Progress on the demand side management in smart grid and optimization approaches

The electrical power system has experienced several changes during the last decade, raised by continuously increasing load demand, rapid depletion in fossil fuels, and newly electrical deregulation policy. In the past, numerous review literatures has been published in the field of Load Frequency Control (LFC), which deals with different and recent control strategies for the successful operation of the power system. Moreover, due to changes in lifestyle, increasing load demand, expansion of industrialization, and environmental issues, Renewable Energy Sources (RES) integration becomes the obvious adaptive choice. Since generation from RES is stochastic in nature and depends upon the weather condition and other aspects at every instant of time. Therefore, high penetration may reflect specific issues regarding voltage instability, frequency stabilization, and reliability obstruction. Hence this issue has been covered effectively in this review work. Furthermore, the work precisely summarized and briefly explained the different scenarios of Energy Storage (ES), micro-grid and Flexible AC Transmission System (FACTS) to explore the possible solutions and future aspects. The merit and demerit of different controllers are also investigated with the help of a comparison's tables and also some other analytical comparisons. The overall study examines an in-depth review of recent technical core aspects for LFC based on classical and modern power system which involves the non-linear model, controller design parameters, soft-computing application, attributes of Load forecasting, as well as integration of RES in a deregulated environment. This effective, comprehensive literature survey is very helpful for researchers to bridge the gap between recent development, implementation, challenges and future trends of RES in LFC. 

A literature survey on load frequency control considering renewable energy integration in power system: Recent trends and future prospects

The influence of electric vehicle charging strategies on the sizing of electrical energy storage systems in charging hub microgrids

https://onlinelibrary.wiley.com/doi/pdf/10.1002/2050-7038.13024

Flywheel energy storage systems: A critical review on technologies, applications, and future prospects

Battery Degradation Prediction Against Uncertain Future Conditions with Recurrent Neural Network Enabled Deep Learning

Hierarchical control of DC micro-grid for photovoltaic EV charging station based on flywheel and battery energy storage system

A new three-level neutral-point-clamped quasi-Z-source inverter topology is proposed. The topology can effectively reduce the Z-source network capacitor voltage stress and inhibit the start inrush current, thus low-voltage capacitors can be selected to reduce the volume and cost of the inverter. In addition, the changed structure will not affect the boost ability and all existing modulation methods can be used directly. The proposed topology is validated by simulations.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/el.2016.3930

Three-level neutral-point-clamped quasi-Z-source inverter with reduced Z-source capacitor voltage

The invention relates to a virtual synchronous generator control method based on self-adapting moment inertia. The output of a grid-connected inverter in distributed generation is connected with an AC bus of a filter capacitor Cf which is in parallel connection with the grid-connected inverter through a filter inductor Lf; sampling is performed to obtain the output power, the voltage and the current of an output interface of an inverter; the output power, the voltage and the current are transmitted to a VSG (virtual synchronous generator) algorithm; the calculated terminal voltage of a VSG stator is sent to be controlled by a voltage external loop; the voltage external loop adopts a PI controller to stably load the voltage; the current of the filter capacitor is sent to be controlled by a voltage internal loop; the voltage internal loop adopts a PI controller to increase the response speed; a control signal is outputted by a voltage-current dual-closed loop to the grid-connected inverter; the moment inertia in the virtual synchronous generator in the control method can be changed in a self-adapted manner according to the change capacity of the system frequency. Through the adoption of the virtual synchronous generator control method disclosed by the invention, the transient state process of the system is reduced; a great deal of harmonic waves in the system is offset; the stability of frequency and the stability of voltage can be improved; the adaptability and the power supply quality of a micro-electrical network are improved; the problem that in a conventional method, the output frequency is reduced, is solved.

Virtual synchronous generator control method based on self-adapting moment inertia

Structure analysis and sliding mode control of new dual quasi-Z-source inverter in microgrid

The invention relates to a three-dimensional fault line selection method based on random resonance and a transient current signal. The method comprises the following steps of: (1) after a power distribution network is faulted, recording the zero-sequence current iZn(t) and the fault phase current iXn(t) of each branch line fault, and computing transient zero-sequence current izn(t) and transient fault phase current ixn(t); (2) performing variable-scale bistable treatment on the transient zero-sequence current izn(t) and transient fault phase current ixn(t); (3) computing a cross correlation coefficient matrix M and an integrated correlation coefficient Mn among the transient characteristic zero-sequence current iczn(t) of the branch lines and selecting the line ln with the minimum Mn; (4) performing seven-layer db10 wavelet packet decomposition on the transient characteristic phase current icxn(t) of each branch line and computing simplified energy E*sn and simplified gravity center frequency f*gn; and (5) forming a three-dimensional coordinate system by using the simplified gravity center frequency f*gn as a horizontal ordinate, the simplified energy E*sn as a vertical coordinate, and a polarity parameter value as a longitudinal coordinate. Compared with a method in the prior art, the method is high in reliability and is not liable to suffer from external interference.

Cheng Qiming

Papers

Hierarchical control of DC micro-grid for photovoltaic EV charging station based on flywheel and battery energy storage system

Three-level neutral-point-clamped quasi-Z-source inverter with reduced Z-source capacitor voltage

Virtual synchronous generator control method based on self-adapting moment inertia

Structure analysis and sliding mode control of new dual quasi-Z-source inverter in microgrid

Three-dimensional fault line selection method based on random resonance and transient current signal