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A full‐panel circuit model of the on‐cell touch AMOLED is introduced to simulate the mutual interference between touch and display operations. The proposed panel model successfully reproduced nonlinear behaviors of the display noise observed in real systems. Also, the reverse‐directional interference, i.e., touch‐to‐display coupling, was simulated, showing that touch stimulation incurs the fluctuation of display charging voltages, possibly causing perceivable line defects. The proposed panel model can be used for various touch/display algorithms to reduce the interference effects and to determine key design parameters for new panels. [ABSTRACT FROM AUTHOR]

This paper proposes a predictive power control strategy for the three‐phase, six‐switch Vienna rectifier without grid voltage sensors to reduce the hardware cost and complexity of a high‐power PWM rectifier system. Firstly, an algorithm for calculating the AC‐side voltage in the αβ coordinate system is derived according to the operating principle of the Vienna rectifier, and a voltage observer is constructed by combining a second‐order low‐pass filter to estimate the grid voltage. Secondly, a soft start method is designed to solve the problem that the rectifier is prone to inrush current when it is started. Furthermore, the control method of grid voltage sensorless is combined with predictive power control with good dynamic characteristics and simple parameter settings to form the control strategy proposed in this paper. Finally, simulation analysis and experimental verification are carried out on the proposed control strategy. Simulation and experimental results show that the grid voltage estimation has high accuracy, a good surge current suppression effect, unit power factor operation, low input current harmonic content, and good dynamic and steady‐state performance. Therefore, the correctness and effectiveness of the strategy proposed in this paper are verified. [ABSTRACT FROM AUTHOR]

The six‐switch inverter has gained significant attention due to its ability to achieve dual AC voltage outputs with fewer semiconductor power devices. However, with existing pulse width modulation (PWM) algorithms, the switching frequency of the two middle‐position power devices is twice that of the other four power devices at the upper and lower ends. Therefore, this paper proposes an improved PWM algorithm for the six‐switch converter based on the unipolar modulation principle. The proposed algorithm can significantly reduce the switching frequency of the two middle‐position power devices. Research results indicate that, under optimal conditions, the switching frequency of the two middle‐position power devices is as low as the frequency of the AC output voltages, and in the worst‐case scenario, it is only half the carrier frequency. Consequently, the efficiency of the inverter is effectively improved. Additionally, analysis results suggest that, given the same switching frequencies of power devices, the modulation algorithm proposed in this paper for controlling the converter also results in lower Total Harmonic Distortion (THD) for the output voltages compared to traditional modulation algorithms. [ABSTRACT FROM AUTHOR]

Proper current sharing, DC bus voltage deviation reduction, and SOCs balancing, along with ensuring stability are the vital challenges of DC microgrids control algorithms. Addressing these challenges without communication links and a central controller is one of the priorities of control methods. Motivated by the above mentions, this paper presents a novel communication‐free control method. In this regard, a new parameter called "virtual current" is defined according to the unit current and its SOC. Then using a piecewise droop curve and the droop curve shift technique, the virtual current for each unit is determined. The units control coefficients and the relationship of the virtual current are allocated based on the location and power of the loads and RESs such that in the worst case; 1) SOCs are converged; 2) the DC bus voltage deviation is reduced; and 3) the current is appropriately distributed. The simulation and experimental results confirm that the proposed method can balance SOCs like SOC‐based methods and share power properly like piecewise droop methods while reducing DC bus voltage deviation. [ABSTRACT FROM AUTHOR]

Summary: In order to achieve efficiency extremum of power conversion independent of parameter values and operational mode, an adaptive dual‐controller on‐line efficiency optimization method is presented in this paper. Firstly, based on tri‐modal analysis for four‐switch buck‐boost (FSBB) converter, efficiency extremum analysis is given and existed for such this converter. Then, adaptive dual controller on‐line efficiency seeking algorithm is shown to adaptive two variables for efficiency optimization and output voltage regulation. Furthermore, perturb and observe detector is described to realize control variables decoupling of dual‐controller and to prevent the instability of the whole system during the algorithm tuning process and to improve the algorithm speed of the dual controller. The proposed method is model independent and does not depend on the circuit parameter values. The detail implement of algorithm and performance analysis is given, and the experimental platform and experimental results are put forward to verify the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

In the current global promotion of environmental protection and low‐carbon, in order to further reduce the power consumption of TFT‐LCD, this paper proposes an algorithm based on image detection for adaptive adjustment of panel voltage, and tests the algorithm on the monitor. The test results shows that the algorithm can achieve power reduction while maintaining image quality. [ABSTRACT FROM AUTHOR]

In this paper, a novel compensation algorithm is proposed for improving multi‐frame drop (MFD) on AMOLED display. The MFD phenomenon occurs as the image switching or sliding when the display with extremely low brightness, resulting in the color shift and distortion at the edge of moving objects. Because the current is too small and the emission time is too short at extremely low brightness, more than one frame is needed to alleviate the impact of the parasitic capacitance between the gate and drain node of driving TFT (DTFT), and the gradual changing of drain voltage (VD) causes the DTFT to move from the linear to saturation region, which also aggravates this phenomenon. This paper analyzes the MFD phenomenon based on the existing 7T1C pixel circuits, records the grayscale changes of multiple frames, and gives the different offsets at dropped frames. By experiment results, this method is not changing the pixel circuit, such as the 8T1C, which could compensate for the dropped frames for reducing MFD issues and is easily implemented in the display driver IC for many different OLED panels. [ABSTRACT FROM AUTHOR]

Wider linear modulation range, less switching loss, and simplicity are the goals pursued by various modulation methods of multilevel inverters. This paper proposes a new hybrid discontinuous pulsewidth modulation (HDPWM) strategy for three‐level neutral‐point‐clamped (3L‐NPC) inverter that can achieve the above goals to a certain extent. According to the position of the reference voltage vector and the actual situation of the neutral point voltage, different control modes and clamping types are selected. The neutral point voltage is controlled by DPWM strategy, which can not only greatly reduce the switch loss but also maintain the balance of the neutral point voltage and expand the linear modulation range. The implementation of the algorithm combines the advantages of carrier‐based PWM (CBPWM) and space vector PWM (SVPWM). There is no need to select the nearest three vectors (NTVs) and calculate their dwell time. Only the reference voltage needs to be modified according to the control requirements, and then by comparing the modified reference voltage with the carrier, the driver pulse required by the switching devices can be generated. Compared with the existing PWM methods, it is more simple and easy to implement. Experimental results verify the validity of the method. [ABSTRACT FROM AUTHOR]

In the current global promotion of environmental protection and low‐carbon, to further reduce the power consumption of TFT‐ LCD, this paper proposes an algorithm based on image detection for adaptive adjustment of panel voltage and tests the algorithm on the monitor. The test results shows that the algorithm can achieve power reduction while maintaining image quality. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes a power factor correction (PFC) method in a single‐phase AC/DC converter using a predictive control algorithm (PCA) through a boost DC/DC converter. The minimum value of the DC‐link capacitor has been evaluated on the DC distribution side for stable operation of the converter. The proposed technique can be applied to the cascade connection of the converters, that is, the uncontrolled rectifier with boost converter and load. The value of the minimum capacitance is obtained as a function of the reference voltage of the DC‐link capacitor, the frequency of the supply, the input power, and the maximum DC‐link voltage. The proposed design is applied to control the boost converter for PFC applications using PCA at the minimum DC‐link capacitor value. The calculated value of DC‐link capacitance has been reduced to a greater extent as compared to the conventional calculation of DC‐link capacitance. The converter operation with the designed value of DC‐link capacitance has been verified through the MATLAB and Typhoon Simulink environment, and an experimental prototype model is used for the validation by using the FPGA based Typhoon HIL‐402 kit. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to develop a hybrid predictor based on intelligence techniques for dynamic voltage restorer (DVR) to estimate the reference load voltage and self‐tuned voltage regulation to enhance voltage power quality issues. The best fitted predictor model is obtained by using the potential merits of metaheuristic algorithms coupled with Antlion Optimization (ALO) and Genetic Algorithm (GA). This article proposes ALO optimized multilayer perceptron (MLP) neural network (NN) control algorithm for appropriate selection of weights and biases to generate the subsequent switching signal with lower error rates for load voltage estimation. The ANFIS‐GA control algorithm is implemented for automatic tuning of fuzzy rules with fewer membership functions (MFs) to obtain the perfect ANFIS (Takagi–Sugeno) predictive models for effective DC and AC link voltage regulation. The proposed hybrid controller counteracts the drawbacks of traditional ANN such as early convergence, slow learning mechanism, less probability of local entrapment, and difficulties to achieve the estimated target under parametric uncertainties, namely, sag, swell, unbalance, and distortion. The accuracy of the prediction model is computed by considering the error indices for the training and testing data set. The result confirms that the hybrid system ALO‐MLP NN establishes satisfactory performance in extracting the reference with the least error values. [ABSTRACT FROM AUTHOR]

Improving network power quality through harmonic reduction requires recognition of Harmonic Sources (HSs) to drive them to compensate their harmonics. This paper proposes a new method for equitable distribution of the Harmonic Compensation Cost of the network among the HSs based on the Harmonic Contribution Matrix. Each element of the Harmonic Contribution Matrix is the harmonic contribution of a specific source to the harmonic voltage of a specific bus. The output of the proposed method is a penalty curve for each HS over time. The amount of the fine estimated for each individual HS per hour is a function of not only the contribution of that HS to the harmonic voltage of different buses, but also the contribution of the Harmonic Compensation Cost from the perspective of each bus, nominal voltage of each bus, and the sensitivity of each bus to the harmonic voltage. The proposed algorithm is evaluated on the IEEE 14‐bus network and Esfahan regional electrical power network in Iran. The simulation results demonstrate the capability of the proposed method to allocate the hourly penalty curve to the HSs. [ABSTRACT FROM AUTHOR]

Conventional modular multilevel converters (MMCs) are widely used in high power applications due to their various astonishing advantages; however, they fail to achieve balanced capacitor voltage in DC operation. In this paper, a hybrid two‐stage modular DC–DC converter is proposed to solve the issue of unbalanced capacitor voltages. The proposed converter consists of a single‐phase half‐bridge MMC with half‐bridge submodules followed by a medium voltage valves‐based H‐bridge rectifier. The proposed converter is used in medium‐voltage applications such as feeding a DC‐load or interconnection between two DC grids of different voltage levels. The proposed configuration achieves successful DC–DC conversion with a low number of switches, a high conversion ratio with bidirectional power flow, low current stresses, soft switching across the second stage, and low switching losses. The operational concept and the control algorithm have been illustrated in detail. Finally, the effectiveness of the proposed DC–DC converter is evaluated based on simulation studies of MATLAB SIMULINK and a scaled‐down laboratory experimental test rig. [ABSTRACT FROM AUTHOR]

In this paper, an online algorithm of automatic power factor correction (APFC) for distribution power grids is presented. The algorithm depends on Pearson similarity of voltage and current signals, which can easily be measured locally using voltage and current transformers, respectively. The proposed method not only evaluates the original power factor (PF), but also functions the APFC more quickly. In this work, the compensation index and reactive power compensation can be identified using new mathematical formulas based on the cross-correlation coefficients calculated between the phase voltage and current signals. Moreover, the coefficients are useful for detecting any abnormal condition. The method performance is examined on a large-scale network with real parameters' data, which is simulated using the alternative transient program (ATP) environment, and the proposed algorithm is developed in MATLAB package. Numerous simulation results confirm the APFC relay feasibility, and the unity PF can be achieved. Besides, the proposed algorithm is characterized by its high operating speed, safety and accuracy for PF compensation, where its performance accuracy is greater than 99.7%. The approach offers novel operating/tripping curves based on the correlation coefficients for both power factor correction (PFC) and protection functions. Therefore, it is described with high level of functionality integration, and its security and sensitivity are controllable easily using the correlation settings. [ABSTRACT FROM AUTHOR]

For the dual three‐phase permanent magnet synchronous motor(dual‐PMSM), the deadtime can introduce fifth and seventh current harmonics, and they are only constrained by the small stator leakage impedance, which means even if there are only small fifth and seventh voltage harmonics, the resulting fifth and seventh current harmonics will be very large. The harmonic current will make an increment of the system loss, thus lead to an reduce of the efficiency of the speed control system. This paper proposes a harmonic current suppression strategy for dual‐PMSM based on least mean square (LMS) adaptive notch filter. This strategy suppresses the fifth and seventh harmonic currents by introducing four LMS adaptive notch filters in the subspace. The proposed algorithm has good dynamic performance and is insensitive to motor parameters that are offset within a certain range. The effectiveness of proposed method is verified by a set of comparative simulations and experiments. [ABSTRACT FROM AUTHOR]

In this paper we present a novel algorithm for compensating OLED luminance drop at first frame. It is due to the unexpected residual voltage from previous frame and IR‐drop of ELVDD power. Our method without complex TFT driving circuits so that the proposed algorithm is easily implemented to driver IC for different panels. Experimental results show that this algorithm enhances the luminance at first frame and reducing temporary image sticking issue. [ABSTRACT FROM AUTHOR]

The increasing use of distributed generation (DG) in power systems can result in frequent online voltage problems. In scenarios in which substantial DG prediction errors occur because of high DG accommodation levels, traditional technical solutions cannot meet the online voltage regulation requirements. Hence, new resources for online voltage regulation are needed. Here, flexible network reconfiguration is proposed to coordinate with the existing resources for severe online voltage deviations. For online topology‐based voltage regulation (OTVR), the authors develop a deep reinforcement learning (DRL) algorithm based on the following specially designed modelling to enhance the computational performance. The mechanism of action incorporates the concepts of local research, branch exchange, and action separation, and it effectively simplifies the action dimension and action space. In addition, for the graph data in OTVR, a graph convolution network (GCN) is applied to obtain better feature extraction. Case studies performed on IEEE 14‐bus, 33‐bus, 141‐bus systems and a practical system verify that our proposed algorithm can obtain close to optimal solutions in 2 s which can meet the needs of online voltage regulation. Moreover, we verify that the developed OTVR effectively increases DG penetration and decreases the need for investment in additional regulating devices. [ABSTRACT FROM AUTHOR]

Secondary direct-current loss within a substation is a severe event. In China, each line protection device is generally powered by one set of secondary direct current (DC) power system within a substation of 110 kV voltage level. In this case, the line protection devices will be immediately taken out of service when the secondary DC is lost, and the lines protected by them will lose their corresponding protections. Once a fault occurs on the line, only the remote back-up protection can be relied on to isolate the fault, which expands the fault influence and increases its clearance time. To handle the above problem, a novel wide-area protection algorithm based on compensation voltage moduli comparison is proposed, which is independent of multi-terminal data synchronism. Then, a comprehensive protection strategy composed of the proposed protection algorithm and the original local distances protection is proposed. The results from a power systems computer aided design/electromagnetic transients including DC (PSCAD/EMTDC)-based simulation verify that the proposed protection algorithm has higher sensitivity. The comprehensive protection strategy could cope with most line faults effectively, even if only partial data are available, the selectivity and speed of which are better than that of distance protections. [ABSTRACT FROM AUTHOR]