521 results about "Signal injection" patented technology

The invention discloses a wireless communication anti-interference method and system based on data analysis, and belongs to the technical field of communication anti-interference, in the wireless communication anti-interference method and system based on data analysis, the active defense capability of the system to unknown interference is improved through virtual interference generation and physical suppression by linkage cooperation of a generative adversarial network and an adaptive beam forming algorithm. The generator continuously simulates a novel interference signal injection training environment, so that a beam forming algorithm learns in advance to form accurate null in an interference direction, and the response time when actual interference occurs is greatly shortened. Meanwhile, interference space features detected by the beam forming module in an actual scene reversely optimize a signal construction rule of the generator, and the matching degree of a generated sample and a real electromagnetic environment is enhanced. The dynamic mutual promotion mechanism not only enhances the timeliness of interference suppression, but also reduces the problems of signal quality fluctuation and excessive consumption of hardware resources caused by passive response in the traditional scheme.

The invention discloses an operation state fault monitoring method, system and device for a heavy-load overhead line, and relates to the technical field of electrical fault detection of the heavy-load overhead line. The method comprises the following steps: injecting a high-frequency test signal into a heavy-load overhead line to carry out predefined fault detection so as to obtain a total harmonic distortion rate; performing first harmonic optimization adjustment according to comparative analysis of the total harmonic distortion rate and a threshold value; performing harmonic second optimization adjustment according to the monitoring analysis result of the external load fluctuation of the heavy-load overhead line; and performing harmonic third optimization adjustment according to the monitoring analysis result of the external environment fluctuation of the heavy-load overhead line. According to the invention, through multi-stage distribution adjustment, the effect of improving the dynamic regulation and control accuracy of the high-frequency test signal injection fault monitoring method of the heavy-load overhead line in extreme weather is achieved; the problem of insufficient dynamic regulation and control accuracy of a high-frequency test signal injection fault monitoring method of a heavy-load overhead line in extreme weather exists.

The invention relates to the technical field of cable positioning, in particular to a one-way grounding fault positioning method based on a signal injection method. The method comprises the following steps: installing an impedance detection unit at a grounding knife switch of a transformer substation, and injecting a controllable AC signal into a power transmission line through a built-in injection coil to enable the line to be in an open circuit state; collecting the injected current signal and performing frequency enhancement to extract the amplitude and phase of a target frequency component; zero-sequence impedance is calculated based on the injection voltage and current, and the zero-sequence impedance is compared with a preset impedance model to judge single-phase grounding; and when a fault is detected, determining a fault distance, a tower position and a grounding phase according to an impedance difference matching result, thereby realizing accurate positioning. According to the invention, by injecting the controllable AC signal into the power transmission line and combining frequency enhancement, phase self-calibration and impedance difference matching analysis, high-sensitivity detection, high-stability signal extraction and high-precision positioning of the single-phase earth fault are realized.

The invention discloses a micro-mechanical gyroscope zero offset online temperature compensation method based on Q value active control, and belongs to the technical field of micro-mechanical gyroscope zero offset temperature compensation. According to the method, on the basis that asymmetry of quality factors of a driving mode and a detection mode is a main cause of an in-phase zero offset error, improvement of in-phase zero offset is achieved in a mode of controlling the quality factors of the modes through parametric excitation. According to the method, online identification of the intrinsic quality factor and the equivalent quality factor of the detection mode is realized by using a signal injection method, and online compensation of the equivalent quality factor is realized through parametric excitation. The method solves the problem of zero offset error drift caused by mismatching of quality factors of a driving mode and a detection mode in a temperature change environment, and a universal scheme is provided for the zero offset temperature stability of the high-performance micromechanical gyroscope.

The invention relates to the technical field of power cable fault detection and positioning, in particular to a middle and high voltage cable insulation defect live detection and positioning method, which comprises the following steps: step 1, injecting a composite detection signal into a cable conductor through a signal injection device; 2, arranging signal acquisition devices at a plurality of preset point positions of the cable; step 3, carrying out adaptive processing on the acquired response signal; step 4, extracting insulation defect features from the response signals after adaptive processing; step 5, based on the extracted insulation defect features, classifying defect types by using a pattern recognition algorithm, and calculating defect positions based on a signal propagation time difference principle; and 6, outputting a defect identification and positioning result to a monitoring system, verifying, and if the deviation between the positioning result and historical data exceeds a threshold value, re-executing the steps 1 to 5. By combining a multi-point synchronous measurement technology and a precise space-time analysis method, the position where the defect occurs can be positioned more accurately.

The invention discloses a permanent magnet motor turn-to-turn short circuit fault diagnosis method considering complex working condition influence, belongs to the technical field of permanent magnet motor fault diagnosis, and aims to solve the problems that a turn-to-turn short circuit diagnosis result of a permanent magnet synchronous motor for an electric vehicle is easily influenced by working conditions and slight faults are difficult to diagnose under complex operation working conditions. The method comprises the following steps: step 1, high-frequency signal injection and information acquisition; injecting the high-frequency rotating voltage signal into a motor control system under a natural coordinate system, and collecting each phase of high-frequency current and each phase of high-frequency voltage of the motor through a band-pass filter; 2, subtracting the high-frequency voltage from the healthy voltage under the condition that the high-frequency signal is injected, and calculating to obtain a high-frequency voltage residual error of each phase; 3, according to the high-frequency voltage residual error of each phase, obtaining two fault characteristic quantities, namely the standard deviation of the high-frequency voltage residual error and the absolute average value of the high-frequency voltage residual error of each phase; and 4, judging whether a turn-to-turn short circuit fault occurs or not according to the fault characteristic quantity, and judging a fault phase.

The invention specifically relates to a standardized fuse fault monitoring and diagnosis system, and relates to the technical field of power system protection equipment monitoring. A signal processing and impedance spectrum calculation module; an intelligent diagnosis and state evaluation module; and a benchmark management and personalized tracking module. According to the invention, controllable micro test signals are actively injected to obtain frequency domain impedance fingerprints, and accurate capture of microscopic degradation is realized; non-intrusive coupling and signal injection are adopted, the topology of a main loop does not need to be changed, the inherent protection characteristic of the fuse is guaranteed, and power frequency interference can be penetrated; the recognition amount of budding faults such as contact oxidation and melt corrosion is improved in advance, and power failure accidents caused by fault expansion are avoided.

The invention relates to the technical field of micro-grids, and provides a network construction type energy storage system reconstruction method and system based on dynamic impedance matching, and the method comprises the steps: obtaining the real-time impedance and real-time reactance of an associated power grid through a high-frequency disturbance signal injection decoupling mode; meanwhile, according to the voltage phase angle and the voltage drop depth of the associated power grid, respectively obtaining a phase compensation item and a dynamic adjustment coefficient, so as to dynamically adjust the virtual impedance through the phase compensation item and the dynamic adjustment coefficient; and real-time output of the target energy storage system is regulated and controlled by combining closed-loop control of the impedance outer loop and the voltage inner loop, so that voltage offset and broadband oscillation of the associated power grid are suppressed. According to the invention, the phase compensation item obtained according to the voltage phase angle and the dynamic adjustment coefficient obtained according to the voltage drop depth are added to the calculation of the virtual impedance, and the closed-loop control of the impedance outer loop and the voltage inner loop is combined, so that transient impact suppression and oscillation suppression can be realized at the same time, the limitation of separate triggering is effectively avoided, and the reliability of the system is improved. And the power grid voltage stabilization control effect is improved.

The invention relates to an electrostatic vibrating diaphragm automobile audio which is mainly used for an electric vehicle and can compensate vehicle-mounted electromagnetic interference audio and solve the problem of electromagnetic interference of a motor PWM switch and rotating speed harmonics on an audio system. The electrostatic diaphragm automobile sound system comprises an electrostatic diaphragm loudspeaker and an interference feature extraction module, the rotating speed of a motor and the PWM frequency are obtained through a CAN bus, and a dynamic interference feature set is analyzed and extracted through adaptive window length FFT; the EMI quantification module is used for calculating an electromagnetic pollution index at a frequency band of 8kHz-20kHz, and triggering compensation when the electromagnetic pollution index exceeds a threshold value of-40dB; the dynamic notch compensation module is used for generating an inversion signal; according to the double-loop feedback control module, the amplitude is adjusted through PID of an inner loop, and the phase is optimized through gradient descent of an outer loop so as to minimize THD. The method comprises five steps of signal acquisition, feature extraction, interference quantification, dynamic compensation and signal injection. Interference frequency drift can be accurately tracked, a tone quality MOS value is improved after compensation, and an over-compensation risk is avoided.

The invention relates to the technical field of power system protection, in particular to an underground power distribution network single-phase grounding protection system and method based on a signal injection method. The system comprises a signal acquisition module, a measurement and control protection module and an online monitoring module. According to the invention, by injecting the independent direct current signal and combining a zero-sequence fundamental wave time sequence identification algorithm and a traveling wave distance measurement method, rapid detection, high-precision positioning and selective protection of the single-phase earth fault of the underground low-voltage power distribution network are realized, and the method is suitable for complex environments such as coal mines and metal mines; through insulation value on-line monitoring and electric leakage protection, the ground insulation value level of a line is reflected to the voltage change of an additional direct current signal and a reactor neutral point. A zero-sequence fundamental wave time sequence identification model is adopted for electric leakage fault judgment so as to judge the fault type. By outputting a relay signal, on-off control is performed on a protected branch, so that a fault line can be quickly cut off when a fault occurs, and equipment and a bus are protected from being damaged by the fault.

The invention discloses a permanent magnet synchronous motor full-speed-domain position-sensorless hybrid control method and a permanent magnet synchronous motor full-speed-domain position-sensorless hybrid control system, and the permanent magnet synchronous motor full-speed-domain position-sensorless hybrid control method is constructed by taking a permanent magnet synchronous motor nonlinear dynamic system model as a starting point. A hybrid control method combining high-frequency pulsating square wave signal injection under a linear dynamic system model, a rotor polarity judgment and rotor initial position estimation algorithm and an unscented Kalman filtering extension algorithm in an additive noise form under a nonlinear discrete dynamic system model is adopted; and obtaining the optimal estimation observation value of the system state variable in the static, low-speed, medium-speed and high-speed full-speed domain range under the condition that the permanent magnet synchronous motor is not provided with a mechanical position sensor. The optimal estimation observation value is used for compensating and feeding back a permanent magnet synchronous motor drive control system adjusting strategy, disturbance of load torque is improved, the noise amount and disturbance amount introduced by three-phase current measurement are eliminated, and efficient and accurate control operation of the permanent magnet synchronous motor is achieved.

The invention discloses a permanent magnet synchronous motor sensorless control method based on a dynamic position error. A transition stage is provided, per-unit estimation position errors between a first position error signal obtained based on a high-frequency signal injection method and a second position error signal obtained based on a sliding mode observer are compared, an optimal switching speed point is dynamically determined, smooth fusion is carried out on the two position errors by using a nonlinear weighting function, and the optimal switching speed point is obtained. And finally, the estimated position and rotating speed are obtained through a phase-locked loop. And finally, position tracking is carried out by adopting different error signals according to the estimated rotating speed. According to the method, the problem of estimation value pulsation and jump caused by the fact that a traditional method depends on fixed experience switching points is solved, smooth and self-adaptive switching of the two estimation methods in the full-speed domain range is achieved, the control precision and operation stability of the system are remarkably improved, the structure is simple, and engineering implementation is easy.

The invention provides a mining motor no-load and load characteristic test analysis method and system, and relates to the field of intelligent image analysis, a Hall array sensor is arranged on a motor stator tooth portion to collect air-gap magnetic field distribution data, and a high-frequency signal injection method and a wavelet singular value decomposition technology are combined, so that the load characteristic of a mining motor is obtained. The air gap magnetic field distortion degree and the air gap dynamic eccentricity index are accurately calculated, and meanwhile a load dynamic compensation coefficient is generated to correct the motor output torque. Therefore, the dynamic characteristics of the motor in the no-load and load states can be comprehensively reflected, the accuracy of the load capacity evaluation of the mining motor is improved, and potential problems in the operation of the motor can be found in time, so that the performance of the motor is optimized, the service life of the motor is prolonged, and the safety and reliability of mining production are improved.

The invention provides an electromagnetic compatibility test system for an integrated circuit, a part or a whole vehicle. The system comprises an interference signal injection or receiving device, a test board, an oscilloscope, an upper computer, a power supply and an isolation communication device, the interference signal injection or receiving device is used for sending a quantitative interference signal to the test board or receiving and measuring the size of the interference signal of the test board; the test board is used for bearing a tested integrated circuit and carrying out an electromagnetic compatibility test according to a working state specified by the upper computer; the isolation communication device is used for performing photoelectric conversion on a control signal and a monitoring signal corresponding to the electromagnetic compatibility test to form photoelectric isolation; the oscilloscope is used for measuring the waveform of the monitoring signal; and the upper computer is used for controlling the test process and analyzing the monitoring signal to judge the test result. The isolation communication device is used for cutting off electrical connection between the test board and the upper computer and the oscilloscope, it is ensured that the test board is not affected by the outside in the electromagnetic compatibility test process, and the accuracy of the electromagnetic compatibility test is improved.

The invention discloses an on-line insulation monitoring system and method for a national railway vehicle, and relates to the technical field of on-line insulation monitoring, and the system comprises a detection signal injection module which is used for injecting a preset broadband active detection signal, and synchronously collecting a response signal set transmitted through a vehicle body grounding network; the fingerprint feature construction module is used for constructing network fingerprint features in a current insulation state; the spatial distribution atlas acquisition module is used for carrying out inversion calculation to obtain an admittance spatial distribution atlas of the whole vehicle; and the insulation abnormal area identification module is used for identifying an insulation abnormal area. According to the invention, the technical problems of long troubleshooting time and poor accuracy caused by incapability of online real-time monitoring of the insulation state of the vehicle body grounding network of the national railway vehicle and low abnormal area positioning precision in the prior art are solved, and online monitoring of the insulation state of the vehicle body grounding network of the national railway vehicle and accurate positioning of the abnormal area are realized. And the efficiency and the accuracy of insulation fault checking are improved.

The invention provides an automobile electronic control unit fuzzy testing method based on partial code coverage rate feedback and a computer, and belongs to the technical field of automobile electronic control unit code testing. The computer performs static analysis on source codes of the automobile electronic control unit, identifies inevitable execution blocks and conditional execution blocks, performs selective instrumentation on the conditional execution blocks, and inserts coverage rate recording instructions of the conditional execution blocks. And the computer source code is loaded into the automobile electronic control unit, and a test input signal is generated through the fuzzy test engine and is injected into the automobile electronic control unit. In the process of executing the program by the automobile electronic control unit, recording the coverage condition of the condition execution block to a bitmap in the memory; the computer reads the coverage rate data of the condition execution block through the debugger every time a complete execution cycle is completed; and the fuzzy test engine adjusts the input generation strategy according to the coverage rate data feedback of the condition execution block and tests again. According to the method, the automobile electronic control unit source code fuzzy test coverage condition is efficiently collected.

The invention discloses a direct-current cable single-pole grounding fault distance measurement method based on instantaneous power curve slope change, relates to the technical field of electrics, and has the advantages that external signal injection is not needed, positioning is realized directly through dynamic slope change of a power curve, the problems of complicated equipment and poor anti-interference performance of a traditional traveling wave method are solved, and the positioning accuracy is improved. According to the technical scheme, the method comprises the following steps that A1, voltage and current signals of conductor layers of a positive electrode and a negative electrode are obtained; a2, calculating a primary slope S0; a3, calculating an equivalent time point tz; a4, the maximum secondary slope pmax is calculated; a5, calculating a constant alpha and correction coefficients lambda and k; a6, an actual secondary slope pavg is obtained; and A7, obtaining a fault distance x. According to the method, the instantaneous power change of the head end of the cable is monitored, and the dynamic change of the power slope is combined, so that the fault position can be accurately identified in real time.

The invention relates to the technical field of fault detection, in particular to an electronic component fault management method and system. The method comprises the following steps: collecting real-time data and constructing a real-time fault monitoring data set; reading historical data and constructing a historical reference data set; comparing the real-time fault monitoring data set with the historical reference data set item by item in a corresponding time window to obtain a drift amplitude, and mapping according to the drift amplitude to generate a reverse excitation amplitude instruction; a reverse current signal according to the reverse excitation amplitude instruction is injected into the loop node to be measured, and a Hall null drift amount is determined according to Hall output; outputting an electronic disturbance quantity based on the Hall null drift quantity; therefore, through dynamic data cooperation and an active excitation response mechanism, the problems of missing detection recessive degradation, misjudgment transient interference and single diagnosis dimension of traditional fault management are solved, and the hidden danger recognition precision and the protection reliability are remarkably improved.

The invention discloses a permanent magnet synchronous motor temperature monitoring and demagnetization early warning method based on chaotic signal injection and multi-parameter fusion. Comprising the steps of 1, generating a wide-spectrum chaotic signal based on a Lorenz chaotic system, and injecting the wide-spectrum chaotic signal into a d-axis voltage channel of a d-q-axis mathematical model of the permanent magnet synchronous motor; 2, identifying stator resistance RS and d-axis inductance Ld by using a least square method; 3, a Kalman state space model with the winding temperature Tw and the magnetic steel temperature Tm as state variables is constructed, the resistance Rs and the inductance Ld which are measured in real time are fused, the observation noise covariance R is adjusted in a self-adaptive mode, and the winding temperature Tw and the magnetic steel temperature Tm are output in a decoupling mode; step 4, establishing a motor back electromotive force model to calculate a real-time flux linkage psi f, and calculating a motor temperature rise rate # imgabs0 # through a sliding window weighted average method; and step 5, performing demagnetization risk grading early warning according to the flux linkage and the temperature rise rate of the motor.

The invention provides an impedance measuring device and method, and relates to the technical field of electrics, and the device comprises a signal transceiver, a current injection probe and a current detection probe. The signal transceiver is used for compensating the amplitude and phase of the sweep frequency signal of each frequency point, and the compensated amplitude and phase of the sweep frequency signal of each frequency point are different; after the compensated sweep frequency signal is injected into the current injection probe through the first port, a first transmission signal fed back by the second port and a first reflection signal of the first port are obtained, and after the compensated sweep frequency signal is injected into the current detection probe through the second port, a second transmission signal fed back by the second port and a second reflection signal of the first port are obtained; acquiring a second transmission signal of the second port and a second reflection signal of the first port; and determining the impedance of the loop to be measured according to the sweep frequency signal before compensation, the first transmission signal, the second transmission signal, the first reflection signal and the second reflection signal. According to the scheme, online impedance measurement can be realized.

The invention belongs to the technical field of nuclear power, and particularly relates to a ground capacitance measurement method based on series capacitance and high-frequency signal injection. In order to solve the problem that a traditional signal injection method cannot accurately calculate the ground capacitance level of a power distribution network, the invention provides a ground capacitance measurement method based on a series capacitor and high-frequency signal injection. The leakage inductance of the voltage transformer is accurately measured by injecting the high-frequency signal, so that a resonance point is convenient to find during frequency sweeping, and the resonance point measured during frequency sweeping is more accurate.

The invention discloses a transformer winding deformation live-line monitoring device for a GIS substation, and belongs to the technical field of winding deformation monitoring. Comprising a signal generation module, a feedback protection module, a sensor module, a weak high-frequency signal processing module, a signal acquisition module and a diagnostic analysis module, the feedback protection module comprises a change-over switch and a feedback unit; the sensor module comprises an excitation sensor and a response sensor; the weak high-frequency signal processing module comprises a filtering unit, an integrating unit and an amplifying unit; the signal generation module, the change-over switch, the feedback unit, the excitation sensor, the response sensor, the filtering unit, the integration unit, the amplification unit, the signal acquisition module and the diagnostic analysis module are connected in sequence. Frequency response signal injection and extraction and transformer winding deformation on-line monitoring are carried out at the tail end of each phase cable terminal bin on the high-voltage side of the transformer of the GIS substation, and key points of a sensor installation method of the monitoring device are provided.

The invention discloses an electric arc dynamic suppression method for hot plugging of an electric meter connector, relates to the technical field of electric energy metering equipment, and aims to solve the problems of electric arc generation, overproof metering error and the like caused by passive protection and lack of dynamic cooperative control in the prior art. The core of the method is that gap distance and power grid voltage phase signals are acquired in real time through a microcontroller, and the plugging speed, the signal injection and the position fine adjustment are dynamically regulated and controlled in three stages of pre-contact, low-current transition and full connection; and a machine learning model is combined to optimize a parameter threshold value, a redundancy safety mechanism and a multi-phase electric meter cooperative control strategy, so that double management and control of arc peak energy and metering errors are realized. The method can actively inhibit arc generation, avoid connector ablation and insulation deterioration, guarantee metering continuity and accuracy, adapt to complex power grid and environment working conditions, and meet the precision requirement of the intelligent electric meter.

The invention provides a low-voltage direct-current power distribution network small-current grounding fault identification method based on active injection and phase characteristic analysis and a related device, and the method comprises the steps: responding to a starting criterion of fault detection, and triggering an active signal injection strategy; collecting the positive and negative electrode current of the head end of each feeder line and extracting the zero-mode current of the head end of each feeder line; calculating the total zero mode current of the system; aligning the zero-mode current of each feeder line with the total zero-mode current; extracting instantaneous phases of the zero-mode current of each feeder line and the total zero-mode current by adopting a wavelet transform method; calculating an average phase difference between the zero-mode current of each feeder line and the total zero-mode current; and judging whether the cosine value of the average phase difference is smaller than a set value, and if so, judging that the section to which the corresponding feeder belongs has a fault. According to the invention, the fault features are enhanced by using the active injection detection signal, and the criterion is constructed through zero-mode current processing and phase analysis, so that the fault identification capability is improved under the condition of not adding an additional injection device.

The invention discloses a three-phase wireless electric energy and signal reverse cooperative transmission system and a parameter design method thereof. The system comprises a direct-current power supply, a three-phase high-frequency inverter circuit, a three-phase primary side compensation capacitor, a three-phase secondary side compensation capacitor, a three-phase primary and secondary side magnetic coupling coil, a signal transmission channel network, a signal modulation-demodulation circuit network, an encoder, a decoder, a three-phase rectification filter circuit, a filter capacitor and a load resistor. The signal transmission channel networks respectively comprise three signal injection networks and three signal separation transmission channel networks; each signal injection network comprises a secondary side signal injection transformer, a secondary side injection signal resonant capacitor and a discharge resistor; and each signal separation transmission channel network comprises a primary side signal pickup transformer, an extraction signal resonant capacitor, a wave blocking network inductor, a wave blocking network capacitor and a sampling resistor. According to the invention, three-phase wireless energy and information parallel reverse transmission is realized, and the signal transmission rate is effectively improved while stable and efficient electric energy transmission is ensured.

The invention discloses a high-frequency residual error-feature correlation type permanent magnet motor turn-to-turn short circuit fault diagnosis method, belongs to the technical field of permanent magnet motor fault diagnosis, and aims to solve the problems that fault features are easily interfered by working conditions and slight faults are difficult to diagnose when turn-to-turn short circuit diagnosis is carried out on an existing motor. The method comprises the following steps: step 1, high-frequency signal injection and information acquisition; injecting the high-frequency rotating voltage signal into a motor control system under a natural coordinate system; collecting each phase high-frequency current and each phase high-frequency voltage of the motor through a band-pass filter; 2, subtracting the high-frequency voltage from the healthy voltage, and calculating to obtain a high-frequency voltage residual error of each phase; step 3, obtaining fault characteristic quantity FIn of each phase according to the motor parameters, the high-frequency voltage of each phase and the high-frequency voltage residual error; and 4, judging whether a turn-to-turn short circuit fault and a fault phase occur or not according to the fault characteristic quantity of each phase.

The invention relates to the technical field of power electronics, and discloses a charging pile circuit detection method and system capable of automatically identifying an electric vehicle and a load, and the method comprises the steps: constructing a high-frequency signal injection unit and a signal collection unit of a charging pile, injecting a specific high-frequency detection signal into a corresponding charging line of the charging pile, acquiring a voltage signal and a current signal of the charging circuit; performing time domain analysis on the voltage signal and the current signal, and calculating an impedance value of the charging circuit; performing frequency domain transformation on the voltage signal and the current signal, analyzing harmonic components of frequency domain data, determining transient response of the frequency domain data, and extracting characteristic parameters of the transient response; analyzing an electric vehicle type and a load type of the charging line, analyzing a load state of the charging line, identifying an abnormal state of the load state, constructing an abnormal alarm mechanism of the abnormal state, and determining an abnormal adjustment parameter of the charging pile; and determining a circuit detection scheme of the charging pile. According to the invention, the accuracy and timeliness of charging pile circuit detection can be improved.

This document describes systems and techniques directed at verifying, in a test environment, that an undefined digital logic signal is unlikely to cause functional impact on a system-on-chip. In various aspects, clock domain crossing (CDC) and reset domain crossing (RDC) results in an undefined digital value. Various paths through a circuit design that may generate an undefined value (e.g., not a value of zero or a value of one) during testing are identified. A signal injection circuit may be inserted into paths identified as possibly providing an undefined value. The signal injection circuit may be configured to inject an undefined signal into identified paths during testing. The injection of undefined signals within a circuit may simulate signal instability at identified paths. The testing of instability at the identified paths provides thorough analysis, which allows failures to be identified early in the design process.

The invention relates to a permanent magnet synchronous motor MTPA control method based on a double-virtual direct current signal injection mode, in particular to a motor control method, and particularly relates to a control method of a built-in permanent magnet synchronous motor. A pair of virtual direct-current signals with the same amplitude and opposite polarities are injected into a current vector angle beta, Taylor expansion is carried out on electromagnetic torque containing the pair of signals, subtraction is carried out on the two signals to obtain an approximate value of the torque to a first-order partial derivative of the current vector angle, and the approximate value is input into an integral regulator; when the input quantity is controlled to be 0, the optimal current vector angle beta mtpa can be obtained, and MTPA control is achieved. In order to improve the dynamic performance and the steady-state performance of control at the same time, virtual direct-current signals with different amplitudes are selected for injection under different working conditions, the motor can be made to rapidly approach the working state of the optimal current vector angle, and fluctuation of the current vector angle in the stable state is reduced.

The invention provides a hardware-in-the-loop test device. The hardware-in-the-loop test device comprises a simulation model verification system used for obtaining real-time data of input and output of an IO terminal of a DCS system in various operation states; the real-time data is transmitted to the fault state detection system; the fault state detection system is used for converting real-time data into a control signal and transmitting the control signal to the simulation data signal IO system; the simulation data signal IO system is used for converting the control signal into an electric signal; the electric signal is transmitted to a fault signal injection system; and the fault signal injection system is used for superposing the fault signal on the electric signal to obtain various types of faults, and transmitting the electric signal superposed with the fault signal to the DCS. According to the invention, the hardware-in-the-loop test device simulates each external signal fault of the DCS system, and injects the fault signal into the DCS system, thereby verifying and improving the robustness of the DCS system and a simulation model, and meeting the reliability test of the DCS system under an extreme working condition.