Zero-crossing distortion inhibition method of three-phase dual-buck inverter

2015 ◽  
Author(s):  
Xinxin Zheng ◽  
Lan Xiao ◽  
Zilong Wang ◽  
Yun Lei
Keyword(s):  
Zero Crossing ◽  
Three Phase

Design and Implementation of Actuator Controller for Greenhouse Control System

2014 ◽  
Vol 532 ◽  
pp. 62-69
Author(s):  
Yi Chuan Gao ◽  
Guo Chang Liu
Keyword(s):  
Control System ◽  
Short Circuit ◽  
Alternating Current ◽  
Electric Arc ◽  
Zero Crossing ◽  
Three Phase ◽  
Detection Circuit ◽  
Task Program ◽  
Current Zero ◽  
Greenhouse Control

A novel actuator controller for greenhouse control system is proposed in this paper. This controller can solve the problems existing in traditional greenhouse control system such as generating electric arc, short circuit risk, lack of communication and smart ability. We adopt five separate magnetic latching relays to control the three-phase motor. In order to prevent generating electric arc in the process of turning off relay, the alternating current zero-crossing detection circuit is designed. In software side, the relay-off task program is running in the real-time operating system, which can ensure turn-off operation at the point of alternating current zero-crossing. In addition, the controller is capable of detecting motors operation parameter and having multiple communication interfaces. Finally, we implement our controller in practice and experimental results meet the design requirements.

Measurement of Unbalanced Voltages in Three-Phase Induction Motors Using Acoustic Transducers and Zero-Crossing-Weighted Energy

2021 ◽  
Author(s):  
Guilherme Beraldi Lucas ◽  
Bruno Albuquerque de Castro ◽  
Brigite Peinado Alves ◽  
Adam Glowacz ◽  
Andre Luiz Andreoli
Keyword(s):  
Induction Motors ◽  
Zero Crossing ◽  
Weighted Energy ◽  
Acoustic Transducers ◽  
Three Phase

DESIGN AND MICROCONTROLLER IMPLEMENTATION OF A THREE PHASE SCR POWER CONVERTER

1996 ◽  
Vol 06 (06) ◽  
pp. 619-633 ◽  
Author(s):  
RICHARD W. WALL ◽  
HERBERT L. HESS
Keyword(s):  
Power Systems ◽  
High Speed ◽  
Power Converter ◽  
Current Control ◽  
Zero Crossing ◽  
Noise Rejection ◽  
Component Design ◽  
Three Phase ◽  
Improved Performance ◽  
Single Processor

A single processor controls a three phase silicon controlled rectifier (SCR) power converter. An inexpensive, dual optoisolator interface to the power line provides noise rejection and an improved measure of the zero crossing. A dynamic digital phase-locked loop (PLL) algorithm implemented in an Intel 87C196KD-20 processor achieves frequency tracking, dynamically changing characteristics for improved performance. Dynamically modifying the PLL characteristics permits independent capture and locked dynamics. A feedforward method provides command tracking for improved response without loss of performance. This three-component design (processor, optoisolator, and SCR gate drivers) represents a minimal implementation with potential for closed loop voltage and current control. High speed input and output resources included on the 87C196KD processor make an efficient single-device implementation possible. The processor is less than 1% utilized allowing for additional functions to be added in the future. This system operates on both 50 Hz and 60 Hz power systems without modification or loss of performance.

scholarly journals VSI Nonlinearity Compensation of a PMSM Drive System Using Deadbeat Prediction Based Current Zero-Crossing Detection

2021 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
Jing Zhou ◽  
Kan Liu ◽  
Juan Li ◽  
Longfei Li ◽  
Wei Hu ◽  
...  
Keyword(s):  
Harmonic Distortion ◽  
Drive System ◽  
Voltage Source ◽  
System Delay ◽  
Zero Crossing ◽  
Phase Current ◽  
Three Phase ◽  
Polarity Determination ◽  
Current Polarity ◽  
Current Zero

Due to the nonlinearities of the voltage-source inverter (VSI) in a permanent magnet synchronous machine (PMSM) drive system, there is always an error between the reference voltage and the actual output voltage. To compensate the voltage error, many schemes have been proposed based on the phase current polarity. However, due to factors such as current clamping, measurement noises, and control system delay, the accuracy of the detected current polarity is relatively low, especially when the current is around zero, which would therefore affect the compensation performance. To solve this issue, a deadbeat prediction-based current zero-crossing detection method (DP-CZD) is proposed in this paper. With the proposed method, the measured three-phase currents are replaced by the predicted three-phase currents in terms of the polarity determination, when the absolute value of the phase current is within the threshold range. Compared with the conventional phase current polarity detecting methods, the proposed method can greatly improve the accuracy of detected current polarity due to its smooth transient waveform, and consequently, contributes to the much higher accuracy and lower total harmonic distortion (THD) in the compensation of VSI nonlinearity, which is verified through a prototype surface-mounted PMSM.

scholarly journals Method for control of the start-up regulating devicefor power transformers of the power supply system

2019 ◽  
Vol 21 (3) ◽  
pp. 135-145 ◽  
Author(s):  
V. S. Klimash ◽  
B. D. Tabarov
Keyword(s):  
Steady State ◽  
Power Supply ◽  
Power Supply System ◽  
Power Transformer ◽  
Electrical Equipment ◽  
Supply System ◽  
Zero Crossing ◽  
Third Phase ◽  
Three Phase ◽  
The Moment

Three-phase thyristor switches are designed for pulsed formation of inrush currents of electrical equipment with their subsequent shunting in steady state operation. In transformer substations, they perform a bumpless turning on of a power transformer by connecting its primary winding first to two phases of the network at the moment of zero crossing by the phase voltage of the network third phase, and then to the network third phase at the moment of zero crossing by the line voltage of the other two network phases. In this case, the starting currents of the transformer almost immediately enter the steady state without the appearance of constant components in the magnetization currents and voltage drop. To expand the functionality of thyristor switches, it is proposed, in addition to bumpless turning on of a power transformer, to disconnect it without arcing between the contacts of electrical equipment, as well as to carry out continuous voltage regulation for consumers when voltage in the network changes. The proposed method and structure for its implementation on the basis of two three-phase thyristor reactor keys and a capacitor bank make it possible while changing the network voltage to stabilize the generated reactive power at the input of the substation without creating the current distortions in the power transformer and power transmission simultaneously with stabilizing the substation output voltage. Modeling and research of the start-regulating device as part of a transformer substation was carried out in the MatLab environment. The results of numerical experiments in stationary and dynamic modes of the substation operation showed the feasibility of using the developed technical solutions for the industrial power supply system.

Design of Capacity Loss Tester of Power Transformer

2012 ◽  
Vol 263-266 ◽  
pp. 378-382
Author(s):  
Wen Cheng Pan
Keyword(s):  
Sampling Method ◽  
Truncation Error ◽  
Power Transformer ◽  
Testing Temperature ◽  
Phase Detection ◽  
Load Testing ◽  
Zero Crossing ◽  
Negative Edge ◽  
Capacity Loss ◽  
Three Phase

A capacity loss tester for no-load and with-load testing of power transformer has been developed. The tester has the ability of sampling the three-phase voltage and current simultaneously. Programmable counter array (PCA) unit in MPU, which captures zero-crossing of signal by the function of positive and negative edge trigger, is applied to the average phase detection of zero-crossing in bi-direction, in order to acquire the phase difference and period accurately. In terms of software, synchronism sampling method based on real-time parameter self-optimizing is adopted to minimize period truncation error, and the measuring accuracy is improved. The capacity of the power transformer is discriminated by table-look-up method in software, corresponding to different load loss. The testing result is converted from the value under testing temperature to the value under the condition of reference temperature (75°C).

A Novel Starting Method for Sensorless Brushless DC Motor with Low Cost

2013 ◽  
Vol 336-338 ◽  
pp. 750-754
Author(s):  
Qiang Wang ◽  
You Ren Wang ◽  
De Ming Kong ◽  
Yong Wu
Keyword(s):  
Low Cost ◽  
Dc Motor ◽  
Phase Delay ◽  
Brushless Dc Motor ◽  
Zero Crossing ◽  
Brushless Dc ◽  
Three Phase ◽  
Detection Circuit ◽  
Novel Method ◽  
Start Process

This paper presents a novel method to improve the starting performance for sensorless brushless DC motor (BLDCM) with low cost, based on the principle of back electromotive force (BEMF). The commutation points are extracted from three phase terminal voltages achieved by AD converters integrated in the microprocessor. The phase delay caused by the detection circuit is compensated. The start process consists of alignment, accelerating, and switching. In the accelerating process, the commutation instants are determined by the zero-crossing points and phase delay table. The motor can be started reliably because of the closed-loop startup strategy. Experimental results have verified the effectiveness of the proposed method.

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