performing self-correlation operation on the target cross-correlation result and a target historical cross-correlation result to obtain a target self-correlation result; analyzing the position of a first target autocorrelation peak in the received signal based on the target autocorrelation result; the first target autocorrelation peak is the autocorrelation peak with the maximum peak value in the received signal; determining a first window including the first target autocorrelation peak according to the position of the first target autocorrelation peak; and determining the position of a synchronization peak in the received signal based on the position of the autocorrelation peak in the first window. According to the invention, the autocorrelation peak is determined by combining cross-correlation and autocorrelation, and the position of the synchronization peak is determined by integrating the position of the autocorrelation peak in the first window, so that the accuracy of signal synchronization is improved.

The invention discloses a power supply communication method and device based on power line carrier communication, and relates to the technical field of power supply communication. Problems of signal attenuation, insufficient anti-interference capability, insufficient stability of power supply communication, insufficient intelligent path switching capability and the like exist in the prior art. According to the method, high-sampling-rate PSD analysis, STFT and LSTM are adopted to predict noise power time sequence data, and a noise-load rate coupling model is established; secondly, based on a transmission line theory, researching channel time-varying characteristics, calculating signal reflection and multipath effects, and calculating channel coherence time through a sliding window; for signal attenuation, low, medium and high frequency band models are respectively established, path attenuation is calculated, and channel capacity is optimized; and finally, through real-time stability analysis, short-term and long-term SNR stability is calculated, and path selection is optimized in combination with a load rate, so that communication quality is ensured. And through integration of channel modeling, time-varying analysis and path optimization, the reliability and stability of power line carrier communication are improved.

The invention discloses a communication data transmission method and system for an intelligent charging pile, and relates to the technical field of intelligent charging pile communication, and the method comprises the steps: constructing a reverse power line transmission channel model based on an equivalent channel response matrix, extracting channel frequency response, generating a channel equalization configuration parameter set through a joint optimization equalization algorithm, and transmitting the channel equalization configuration parameter set to a communication module. Subcarrier modulation orders are dynamically allocated according to the signal-to-noise ratio parameter, and a pre-balanced OFDM time domain signal is generated; on the basis of the channel equalization configuration parameter set and the pre-equalization OFDM time domain signal, dynamically monitoring power frequency harmonic noise of the cable, and inhibiting interference through a filtering algorithm to generate a clean power line carrier signal; and generating a verified V2G communication control instruction through a cyclic redundancy check method based on the clean power line carrier signal in combination with the main polarization direction feature vector. According to the method, an accurate channel model is constructed by combining an equivalent channel response matrix and cable characteristics, and dynamic subcarrier distribution is realized based on signal-to-noise ratio parameters.

The invention relates to an intelligent power distribution network fault positioning method and system based on HPLC (High Performance Liquid Chromatography) multi-modal communication, and relates to the technical field of power system automation, and the method comprises the following steps: S1, constructing a multi-modal communication link through an HPLC communication network and at least two auxiliary communication networks, and dynamically selecting an optimal communication channel; s2, collecting multi-source fault data of the power distribution network monitoring terminal in real time through the selected communication channel, and performing encryption transmission; s3, performing space-time fusion processing on the transmitted fault data to generate a space-time correlation feature vector; s4, based on the space-time correlation feature vector, extracting fault space-time features through a deep learning model; and S5, in combination with the power grid topological structure and the fault spatio-temporal characteristics, performing fault positioning decision. Through a multi-modal communication link dynamic preferential mechanism and a space-time fusion processing model, the problem of time delay sensitivity of traditional single-channel transmission is effectively solved, and stable fault feature extraction capability can be maintained under the conditions of strong noise interference and partial data missing.

The invention discloses a method for switching between a first communication mode and a second communication mode, and the method comprises the steps: determining a dual-mode phase difference between a first mode baseband signal and a second mode parameter based on the first mode baseband signal and the second mode parameter; generating an interleaved phase coding sequence in response to the dual-mode phase difference; pre-modulating the first mode signal in parallel before switching by using the coding sequence, and generating a pre-activated second mode virtual signal; switching from the first mode to the second mode is executed based on a parallel fusion phase track generated after the phases of the two preprocessed signals are subjected to time-varying weighted fusion. According to the method, a smooth switching track is constructed through parallel phase preview and phase domain fusion, phase continuity and frequency stability in the switching process are ensured, switching time delay and the data error rate are remarkably reduced, and the communication service quality of the heterogeneous network is improved.

The invention provides a communication method and system based on HPLC and HRF dual-mode fusion, belongs to the field of power line carrier communication, and solves the problem that the communication performance is still insufficient in a three-phase four-wire system low-voltage power grid environment. The method comprises the following steps: in a high-speed power line carrier communication channel of a three-phase four-wire system power grid, dynamically learning an electric phase of each terminal through a carrier coupling success rate, constructing an electric phase identification model, and recording communication characteristics of a phase line to which each terminal belongs; identifying link isolation states among different phase lines by combining an electric phase communication map generated on the concentrator side based on the phase information of each terminal; and under the condition of determining that a cross-phase communication bottleneck exists based on the link isolation state, executing a preset collaborative packet sending optimization strategy, and in the optimization process, establishing an out-phase relay path through a high-speed wireless communication channel.

The invention relates to the technical field of frequency band detection, in particular to a broadband power line carrier communication frequency band detection method and a broadband power line carrier communication frequency band detection system. According to the difference between energy corresponding to each peak value in the modal component and the peak width ratio of each peak value, obtaining a characteristic value of the modal component influenced by interference, and according to the difference between the frequency range of the modal component and the frequency range of energy change, obtaining the interference degree of each modal component, and obtaining a signal adjustment coefficient to adjust a wavelet threshold value; and analyzing the difference between the signal-to-noise ratios of the filtered modal components, reconstructing the modal components, and obtaining the working frequency band of the power line carrier communication signal according to the similarity between the reconstructed signals and the standard signals of the frequency bands corresponding to the modal components in combination with the bit error rate of the frequency bands. According to the invention, more accurate broadband power line carrier communication frequency band detection can be realized.

The invention discloses a power grid system time service method and system based on a Beidou satellite, and relates to the technical field of power grid system time service, and the method comprises the following steps: obtaining a Beidou satellite signal through a Beidou ground control center, and generating a time frequency reference signal; transmitting the time frequency reference signal to each level of node through a communication network of a power system; and deploying a Beidou time service processing module in local side equipment of the power system, processing the received time frequency reference signal, and generating a system clock signal consistent with the Beidou satellite time reference. According to the invention, triple guarantee is formed through Beidou satellite signals and a dual-channel transmission architecture, i.e., an optical fiber channel and a power line carrier channel; when any transmission channel has a fault, the redundancy switching module automatically selects an optimal path, namely a time delay deviation gt is passed; the threshold triggers switching, and after the Beidou signal is interrupted, a hierarchical timekeeping strategy (atomic clock-adjacent node synchronization-power frequency synchronization) is started.