167 results about "Series compensation" patented technology

The invention belongs to the technical field of flexible alternating-current power transmission and distribution and power electronics, and discloses a unified power quality adjusting device and method so as to achieve the purpose of power quality control. The device comprises a direct current bus, a compensation unit and an adjusting unit, the compensation unit comprises a series compensation subunit and a parallel compensation subunit; the series compensation subunit is used for compensating load voltage; the direct-current bus is used for providing compensation energy for the series compensation subunit; the parallel compensation subunit is used for compensating harmonic waves, three-phase imbalance and reactive current of a load, and is also used for providing voltage support for a direct-current bus and providing energy for the series compensation subunit; the adjusting unit comprises a super capacitor energy storage system and a photovoltaic power generation system which are connected in parallel; the super capacitor energy storage system comprises a super capacitor and a first DC / DC converter; the photovoltaic power generation system comprises a photovoltaic array and a second DC / DC converter. According to the invention, the coupling problem of series-parallel inverters of the device is solved, so that the voltage of the direct-current side bus is stable.

The present application relates to an energy-storage power-conversion series compensation system and a stability analysis method therefor, a damping controller, and an energy storage system, wherein a voltage signal on a capacitor arranged between an energy storage battery pack and a converter of the energy-storage power-conversion series compensation system can be collected, and whether an activation condition is met is determined based on the voltage signal; when the activation condition is met, an adaptive adjustment filter is activated to bring the damping controller into operation within the energy-storage power-conversion series compensation system. A voltage synchronization controller determines, on the basis of a sub-synchronous frequency band voltage signal output by the adaptive adjustment filter and an initial voltage signal, a required output phase angle signal corresponding to a pulse width modulation signal for controlling operation of the converter.

The invention belongs to the field of power system stability analysis, and discloses a response data and model fused subsynchronous oscillation parameter identification method for a wind power plant grid-connected system. Firstly, the current of a grid-connected line is monitored, the energy is calculated, and an early warning is given out when the energy is continuously increased along with time. Then, self-adaptive VMD decomposition is carried out on the early warning signal, and the system state is preliminarily determined; then, proper band-pass filter parameters are set according to the decomposition result, and filtering operation is carried out on the signals. And solving a complete SSO current component from the filtering signal according to a derived mathematical relationship between related electrical quantities and parameters of the series compensation power transmission line, and further obtaining an oscillation frequency and a damping factor. And finally, carrying out a simulation test based on series compensation capacitor grid-connected data of the direct-driven wind power plant. The oscillation identification method provided by the invention has strong noise immunity and robustness, and can realize accurate and rapid identification of the dominant SSO mode.

The invention provides a strong series compensation grid-connected stability regulation and control method of a grid-forming type energy storage converter and a related device, and belongs to the technical field of grid connection of a power grid. According to the method, a three-phase grid-connected inverter complete sequence impedance model controlled by the virtual synchronous generator is established by using a harmonic linearization method, and reasons for causing subsynchronous oscillation by using a double-closed-loop control strategy are analyzed. In order to improve the grid-connected stability of a strong series compensation power grid of a grid-forming type energy storage converter, a PI-LADRC control strategy is provided, a sequence impedance model under the control mode is established, and grid-connected stability margin information under the PI-LADRC control strategy is obtained by comparing output impedance characteristics of a grid-connected inverter under a double closed-loop control mode and a PI-LADRC control mode. According to the invention, the PI-LADRC control strategy is adopted, so that the grid-connected stability can be effectively regulated and controlled.

The invention relates to a multi-phase magnetic coupling structure, a series compensation circuit and a wireless charging system, and relates to the technical field of wireless power transmission, the multi-phase magnetic coupling structure comprises a primary side magnetic energy emission structure and a secondary side magnetic energy receiving structure, the primary side magnetic energy emission structure comprises a first magnetic core and an emission coil; the secondary side magnetic energy receiving structure comprises a second magnetic core and a receiving coil; the transmitting coil and the receiving coil are both multi-phase bipolar coils; therefore, the magnetic coupling structure provided by the invention is higher in magnetic field intensity, higher in power density and obviously improved in transmission efficiency, the transmission efficiency of the structure can reach more than 94% after the front end voltage is increased to 50V, and the highest efficiency is close to 96%.

The invention discloses a series compensation-based uninterrupted load transfer control method and system for a power distribution network, and solves the related problems of instantaneous impact of loop closing, short-time power failure of a user and the like. The invention provides a topological structure of a non-power-cut load transfer system, introduces the working principle of the system, utilizes the voltage amplitude and phase angle compensation function provided by series compensation to realize sewing-ring-free control, and further adopts an impedance compensation function to realize smooth load transfer control. According to the method, the impact influence of voltage and current at the moment of loop closing can be avoided, the power supply transfer process is stable, power-off-free power supply transfer is realized, the application range of loop closing power supply transfer is expanded, and the safety and reliability of loop closing power supply transfer are improved.

The invention discloses an IGBT full-bridge series inverter power supply control system, which relates to the technical field of inverter power supplies and comprises an inverter output module, the inverter output module inverts direct-current electric energy accessed by a power supply module, and when the detected electric energy is larger than a first voltage threshold value or smaller than a second voltage threshold value, the inverter output module outputs the inverted electric energy. The intelligent control module controls the soft switching module to carry out zero-voltage and zero-current soft switching-on processing on a switching element which is not switched on in the inversion output module, the terminal voltage change rate of the switching element in a switched-off state is reduced, zero-voltage soft switching-off is carried out, and when the detected electric energy is smaller than a first voltage threshold value or a second voltage threshold value, the soft switching-off is carried out. The soft switch module cooperates with the auxiliary capacitor module to carry out half-bridge inversion and carries out output compensation or enlarges the output voltage range through the electric energy output by the series compensation module and the inversion control module. According to the IGBT full-bridge series inverter power supply control system, the switching loss can be reduced, the electric energy conversion efficiency and the power supply precision are improved, and the power supply voltage range is enlarged.

The invention discloses a DWT-RBF-based power transmission line equipment fault classification method, system and equipment, and the method comprises the steps: firstly building a simulation system of three-phase series compensation power, defining a fault type, then obtaining a sampling signal of a transient current when a power transmission line has a fault, carrying out the decomposition through DWT, and then carrying out the denoising based on an improved wavelet threshold algorithm, the method comprises the following steps: sampling a DWT-RBF signal, acquiring an energy value of the sampling signal, performing normalization processing on the energy value, finally optimizing a DWT-RBF simulation system based on an IWOA algorithm, and inputting the energy value to complete fault classification; according to the method, the sampling signals are decomposed through DWT, fault features are extracted, the response speed of fault classification is increased, the wavelet threshold denoising algorithm is adopted for noise filtering, the recognition accuracy is improved, meanwhile, the RBF model is optimized through the IWOA algorithm, the convergence speed and generalization fitting capacity of the model are improved, and the fault classification accuracy is improved. Therefore, the method has good network performance, and can accurately and quickly classify different types of power transmission line equipment faults.

Systems and method to minimize conditions that cause sub-synchronous oscillation (SSOs) associated with series compensated transmission grids. The implementations ensures the correct development of methods and systems that can mitigate sub-synchronous oscillation (SSOs) associated with a series compensated transmission grid and enhance the series compensation efficiency. An example implementation is a network-based SSO mitigation technology, and another example implementation is a generator-based SSO mitigation technology. The discovery and example implementations are applicable to series compensated transmission networks with synchronous generators, induction generators, wind turbines, solar photovoltaic generators, charging stations, battery storage systems, high-voltage DC transmission systems, STATCOMs, inverter-based data centers, and other inverter-based resources.

The invention relates to the technical field of hydrogen production power supplies, in particular to an alkaline water electrolysis hydrogen production power supply system. Comprising an energy storage battery, a first DC / DC converter, a second DC / DC converter, an AC / DC converter, a first switch, a second switch, a third switch and a series compensation capacitor, the AC / DC converter realizes a function of converting alternating current of a power grid into direct current, the first DC / DC converter realizes a function of converting direct current into direct current, the second DC / DC converter realizes a function of converting direct current into direct current, and the series compensation capacitor realizes a function of converting direct current into direct current. And the series compensation capacitor realizes an additional reactive compensation function. Reactive power compensation is realized by adding the series compensation capacitor, rapid drop of power grid voltage is avoided, and stability of system voltage is guaranteed. The DC / DC is bypassed by closing the isolating switch, and the hydrogen production electrolytic bath is directly driven by the AC / DC, so that the utilization efficiency of electric energy is improved.

The invention belongs to the technical field of power systems, and particularly relates to a power grid impedance simulation device, a design method and a use method.The design of the device comprises the steps that the types of needed components are determined, and the number of the components and electrical parameter values are obtained according to the actual national standard in combination with the minimum component number criterion; all components are connected according to needs, and a controller is adopted to realize corresponding control so as to support working condition simulation and switching of different short circuit ratios and series compensation degrees; a switch logic control program is set in the controller, so that when the controller receives a power grid working condition switching instruction, switching of working conditions corresponding to the power grid short-circuit ratio and the series compensation degree is achieved by executing the preset switch logic control program. According to the technical scheme, through the integrated design of parameter calculation, hardware topology and logic control, the problems of low test efficiency, poor simulation precision and high cost in the prior art are solved, and an efficient, accurate and economical solution is provided for the adaptability test of the new energy converter under a double-high power system.

The invention relates to the technical field of controllable series compensation, in particular to a power distribution area voltage rapid compensation device and compensation method based on controllable series compensation, and the method comprises the steps: collecting various monitoring data of each phase of each key node of a power distribution area in real time; obtaining each sub-time period of each monitoring data of each phase; acquiring a change correlation value and a deviation change characteristic value of various monitoring data of each phase in each sub-time period; comparing the deviation change characteristic values of various monitoring data between each phase and each of the other phases of the key node where the phase is located so as to obtain a dynamic change factor of the various monitoring data of each phase at each moment and obtain an influence weight and a voltage characteristic value of each phase of each key node at each moment; and compensating the voltage of the power distribution area based on a controllable series compensation technology. According to the method, the trigger angle in the voltage compensation process is accurately determined by accurately evaluating the voltage deviation of each key node, and the accuracy of voltage compensation of the power distribution area is improved.

The invention discloses a series compensation control method and control system for a dual-active bridge converter, and belongs to the technical field of direct current converter control, and the series compensation control method comprises the steps: determining a current working mode corresponding to a kth beat, calculating a series compensation coefficient of the kth beat in the current working mode by using the voltage transmission ratio of the kth beat, the actual battery current, the control phase shift angle of the previous beat and the duty ratio of the input bus side of the previous beat, and inputting a middle phase shift angle of the kth beat into a series compensation link of the kth beat to obtain a control phase shift angle of the kth beat, and finally, generating a kth-beat driving signal by using the kth-beat control phase shift angle and the kth-beat input bus side duty ratio so as to drive a power switch device of the dual-active bridge converter. The series compensation link can dynamically adjust and expand the working characteristics of the phase-shifted dual-active bridge converter under different working conditions, so that the defect of poor dynamic adaptive capacity of a traditional PI control surface to a wide load range can be overcome.

The present application belongs to the field of flexible AC transmission and distribution and power electronics, and discloses a unified power quality conditioner and method to achieve the goal of power quality management. The device comprises a DC bus and a compensation unit and a regulating unit connected thereto; the compensation unit comprises a series compensation subunit and a parallel compensation subunit; the series compensation subunit is used for compensating the load voltage; the DC bus is used for providing compensation energy for the series compensation subunit; the parallel compensation subunit is used for compensating the load harmonic, three-phase imbalance and reactive current, and also used for providing voltage support for the DC bus and energy for the series compensation subunit; the regulating unit comprises a parallel super capacitor energy storage system and a photovoltaic power generation system; the super capacitor energy storage system comprises a super capacitor and a first DC / DC converter; the photovoltaic power generation system comprises a photovoltaic array and a second DC / DC converter. The present application solves the coupling problem of the series and parallel inverters of the device, and makes the DC side bus voltage stable.

The invention relates to an adaptive temperature compensation technique for an electrochemical geophone. Through the combination of frequency response self-calibration and a variable feedback compensator system, a method capable of compensating the frequency response of the detector under different temperature conditions is provided. According to the method, the frequency response of the detector is measured in real time by using a sweep frequency vibration test signal generated by an excitation coil, feedback parameters are updated online through a digital signal processing technology, compensation is performed in a low-frequency band, and meanwhile, a multi-stage series compensation system is introduced to further improve the temperature compensation effect of a high-frequency band. According to the method, the frequency response temperature drift is remarkably reduced, and the acquisition quality and reliability of the seismic data are improved.

The invention discloses a method and a system for suppressing subsynchronous oscillation of a virtual synchronous doubly-fed wind turbine connected to the grid through series compensation. The method includes: obtaining an expression of the output impedance of the grid-side converter based on VSG; revealing the positive damping characteristic of the grid-side converter based on VSG for subsynchronous oscillation from the perspective of the equivalent impedance of the doubly-fed wind turbine grid-connected system; analyzing the mechanism of suppressing subsynchronous oscillation of the virtual synchronous doubly-fed wind turbine grid-connected system in combination with active disturbance rejection control; and constructing an improved active disturbance rejection controller to suppress subsynchronous oscillation. The subsynchronous oscillation analysis method adopted by the invention has a certain universality and can provide a theoretical analysis basis for the subsynchronous oscillation problem caused by a high proportion of power electronic devices participating in the new energy power generation system. At the same time, the suppression method proposed by the invention is not only applicable to doubly-fed generating units, but also applicable to suppressing subsynchronous oscillation in direct-drive wind turbines and weak AC systems extended thereto.

The embodiment of the invention discloses a control method for suppressing subsynchronous oscillation of a doubly-fed fan and related equipment, relates to the technical field of stable control of a power system, and directly estimates subsynchronous frequency based on inherent parameters such as series compensation capacitance reactance, equivalent inductive reactance and power grid synchronous frequency. The influence of the power grid resistance parameter change on the sub-synchronous frequency estimation value is eliminated; quickly locking a spectrum analysis range based on the obtained subsynchronous frequency estimation value; according to the method, the oscillation frequency, namely the subsynchronous resonant frequency, is accurately locked through fast Fourier decomposition of the rotor current in combination with an amplitude comparison strategy in a preset spectral analysis range, and the subsynchronous resonant frequency in a doubly-fed fan rotor side control system is filtered out, so that oscillation suppression is achieved.

The invention provides a fault diagnosis method and device for voltage limiters of a series compensation device, and the method comprises the steps: collecting the currents of a plurality of voltage limiter groups of a target series compensation device, the target series compensation device comprises a plurality of voltage limiter branches which are connected in parallel, and each voltage limiter branch comprises at least two voltage limiter groups; determining the current unbalance degree between every two voltage limiter groups according to the current of each voltage limiter group; whether the maximum value of the current unbalance degree between every two voltage limiter sets is larger than a set unbalance degree threshold value or not is diagnosed, and if yes, the voltage limiter set with the large current in the two voltage limiter sets corresponding to the maximum value of the current unbalance degree is determined as the fault voltage limiter set. According to the invention, the efficiency and timeliness of fault diagnosis can be improved on the basis of ensuring the precision of fault diagnosis of the voltage limiter.

The present application discloses a method for suppressing subsynchronous oscillations of a doubly-fed wind turbine and related equipment, belonging to the field of wind power generation technology. The method comprises: when the doubly-fed wind turbine is connected to the power grid via a series compensation capacitor, obtaining a voltage control signal of the doubly-fed wind turbine in a synchronous rotating coordinate system; using a filter to extract the voltage control signal within a specified frequency band, and using a phase shifter to perform phase shift compensation on the signal extracted by the filter with the goal of ensuring that the doubly-fed wind turbine satisfies the positive impedance characteristic within the specified frequency band; performing an inverse Park transform on the voltage control signal after phase shift compensation, and using the voltage control signal after the inverse Park transform to control the three-phase AC power output by the doubly-fed wind turbine. This method can solve the current technical problems of high cost, complex modeling, and difficulty in engineering application when suppressing subsynchronous oscillations of doubly-fed wind turbines.

The present invention relates to the field of wireless power transmission technology, and discloses a highly anti-offset wireless power transmission system with four reconstruction modes, comprising a reconfigurable inverter module, a primary-side compensation network module, a secondary-side compensation network module, and a rectifier filter circuit module; through the coordination of compensation topology reconstruction and parameter optimization design, constant power output within a coupling coefficient variation range of about 620% is achieved, and the secondary-side loop only uses a single capacitor series compensation. The system structure is more compact, simple, and lightweight, and is more in line with actual application requirements. It can achieve constant power output within a coupling coefficient variation range of about 620% at a fixed operating frequency and without the need for additional control hardware or complex mechanical adjustments, only through simple switch tube control.

The invention discloses a power grid operation mode voltage automatic adjustment method and system suitable for different new energy coincidence rates, and belongs to the technical field of power systems. According to the method, series compensation and parallel compensation of a plant station with an out-of-limit bus in a third power flow result are output, a capacitor is automatically input or reactance is automatically quitted from the plant station with the voltage exceeding the lower limit according to the difference between the voltage and the limit voltage, and a reactive power is automatically output from the plant station with the voltage exceeding the upper limit according to the difference between the voltage and the limit voltage. And the capacitor is automatically withdrawn or the reactance is input. According to the invention, under the condition that the voltage cannot be adjusted, surrounding reactive power resources can be automatically adjusted, the terminal voltage of a new energy machine is cooperatively adjusted, and the voltage of a high voltage level can be automatically switched to a target level through series-parallel compensation.

The invention belongs to the field of wireless electric energy transmission, and discloses a three-coil structure constant-current constant-voltage type wireless electric energy transmission system suitable for an office table, the system comprises an electric energy sending unit, a relay unit and a receiving unit, and the relay unit forms a series resonance network through a relay coil L2 and a relay series compensation capacitor C2; the receiving unit consists of a receiving coil L3, a receiving end compensation network, a rectifier D and a battery load R; the input end of the rectifier D is connected with the receiving coil L3, a constant current mode compensation capacitor C3CC and a constant voltage mode compensation capacitor C3CV which can be switched through a switch S are connected in series between the rectifier D and the receiving coil L3, and the output end of the rectifier is connected with a battery load R. The system can realize constant-current and constant-voltage output characteristics meeting battery charging requirements when the equivalent impedance of the battery is changed, and can ensure that the inverter realizes zero-phase-angle switching operation when the equivalent impedance of the battery is changed and the system is subjected to position offset.

An S2G charging station harmonic current detection and UPQC suppression method fusing wavelet transform and an LVQ neural network performs multi-scale decomposition on a current signal by using the wavelet transform, extracts time-frequency characteristics of different frequency bands, realizes real-time detection and classification of harmonic current in combination with the LVQ neural network, suppresses the harmonic current at the charging station side through a UPQC parallel compensation unit, and improves the harmonic current detection and UPQC suppression efficiency. The series compensation unit eliminates power grid side voltage harmonics. According to the method, high-precision harmonic current detection can be realized in the S2G charging station, harmonic current of different frequency bands can be quickly and accurately identified and classified, and amplitude and phase information of the harmonic current can be extracted, so that accurate analysis of the harmonic current is realized; through the dynamic compensation function of the UPQC, the harmonic current of the power grid and the charging station can be effectively suppressed, and the stability of the electric energy quality of the system is ensured. The method has efficient real-time detection and compensation capability, and can significantly reduce the negative influence of harmonic distortion on the power grid and the charging station.

The invention discloses a series compensation capacitor and PMU measurement tampering-based concealment attack method. The method comprises the following steps: S1, establishing a complete dynamic model of a grid-connected doubly-fed induction wind generator; s2, in order to improve the transmission capacity of the power transmission line and reduce the energy loss in the transmission process, the DFIG wind power plant is often connected with an external power grid through a series compensation line, and a series compensation line module differential equation is constructed; a PMU is installed at the machine end of each DFIG to obtain the electrical quantity; s3, providing a group of unstable feature roots, inversely solving a capacitance value corresponding to the feature value, and taking the capacitance value as an attack value of the capacitance in the step S2; and S4, calculating the variable quantity of the measured value caused by the attack, subtracting the measured variable quantity from the measured value after the system is attacked so as to obtain a normal measured value, and tampering the measured value of the PMU into a normal value on a transmission line so as to realize the hidden attack.

The application discloses a kind of second-order general type fast desaturation controller determination method and system, it is related to engineering system control field, this method includes: determining the saturation gain of actuator in target industrial control system;Using the input-output deviation of actuator, second-order general type fast integral desaturation compensator is constructed;Based on saturation gain, second-order general type fast integral desaturation compensator is equivalent into the desaturation structure of series compensation, and the compensation link and desaturation channel in desaturation structure are determined;Using the linkage relationship of bandwidth PID controller and desaturation bandwidth, the value of desaturation bandwidth in compensation link and desaturation channel is determined, to obtain the second-order general type fast desaturation controller of target industrial control system.The application can realize control while selecting less parameters, and improve the stability of control.

The utility model discloses a low pressure series compensation device relates to the technical field of compensation circuit, including the soft start power supply circuit for controlling starting current slow rise, the surge impact is suppressed, the capacitive reactive power output for the dynamic regulation series capacitor, the low pressure reactive power compensation circuit of compensation inductive load's reactive power shortage, the voltage detection circuit for real -time tracking circuit voltage fluctuation, generates the voltage feedback signal required for compensation control. The utility model discloses through the voltage detection circuit, thereby through the accurate detection of resistance voltage dividing network and operational amplifier IC1, realizes real -time monitoring and signal conditioning to the grid voltage, ensures that compensation system can accurately obtain voltage variation information, provides reliable data support for reactive power compensation control.

A static synchronous series compensation system and method, the scheme includes: a primary circuit installed on a high potential platform and a secondary circuit installed in a control protection room; the high potential platform is connected with a power transmission line at the same potential; the primary circuit is connected in series with the power transmission line to compensate the voltage of the power transmission line; the secondary circuit is connected with the primary circuit, and compensation instructions are issued to the primary circuit according to the voltage loss value of the power transmission line. The static synchronous series compensation system in the scheme does not need a series transformer or only needs a low insulation grade series transformer, greatly reduces the insulation design difficulty of the series transformer, reduces the device cost, reduces the equipment weight, reduces the equipment cost, and greatly reduces the occupied area. In the scheme, the high potential platform is connected with the power transmission line at the same potential, and the primary circuit is installed on the high potential platform, which reduces the energy loss of the primary circuit caused by corona discharge and the electromagnetic interference of the adjacent equipment.

The present invention discloses an autonomous coreless transformer and a refined design method thereof. The transformer comprises an autonomous voltage source, a circular winding bobbin, a primary winding, a secondary winding, a primary series compensation capacitor, a secondary series compensation capacitor, an uncontrolled rectifier module, an output filter capacitor, and a load resistor. The secondary winding is wound around the center of the circular winding bobbin, and the primary winding is evenly distributed on both sides of the secondary winding. Adjusting the number of turns and gap between the primary and secondary windings can control the transformer parameters. The present invention achieves refined design of the autonomous coreless transformer parameters by combining winding structure design with voltage deviation compensation.

The invention discloses a constant-current constant-voltage wireless power transmission system based on an integrated composite compensation topology, and belongs to the technical field of wireless power transmission, the constant-current constant-voltage wireless power transmission system comprises a transmitting end and a receiving end, the transmitting end comprises an H-bridge inversion module, a transmitting end controller, a primary side integrated LCCLC composite compensation network and a transmitting coil, and the receiving end comprises a receiving coil, a series compensation network and a full-bridge rectifier module. The compensation inductor L1 in the integrated LCCLC-S composite compensation and the transmitting end coil are coaxially and tightly installed in the same plane, so that the coupling effect between magnet exciting coils is enhanced; the switching between the LCC-S compensation structure and the LC-S compensation structure is realized through switch control; constraint conditions of composite compensation structure parameter design are further given, and the constant current output characteristic and the constant voltage output characteristic of the LC-S compensation state are achieved.

The invention relates to the field of current reducing systems, and particularly discloses a system and a method for reducing current and improving electric energy quality, comprising at least one current limiting module, a first current transformer, at least one capacitive module, a first switch, a second switch, a third switch, a fourth switch, a control protection system and a voltage transformer, the current limiting module is connected in series with the third switch, then connected in parallel with the fourth switch, and then integrally connected in series with the first current transformer; the capacitive module is connected in series with the second switch and then connected in parallel with the third switch; one end of the first switch is connected with the capacitive module and a connecting line of the second switch, and the other end of the first switch is grounded. Functions of current limiting, reactive compensation, series compensation, harmonic filtering and the like can be realized, and the number of equipment is reduced.