Parlay Multi Media Call Control Services （ MMCCS） Application Programming Interfaces （API） based on Session Initiation Protocol （SIP） is essential for the implementation of Parlay Call Control （ CC） API. This ...Parlay Multi Media Call Control Services （ MMCCS） Application Programming Interfaces （API） based on Session Initiation Protocol （SIP） is essential for the implementation of Parlay Call Control （ CC） API. This paper first proposes an implementation model of Parlay MMCCS API based on SIP, then presents a mapping between SIP and MMCCS AP1 as far as methods and parameters are concerned, illustrates corresponding relationships between different components of SIP and MMCCS API by means of an application collaboration diagram, and finally presents an application using Java codes as well as some SIP messages. The application shows that a majority of MMCCS API based on SIP can be implemented and therefore verifies our mapping between MMCCS API and SIP.展开更多
New circuit implementations of electronically tunable first and second order allpass filter (AP) structures using a Multiplication Mode Current Conveyor (MMCC) building block are presented. The control voltage (V) of ...New circuit implementations of electronically tunable first and second order allpass filter (AP) structures using a Multiplication Mode Current Conveyor (MMCC) building block are presented. The control voltage (V) of the MMCC tunes the desired phase (θ) while the time constant (τ) is adjustable by a Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA)-based synthetic lossless grounded inductor (L). The circuits are analyzed taking into account the device imperfections which show low active sensitivity features of the designs. The effects of port transfer error (ε) and that of the parasitic capacitances of the active devices had been meticulously examined which indicated that certain deviations in nominal design equations occur;these however, could be minimized with appropriate choice of the circuit passive components. Readily available AD-844 type Current Feedback Amplifier (CFA) elements are utilized for the topology implementation. Satisfactory test results on electronic θ-tunability, upto about 300 KHz, had been verified by PSPICE simulation and with hardware experimentation.展开更多
Using the new building block Multiplication-Mode Current Conveyor (MMCC), some inverting/non-inverting type integrator and differentiator designs are presented, wherein the time constant (τ) is tuned electronically. ...Using the new building block Multiplication-Mode Current Conveyor (MMCC), some inverting/non-inverting type integrator and differentiator designs are presented, wherein the time constant (τ) is tuned electronically. The MMCC is implemented by a readily available chip-level configuration using a multiplier (ICL 8013) and a current feedback amplifier (AD-844 IC) CFA. Detailed analysis, taking into account the device non-idealities, had been carried out that indicates slight deviations affecting the values of the nominal time constant but the design is practically insensitive to the port mismatch errors (ε). Satisfactory response on wave conversion, for signal frequencies up to 600 Khz had been verified with both hardware circuit test and PSPICE macromodel simulation.展开更多
This paper presents a modified modular multilevel cascaded converter based on a triple star bridge cell(MMCCTSBC)for integrating different types of energy storage to form a hybrid energy storage system(HESS).The propo...This paper presents a modified modular multilevel cascaded converter based on a triple star bridge cell(MMCCTSBC)for integrating different types of energy storage to form a hybrid energy storage system(HESS).The proposed HESS comprises battery energy storage,supercapacitor energy storage and a doubly-fed induction machine(DFIM)based variable speed pump storage(VSPS).Different low-rated energy storage units can be intermixed in this converter to form an HESS.This is possible due to the modular structure of the modified converter and provides an advantage in a high-power energy storage system.To validate the performance of HESS,real-time power variation data is accumulated from online sources and a weighted median filter(WMF)is employed for generating appropriate references for battery energy storage system(BESS)and supercapacitor storage to mitigate both low frequency and high-frequency power variations.Here,the control approach permits independent regulation of grid current and DFIM current through the modified MMCC-TSBC converter.The simulation and experimental results validate the effectiveness of the control scheme for the proposed HESS.展开更多
This paper presents a novel inter-cluster direct current(DC)capacitor voltage balancing control scheme for the single-star configured modular multilevel cascaded converter(MMCC)-based static synchronous compensator(ST...This paper presents a novel inter-cluster direct current(DC)capacitor voltage balancing control scheme for the single-star configured modular multilevel cascaded converter(MMCC)-based static synchronous compensator(STATCOM)under unbalanced grid voltage.The negative-sequence component of grid voltage at the point of common connection(PCC)causes unbalanced active power flow in the phase limbs of converter.This leads to the imbalance of DC voltages of the sub-module capacitors across the MMCC phases,and consequently,the malfunction of converter.The proposed solution is to inject both negative-sequence current(NSC)and zero-sequence voltage(ZSV)into the phase limbs of MMCC.A quantification factor Qf is used to achieve the sharing of inter-cluster active pow-er between the NSC and ZSV injection methods.Accurate determination of the quantification factor has been presented.In addition to maintaining the DC voltages of sub-module capacitor across the MMCC phases balanced,it also prevents the overcurrent and overvoltage of converter by injecting NSC and ZSV with the right proportion.The control scheme is validated on a 3.54 kV 1.2 MVA power system using MMCC-based STATCOM with 3-level bridge cells as sub-modules.The results show that the proposed scheme provides superior effectiveness in eliminating the voltage imbalance of DC capacitor in the phase limb while maintaining low voltage and current ratings.展开更多
文摘Parlay Multi Media Call Control Services （ MMCCS） Application Programming Interfaces （API） based on Session Initiation Protocol （SIP） is essential for the implementation of Parlay Call Control （ CC） API. This paper first proposes an implementation model of Parlay MMCCS API based on SIP, then presents a mapping between SIP and MMCCS AP1 as far as methods and parameters are concerned, illustrates corresponding relationships between different components of SIP and MMCCS API by means of an application collaboration diagram, and finally presents an application using Java codes as well as some SIP messages. The application shows that a majority of MMCCS API based on SIP can be implemented and therefore verifies our mapping between MMCCS API and SIP.
文摘New circuit implementations of electronically tunable first and second order allpass filter (AP) structures using a Multiplication Mode Current Conveyor (MMCC) building block are presented. The control voltage (V) of the MMCC tunes the desired phase (θ) while the time constant (τ) is adjustable by a Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA)-based synthetic lossless grounded inductor (L). The circuits are analyzed taking into account the device imperfections which show low active sensitivity features of the designs. The effects of port transfer error (ε) and that of the parasitic capacitances of the active devices had been meticulously examined which indicated that certain deviations in nominal design equations occur;these however, could be minimized with appropriate choice of the circuit passive components. Readily available AD-844 type Current Feedback Amplifier (CFA) elements are utilized for the topology implementation. Satisfactory test results on electronic θ-tunability, upto about 300 KHz, had been verified by PSPICE simulation and with hardware experimentation.
文摘Using the new building block Multiplication-Mode Current Conveyor (MMCC), some inverting/non-inverting type integrator and differentiator designs are presented, wherein the time constant (τ) is tuned electronically. The MMCC is implemented by a readily available chip-level configuration using a multiplier (ICL 8013) and a current feedback amplifier (AD-844 IC) CFA. Detailed analysis, taking into account the device non-idealities, had been carried out that indicates slight deviations affecting the values of the nominal time constant but the design is practically insensitive to the port mismatch errors (ε). Satisfactory response on wave conversion, for signal frequencies up to 600 Khz had been verified with both hardware circuit test and PSPICE macromodel simulation.
文摘This paper presents a modified modular multilevel cascaded converter based on a triple star bridge cell(MMCCTSBC)for integrating different types of energy storage to form a hybrid energy storage system(HESS).The proposed HESS comprises battery energy storage,supercapacitor energy storage and a doubly-fed induction machine(DFIM)based variable speed pump storage(VSPS).Different low-rated energy storage units can be intermixed in this converter to form an HESS.This is possible due to the modular structure of the modified converter and provides an advantage in a high-power energy storage system.To validate the performance of HESS,real-time power variation data is accumulated from online sources and a weighted median filter(WMF)is employed for generating appropriate references for battery energy storage system(BESS)and supercapacitor storage to mitigate both low frequency and high-frequency power variations.Here,the control approach permits independent regulation of grid current and DFIM current through the modified MMCC-TSBC converter.The simulation and experimental results validate the effectiveness of the control scheme for the proposed HESS.
文摘This paper presents a novel inter-cluster direct current(DC)capacitor voltage balancing control scheme for the single-star configured modular multilevel cascaded converter(MMCC)-based static synchronous compensator(STATCOM)under unbalanced grid voltage.The negative-sequence component of grid voltage at the point of common connection(PCC)causes unbalanced active power flow in the phase limbs of converter.This leads to the imbalance of DC voltages of the sub-module capacitors across the MMCC phases,and consequently,the malfunction of converter.The proposed solution is to inject both negative-sequence current(NSC)and zero-sequence voltage(ZSV)into the phase limbs of MMCC.A quantification factor Qf is used to achieve the sharing of inter-cluster active pow-er between the NSC and ZSV injection methods.Accurate determination of the quantification factor has been presented.In addition to maintaining the DC voltages of sub-module capacitor across the MMCC phases balanced,it also prevents the overcurrent and overvoltage of converter by injecting NSC and ZSV with the right proportion.The control scheme is validated on a 3.54 kV 1.2 MVA power system using MMCC-based STATCOM with 3-level bridge cells as sub-modules.The results show that the proposed scheme provides superior effectiveness in eliminating the voltage imbalance of DC capacitor in the phase limb while maintaining low voltage and current ratings.
