44 results about "Current compensation" patented technology

The invention relates to the technical field of current compensation, and discloses a current compensation strategy and a compensation system for improving the direct current fast charging rate of an electric automobile. According to the scheme, the total current of a high-voltage loop and the input current of a battery are detected in real time, the dynamic load current difference value is calculated, and the battery health state and historical charging data are combined; and the charging pile request current value is adaptively adjusted to counteract the shunting influence of the load power. Meanwhile, a closed-loop feedback regulation mechanism is adopted, a compensation coefficient is corrected in real time through a PID algorithm, and the stability of the charging current is ensured. When the power of the charging pile is limited, the system dynamically reduces unnecessary loads (such as an air conditioner and a heater) according to a preset priority request, and the charging power of the battery is guaranteed preferentially. The charging rate is improved (the charging time is shortened by 10%-15%), the adaptability of the system to dynamic load fluctuation is enhanced, and the service life of the battery is prolonged.

The invention discloses a sampling current bias error compensation method for a permanent magnet synchronous motor. The sampling current bias error compensation method comprises the following steps: step 1, acquiring the shortest duration required by sampling current bias; 2, the permanent magnet synchronous motor is controlled in a vector mode; 3, the zero-voltage vector holding time is obtained, a sampling current compensation mode is selected according to the zero-voltage vector holding time and the shortest time needed by sampling current bias, and the compensation mode comprises the steps that when the zero-voltage vector holding time is larger than or equal to the shortest time needed by sampling current bias, a direct compensation mode is carried out; when the zero voltage vector holding duration is smaller than the shortest duration required by sampling current bias, terminal voltage integration is carried out to judge a compensation mode; and 4, performing vector control on the permanent magnet synchronous motor through the compensated sampling current, and performing closed-loop control. According to the invention, the operation precision of the permanent magnet synchronous motor can be improved, and the motor operation system can adapt to the dynamic change of the offset error.

The invention discloses a parallel electronic load current control method and device and electronic equipment. The method comprises the following steps: acquiring a target current value; based on the target current value, controlling the feedback type electronic load to output at a first output current; based on the target current value and the first output current, controlling the consumable electronic load to output with a second output current; under the condition that the output current of the electronic load system is the target current value, the consumption type electronic load is controlled to output with a third output current, so that the output current of the electronic load system is kept at the target current value until the output current of the feedback type electronic load reaches the target current value; and in response to the output ending instruction, controlling the feedback electronic load to output with a fourth output current until the output current of the feedback electronic load returns to the steady-state working current, and controlling the current compensation unit to output a reverse compensation current, so that the output current of the electronic load system is consistent with the current preset output curve.

The invention discloses a sampling current compensation method based on an extended state observer, solves the problems that an existing current sampling compensation method based on a current loop is small in application range and is limited by the number and position of current sensors, and belongs to the field of motor driving. The method comprises the steps that sampling currents idm, iqm, iz1m and iz2m and sampling voltages ud, uq, uz1 and uz2 are acquired; inputting ud, uq, uz1, uz2, idm, iqm, iz1m, iz2m and error currents id and iqe obtained by current observation into an extended state observer to obtain estimated values # imgabs0 # # imgabs1 #, wherein the extended state observer comprises a d-q plane extended state observer and a z1-z2 plane extended state observer; according to the obtained estimated value # imgabs2, error currents id, iqe, iz1e and iz2e are obtained; and subtracting the obtained error current from the sampling current under the rotating coordinate system to realize error compensation of the sampling current. The compensation method is irrelevant to the number and position of the current sensors, and the application range is wide.

The invention discloses a pilot protection method and device based on instantaneous power total and incremental waveform similarity, and belongs to the technical field of power systems. According to the method, fault detection is started through voltage or current abrupt change, differential capacitance current compensation is carried out based on a full current sampling value, and a compensated voltage value is calculated by combining an electromagnetic wave transmission equation and a line Bergeron model so as to eliminate the influence of line parameters; and judging a passive load branch fault through a current amplitude and an integral value, otherwise, synchronously adopting an instantaneous power full-quantity waveform cosine similarity longitudinal main protection criterion and an instantaneous power increment waveform cosine similarity criterion to identify an internal fault, and overcoming a reliability'dead zone 'defect caused by near-zone fault voltage drop. The method does not need to depend on power frequency phasor calculation, and can improve the sensitivity and reliability of protection in scenes of a high-proportion new energy power grid, a micro-grid and the like.

The present invention relates to the technical field of power switch voltage compensation and monitoring, and discloses a system and method for monitoring and compensating the losses of a switching power supply, including a load compensation module for compensating for current changes caused by changes in line load, a line loss compensation module for compensating for the voltage drop generated when current flows through a wire, a variable resistance module for generating different compensation amounts for different power switch line losses, and a line loss current compensation monitoring module for monitoring the line loss compensation current of the power switch and optimizing the current monitoring model, realizing a new type of shiftable switching power supply loss compensation method, and at the same time realizing the intellectualization, automation and autonomy of power grid distribution loss compensation.

The present application is applicable to the field of motor technology, and provides a current compensation method, device, motor controller and storage medium. The phase current at the v-phase comparison value moment is obtained according to two bus currents respectively sampled during the durations of the first effective vector and the second effective vector; the rotor angle at the uvw-phase comparison value moment of the k-th period is obtained according to the uvw-phase comparison values of the k-th period, the rotor angle at the current control moment, and the rotor angle at the current control moment of the (k-1)-th period; the second effective vector is obtained according to the bus voltage and the abc-phase comparison values; the phase current at the current control moment is obtained according to the duration of the second effective vector, the duration of the second zero vector, the phase current at the v-phase comparison value moment, the second effective vector, and the rotor angle at the uvw-phase comparison value moment, so as to achieve the effect of current delay compensation, improve the current control performance, and reduce current harmonics.

This application discloses a method, device, and medium for setting the zero-sequence current compensation coefficient in a mixed cable line, belonging to the field of relay protection technology for mixed transmission lines. It includes: obtaining the power frequency impedance and length parameters of an N-segment mixed cable line; and obtaining the comprehensive zero-sequence current compensation coefficient K at each connection point of the N-segment mixed cable line. i 1≤i≤N and i is an integer; obtain the comprehensive zero-sequence compensation coefficient K of the fault point. ’ j 1≤j≤N and j is an integer; obtain the comprehensive zero-sequence current compensation coefficient K0 at the end of the operating range of the grounding distance I protection; determine K ’ j The monotonicity of K0; based on monotonicity, compare K0 with N K's. i The value of the zero-sequence current compensation coefficient K is obtained by considering the magnitude of the zero-sequence current compensation coefficient; N≥2 and N is an integer. This application improves the accuracy of the zero-sequence current compensation coefficient setting, which can ensure the reliability of the grounding distance I-stage protection operation and avoid overshooting and false operation when there is a fault at the end of a mixed line.

The invention discloses a motor heating method and device, and a frequency converter. The method comprises the steps of determining an initial current instruction, and performing adjustment amplitude limiting and current compensation processing on the initial current instruction based on a voltage utilization rate to obtain a rotation current angular frequency and a compensation current instruction; a target axis given current instruction is determined based on the given heating power, and a target axis current instruction is obtained based on the target axis given current instruction and the compensation current instruction; acquiring a voltage vector compensation angle and a current vector angle based on the rotating current angular frequency, and acquiring a voltage vector angle based on the voltage vector compensation angle and the current vector angle; and inputting the target shaft current instruction and the voltage vector angle to a preset current controller, so that an inverter outputs high-frequency alternating current to a motor to heat the motor. The power control precision and the control robustness are improved, the dynamic control with a wider heating power range can be realized, and excessive computing resources are not needed.

The application provides a time calibration method, and relates to the technical field of electronic equipment, which comprises the following steps: when entering a starting mode, obtaining a historical time synchronization time and a system time; obtaining a first time difference according to the historical time synchronization time and the system time; obtaining a current compensation time according to the first time difference, a historical time deviation parameter and a historical compensation time; obtaining a compensated system time according to the system time and the current compensation time, and updating the historical compensation time to the current compensation time; if a time synchronization signal is received, obtaining an input time and the compensated system time, and updating the historical time deviation parameter according to the input time, the compensated system time and the historical time synchronization time, so that the method is more stable, accurate and adaptive to an offline environment.

The invention discloses an electric energy quality control module function demand control method and device and a storage medium, and belongs to the technical field of electric energy quality control. Performing current distribution according to the load side reactive current vacancy demand, the harmonic current vacancy demand and the unbalanced current vacancy demand of the current demand period, and obtaining a function demand parameter of the next slip frequency period according to the distributed current and the total current vacancy demand; and under the constraint of the functional compensation current component upper limit, performing functional current compensation on the load in the power grid based on the reactive current vacancy demand, the harmonic current vacancy demand and the unbalanced current vacancy demand on the load side. The technical problems that an existing electric energy quality treatment scheme cannot completely adapt to the actual electric energy quality treatment requirement, and when the actual requirement does not conform to the capacity configuration of all the functions, the number of all the function modules can only be adjusted through power failure again can be solved.

The invention relates to a peak current limiting method for a static var generator, which comprises the following steps of: performing amplitude limiting on the maximum output current value of a fundamental wave and a harmonic wave by adopting a working mode of a reactive compensation priority, calculating a reactive current component, an unbalanced current component and a zero sequence current component of a power grid current, and calculating the peak current of the static var generator. Obtaining a reactive current compensation output value, an unbalanced current compensation output value and a zero sequence current compensation output value; and calculating a three-phase sine instruction value of the fundamental current, carrying out amplitude limiting on each harmonic component, and carrying out compensation output on each current after amplitude limiting output. The method has the advantages that the static var generator adopts a compensation priority, reactive power, unbalance and harmonic current compensation functions of the compensation device are flexibly set according to different working condition requirements of users, and a single or comprehensive compensation function is realized; the static var generator carries out independent amplitude limiting on each harmonic output current instruction value, and harmonic compensation times and amplitudes can be reasonably configured according to harmonics of different times generated under different working conditions.

A current inner loop reference current value compensation method, a control method, a system and a medium are applied to a PI control process of a DC converter, and the method comprises the following steps: according to a power frequency ripple oscillation condition at a bus voltage and a first bus deviation value at a current moment, determining whether PI control at the current moment satisfies a current inner loop reference current value compensation condition; when a compensation condition is met, determining a current compensation value according to the second bus deviation value at the current moment; wherein the first bus deviation value is an absolute difference value between a preset reference voltage value and a filtering result of the bus voltage sampling value through the first filter, and the second bus deviation value is an absolute difference value between the preset reference voltage value and a filtering result of the bus voltage sampling value through the second filter; the first filter and the second filter are both first-order RC filters, the filter coefficient of the first filter is larger than that of the second filter, and stable operation of PI control is guaranteed under the extreme heavy load transient working condition.

The invention belongs to the technical field of resistance welding machines, and particularly relates to a current dynamic compensation method and system of a resistance welding machine and application. Continuous production and non-continuous production are distinguished by increasing the starting point reset time t2, the function that current compensation is not needed due to the fact that temperature rise is not obvious at the beginning in continuous production is achieved by increasing the starting point N, and whether continuous welding of the same workpiece is conducted or not is distinguished through the timeout time t1. The problem of current instability caused by load fluctuation in continuous production is solved through a time-counting two-dimensional judgment (T is smaller than or equal to t1 and N1 is larger than or equal to N) activation compensation method.

The invention discloses a current control method, device and system, electronic equipment and a storage medium. The method comprises the following steps: acquiring a target current value; based on the target current value, controlling the feedback type electronic load to output at a first output current; based on the target current value and the first output current, controlling the consumable electronic load to output with a second output current; under the condition that the output current of the electronic load system is the target current value, the consumption type electronic load is controlled to output with a third output current, so that the output current of the electronic load system is kept at the target current value until the output current of the feedback type electronic load reaches the target current value; and in response to the output ending instruction, controlling the feedback electronic load to output with a fourth output current until the output current of the feedback electronic load returns to the steady-state working current, and controlling the current compensation unit to output a reverse compensation current, so that the output current of the electronic load system is consistent with the current preset output curve.

The present application discloses a parallel electronic load current control method, device, and electronic device. The method includes: obtaining a target current value; controlling a feedback electronic load to output at a first output current based on the target current value; controlling a consumption electronic load to output at a second output current based on the target current value and the first output current; when the output current of the electronic load system is the target current value, controlling the consumption electronic load to output at a third output current so that the output current of the electronic load system remains at the target current value until the output current of the feedback electronic load reaches the target current value; in response to an output end instruction, controlling the feedback electronic load to output at a fourth output current until the output current of the feedback electronic load returns to a steady-state operating current; and controlling a current compensation unit to output a reverse compensation current so that the output current of the electronic load system is consistent with a preset current output curve.

The present invention discloses a fast time-domain distance protection method and system based on random correction of zero-sequence current. Sampling is performed on a new energy grid-connected line system to obtain the three-phase voltage, three-phase current, and zero-sequence current at one end of the line. If the zero-sequence current is greater than the threshold value, zero-sequence current compensation is carried out. If the zero-sequence current is less than the threshold value, random correction is performed on the zero-sequence current, and zero-sequence current compensation is not carried out currently. Using the voltage / current sampling of a unit data window, a voltage / current information matrix within the unit data window is constructed, and the least squares method is used to calculate the single-fitting distance result and the fitting error and calculate the weight. The final cumulative weighted distance result is calculated. If the cumulative distance calculation result continuously and stably is less than the fixed value, it is judged that a fault occurs within the zone, and the distance protection operates to trip. Otherwise, it is judged that a fault occurs outside the zone, and the distance protection does not operate. Compared with the prior art, the present invention realizes weighted summation type fast time-domain distance protection based on random correction of zero-sequence current.

This invention provides a multi-dimensional method and system for assessing damage to DC contactors in charging piles. The method includes: a host acquiring the current current value, current temperature, and previous temperature during the charging process of the DC contactor, as well as the voltage sequence and / or current sequence during the previous disconnection process, and historical charging and disconnection data; obtaining a disconnection damage score based on the voltage transient characteristics of the voltage sequence and / or the current drop characteristics of the current sequence; obtaining the current drift degree based on the difference between the current current value and the current compensation current value; obtaining the temperature rise rate deviation of the contact resistance based on the deviation between the actual temperature rise rate and the expected temperature rise rate; the actual temperature rise rate is obtained from the current temperature and the previous temperature, and the expected temperature rise rate is obtained based on the compensation current value and a preset temperature rise model; analyzing historical charging and disconnection data to obtain cumulative operating load data; and comprehensively analyzing the above four indicators to assess the damage status of the DC contactor.

The present application relates to the technical field of power electronics and motor control, and particularly relates to a SVPWM dead zone accurate compensation method based on an oscilloscope phase marker, comprising: in a frequency converter control software, setting a compensation angle to 0, and inserting an IO conversion flag bit at a 0 phase of a U phase wave; running the frequency converter, observing a position of the flag bit in a U phase current through an oscilloscope, and obtaining a position angle as the compensation angle; adding the compensation angle to the software to obtain a current compensation angle as: an angle of an output voltage waveform + an output current angle + the compensation angle; running the frequency converter again, observing the position of the flag bit in the U phase current through the oscilloscope, and judging whether the position is on a 0 phase angle of the current. The present application directly finds and determines an optimal compensation angle through an oscilloscope, so as to realize accurate compensation of a SVPWM dead zone.

The present invention discloses a method and system for monitoring track circuits based on redundant data. The method is applied to on-site current monitoring on the track side designed with four-way redundant wiring, and includes: obtaining in real time four-way current data on the track side designed with four-way redundant wiring; based on the redundant wiring design on the track side and current characteristics, combining the four-way current data to determine whether the current on the track side is normal or abnormal; when at least one-way current data is normal, the current compensation method is used to compensate other-way current data with the normal-way current data, repair other-way current data into normal current data, and no alarm is made; when all four-way current data are abnormal, the current on the track side is abnormal, the true value is reported, and an alarm is made; when all four-way current data are normal, the current on the track side is normal, and no alarm is made. The present invention accurately judges the monitoring of track circuits and reduces the number of false alarms generated by the station machine software due to abnormal detection of monitoring equipment.

A current inner loop reference current value compensation method, control method, system and medium are applied to the PI control process of a DC converter. The method comprises: determining whether the PI control at the current moment satisfies the current inner loop reference current value compensation condition according to the power frequency ripple oscillation condition at the bus voltage and the first bus deviation value at the current moment; when the compensation condition is satisfied, determining the current compensation value according to the second bus deviation value at the current moment; wherein the first bus deviation value is the absolute difference between the preset reference voltage value and the filtering result of the bus voltage sampling value through a first filter, and the second bus deviation value is the absolute difference between the preset reference voltage value and the filtering result of the bus voltage sampling value through a second filter; the first filter and the second filter are both first-order RC filters, and the filtering coefficient of the first filter is greater than the filtering coefficient of the second filter, thereby ensuring stable operation of the PI control under extreme overload transient conditions.

Disclosed are a current output device, method, apparatus and system, and a medium. A multi-channel detection module in the device is connected to a plurality of single-phase power supply chips to transmit temperature values and current values of the chips, and at least one chip is different from other chips in type. A system control module has one end connected to the multi-channel detection module, to obtain constraint based on pre-collected related parameters to adjust the current values. A variable current compensation module is connected to the other end of the system control module to obtain an output current value of each chip and output a current. The system control module acquires the temperature values and the current values obtains the constraint, and adjusts the current values according to the constraint, and the output current value of each chip is obtained and the current is output.

The sampling current compensation method based on the extended state observer solves the problem that the current sampling compensation method based on the current loop has a small application range and is limited by the number and position of current sensors, and belongs to the field of motor driving.The application comprises the following steps: obtaining sampling current i dm 、 qm 、 z1m 、 z2m , sampling voltage u d 、 u q 、 u z1 、 u z2 , u d 、 u q 、 u z1 、 u z2 、 i dm 、 i qm 、 i z1m 、 i z2m , and error current i de 、 i qe , obtained by current observation are input into an extended state observer to obtain an estimated value, the extended state observer comprises a d-q plane extended state observer and a z1-z2 plane extended state observer; error current i de 、 i qe 、 i z1e 、 i z2e , is obtained according to the estimated value; and the error current obtained is subtracted from the sampling current in the rotating coordinate system to realize error compensation of the sampling current.The compensation method of the application is independent of the number and position of current sensors and has a wide application range.

The application discloses a Si / SiC topology parallel inverter harmonic suppression method based on multi-harmonic observation and feedforward compensation, and relates to the technical field of power electronics. The method comprises the following steps: monitoring each harmonic signal output by a Si IGBT inverter of a Si / SiC topology parallel inverter in real time, and determining the amplitude and phase of each harmonic signal; the Si / SiC topology parallel inverter is a parallel structure of a Si IGBT inverter and a SiC MOSFET inverter; according to the amplitude and the phase, an adjusted current compensation signal is generated based on a gain scheduling mechanism; the adjusted current compensation signal is a current compensation signal that is equal in amplitude and opposite in direction to a harmonic signal of the SiC MOSFET inverter; and the harmonic signal output by the SiC MOSFET inverter is suppressed according to the adjusted current compensation signal. The application can improve the harmonic suppression capability and power quality, and is suitable for high-power power systems and application occasions with strict requirements on power quality.

The application discloses a photovoltaic sending-out line pilot protection method and system based on a Dice waveform similarity, and belongs to the technical field of line pilot protection. The method comprises the following steps: selecting the sampling data window length on both sides of the photovoltaic sending-out line, and continuously sampling the voltage and current on both sides of the line; calculating the Dice similarity of the sampling current of each phase on both sides of the line after transient capacitance current compensation according to the voltage and current sampling values on both sides of the line, wherein the Dice similarity criterion is 1 if the Dice similarity is greater than the setting value, and the Dice similarity criterion is 0 otherwise; and sending the corresponding phase tripping signal according to the Dice similarity criterion, wherein the corresponding phase protection tripping signal is sent if the Dice similarity criterion is 1, and the corresponding phase protection tripping signal is not sent if the Dice similarity criterion is 0, so that the photovoltaic sending-out line pilot protection can correctly act in the internal fault and external fault of the 500kV line. Through the application, the problem of the sensitivity reduction of the photovoltaic sending-out line differential protection can be effectively solved under various transition resistance short-circuit faults and other complex conditions at various positions of the line, and the application has the characteristics of simplicity, reliability, easy operation and strong applicability.

The invention relates to the technical field of motor control, and discloses a linear motor system motor cogging force compensation method, device, equipment and medium, and the method comprises the following steps: determining acceleration and deceleration segment displacement according to speed and acceleration, and expecting to carry out n motor pitch sampling so as to obtain total motion displacement Moveis and Movedisgt; the sum of n motor pitches and acceleration and deceleration section displacements; selecting a constant speed section electrical angle according to the acceleration section displacement and the initial position electrical angle, moving along the same direction at equal interval angles, and recording a position where an electrical angle compensation value can be obtained; counting the Q-axis current absolute value corresponding to the position where the electrical angle compensation value can be obtained, and obtaining the current compensation value of the motor cogging force; and performing feed-forward current compensation on the current compensation value. According to the scheme, feedforward compensation is carried out based on the current value corresponding to the electrical angle, the current is given in advance to actively suppress the influence of cogging force fluctuation, and the speed error and the position error of the constant speed section in the motion of the linear motor can be effectively reduced.

The application relates to a current transformer output current compensation method, device, equipment and storage medium, which is applied to the field of current transformers, and the method comprises the following steps: acquiring a starting point of a linear section of a current transformer output current; selecting a fixed number of sample current data in a plurality of output current data of the current transformer with the starting point as an end point; performing effective value calculation according to the sample current data to obtain the root mean square corresponding to the sample current data; and performing data compensation on the output current of the current transformer according to the root mean square. The application has the technical effect that the problems of the measurement accuracy of plastic shell electronic products and the reliability of large current protection are effectively solved.

The invention provides a non-full-line parallel line grounding distance protection method for coupling zero sequence current compensation, and relates to the technical field of relay protection, and the method comprises the steps: collecting the three-phase voltage and three-phase current of a protected line in real time, and judging the operation mode of the line; calculating a fault distance based on different operation modes, constructing a segmented zero-sequence network fault coupling equation based on a mutual inductance difference between a parallel segment and a non-parallel segment, and solving the segmented zero-sequence network coupling equation to obtain a coupling zero-sequence current; the fault distance is compared with the length of the parallel section to judge that the fault is located in the parallel section, the junction area or the non-parallel section, and regional self-adaptive compensation is carried out based on the judgment result; introducing a compensation item formed by the coupling zero-sequence current and the coupling zero-sequence current compensation coefficient into a measurement impedance calculation formula for grounding distance protection, and calculating to obtain corrected measurement impedance; if the corrected measured impedance meets the amplitude criterion and the phase angle criterion at the same time, a tripping signal is sent out.

The invention provides a peak overcurrent protection system and method for a three-phase rectification power supply, and relates to the technical field of circuit protection, and the method comprises the steps: carrying out the clustering analysis of multi-dimensional electric quantity data during the operation of the three-phase rectification power supply, constructing a state recognition model, and obtaining a risk early warning signal of the operation state of the three-phase rectification power supply; according to the risk early warning signal and the constraint condition of the three-phase rectification power supply, reactive current compensation amount is calculated, and a reactive current control instruction is obtained; executing the reactive current control instruction to inject reactive current into the three-phase rectification power supply, and monitoring to obtain change characteristics of electrical characteristics of a port of the three-phase rectification power supply; and performing protection logic judgment on the basis of the current amplitude change rate and the phase deviation characteristic in the change characteristic to obtain a fusion judgment result, and outputting a tripping signal and executing overcurrent isolation. According to the application, peak current advanced interception and multi-criterion collaborative decision based on intelligent early warning can be realized; therefore, over-current protection from passive cut-off to active defense is completed.

A method for modifying an effect of a disturbance in an electrical network (384) on a generator (120) connected to the network (384), the method comprising: Tracking at least one negative sequence component and one positive sequence component of a signal of the electricity network (384), Aligning at least a portion of the magnitude of the negative sequence component for feeding into the electricity grid (384) and feeding the at least one portion into the electrical grid (384) to modify the effect of the disturbance, wherein a power converter component (362) having a DC link (435) with a DC link capacitor (436) is used and wherein the power converter component (362) receives control signals from a control system (300) via a control unit (374), the control signals being based on measured conditions or characteristic operating properties; and wherein the generator (120) is a doubly fed asynchronous generator (120) and the tracking, the aligning and the injection (540) implement a current compensation (500), wherein after the alignment, the aligned signal is applied to a fault connection of a current regulator of the control unit (374), and wherein the control unit (374) controls the power converter component of the doubly fed asynchronous generator (120).