scholarly journals Influence of Single-Phase Voltage Loss and Load Carrying Mode on Mine Drainage Pump Motor in Vietnam

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Nhu Y DO ◽  
Xuan Cuong NGO
Keyword(s):  
Power Supply ◽  
Single Phase ◽  
Mine Drainage ◽  
Torque Ripple ◽  
Positive Sequence ◽  
Phase Voltage ◽  
Negative Sequence ◽  
Copper Loss ◽  
Voltage Loss ◽  
Load Carrying

Mine drainage pump is the most important load in mining which requires high reliabilitywhen operating. Currently, the power supply of a mine drainage pump is connected to the same powerline with many nonlinear loads, and is equipped with power electronic converters, which makes thepower supply nonsinusoidal. During the working process of a mine drainage pump, the load-carryingfactor often changes, and many types of failures occur, among which single-phase voltage loss is themost common problem. In the case of a nonsinusoidal power supply, if a single-phase voltage lossoccurs in different load modes, it will greatly affect the working mode of the mine drainage pumpleading to influences on the working efficiency, the life of the pump, and sometimes it is necessary torecalculate the protection parameters. This paper studies the influence of single-phase voltage loss andload carrying mode on the working mode of mine drainage pump motor in case the of nonsinusoidalpower supply. Research results show that, in the case of nonsinusoidal power supplied with single-phasevoltage loss, copper losses in the rotor and stator circuits increase with increases in voltage totalharmonic distortion (THD) and load-carrying factor, 5th order reverse harmonic increases copper loss inasynchronous motor the most, and higher harmonic components have less effect on copper loss in themotor. At the same time, the speed ripple decreases with the increase of the motor load factor anddecreases in the presence of the 5th order negative sequence harmonic, and increases significantly in thepresence of the 7th order positive sequence harmonic. 5th order negative sequence harmonic increases,the torque ripple increases, while the 7th order positive sequence harmonic reduces the torque ripple inthe case of single-phase voltage loss. The results of the paper will help improve the operationalefficiency of the mine drainage pump in Vietnam's mines.

Operation of an induction motor supplied by voltage containing subharmonics

2017 ◽  
Vol 1 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Tomasz Drabek
Keyword(s):  
Induction Motor ◽  
Power Supply ◽  
Induction Machine ◽  
Induction Machines ◽  
Positive Sequence ◽  
Rotor Speed ◽  
Phase Voltage ◽  
Negative Sequence ◽  
Three Phase

The paper discusses the effects of the presence of subharmonics (i.e. frequencies lower than the basic 50 Hz) in the voltage supplying the induction machine. Subharmonics in a three-phase grid are the result of the oscillations of peak values of the voltages. In induction machines, this results in the subharmonic and interharmonic currents, the generation of alternating moments, the increase in the rms value of the current of the fundamental harmonic and the oscillations of the rotor speed. In the paper is derived expression on the thermally acceptable load of the motor (by torque and power), in the case of supplying it by three-phase voltage containing a positive sequence of subharmonics. It presented the obstacles to derive the analogical expression for power supply containing a negative sequence of subharmonics.

Experimental Analysis on the Operating Performance of Induction Motor with Unbalance Power Supply Conditions

2014 ◽  
Vol 635-637 ◽  
pp. 1404-1407
Author(s):  
Yuan Xing Zhang ◽  
Fei Li ◽  
Ya Li Shen ◽  
Lei Juan Yang ◽  
Jie Li ◽  
...  
Keyword(s):  
Induction Motor ◽  
Power Supply ◽  
Power Efficiency ◽  
Single Phase ◽  
Reactive Power ◽  
Phase Voltage ◽  
Three Phase ◽  
Unbalanced Voltage ◽  
Negative Sequence Current ◽  
Domestic Appliances

Problems of power quality have been increasingly concerned by the researchers, as the domestic appliances we are usually used are single-phase load, which mainly causes the unbalance of three-phase voltage of power supply. If the induction motor is supplied by three-phase unbalanced voltage, the currents, active and reactive power, efficiency, and losses are affected as the negative-sequence current appears, this paper is emphasized on the induction motor’s characteristics when its’ power supply is three-phase unbalanced voltage by experimental research.

Study on the Characteristic of Sensitive Load under Voltage Sags

2013 ◽  
Vol 418 ◽  
pp. 269-272
Author(s):  
Rong Hui Liu ◽  
Ai Qang Pan ◽  
Hai Bo Wang ◽  
Xiu Yang
Keyword(s):  
Power Supply ◽  
Single Phase ◽  
Voltage Sensitivity ◽  
Voltage Sags ◽  
Phase Voltage ◽  
Three Phase ◽  
Simulation Results

In this paper, the characteristics of AC/DC converter under single-phase voltage sags and three-phase voltage sags are simulated with Matlab emulator. The simulation results show that effects on rectifier equipment under three-phase voltage sags are more serious than those under single-phase voltage sags. The flat wave capacitance plays an important role in voltage sensitivity of sensitive loads. In practice, the capacitance of flat wave capacitor is chosen according to the power supply and load requirements so as to realize the best balance of performance and price.

scholarly journals A rapid harmonic detection method for grid-connected photovoltaic when three-phase voltage is unbalanced

2021 ◽  
Author(s):  
Tiezhou Wu ◽  
An Wang ◽  
Yawen Xu
Keyword(s):  
Phase Angle ◽  
Detection Method ◽  
Positive Sequence ◽  
Harmonic Detection ◽  
Phase Voltage ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Negative Sequence ◽  
Three Phase ◽  
Low Pass

Abstract By using power electronic devices, photovoltaic grid-connected power generation may inject harmonics into the power system. As the photovoltaic grid-connected inverter has the same basic structure as the active power filter, so the unified control of the photovoltaic grid and active filtering can be achieved. When the current unified control system compensates harmonics of the grid side, it mainly uses ip-iq harmonic detection method, which is based on instantaneous reactive power theory. When the three-phase voltage is unbalanced, the method has a large voltage phase angle detection error and the signal of the low-pass filter tracking system is long, detection time delay and even failure occur. This paper proposes an improved fast harmonic detection method. When phase deviation or amplitude change occurs to the three-phase voltage, the positive and negative-sequence voltages are simultaneously park transformed. The negative-sequence component is filtered by the current average module to obtain the fundamental amount of the voltage, then the phase angle of the positive-sequence voltage is accurately calculated to improve the harmonic current detection accuracy. Through the study of the integral method, it is found that the least common multiple of each harmonic period can be used as the integral interval, and the integral value is also zero, so the detection delay time is reduced by replacing the low-pass filter with an integration module. The simulation results show that the proposed harmonic detection algorithm can accurately detect harmonics when the three-phase voltage is unbalanced, and about 0.057 s improve the harmonic detection speed compared with the commonly used ip-iq method.

scholarly journals Implementation of Single Phase SRF based Dynamic Voltage Restorer in Distribution System for Power Quality Improvement

2019 ◽  
Vol 8 (12) ◽  
pp. 3451-3456
Keyword(s):  
Power Quality ◽  
Power Supply ◽  
Single Phase ◽  
Positive Sequence ◽  
Voltage Sag ◽  
Phase System ◽  
Major Power ◽  
Dynamic Voltage Restorer ◽  
Voltage Restorer ◽  
Dynamic Voltage

Power Quality (PQ) is becoming an important issue as the increase in electricity use continues. Reduction in the quality of electrical power is due to various kinds of voltage related problems such as voltage sag, voltage swell, short-lived interruptions, harmonic distortions, notches, flickers, spikes and transients. The major power quality problems in single phase system are voltage sag and harmonics. The Mitigation of voltage sag and harmonics in single phase system under the distorted power supply situations was effectively eliminated with Dynamic Voltage Restorer (DVR). The single-phase SRFT (Synchronous Reference Frame Theory) was implemented in the controller design for DVR. DVR will produce required amount of instantaneous voltage to be injected. Designed controller technique will utilize the function of Moving Average Filter (MAF) for getting the fundamental quantity of positive sequence component from the disturbed supply voltage. Experimental results of DVR prove its effectiveness to mitigate voltage sag and harmonics during disturbed power supply condition.

Study of the Two-Phase Operation Mechanism of Three-Phase Motors Based on LC Phase Shifting Method

2015 ◽  
Vol 741 ◽  
pp. 714-719
Author(s):  
Zai Ping Zheng ◽  
Yu Ping Huang ◽  
Yue Zhong ◽  
Hong Xing Wu
Keyword(s):  
Power Supply ◽  
Single Phase ◽  
Simulation Software ◽  
Phase Shifting ◽  
Practical Significance ◽  
Positive Sequence ◽  
Two Phase ◽  
Symmetrical Components ◽  
Three Phase ◽  
Phase Shifting Method

In the absence of three-phase power supply, it has certain practical significance to connect the three-phase induction motor to the single-phase power supply for single phase operation. This paper analyzes the asymmetric circuit system of the motor by the method of symmetrical components-Lc phase shifting, disassembles the voltage and current of the three-phase motor stator winding into three groups of symmetrical components: positive sequence, negative sequence and zero sequence. We derivate and analysis the LC phase shifting method to simulate and validate the Lc phase shifting method theory, deduce the formula for calculating of optimum external capacitance and inductance, simulate and calculate all kinds of single phase operation method, finally we use the simulation software to simulate and validate three-phase induction motors single phase operation.

Sign in / Sign up

Export Citation Format

Share Document