Interline Unified Power Quality Conditioner Research Articles

Interline Unified Power Quality Conditioner for Enhancing Power Quality using FOFPID-based Interleaved CUK Converter

Electrical distribution systems face increased non-linear loads due to using power electronics for the converters. Due to these non-linear loads, the system exhibits PQ problems in the distributed feeders. To enhance PQ problems in the dual feeder, fractional order fuzzy proportional integral derivative controller (FOFPID) is introduced with interline unified power quality (IUPQC) conditioner. IUPQC conditioner includes a distribution static compensator (DSTATCOM), dynamic voltage restorer (DVR) and interleaved cuk converter (ICC). DSTATCOM and DVR are used for compensating the voltages and current in the dual feeders (feeder-1 and feeder-2). Also, ICC monitors the switching between the DSTATCOM and DVR compensators by providing proper power flow. Moreover, the FOFPID controller regulates an input supply from both feeders. The simulation is performed through MATLAB/Simulink platform, demonstrating the robustness of a proposed FOFPID with an IUPQC controller. The performance of a proposed controller is analyzed through two cases for both feeders. Furthermore, the total harmonic distortions (THD) are calculated for the feeder parameters. The proposed FOFPID with IUPQC controller also maintains stability in a dual feeder. Therefore, the entire response shows the functionality and feasibility of a proposed controller.

Performance of Interline Unified Power Quality Conditioner IUPQC With PI, Fuzzy and ANFIS Controllers

Several artificial intelligent control schemes are highly used in several applications, in that ANFIS controller has been greatly recognized due to enhanced performance over the classical PI and Fuzzy controllers. At present the multi-feeder power distribution system is deteriorated with continuity of supply and poor power quality standards. In this multi-feeder distribution system, it is a regular consumer related issue which is acquired due to malfunctioning of massive non-linear loads. These loads create the voltage or current imperfections on distribution networks which disrupts the power quality of distribution system. An efficient and reliable active compensation scheme is used for attaining enhanced power quality features at PCC of multi-feeder distribution system with effective control functions. The Multi-Feeder Unified Power Quality Compensator (MF-UPQC) is optimal choice for attaining enhanced power quality features and it is a combined shunt or series compensator driven by common DC-link. This paper recommends the Adaptive Neuro-Fuzzy Intelligent Controller (ANFIS) based prediction technique for generation of optimal switching states to enhance performance of proposed MF-UPQC to compensate all voltage-current PQ imperfections. The performance of proposed MF-UPQC is verified by classical PI, Fuzzy and proposed ANFIS control functions by using MATLAB/SIMULINK tool and results are conferred with proper comparisons.

Development of fuzzy logic controller for improved interline unified power quality conditioner

This paper presents the improved interline unified power quality conditioner (iUPQC) and its controlling aspects for nonlinear loads. The nonlinear loads are the major sources of harmonics and raise the power quality issues. However, the iUPQC compensates the harmonics that are generated by a nonlinear load besides reactive power support. This in turn minimises the harmonic distortion both in the source current as well as voltage. Furthermore, it also provides the current and voltage imbalance compensations, reactive power, frequency and voltage support at grid. The simulation of entire power system is fulfilled using proposed FUZZY controller and compared with the conventional PI controller. The performance of both the controllers is sifted in terms of % total harmonic distortion (THD) by considering different case studies having the 3-φ diode rectifier connected to R, RL and RLE loads. The MATLAB/Simulink version R2012b is used for accomplishing the in depth simulation studies.

Development of fuzzy logic controller for improved interline unified power quality conditioner

Development of fuzzy logic controller for improved interline unified power quality conditioner

Fuzzy Logic Based Interline Unified Power Quality Conditioner for Voltage Regulation of Critical Load Bus

Interline unified power quality conditioner is the recent advancement in the world of FACTS devices and technology. The new equipment is only a mere extension of the existing FACTS device features like Distributed Static Compensator which does not limit to better voltage regulation at the gird side as well as load side bus. The effectiveness of the new FACTS device is compared with its homologous counterpart, namely conventional Unified power quality conditioner. It is observed that there is significant difference with respect to the arrangement of parallel and series connected converters. Soft computing technique namely fuzzy logic based controller for the proposed Interline unified power quality conditioner is presented in the paper. The implementation and usefulness of the proposed control topology is tested and simulated in MATLAB/SIMULINK environment.

Power Angle Control-based Method for Interline Unified Power Quality Conditioner and Multi-converter Unified Power Quality Conditioner under Unbalanced and Distorted Load Conditions

This article proposes a new control approach for an interline unified power quality conditioner and a multi-converter unified power quality conditioner to optimize the utilization of the inverters of these structures. In this method, the series active power filter is controlled by the application of a power angle control concept to compensate an unbalanced voltage (asymmetrical voltage sag/swell with or without phase angle jumps) and also partial-load reactive power for power factor correction. Since voltage variation (sag/swell, unbalance, etc.) is a short-duration power quality problem in distribution systems, under normal operating conditions, series inverters are not utilized effectively in conventional methods. By using the proposed method, optimal utilization of series inverters of both structures and also a reduction in the shunt inverter rating of a multi-converter unified power quality conditioner will be achieved. Also, the shunt active power filter is controlled to compensate the unbalanced current, harmonics, and neutral current of a three-phase four-wire system and to take part in power factor correction. The proposed approach is validated through MATLAB/SIMULINK-based (The MathWorks, Natick, Massachusetts, USA) simulation and the results are discussed.

Power Quality Improvement by IUPQC with Fuzzy Control Technique

This paper proposes a new connection for a unified power quality conditioner (UPQC) to improve the power quality of two feeders in a distribution system. A UPQC consists of a series voltage-source converter (VSC) and a shunt VSC both joined together by a common dc bus. It is demonstrated how this device is connected between two independent feeders to regulate the bus voltage of one of the feeders while regulating the voltage across a sensitive load in the other feeder. Since the UPQC is connected between two different feeders (lines), this connection of the UPQC will be called an interline UPQC (IUPQC). The structure, control and capability of the IUPQC with PI and FUZZY controller technique are discussed in this paper. The efficiency of the proposed configuration has been verified through simulation studies using MATLAB. Index Terms: distribution static compensator (DSTATCOM), distribution system, dynamic voltage restorer (DVR), fuzzy logic controller, power quality (PQ), Interline unified power quality conditioner (IUPQC) . I. Introduction Voltage Source Converter (VSC) based custom power devices are increasingly being used in custom power applications for improving the power quality (PQ) of power distribution systems. Devices such as distribution static compensator (DSTATCOM) and dynamic voltage restorer (DVR) are the facts devices. A DSTATCOM can compensate for distortion and unbalance in a load such that a balanced sinusoidal current flows through the feeder. It can also regulate the voltage of a distribution bus. A DVR can compensate for voltage sag/swell and distortion in the supply side voltage such that the voltage across a sensitive/critical load terminal is perfectly regulated .A unified power quality conditioner (UPQC) can perform the functions of both DSTATCOM and DVR. The UPQC consists of two voltage-source converters (VSCs) that are connected to a common dc bus. One of the VSCs is connected in series with a distribution feeder, while the other one is connected in shunt with the same feeder. The dc links of both VSCs are supplied through a common dc capacitor. It is also possible to connect two VSCs to two different feeders in a distribution system. In, a configuration called IDVR has been discussed in which two DVRs are connected in series with two separate adjacent feeders. The dc buses of the DVRs are connected together. The IDVR absorbs real power from one feeder and maintains the dc link voltage to mitigate 40% (about 0.6p.u.) voltage sag in the other feeder with balanced loads connected in the distribution system. It is also possible to connect two shunt VSCs to different feeders through a common dc link. This can also perform the functions of the two DVRs mentioned above, albeit with higher device rating. This paper presents a new connection for a UPQC called interline UPQC (IUPQC). The single-line diagram of an IUPQC connected distribution system is shown in Fig. 1.

Improving Power Quality in a Multi bus Multi Feeder System Using MC-UPQC

A b s t r a c t : This paper presents a new Unified Power-Quality Conditioning System (MC-UPQC), capable of simultaneous compensation for voltage and current in multi-bus/multi-feeder systems. By using one shunt Voltage-Source Converter (VSC) and two or more series VSCs the configuration is made. The system can be applied to adjacent feeders to compensate for supply-voltage and load current imperfections on the main feeder and full compensation of supply voltage imperfections on the other feeders. The configuration will be designed as all converters are connected back to back on the dc side and share a common dc-link capacitor. The system is also capable of compensating for interruptions without the need for a battery storage system and consequently without storage capacity limitations. By the simulation the performance of MC-UPQC as well as the adopted control algorithm will be illustrated. Index- terms: Voltage-Source Converter (VSC), Interline Power Flow Controller (IPFC), Unified PowerQuality Conditioning System (UPQC), I. Introduction When the power flows of two lines starting in one substation need to be controlled, an Interline Power Flow Controller (IPFC) can be used. An IPFC consists of two series VSCs whose dc capacitors are coupled. This allows active power to circulate between the VSCs. With this configuration, two lines can be controlled simultaneously to optimize the network utilization. The GUPFC combines three or more shunt and series converters. It extends the concept of voltage and power-flow control beyond what is achievable with the known two-converter UPFC. The simplest GUPFC consists of three converters—one connected in shunt and the other two in series with two transmission lines in a substation. The basic GUPFC can control total five power system quantities, such as a bus as well. By using GUPFC devices, the transfer capability of transmission lines can be increased significantly. Furthermore, by using the multiline-management capability of the GUPFC, active power flow on lines cannot only be increased, but also be decreased with respect to operating and market transaction requirements. In general, the GUPFC can be used to increase the transfer capability and relieve congestions in a flexible way. This concept can be extended to design multiconverter configurations for PQ improvement in adjacent feeders. For example, the interline unified power-quality conditioner (IUPQC), which is the extension of the IPFC concept at the distribution level, has been proposed in the IUPQC consists of one series and one shunt converter. It is connected between two feeders to regulate the bus voltage of one of the feeders, while regulating the voltage across a sensitive load in the other feeder. In this configuration, the voltage regulation in one of the feeders is performed by the shunt-VSC. However, since the source impedance is very low, a high amount of current would be needed to boost the bus voltage in case of a voltage sag/swell which is not feasible. It also has low dynamic performance because the dc-link capacitor voltage is not regulated. In this paper, a new configuration of a UPQC called the multiconverter unified power-quality conditioner (MC-UPQC) is presented. The system is extended by adding a series-VSC in an adjacent feeder. The proposed topology can be used for simultaneous compensation of voltage and current imperfections in both feeders by sharing power compensation capabilities between two adjacent feeders which are not connected. The system is also capable of compensating for interruptions without the need for a battery storage system and consequently without storage capacity limitations.

Enhancement for Power Quality in Distribution Side Using Custom Power Devices

Power quality (PQ) of power operating device is one of today's most discussed topic but also it is a most problematic subject in recent years. With increasing applications of nonlinear and electronically switched devices in distribution systems and industries, power-quality (PQ) problems, such as harmonics, neutral current elimination, reactive power has become an unavoidable issues. The introduction of Unified Power Quality Conditioner in distribution side in one feeder network has made it possible to mitigate the following problems effectively. Interline Unified Power Quality Conditioner which is installed between two feeders is its one of the advancement .The controlling algorithm determines the production of controlling signals which is used by the Voltage Source Converters for the generation of their gating signals. The variation of performance of the device occurs with the different controlling algorithms .This paper proposes the usage of Synchronous Reference Frame Controlling algorithm for the gate signal generation and the usage of modified PLL for better performance. Due to the effective usage of fuzzy controller based on PSO algorithm in the series side of the device make it more advantageous than other commonly used controllers. The main power quality issues we concentrate upon relates to reactive power compensation, harmonics elimination and neutral current

Power Quality Improvement Using Interline Unified Power Quality Conditioner

Power Quality Improvement Using Interline Unified Power Quality Conditioner

Interline Unified Power Quality Conditioner

This paper proposes a new connection for a unified power quality conditioner (UPQC) to improve the power quality of two feeders in a distribution system. A UPQC consists of a series voltage-source converter (VSC) and a shunt VSC both joined together by a common dc bus. It is demonstrated how this device is connected between two independent feeders to regulate the bus voltage of one of the feeders while regulating the voltage across a sensitive load in the other feeder. Since the UPQC is connected between two different feeders (lines), this connection of the UPQC will be called an interline UPQC (IUPQC). The structure, control and capability of the IUPQC are discussed in this paper. The efficacy of the proposed configuration has been verified through simulation studies using PSCAD/EMTDC