Body-Effect-Free OLED-on-Silicon Pixel Circuit Based on Capacitive Division to Extend Data Voltage Range

This paper proposes an OLED pixel compensation circuit that copes with threshold voltage variation, narrow data voltage range, and body effect on a backplane of silicon-based transistors. It consists of six PMOS transistors and two capacitors. The data voltage range is extended by the capacitor division with two capacitors, and the connection of both source and gate nodes to the supply voltage makes the driving transistor free from the body effect. In addition, the reference voltage is used to initialize the gate node voltage of the driving transistor as well as to adjust the data voltage region. By the SPICE simulation, it is verified that the current error over the threshold voltage variations of ±10 mV is reduced to be −1.200% to 0.964% at the maximum current range of around 8 nA, and the data voltage range is extended to 3.4 V, compared to the large current error range from −21.46% to 27.36% and the data voltage range of 0.41 V in the basic 2T1C circuit. In addition, the body-effect-free circuit outperforms the latest 4T1C circuit of the current error range from −3.279% to 3.388%.

Self-Adaptive Rainfall Optimization-Based Reconfiguration of Distribution Networks

Reconfiguration that alters on/off status of sectionalizing and tie switches attempts to improve the operational performances of distribution networks (DNWs). This paper formulates the reconfiguration problem as a multi-objective optimization problem of reducing the net feeder loss(NFL), improving the node voltage profile (NVP) and enhancing the node voltage stability (NVS) and proposes a new reconfiguration method involving rainfall optimization (RO) for obtaining robust solutions. The method performs search for optimal tie switches in several sets of sectionalizing switches; each set is obtained from a closed loop formed for each tie switch, with a view of reducing the computational burden and adapting a self-adaptive technique for tuning the RO parameters for improving convergence. It performs study on 33-, 69- and 119-node DNWs and exhibits its superior performance over existing methods.

An effective network reconfiguration approach of radial distribution system for loss minimization and voltage profile improvement

Distribution system represents a crucial portion of power system as it is the connection between the bulk power transmission network and the customers connected at load point. Distribution networks are increasing in size and are spread too far. Low reactance to resistance ratio and large size of network leads to higher power losses in lines and low node voltage at customer end. High power losses reduce the efficiency and affect the economy. Therefore, in this paper an algorithm for reconfiguration of distribution system for loss reduction and voltage profile enhancement is proposed. The proposed reconfiguration approach has been applied to 16 bus radial distribution system (RDS).

Adaptive Power Flow Prediction Based on Machine Learning

Power flow analysis is an inevitable methodology in the planning and operation of the power grid. It has been performed for the transmission system, however, along with the penetration of the distributed energy resources, the target has been expanded to the distribution system as well. However, it is not easy to apply the conventional method to the distribution system since the essential information for the power flow analysis, say the impedance and the topology, are not available for the distribution system. To this end, this paper proposes an alternative method based on practically available parameters at the terminal nodes without the precedent information. Since the available information is different between high-voltage and low-voltage systems, we develop two various machine learning schemes. Specifically, the high-voltage model incorporates the slack node voltage, which can be practically obtained at the substation, and yields a time-invariant model. On the other hand, the low voltage model utilizes the deviation of voltages at each node for the power changes, subsequently resulting in a time-varying model. The performance of the suggested models is also verified using numerical simulations. The results are analyzed and compared with another power flow scheme for the distribution system that the authors suggested beforehand.

Low Power Restoration Circuits Reduce Swing Voltages of SRAM Cell With Improved Read and Write Margins

This paper examines the factors that affect the static noise margin (SNM) of static random access memories which focus on optimizing read and write operation of 8T SRAM cell which is better than 6T SRAM cell using swing restoration for dual node voltage. New 8T SRAM technique on the circuit or architecture level is required. In this paper, comparative analysis of 6T and 8T SRAM cells with improved read and write margin is done for 130nm technology with cadence virtuoso schematics tool.

High Voltage Ride through Strategy of Wind Farm Considering Generator Terminal Voltage Distribution

When wind power is transmitted via high-voltage direct current (HVDC), the problem of high-voltage ride-through (HVRT), caused by direct-current (DC) blocking must be seriously taken into account. All the wind turbines in a wind farm are usually equivalent to a single turbine in the existing research on HVRT, which ignores the generator terminal voltage distribution in a wind farm. In view of the fact that the severity of fault voltage felt by each wind turbine in the field is different, an improved HVRT strategy considering voltage distribution is proposed in this article. First, this article analyzes the mechanism of voltage swell failure caused by DC blocking, and the characteristics of the generator terminal voltage distribution in wind farms. Second, the reactive power characteristic equations of the synchronous condenser and the doubly-fed induction generator (DFIG) are derived. Third, based on the extraction of the key node voltage, this article takes the key node voltage as the compensation target, and put forwards a HVRT strategy combining the synchronous condenser and wind turbine. Finally, the simulation is carried out to demonstrate the effectiveness of the proposed strategy in improving the HVRT capability of all wind turbines.