Abstract: The present invention relates to the technical field of power electronics converters and discloses a grid-forming energy storage converter on/off-grid switching control method and system, where the method includes the following steps: S1: using a single-loop power control strategy in an off-grid state when an on-grid relay of target energy storage drops out; S2: using a parallel virtual impedance loop-based power control strategy in a transient on-grid state when the on-grid relay of target energy storage pulls in; and S3: using a cascaded dual-loop power control strategy with a virtual admittance voltage loop and an inner current loop when a stable on-grid state is established. The present invention solves the problems of large current impact and unstable switching process state in the existing working strategy for on/off-grid switching in the prior art.

Abstract: An online voltage control method for coordinating multi-type reactive power resources is provided. First, a linearized power flow equation of branch reactive power is established, and an online voltage control model of multi-type reactive power resources including an objective function and constraint conditions is constructed. The constraint conditions includes generator reactive power constraints, reactive power compensator constraints, transformer tap position constraints, a nodal reactive power balance constraint, and slack contained nodal voltage constraints. Then, an optimization result of voltage control is obtained by solving the model.

Abstract: A transformer bushing partial discharge monitoring chip device and method are provided. An acquisition unit comprises three sensor modules installed at end screens of three-phase bushings of a transformer respectively for acquiring partial discharge signals and power frequency current signals from the transformer bushing end screens; each of the sensor modules is connected to an SIP digitization unit through a wire; the SIP digitization unit is fixedly installed beneath a base of the acquisition unit for digitizing the partial discharge signals and the power frequency current signals; an output end of the SIP digitization unit is connected to an input end of a background processing terminal.

Abstract: Provided are a method and apparatus for evaluating a degree of frequency regulation urgency of a generator set, a power system and a storage medium.

Abstract: A current signal segmentation algorithm is provided. The segmentation algorithm divides a current signal waveform into mutually different segments according to a physical feature thereof, extracts shape distribution, statistical and harmonic features of the segments, and calculates a similarity between a segment pair. The segmentation algorithm includes the following steps: segmenting a current signal to separate a standby current and an overshoot current, only leaving a working current; extracting a shape distribution feature of a working current segment; extracting a statistical feature of the working current segment; extracting a harmonic feature of the working current segment; calculating a similarity between a segment pair; and deriving a maximum clique set in a similarity graph through a maximum clique search algorithm as a class from automatic segmentation.

Abstract: Disclosed is an estimation method for a whole life cycle cost of a power battery in echelon utilization. In this method, echelon utilization grades are established for the power battery according to an SOH of the power battery; a whole battery capacity model is constructed corresponding to the echelon utilization grades; a cost model is constructed corresponding to the echelon utilization grades; and a variation trend of the whole life cycle cost of the power battery is estimated according to the echelon utilization grades for the power battery, the power battery capacity model and the cost model, and a result of estimation is outputted.

Abstract: Disclosed is an intelligent on-line diagnosis method for winding deformation of power transformer. When a transformer is subjected to short-circuit shock or transportation collision, transformer windings may undergo local twisting, swelling or the like under the action of an electric power or mechanical force, which is called winding deformation and will cause a huge hidden danger to the safe operation of the power network. Commonly used diagnosis methods for winding deformation are all off-line diagnosis methods, which have the disadvantages that transformers need to be shut down and highly skilled operators are required. The present invention provide an intelligent on-line diagnosis method for winding deformation on the basis of combination of information entropy and support vector machine.

Abstract: Disclosed is an estimation method for a whole life cycle cost of a power battery in echelon utilization. In this method, echelon utilization grades are established for the power battery according to an SOH of the power battery; a whole battery capacity model is constructed corresponding to the echelon utilization grades; a cost model is constructed corresponding to the echelon utilization grades; and a variation trend of the whole life cycle cost of the power battery is estimated according to the echelon utilization grades for the power battery, the power battery capacity model and the cost model, and a result of estimation is outputted.

Abstract: Disclosed is a condition assessment method for an outdoor post-mounted vacuum switch. The method includes: establishing a condition assessment mathematical model for the post-mounted vacuum switch and acquiring scores of condition indicators of the post-mounted vacuum switch; and acquiring a condition assessment score based on the condition assessment mathematical model of the post-mounted vacuum switch and according to the scores of the condition indicators of the post-mounted vacuum switch so as to realize on-line monitoring of a health condition of the post-mounted vacuum switch and assess the health condition of the post-mounted vacuum switch. Further disclosed is a condition assessment device for the outdoor post-mounted vacuum switch.

Abstract: Provided are a method and apparatus for evaluating a degree of frequency regulation urgency of a generator set, a power system and a storage medium.

Abstract: A wearable equipment is adapted for substation maintenance mobile inspection and includes a binding strap and a controlling wireless communication module. A thermal imager is disposed on one side of the binding strap. A prism display component and a voice interaction module are disposed on the other side of the binding strap. The thermal imager, the prism display component, and a microphone and a speaker of the voice interaction module are connected to the controlling wireless communication module through cables, to transmit information in a power system intranet. An application method includes mounting the wearable equipment to an electric power helmet, and automatically sending an infrared image, a visible light image, power monitoring information, voice, and a video in a power operation area to a background management controlling system for the substation maintenance mobile inspection.

Abstract: Provided is a photovoltaic power converter receiver, including a photovoltaic cell, a waveguide coupled to the photovoltaic cell, and an optical transmission device of which an end is coupled to the waveguide for transmitting an optical wave to the photovoltaic cell through the waveguide, wherein the end of the optical transmission device is offset from a longitudinal central axis of the waveguide by a distance Doffset.

Abstract: A support tensor machine based neutral point grounding mode decision method and system adopts a support tensor machine method Based on three indexes, i.e., the power supply reliability index, safety index, and economical efficiency index, influences of different neutral point grounding modes are analyzed by employing the support tensor machine method to finally obtain a neutral point grounding mode capable of maximizing power supply reliability of a distribution network.

Abstract: A wearable equipment is adapted for substation maintenance mobile inspection and includes a binding strap and a controlling wireless communication module. A thermal imager is disposed on one side of the binding strap. A prism display component and a voice interaction module are disposed on the other side of the binding strap. The thermal imager, the prism display component, and a microphone and a speaker of the voice interaction module are connected to the controlling wireless communication module through cables, to transmit information in a power system intranet. An application method includes mounting the wearable equipment to an electric power helmet, and automatically sending an infrared image, a visible light image, power monitoring information, voice, and a video in a power operation area to a background management controlling system for the substation maintenance mobile inspection.

Abstract: A renewable energy-based hybrid bi-directionally interactive DC traction power supply system includes two traction substations. Each substation includes transformers, rectifiers, bidirectional AC-DC converters, a DC bus, a catenary, a steel rail and a section post. A DC bus between two adjacent traction substations is provided with a DC renewable energy system constructed by an electric vehicle charging-discharging system, a distributed generation and more than one low voltage DC microgrid. The DC renewable energy system is connected to the DC bus between two adjacent traction substations through a high voltage DC bus, thus a DC circular microgrid being formed in a power supply section post. The electric vehicle charging-discharging system is formed by more than one bidirectional DC-DC charging-discharging equipments which are intended for in connection with the power batteries of the electric vehicle.

Abstract: A digital AC/DC power converter comprises an active PFC module, a single switch module having a single switch, a power output module having a transformer, a digital control module having a microcontroller, and a rectifying and filtering module having a full-bridge rectifier, an EMI filter, and a capacitor that is less than 1 ?F. The single switch is electrically connected to the active PFC module, and a primary winding of the transformer is electrically connected to the active PFC module. The microcontroller provides a PWM signal to control the switching state of the single switch, so that the active PFC module transforms AC frequency from less than 300 Hz into over 30,000 Hz and outputs a rectified AC voltage waveform. The EMI filter blocks high electromagnetic frequencies and the capacitor smooths a variation in the rectified voltage waveform and output the smoothed rectified voltage waveform to the active PFC module.

Abstract: A digital AC/DC power converter comprises an active PFC module, a single switch module having a single switch, a power output module having a transformer, and a digital control module having a microcontroller. The single switch is electrically connected to the active PFC module, and a primary winding of the transformer is electrically connected to the active PFC module. Moreover, the microcontroller provides a PWM signal to control the switching state of the single switch, so that the active PFC module transforms AC frequency from no more than 300 Hz into at least 30,000 Hz and outputs a rectified AC output voltage waveform to improve power factor.

Abstract: The invention provides an LED lighting device having a plurality of LED modules. Each LED module includes a housing structure, a plurality of LEDs disposed on the housing structure and a power converter that provides power to the LEDs. Each power converter of the LED modules operates independently. The LED lighting device of the present invention is more difficult to fail and may effectively reduce maintenance costs.

Abstract: A renewable energy-based hybrid bi-directionally interactive DC traction power supply system includes two traction substations. Each substation includes transformers, rectifiers, bidirectional AC-DC converters, a DC bus, a catenary, a steel rail and a section post. A DC bus between two adjacent traction substations is provided with a DC renewable energy system constructed by an electric vehicle charging-discharging system, a distributed generation and more than one low voltage DC microgrid. The DC renewable energy system is connected to the DC bus between two adjacent traction substations through a high voltage DC bus, thus a DC circular microgrid being formed in a power supply section post. The electric vehicle charging-discharging system is formed by more than one bidirectional DC-DC charging-discharging equipments which are intended for in connection with the power batteries of the electric vehicle.

Abstract: The present invention relates to a system and method for harvesting wind energy from air exhausted by other systems. Ventilation and heat exchange systems force air movement using fans. Exhaust airflow may also be the result of a combustion system. The exhaust air is generally wasted as it is diffused back to the atmosphere. Significant energy may be recovered from this exhaust air using relatively small turbines inserted into the airflow. Careful positioning of the turbine maximizes the recovery efficiency.