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Total harmonic distortion (%) during sag
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This paper presents modelling aspects of several types of dynamic voltage restorer (DVR) working against various voltage sags by simulation in PSCAD/EMTDC. It then provides analyses of working performance of the device, including capability and quality of compensation. Comparisons of working performance among these different types of DVR are also a...
Citations
... Therefore, as compared to UPS, DVR required power rating and the operating losses is very low. Thus DVR is seen as a power-efficient device compared to the UPS [18]. Among custom power devices, the DVR provides the most economical solution in overcoming the voltage-related PQ problems [19]. ...
... Distributed FACTS have the attributes of short time response manifestation especially in millisecond range. Distributed Dynamic Voltage Restorer (D-DVR) is one of the power electronics devices connected in series to the network, that is used to compensate for under-voltage power quality problems and unbalance voltage [13,15,16]. On the contrary, distribution STATCOM (D-STATCOM) is another type of power electronic device connected in parallel to the networks which has been utilized to mitigate some PQ problems such as unbalanced load current [12,15,17]. ...
... Comparison of UPQC models based on voltage profile and power loss amelioration in RDS[14,16] I-UPQC Model ...
This paper presents the investigative study on the Unified Power Quality Conditioner (UPQC) impact on Radial Distribution System (RDS). The architecture of Power Angle Controlled UPQC named Improved Unified Power Quality Conditioner (I-UPQC) was implemented in RDS. The problem of power loss, under-voltage, and reactive power burden on shunt inverters are the significant issues addressed in this study. The allocation of I-UPQC by placing it at each bus of the RDS one node at each iteration, excluding the swing bus, is studied by considering its impact on each bus of the radial network. The Power Loss Index (PLI) and Degree of Under Voltage Mitigation Node (DUVMN) values of all the buses are calculated analytically using distribution framework expressions of I-UPQC. Hence, the bus having the highest PLI value, and the minimum permissible node voltage is the most favourable. The determination of the candidate bus for I-UPQC was achieved by the load flow algorithm. The results obtained in this study on IEEE 33 and 69 bus system shows 3.9% and 4.2% power loss reduction respectively for both networks. Also, the minimum bus voltage was improved to 0.954 p.u. and 0.955 p.u. in each case for both networks, after the allocation of I-UPQC in RDS, compared to the base case. Consequently, the VA burden on shunt inverter was reduced by reactive power compensation of the series inverter. The results and simulation obtained in MATLAB / SIMULINK environment and discussion to support the concept developed are also presented. The results from the study confirmed that the concept of I-UPQC placement impacted the operation of RDS compared to the other connected UPQC model.
... Distributed FACTS have the attributes of short time response manifestation especially in millisecond range. Distributed Dynamic Voltage Restorer (D-DVR) is one of the power electronics devices connected in series to the network, that is used to compensate for under-voltage power quality problems and unbalance voltage [13,15,16]. On the contrary, distribution STATCOM (D-STATCOM) is another type of power electronic device connected in parallel to the networks which has been utilized to mitigate some PQ problems such as unbalanced load current [12,15,17]. ...
... Comparison of UPQC models based on voltage profile and power loss amelioration in RDS[14,16] I-UPQC Model ...
This paper presents the investigative study on the Unified Power Quality Conditioner (UPQC) impact on Radial Distribution System (RDS). The architecture of Power Angle Controlled UPQC named Improved Unified Power Quality Conditioner (I-UPQC) was implemented in RDS. The problem of power loss, under-voltage, and reactive power burden on shunt inverters are the significant issues addressed in this study. The allocation of I-UPQC by placing it at each bus of the RDS one node at each iteration, excluding the swing bus, is studied by considering its impact on each bus of the radial network. The Power Loss Index (PLI) and Degree of Under Voltage Mitigation Node (DUVMN) values of all the buses are calculated analytically using distribution framework expressions of I-UPQC. Hence, the bus having the highest PLI value, and the minimum permissible node voltage is the most favourable. The determination of the candidate bus for I-UPQC was achieved by the load flow algorithm. The results obtained in this study on IEEE 33 and 69 bus system shows 3.9% and 4.2% power loss reduction respectively for both networks. Also, the minimum bus voltage was improved to 0.954 p.u. and 0.955 p.u. in each case for both networks, after the allocation of I-UPQC in RDS, compared to the base case. Consequently, the VA burden on shunt inverter was reduced by reactive power compensation of the series inverter. The results and simulation obtained in MATLAB / SIMULINK environment and discussion to support the concept developed are also presented. The results from the study confirmed that the concept of I-UPQC placement impacted the operation of RDS compared to the other connected UPQC model.
... This study shows how current and voltage can be used to protect distribution systems. [7] Positive sequence; low sequence; negative sequence voltage and current are recorded and determined in compliance with measurement equipment situated at both ends of the transmission line [12][13]. Calculated parameters make up the different designs. ...
... This can be obtained by eliminating the unwanted higher order harmonic components generated from the DC to AC conversion in the VSC that will distort the compensated output voltage [179]. Placement of these filters can be either in the high voltage side (load side-shown in Fig. 4.3-left) or in the low-voltage side (VSC side-shown in Fig. 4.3-right) of the injection transformers [167], [180]. Higher order harmonics can be removed from passing through the injection transformer by connecting filters in the VSC side. ...
... This necessitates the use of higher rating of the transformer [167], [181]. However, the transformer leakage reactance may be used as a part of the filter, which will be supportive in tuning the filter [168], [180], [181]. ...
... Fig. 4.12 DVR without energy storage and load-side-connected shunt converter [195]. [180]. Analysis shown in Table 4.1 has revealed that the no-energy storage concept is feasible, but an improved performance can be achieved for certain voltage sags using stored energy topologies. ...
... DVR voltage sag compensation is a cost effective method applicable in small and large loads up to 45MVA or even larger [9]. DVR is mainly composed of components such as the Voltage Source Inverter (VSI), a voltage injection device, a filter, an energy storage device, and a controlling device [12,13]. Figure 1 shows the proposed DVR topology. ...
... Figure 1 shows the proposed DVR topology. [12][13][14]. ...
... This would result in distortion in the output voltage waveforms. To avoid the problem of distorted wave forms, a filter is employed to get distortion free voltage to the load [9,12,15]. ...
Power quality problems are becoming a major issue. Every utility company consumer desires to receive steady-state voltage, i.e. a sinusoidal waveform of constant frequency as generated at power stations, but the influence of disturbances in the shape of sags and swells, interruptions, transients and harmonic distortions which affect power quality, resulting in loss of data, damaged equipment, and augmented cost. The most powerful voltage disturbance is the sag voltage. In this paper, a Dynamic Voltage Restorer (DVR) is proposed for sag voltage compensation. It is cost-effective and protects critical loads in a good manner from balanced or unbalanced sag voltage. Control strategy (such as a PI controller) is adopted with DVR topology and the performance of such a device with the proposed controller is analyzed through simulation in MATLAB/Simulink. Three types of faults are utilized, which are available in MATLAB/Simulink pack, for obtaining the sag voltage. The specific range of total harmonic distortion percentage is also discussed. After the result validation of the DVR topology in MATLAB/Simulink, it has been seen that the proposed topology is able to compensate the sag voltage of any type of fault and reduce the unbalancing and voltage distortions of the grid.
... Any F I G U R E 1 Schematic diagram of distribution system with DVR deviation of voltage from rated value caused by transient disturbance in the distribution network compensates the voltage by DVR in the line. 19 DVR has two operating modes, namely, standby and active mode. Whenever there is no deviation from rated voltage in line, DVR will be idle in this mode. ...
In the distribution power system, voltage sag and swell are the critical issues. The impact of this issue creates major economic loss and power loss in the distribution system. There are several detection methods available, mainly, connecting the FACTS devices such as Static Compensator (STATCOM), Unified Power Quality Conditioner (UPQC), and dynamic voltage restorer (DVR) at the point of sag or swell. DVR is one of the custom power devices to mitigate the voltage sag and swell. Sliding mode controller (SMC) is proposed in the paper, which is used to regulate the DVR to mitigate the voltage sag issue. Particle swarm optimization (PSO) algorithm is utilized in this work to find the optimum value of SMC parameters, namely, Kp and Ki, with the objective of minimizing the integral square error (ISE). A simple two feeder distribution network with DVR is developed in MATLAB‐SIMULINK to assess the performance of DVR under various faults and disturbed situations. The mitigation level and THD values of PSO‐optimized SMC‐based DVR results are compared with the PI controller–based DVR, PSO‐optimized PI controller DVR, and SMC‐based DVR. At last, in the proposed method, the trial is taken by adding a renewable energy resource, that is, PV farm at 400‐kW power rating. The solar energy is integrated with the existing distribution system, and the results are incorporated. Simulation results show that the PSO‐optimized SMC‐based DVR can compensate the voltage sag and swell and also reduce the load voltages efficiently.
... Of all the power quality problems, voltage sag is significant as it accounts for roughly 92% of the interruptions in industrial processes [8]. Voltage sag is a sudden decrease in the root mean square (RMS) AC Voltage magnitude between 10% and 90% of the nominal voltage with the duration from 0.5 cycles to a few second [9]. The main factors resulting into voltage sags are faults (short circuits faults), abrupt increases in loads, large motor starting, and transformer energization. ...
... Energies 2018, 11, 2742 2 of 18 in wide variety, the compensators type Switching Power Converter (SPC) or Switching Compensator (SC) [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] are also part of the Custom Power Devices (CPD) category [44][45][46][47][48][49]. ...
... From the SPC category, the most common are Distribution Static Synchronous Compensator (D-STATCOM) [31,42,50,51], Dynamic Voltage Restorer (DVR) [31,34,35,44,52,53], and Unified Power Quality Conditioner (UPQC) [41,43,46,47,54]. Their basic component is a Voltage Source Inverter (VSI) [40,48,49]. ...
... At present, the second-generation of static compensators, type SPC, is being developed, which is based on high-power switching elements: Insulated Gate Bipolar Transistors (IGBT) or Thyristor Integrated Gate Commutated Thyristors (IGCT), belonging to the so-called Solid-State Devices (SSD) [29][30][31][32][33][34]. Found The compensation of the reactive components of the load positive sequence currents is also possible. ...
To increase the electrical power quality, in the last decades, an intense development in the last decades of high-performance equipment built as advanced power electronics applications, such as the compensators from Switching Power Converter category, has taken place. For all that, Reactive Power Compensators (RPC) based on passive circuit elements, such as Static var Compensators (SVCs), still occupy a wide range of applications in customer and installations of the distribution system installations. The functions of power factor (PF) improvement and load balancing in a three-phase distribution network can be achieved with an unbalanced SVC, known as the Adaptive Balancing Reactive Compensator (ABRC). Presenting first the mathematical model of the initial sizing and the working mechanism of a Balancing Reactive Compensator (BRC) for a three-phase four-wire network, this article develops a compensator resizing algorithm through an iterative change of the initial sizing to transform the compensator into a Balancing Capacitive Compensator (BCC), which keeps the same functions. By using two computational and modeling software tools, a case study on the application of the method was carried out, demonstrating the availability of the sizing problem solution and validating the unbalanced capacitive compensation as an efficient way to PF improving and load balancing in a PCC (Point of Common Coupling).
... • using the balancing schemes with single-phase transformers (Scott wiring or V wiring) [1][2][3]; • using the Reactive Power Compensators (RPCs) ; • using the advanced compensators type Switching Power Converter (SPC) [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]; • using hybrid solutions, containing components from the above categories [32]. ...
... SPCs are pieces of equipment built as applications of the most performing power electronics technology, based on high-power switching elements: Insulated Gate Bipolar Transistor IGBT or Insulated Gate Commutated Thyristor (IGCT) included into the so-called Solid State Devices (SSDs) [30][31][32][33][34][35]. ...
... The most common equipment in the category of SPCs are: Distribution Static Synchronous Compensators (D-STATCOMs) [32,43,51], Dynamic Voltage Restorers (DVRs) [32,35,36,45], Unified Power Quality Conditioners (UPQCs) [42,44,47,48] respectively. The main part of this equipment is a VSI [41,49,50]. ...
Nowadays, improving the power quality at the Point of Common Coupling (PCC) between the consumers’ installations and the distribution system operators’ installations depends more and more on the use of specialized equipment, able to intervene in the network to eliminate or diminish the disturbances. The reactive power compensators remain valid solutions for applications in consumer and electricity distribution, in those situations when the criterion regarding the costs of installing and operating the equipment is more important than the ones related to the reaction speed or the control accuracy. This is also the case of the equipment for power factor improvement and load balancing in a three-phase distribution network. The two functions can be achieved simultaneously by using an unbalanced static var compensator, known as an adaptive balancing compensator, achieved by adjusting the equivalent parameters of circuits containing single-phase coils and capacitor banks. The paper presents the mathematical model for the sizing and operation of a balancing reactive compensator for a three-phase four-wire network and then presents some resizing methods to convert it into a balancing capacitive compensator, having the same functions. The mathematical model is then validated by a numerical application, modelling with a specialized software tool, and by experimental laboratory determinations. The paper contains strong arguments to support the idea that a balancing capacitive compensator becomes a very advantageous solution in many industrial applications.
