Abstract: A synchrophasor measurement-based disturbance identification method is described considering different penetration levels of renewable energy. A differential Teager-Kaiser energy operator (dTKEO)-based algorithm is first utilized to improve multiple-disturbances detection accuracy. Then, feature extractions via the integrated additive angular margin (AAM) loss and the long short-term memory (LSTM) network is described. This enables one to deal with intra-class similarity and inter-class variance of disturbances when high penetration renewable energy occurs. With the extracted features, a multi-stage weighted summing (MSWS) loss-based criterion is described for adaptive data window determination and fast disturbance pre-classification. Finally, the re-identification model based on feature similarity is established to identify unknown disturbances, a challenge for existing machine learning algorithms.

Abstract: The present application proposes a method of locating oscillation sources of wind power integrated system based on energy spectrums. The method include: collecting information of voltage and current at the terminal of each generator and obtaining a dynamic energy curve of each generator over time; choosing the generators whose curve shows an upward trend in the dynamic energy over time curve into alternative generators; obtaining and processing energy spectrums of synchronous generator, DFIG with PLL, and/or an analogical energy spectrum of DFIG with virtual inertia among the alternative generators; selecting generator with maximum proportion of dominant oscillation mode as an oscillation source reference generator; and calculating the similarity coefficients between energy spectrums of each remaining candidate generator and the oscillation source reference generator, determining the oscillation source generators.

Abstract: A power margin tracking control method and system for a multi-terminal high-voltage direct current converter station are provided. A power adjustment factor is introduced on the basis of a droop coefficient, to realize a self-adaptive regulation of a converter station operation mode to a real-time fluctuation of a wind and solar power. In this way, the system operation stability and the power fluctuation allocation capability in a grid-connected system are improved. Furthermore, a DC voltage deviation in the multi-terminal high-voltage direct current grid is reduced.

Abstract: A method for quantum key fusion-based virtual power plant security communication includes: identity authentication, performing identity authentication between a client and a server in a virtual power plant based on a communication requirement to acquire a root key; key distribution: generating a key encryption key and a message authentication key based on the acquired root key and performing negotiation on a data encryption key to obtain the data encryption key; and data encryption: encrypting to-be-encrypted data using the data encryption key, and implementing communication of the data. During the identity authentication or the key distribution, negotiation on a quantum key is performed by a quantum key server, and the quantum key obtained by the negotiation is used for implementing the identity authentication or used as the data encryption key. A device for quantum key fusion-based virtual power plant security communication and a computer storage medium are provided.

Abstract: A data-driven PMU bad data detection algorithm based on spectral clustering using single PMU data is described. The described algorithm does not require the system topology and parameters. First, a data identification method based on a decision tree is described to distinguish event data and bad data by using the slope feature of each set of data. Then, a bad data detection method based on spectral clustering is described. By analyzing the weighted relationships among all the data, this method can detect the bad data that has a small deviation.

Abstract: The disclosure relates to an active damping control method and system for sub-synchronous oscillation of DFIG, and storage medium. The method comprises the following steps: collecting oscillation components of stator current and/or stator voltage; determining each energy branch in DFIG converter according to the flow path of the oscillation component(s) of the stator current and/or the stator voltage in DFIG converter; determining the corresponding function of each energy branch according to oscillation component(s) the stator current and/or the stator voltage; determining the energy compensation branch and its corresponding energy compensation function in DFIG converter according to the corresponding function of each energy branch and converter parameters; controlling the sub-synchronous oscillation of DFIG by controlling the energy compensation branch according to the energy compensation function.

Abstract: The disclosure relates to a method, system and storage medium for suppressing sub/super-synchronous oscillation for direct-drive wind turbine based on energy compensation.

Abstract: The disclosure discloses a commutation failure prediction method, device and storage medium based on energy accumulation features of inverter. The method includes the following steps: collecting instantaneous values of three-phase valve side current and calculating the derivatives of the three-phase valve side current according to the instantaneous values of three-phase valve side current; the derivative includes positive, negative and zero states; according to the derivatives of the three-phase valve side current, determining the locations of incoming valve and ongoing valve; based on the valve side current of the incoming valve and ongoing valve, calculating energy accumulation features of the 12-pulse inverter; predicting whether the commutation failure from the incoming valve to the ongoing valve will happen according to the states of the derivatives of the three-phase valve side current and the energy accumulation features of the 12-pulse inverter.

Abstract: The disclosure relates to a method and system for evaluating the stability of HVDC receiving end system and storage medium, which relates to the technical field of high voltage direct current transmission. The method includes: collecting voltage at a generator port, current at the generator port and rotational speed of the generator after eliminating fault; determining a corresponding relationship between the generator dynamic energy and the time according to the voltage at the generator port, the current at the generator port and the rotational speed of the generator; determining the attenuation intensity of the generator dynamic energy according to the corresponding relationship between the generator dynamic energy and the time; determining stability of the HVDC receiving end system according to the attenuation intensity of the generator dynamic energy.

Abstract: The present disclosure is directed to a single-phase reclosing method, device and storage medium for AC/DC system. The method comprises: acquiring three-phase voltages at inverter-side AC bus close to the transformer, three-phase currents measured at the outlet of inverter-side AC line and three-phase voltages at inverter-side AC bus far from the transformer; calculating the energy calculation value and energy operation value of the fault line; identifying the fault nature of fault line within the maximum time delay, according to the energy calculation value and energy operation value of fault line and an energy criterion of transient/permanent fault; issuing a reclosing control signal based on the fault nature of fault line to realize effective reclosing of the fault line.

Abstract: The disclosure relates to a method and system for AC line distance protection in AC/DC hybrid power grid, and storage medium.

Abstract: A coal-fired power generation system and a supercritical CO2 cycle system thereof are provided. The supercritical CO2 cycle system includes a compressor unit and a turbine unit. The turbine unit includes a preceding stage heater, a preceding stage turbine, a last stage heater and a last stage turbine successively connected in series. An exhaust port of at least one of compressors in the compressor unit is in communication with the turbine unit through a split flow pipe, and a communication position between the split flow pipe and the turbine unit is located downstream of a suction port of the preceding stage turbine. An auxiliary regenerator and an auxiliary heater are provided at the split flow pipe, and the auxiliary regenerator is located upstream of the auxiliary heater.

Abstract: A strong cooling direct air-cooled condenser radiating unit and an air-cooled island are provided, comprises a cooling wall, an air supply device and a flow guide device located in the cooling wall. The air supply device comprises a unit air supply channel, an air supply ring, and an air collecting cavity. The air supply ring is located at the lower part of the cooling wall and is an annular body with a cavity. An annular slit outlet is formed in the lower part of the air supply ring. The upper part of the air collecting cavity communicates with the air supply ring. A separating plate is provided in the unit air supply channel and divides the unit air supply channel into upper and lower air flues. The upper air flue communicates with the cavity of the air supply ring. The lower air flue communicates with the air collecting cavity.

Abstract: A synchrophasor measurement-based disturbance identification method is described considering different penetration levels of renewable energy. A differential Teager-Kaiser energy operator (dTKEO)-based algorithm is first utilized to improve multiple-disturbances detection accuracy. Then, feature extractions via the integrated additive angular margin (AAM) loss and the long short-term memory (LSTM) network is described. This enables one to deal with intra-class similarity and inter-class variance of disturbances when high penetration renewable energy occurs. With the extracted features, a multi-stage weighted summing (MSWS) loss-based criterion is described for adaptive data window determination and fast disturbance pre-classification. Finally, the re-identification model based on feature similarity is established to identify unknown disturbances, a challenge for existing machine learning algorithms.

Abstract: A data-driven PMU bad data detection algorithm based on spectral clustering using single PMU data is described. The described algorithm does not require the system topology and parameters. First, a data identification method based on a decision tree is described to distinguish event data and bad data by using the slope feature of each set of data. Then, a bad data detection method based on spectral clustering is described. By analyzing the weighted relationships among all the data, this method can detect the bad data that has a small deviation.

Abstract: The wide application of power electronic components in power systems with renewable energy sources has changed the fault characteristics of conventional power systems, resulting in the performance degradation of conventional protections. To solve these problems, a novel principle of pilot protection based on structural similarity and square error criteria is provided. The structural similarity criterion utilizes the difference of fault characteristics between renewable sources and synchronous generators to identify internal faults, and the square error criterion is used to solve abnormal calculation of the conventional similarity based protection. Compared with conventional differential protections, the disclosed protection shows excellent performance in speed and reliability during various faults.

Abstract: A data recovery method framework is described, in which the data is classified as either ambient or disturbance data, and recovered by different methods to achieve good performance efficiently. An approach based on decision tree is described for identifying ambient and disturbance data. Then, an improved cubic spline interpolation based on the priority allocation strategy is described for ambient data loss, which can quickly and accurately recover ambient data. Simultaneously, a disturbance data recovery method based on singular value decomposition is described. It can achieve disturbance data recovery accurately by a single channel of measurement.

Abstract: A sparse voltage measurement-based fault location determination system and method for an alternating current (AC) distribution network is described. This method can use sparse voltage measurements and Bayesian compressive sensing (BCS) algorithm to reconstruct a sparse current vector. A fault location is then determined based on the reconstructed sparse current vector. The disclosed method provides robust fault location results under a variety of asymmetrical fault scenarios. Fewer intelligent electronic devices (IEDs) allocated in the terminal buses are needed for determining the fault location; therefore, this implementation is relatively cost effective.

Abstract: An improved phasor estimation method for M-class phasor measurement units (PMUs) with a low computational burden is described. The method contains three steps: 1) A phasor measurement filter is designed by selecting parameters of Taylor weighted least square method to prioritize dynamic phasor accuracy and a high level of suppression on high-frequency interferences; 2) A finite impulse response lowpass filter is designed by the equal-ripple method is put forward to suppress low-frequency interferences; and 3) Phasor amplitude is corrected under off-nominal conditions.

Abstract: A distance protection system and method based on a high-frequency fault component is provided for a renewal energy source (RES) system. The voltage drop caused by a fault has a full frequency of components and this can be extracted by a wavelet transform. A frequency selection principle that renders high-frequency impedance models a stable impedance phase angle is determined. On this basis, internal and external faults with respect to a transmission line are determined by comparing the magnitude of a high-frequency operating voltage with the magnitude of a high-frequency voltage at the fault point. This disclosed protection system and method can eliminate the influence of frequency offset and weak feed of the RES system by using high-frequency signals generated by voltage drops at the fault point, and can also tolerate signal noises and fault resistance.