This article investigates the power quality enhancement in power system using one of the most famous series converter based FACTS controller like IPFC (Interline Power Flow Controller) in Power Injection Model (PIM). ...This article investigates the power quality enhancement in power system using one of the most famous series converter based FACTS controller like IPFC (Interline Power Flow Controller) in Power Injection Model (PIM). The parameters of PIM are derived with help of the Newton-Raphson power flow algorithm. In general, a sample test power system without FACTs devices has generated more reactive power, decreased real power, more harmonics, small power factor and poor dynamic performance under line and load variations. In order to improve the real power, compensating the reactive power, proficient power factor and excellent load voltage regulation in the sample test power system, an IPFC is designed. The D-Q technique is utilized here to derive the reference current of the converter and its D.C link capacitor voltage is regulated. Also, the reference voltage of the inverter is arrived by park transformation technique and its load voltage is controlled. Here, a sample 230 KV test power system is taken for study. Further as the conventional PI controllers are designed at one nominal operating point they are not competent to respond satisfactorily in dynamic operating conditions. This can be circumvented by a Fuzzy and Neural network based IPFC and its detailed Simulink model is developed using MATLAB and the overall performance analysis is carried out under different operating state of affairs.展开更多
The restructuring of the electric power market has led to complex power transmission congestion problems.Additionally,scheduled power flows in the transmission line,as well as spontaneous power exchanges have also ris...The restructuring of the electric power market has led to complex power transmission congestion problems.Additionally,scheduled power flows in the transmission line,as well as spontaneous power exchanges have also risen sharply in recent years.The proper placement of IPFC can improve the transmission line congestion problem to a great extent.This paper proposes a disparity line utilization factor(DLUF)for the optimal placement of IPFC to control the congestion in transmission lines.DLUF determines the difference between the percentages of Mega Volt Ampere utilization of each line connected to the same bus.The IPFC is placed in the lines with maximum DLUF.A multiobjective function consisting of reduction of active power loss,minimization of total voltage deviations,minimization of security margin and minimization of installed IPFC capacity is considered for the optimal tuning of IPFC using differential evolution algorithm.The proposed method is implemented for IEEE-30 bus test system under different loading conditions and the results are presented and analyzed to establish the effectiveness on the reduction of congestion.展开更多
The fast-response feature from a superconducting magnetic energy storage(SMES)device is favored for suppressing instantaneous voltage and power fluctuations,but the SMES coil is much more expensive than a conventional...The fast-response feature from a superconducting magnetic energy storage(SMES)device is favored for suppressing instantaneous voltage and power fluctuations,but the SMES coil is much more expensive than a conventional battery energy storage device.In order to improve the energy utilization rate and reduce the energy storage cost under multiple-line power distribution conditions,this paper investigates a new interline DC dynamic voltage restorer(IDC-DVR)scheme with one SMES coil shared among multiple compensating circuits.In this new concept,an improved current-voltage(I/V)chopper assembly,which has a series of input/output power ports,is introduced to connect the single SMES coil with multiple power lines,and thereby satisfy the independent energy exchange requirements of any line to be compensated.Specifically,if two or more power lines have simultaneous compensating demands,the SMES coil can be selectively controlled to compensate the preferable line according to the priority order of the line.The feasibility of the proposed scheme is technically verified to maintain the transient voltage stability in multiple-line voltage swell and sag cases caused by either output voltage fluctuations from external power sources or power demand fluctuations from local sensitive loads.The simulation results provide a technical basis to develop a cost-effective SMES-based IDC-DVR for use in various DC distribution networks.展开更多
With the continuous expansion of power systems and the application of power electronic equipment, forced oscillation has become one of the key problems in terms of system safety and stability. In this paper, an interl...With the continuous expansion of power systems and the application of power electronic equipment, forced oscillation has become one of the key problems in terms of system safety and stability. In this paper, an interline power flow controller (IPFC) is used as a power suppression carrier and its mechanism is analyzed using the linearized state-space method to improve the system damping ratio. It is shown that although the IPFC can suppress forced oscillation with well-designed parameters, its capability of improving the system damping ratio is limited. Thus, combined with the repetitive control method, an additional repetitive controller (ARC) is proposed to further dampen the forced power oscillation. The ARC control scheme is characterized by outstanding tracking performance to a system steady reference value, and the main IPFC controller with the ARC can provide higher damping, and further reduce the amplitude of oscillations to zero compared with a supplementary damping controller (SDC). Simulation results show that the IPFC with an ARC can not only greatly reduce the oscillation amplitude, but also actively output the compensation power according to the reference value of the ARC tracking system.展开更多
Cuprammonium fabrics are susceptible to punctuation of the sewing needle during the manufacturing processes of a garment.This type of punctuation splits the yarns in the fabrics,creates ladder-like sewing defects,and ...Cuprammonium fabrics are susceptible to punctuation of the sewing needle during the manufacturing processes of a garment.This type of punctuation splits the yarns in the fabrics,creates ladder-like sewing defects,and seriously affects the aesthetics of the finished garment.To minimize this seam damage,a sandwiched structure of cuprammonium fabrics with a fusible interlining was proposed to enhance the friction between the yarns in the fabrics.A measurement system was set up to evaluate the seam damage,and the effects of stitch length and seam width on the seam damage were studied.The seam damage tended to become less severe as the stitch length increased.The addition of the fusible interlining between two pieces of the fabrics could effectively suppress the seam damage.The seam margin should be below or equal to 5 mm for the stitch length of 2.0 mm.An excessive seam margin might lead to a distorted seam.展开更多
Established in 1988, and put integrity, pragmatic, win-win as principle to guide the products’ research and development, production and sales which enjoys high reputation all over the world. Based on domestic and imp...Established in 1988, and put integrity, pragmatic, win-win as principle to guide the products’ research and development, production and sales which enjoys high reputation all over the world. Based on domestic and imported from Germany interlining production line, we have the specialized strong technical force, advanced detection system to guarantee the stability of the product quality Our goods are varied and with complete specifications. The main products as following: shirt fusible interlining, outwear fusible interlining, fashion fusible interlining, fur coating interlining, resin interlining, interlining used for shoes, caps and bags, all kinds of fabric and pocket cloth.展开更多
文摘This article investigates the power quality enhancement in power system using one of the most famous series converter based FACTS controller like IPFC (Interline Power Flow Controller) in Power Injection Model (PIM). The parameters of PIM are derived with help of the Newton-Raphson power flow algorithm. In general, a sample test power system without FACTs devices has generated more reactive power, decreased real power, more harmonics, small power factor and poor dynamic performance under line and load variations. In order to improve the real power, compensating the reactive power, proficient power factor and excellent load voltage regulation in the sample test power system, an IPFC is designed. The D-Q technique is utilized here to derive the reference current of the converter and its D.C link capacitor voltage is regulated. Also, the reference voltage of the inverter is arrived by park transformation technique and its load voltage is controlled. Here, a sample 230 KV test power system is taken for study. Further as the conventional PI controllers are designed at one nominal operating point they are not competent to respond satisfactorily in dynamic operating conditions. This can be circumvented by a Fuzzy and Neural network based IPFC and its detailed Simulink model is developed using MATLAB and the overall performance analysis is carried out under different operating state of affairs.
文摘The restructuring of the electric power market has led to complex power transmission congestion problems.Additionally,scheduled power flows in the transmission line,as well as spontaneous power exchanges have also risen sharply in recent years.The proper placement of IPFC can improve the transmission line congestion problem to a great extent.This paper proposes a disparity line utilization factor(DLUF)for the optimal placement of IPFC to control the congestion in transmission lines.DLUF determines the difference between the percentages of Mega Volt Ampere utilization of each line connected to the same bus.The IPFC is placed in the lines with maximum DLUF.A multiobjective function consisting of reduction of active power loss,minimization of total voltage deviations,minimization of security margin and minimization of installed IPFC capacity is considered for the optimal tuning of IPFC using differential evolution algorithm.The proposed method is implemented for IEEE-30 bus test system under different loading conditions and the results are presented and analyzed to establish the effectiveness on the reduction of congestion.
基金This work was supported in part by the National Natural Science Foundation of China under Grant No.51807128State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources under Grant No.LAPS20017.
文摘The fast-response feature from a superconducting magnetic energy storage(SMES)device is favored for suppressing instantaneous voltage and power fluctuations,but the SMES coil is much more expensive than a conventional battery energy storage device.In order to improve the energy utilization rate and reduce the energy storage cost under multiple-line power distribution conditions,this paper investigates a new interline DC dynamic voltage restorer(IDC-DVR)scheme with one SMES coil shared among multiple compensating circuits.In this new concept,an improved current-voltage(I/V)chopper assembly,which has a series of input/output power ports,is introduced to connect the single SMES coil with multiple power lines,and thereby satisfy the independent energy exchange requirements of any line to be compensated.Specifically,if two or more power lines have simultaneous compensating demands,the SMES coil can be selectively controlled to compensate the preferable line according to the priority order of the line.The feasibility of the proposed scheme is technically verified to maintain the transient voltage stability in multiple-line voltage swell and sag cases caused by either output voltage fluctuations from external power sources or power demand fluctuations from local sensitive loads.The simulation results provide a technical basis to develop a cost-effective SMES-based IDC-DVR for use in various DC distribution networks.
基金funded by Jiangsu electric power company project“key technology research on planning and demonstration application of inter line power flow controller”,J2020088.
文摘With the continuous expansion of power systems and the application of power electronic equipment, forced oscillation has become one of the key problems in terms of system safety and stability. In this paper, an interline power flow controller (IPFC) is used as a power suppression carrier and its mechanism is analyzed using the linearized state-space method to improve the system damping ratio. It is shown that although the IPFC can suppress forced oscillation with well-designed parameters, its capability of improving the system damping ratio is limited. Thus, combined with the repetitive control method, an additional repetitive controller (ARC) is proposed to further dampen the forced power oscillation. The ARC control scheme is characterized by outstanding tracking performance to a system steady reference value, and the main IPFC controller with the ARC can provide higher damping, and further reduce the amplitude of oscillations to zero compared with a supplementary damping controller (SDC). Simulation results show that the IPFC with an ARC can not only greatly reduce the oscillation amplitude, but also actively output the compensation power according to the reference value of the ARC tracking system.
基金Education and Scientific Research Foundation for Middle-Aged and Young Teachers of Fujian Province,China(No.JAT170498)。
文摘Cuprammonium fabrics are susceptible to punctuation of the sewing needle during the manufacturing processes of a garment.This type of punctuation splits the yarns in the fabrics,creates ladder-like sewing defects,and seriously affects the aesthetics of the finished garment.To minimize this seam damage,a sandwiched structure of cuprammonium fabrics with a fusible interlining was proposed to enhance the friction between the yarns in the fabrics.A measurement system was set up to evaluate the seam damage,and the effects of stitch length and seam width on the seam damage were studied.The seam damage tended to become less severe as the stitch length increased.The addition of the fusible interlining between two pieces of the fabrics could effectively suppress the seam damage.The seam margin should be below or equal to 5 mm for the stitch length of 2.0 mm.An excessive seam margin might lead to a distorted seam.
文摘Established in 1988, and put integrity, pragmatic, win-win as principle to guide the products’ research and development, production and sales which enjoys high reputation all over the world. Based on domestic and imported from Germany interlining production line, we have the specialized strong technical force, advanced detection system to guarantee the stability of the product quality Our goods are varied and with complete specifications. The main products as following: shirt fusible interlining, outwear fusible interlining, fashion fusible interlining, fur coating interlining, resin interlining, interlining used for shoes, caps and bags, all kinds of fabric and pocket cloth.