EPE Association: EPE 2016 - DS3b: Estimation and Identification Methods

EPE 2016 - DS3b: Estimation and Identification Methods
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 03: Measurement and Control > EPE 2016 - DS3b: Estimation and Identification Methods

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   A Generalised Harmonic Linearisation Method for Power Converters Input/Output Impedance Calculation
By Valerio SALIS [View]
[Download]

Abstract: A general method for the evaluation of small-signal input impedances of power converters is presented inthis paper. The method is based on harmonic linearisation and Fourier analysis techniques and a singlephaseboost PFC is considered as case study. The analysis is based on the average model of the converterbut no further approximations have been made and both voltage and current loops are included. Acomparison between time domain and numerical simulation is presented to validate the proposed model.

   A novel Algorithm for Position Estimation in Coreless Current Measurement Applications
By Nathan TROESTER [View]
[Download]

Abstract: This paper presents a novel algorithm to measure current without a flux concentrating ferromagneticcore enclosing the current carrying conductor. First the algorithm is presented; the algorithm requiresthree magnetic field sensors around the circular conductor. The information about the magnetic field isused to estimate the position of the conductor and to calculate the current to be measured. Secondmeasurements are presented to verify the concept.

   Averaged inverter loss estimation algorithm
By Michal BONISLAWSKI [View]
[Download]

Abstract: Proposed paper presents a fast algorithm for determining static and switching losses of power electronic devices in three-phase DC/AC inverters for different semiconductor materials. This method uses table - form, stored characteristics of individual semiconductor devices, without a necessity of detailed, time resolved analysis of the commutation process. Using such algorithm accelerates total loss calculation, as a result electric machine control strategy can be developed allowing the improvement of the efficiency of the entire propulsion system.

   Converter Efficiency Measurement with PWM Duty Cycle Jitter
By Yaow-Ming CHEN [View]
[Download]

Abstract: A methodology to measure and to demonstrate the impact of the PWM duty cycle jitter on the power conversion efficiency is proposed. The equivalent circuit model with corresponding equations is developed to determine the power loss mechanism. An automatic measurement system without thermal drift is established to verify the converter's efficiency drop.

   DC Bus Current Analysis Considering AC Current Ripple in Three-phase Voltage Source Converters
By Dong JIANG [View]
[Download]

Abstract: DC current is an important parameter for the three-phase voltage source converter (VSC). It determines the thermal and reliability status of DC-link capacitor or battery. Analysis and prediction of DC current is associated with three-phase AC current and its ripple, together with the pulse-width-modulation (PWM) method. Based on the AC current ripple prediction method, this paper gives a general DC bus current prediction method with consideration of the AC current ripple. Comparison with simulation results shows the benefits of the method for DC bus current prediction. Experimental results are also provided to validate the prediction result. The predicted DC current ripple can match well with the experimental result.

   Efficient Intelligent Control Techniques for DC-DC Converters: A Comparative Study
By Mohamed YOUSSEF [View]
[Download]

Abstract: This paper describes the design of different intelligent control techniques including fuzzy logic and adaptive neuro-fuzzy inference system, using the output voltage as a feedback in order to enhance the dynamic and transient response for DC-DC converters and specifically boost converters. The implementation was achieved using MATLAB and Simulink simulation tools. Simulations were performed for different control techniques and also for the open loop system to show the merits and demerits of these techniques.

   Energy Control of Modular Multilevel Converter with a Novel Analytic Filter
By Kosei SHINODA [View]
[Download]

Abstract: The complex topology of the Modular Multilevel Converter (MMC) requires some additional controllers to keep its functionalities. One of the important requirements on the MMC control is to balance the energy stored in the distributed capacitors in the arms on the three legs. However, due to the superimposed internal DC and AC power flows in the converter, the energy stored in the arms contains intrinsic oscillations. This paper provides a thorough analysis on those intrinsic oscillations on the internal energy of the MMC. Based on the analysis, a novel analytic filter is proposed, which enables to extract average value of the energy while keeping other internal dynamics stable. The proposed filter is implemented on an EMTP-RV platform. The simulation demonstrates its improved dynamic response and reduction of the internal losses compared to the existing solutions.

   Extended Observer-Based Simultaneous Online Parameter Estimation of Inverter-Fed Squirrel-Cage Induction Machines Considering the Influence of Current and Speed
By Jaroslav KOUPENY [View]
[Download]

Abstract: This paper deals with the online parameter estimation of squirrel-cage induction machines using the Gradient Descent Method and coupled stator and rotor flux observers. Stator resistance, rotor resistance and mutual inductance can be estimated simultaneously in real time.For a non-ambiguous parameter tracking, an additional voltage is superimposed. The influence of inverter nonlinearity, current and speed measurement errors is investigated. The presented approach is applicable to a standard industrial drive, including current measurement and motor speed feedback. The concept is verified by experimental tests for open loop V/Hz control as well as for field-oriented control.

   Investigation of the Characteristic Thermal Properties of IGBT Power Modules for Robust In-situ Health Monitoring
By Marco DENK [View]
[Download]

Abstract: This paper investigates the characteristic thermal properties of IGBT power modules and develops a very robust health monitoring concept to identify an aged chip-solder within a voltage source inverter. It is shown that at an optimum excitation frequency the power module structure enables a selective identification of an increased thermal chip-solder resistance Rth,1 with a maximum Rth,1 measuring sensitivity. These outstanding features of the thermal power module structure were investigated in the frequency domain and verified by experimental measurements with artificially aged power modules.

   Non-Invasive IGBT Power Loss Model Identification in Two-Level Voltage Source Converters
By Stefan George ROSU [View]
[Download]

Abstract: This paper proposes a method for the identification of the electrical and thermal model of low power voltage source converters (VSCs) under nominal operating conditions. The identified model of the insulated-gate bipolar transistors (IGBTs) and heat-sink thermal resistance can then be used with existing power loss estimation methods. Only steady state measurements are performed on the assembled converter, without the need of a complicated test bench. The method is validated with three two-level three-phase VSCs in two test locations. Estimated power loss with the obtained model using recorded load current and one transistor command signal is compared with calorimetric measurements with good results.

   Novel Screening Techniques for Wind Turbine Power Converters
By Asger Bjørn JØRGENSEN [View]
[Download]

Abstract: Power converters represent one of the highest failure rates in the wind turbine. Therefore convertermanufacturers perform burn-in tests to prevent shipping of faulty converters. Recent developments injunction temperature estimation, based on accurate online IGBT collector-emitter voltage measurements,allow for thermal stress estimation of the IGBT modules. This is utilized to detect infant mortalities inpower converters, by comparing thermal responses of IGBTs for faulty and non-faulty converters. Themethod proves to be a time and cost efficient candidate to replace burn-in tests of power converters forwind turbines applications.

   Revisiting the EKF Concept for Low Speed Sensorless Control of Cage Induction Motors
By Cesar SILVA [View]
[Download]

Abstract: The use of the EKF for induction machine sensorless control is revisited with focus on the improvement of the method for low speed operation. An appropriate discretization method is discussed, the converter non-linearities are compensated for and the observer includes stator resistance estimation. Sensorless speed closed loop experimental results show stable operation down to standstill in motoring and stable transition through zero frequency in any mode of operation. Limitations are observed for permanent operation near or at zero frequency in regenerative operation, consistent with well known theoretical limitations.

   The Switching Frequency Based Active Power as Highly Dynamic Approximation of Conventional Active Power Calculation
By Alexander STOCK [View]
[Download]

Abstract: In this contribution, the switching frequency based active power will be presented as a new power definition. Itcombines the information of the instantaneous power, as product of voltage and current, and the conventionalactive power representing the mean value of the instantaneous power over the fundamental period. Under severaltheoretical conditions the switching frequency based active power is absolutely equal to the well-known activepower definition. In practical applications it approximates the active power but with the advantage of considerationof highly dynamic load changes and transients in voltages and currents. Because of this aspect, it is very useful forreal time applications, especially for active power control.

EPE 2016 - DS3b: Estimation and Identification Methods
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 03: Measurement and Control > EPE 2016 - DS3b: Estimation and Identification Methods
	[return to parent folder]

	A Generalised Harmonic Linearisation Method for Power Converters Input/Output Impedance Calculation By Valerio SALIS	[View] [Download]
Abstract: A general method for the evaluation of small-signal input impedances of power converters is presented inthis paper. The method is based on harmonic linearisation and Fourier analysis techniques and a singlephaseboost PFC is considered as case study. The analysis is based on the average model of the converterbut no further approximations have been made and both voltage and current loops are included. Acomparison between time domain and numerical simulation is presented to validate the proposed model.

	A novel Algorithm for Position Estimation in Coreless Current Measurement Applications By Nathan TROESTER	[View] [Download]
Abstract: This paper presents a novel algorithm to measure current without a flux concentrating ferromagneticcore enclosing the current carrying conductor. First the algorithm is presented; the algorithm requiresthree magnetic field sensors around the circular conductor. The information about the magnetic field isused to estimate the position of the conductor and to calculate the current to be measured. Secondmeasurements are presented to verify the concept.

	Averaged inverter loss estimation algorithm By Michal BONISLAWSKI	[View] [Download]
Abstract: Proposed paper presents a fast algorithm for determining static and switching losses of power electronic devices in three-phase DC/AC inverters for different semiconductor materials. This method uses table - form, stored characteristics of individual semiconductor devices, without a necessity of detailed, time resolved analysis of the commutation process. Using such algorithm accelerates total loss calculation, as a result electric machine control strategy can be developed allowing the improvement of the efficiency of the entire propulsion system.

	Converter Efficiency Measurement with PWM Duty Cycle Jitter By Yaow-Ming CHEN	[View] [Download]
Abstract: A methodology to measure and to demonstrate the impact of the PWM duty cycle jitter on the power conversion efficiency is proposed. The equivalent circuit model with corresponding equations is developed to determine the power loss mechanism. An automatic measurement system without thermal drift is established to verify the converter's efficiency drop.

	DC Bus Current Analysis Considering AC Current Ripple in Three-phase Voltage Source Converters By Dong JIANG	[View] [Download]
Abstract: DC current is an important parameter for the three-phase voltage source converter (VSC). It determines the thermal and reliability status of DC-link capacitor or battery. Analysis and prediction of DC current is associated with three-phase AC current and its ripple, together with the pulse-width-modulation (PWM) method. Based on the AC current ripple prediction method, this paper gives a general DC bus current prediction method with consideration of the AC current ripple. Comparison with simulation results shows the benefits of the method for DC bus current prediction. Experimental results are also provided to validate the prediction result. The predicted DC current ripple can match well with the experimental result.

	Efficient Intelligent Control Techniques for DC-DC Converters: A Comparative Study By Mohamed YOUSSEF	[View] [Download]
Abstract: This paper describes the design of different intelligent control techniques including fuzzy logic and adaptive neuro-fuzzy inference system, using the output voltage as a feedback in order to enhance the dynamic and transient response for DC-DC converters and specifically boost converters. The implementation was achieved using MATLAB and Simulink simulation tools. Simulations were performed for different control techniques and also for the open loop system to show the merits and demerits of these techniques.

	Energy Control of Modular Multilevel Converter with a Novel Analytic Filter By Kosei SHINODA	[View] [Download]
Abstract: The complex topology of the Modular Multilevel Converter (MMC) requires some additional controllers to keep its functionalities. One of the important requirements on the MMC control is to balance the energy stored in the distributed capacitors in the arms on the three legs. However, due to the superimposed internal DC and AC power flows in the converter, the energy stored in the arms contains intrinsic oscillations. This paper provides a thorough analysis on those intrinsic oscillations on the internal energy of the MMC. Based on the analysis, a novel analytic filter is proposed, which enables to extract average value of the energy while keeping other internal dynamics stable. The proposed filter is implemented on an EMTP-RV platform. The simulation demonstrates its improved dynamic response and reduction of the internal losses compared to the existing solutions.

	Extended Observer-Based Simultaneous Online Parameter Estimation of Inverter-Fed Squirrel-Cage Induction Machines Considering the Influence of Current and Speed By Jaroslav KOUPENY	[View] [Download]
Abstract: This paper deals with the online parameter estimation of squirrel-cage induction machines using the Gradient Descent Method and coupled stator and rotor flux observers. Stator resistance, rotor resistance and mutual inductance can be estimated simultaneously in real time.For a non-ambiguous parameter tracking, an additional voltage is superimposed. The influence of inverter nonlinearity, current and speed measurement errors is investigated. The presented approach is applicable to a standard industrial drive, including current measurement and motor speed feedback. The concept is verified by experimental tests for open loop V/Hz control as well as for field-oriented control.

	Investigation of the Characteristic Thermal Properties of IGBT Power Modules for Robust In-situ Health Monitoring By Marco DENK	[View] [Download]
Abstract: This paper investigates the characteristic thermal properties of IGBT power modules and develops a very robust health monitoring concept to identify an aged chip-solder within a voltage source inverter. It is shown that at an optimum excitation frequency the power module structure enables a selective identification of an increased thermal chip-solder resistance Rth,1 with a maximum Rth,1 measuring sensitivity. These outstanding features of the thermal power module structure were investigated in the frequency domain and verified by experimental measurements with artificially aged power modules.

	Non-Invasive IGBT Power Loss Model Identification in Two-Level Voltage Source Converters By Stefan George ROSU	[View] [Download]
Abstract: This paper proposes a method for the identification of the electrical and thermal model of low power voltage source converters (VSCs) under nominal operating conditions. The identified model of the insulated-gate bipolar transistors (IGBTs) and heat-sink thermal resistance can then be used with existing power loss estimation methods. Only steady state measurements are performed on the assembled converter, without the need of a complicated test bench. The method is validated with three two-level three-phase VSCs in two test locations. Estimated power loss with the obtained model using recorded load current and one transistor command signal is compared with calorimetric measurements with good results.

	Novel Screening Techniques for Wind Turbine Power Converters By Asger Bjørn JØRGENSEN	[View] [Download]
Abstract: Power converters represent one of the highest failure rates in the wind turbine. Therefore convertermanufacturers perform burn-in tests to prevent shipping of faulty converters. Recent developments injunction temperature estimation, based on accurate online IGBT collector-emitter voltage measurements,allow for thermal stress estimation of the IGBT modules. This is utilized to detect infant mortalities inpower converters, by comparing thermal responses of IGBTs for faulty and non-faulty converters. Themethod proves to be a time and cost efficient candidate to replace burn-in tests of power converters forwind turbines applications.

	Revisiting the EKF Concept for Low Speed Sensorless Control of Cage Induction Motors By Cesar SILVA	[View] [Download]
Abstract: The use of the EKF for induction machine sensorless control is revisited with focus on the improvement of the method for low speed operation. An appropriate discretization method is discussed, the converter non-linearities are compensated for and the observer includes stator resistance estimation. Sensorless speed closed loop experimental results show stable operation down to standstill in motoring and stable transition through zero frequency in any mode of operation. Limitations are observed for permanent operation near or at zero frequency in regenerative operation, consistent with well known theoretical limitations.

	The Switching Frequency Based Active Power as Highly Dynamic Approximation of Conventional Active Power Calculation By Alexander STOCK	[View] [Download]
Abstract: In this contribution, the switching frequency based active power will be presented as a new power definition. Itcombines the information of the instantaneous power, as product of voltage and current, and the conventionalactive power representing the mean value of the instantaneous power over the fundamental period. Under severaltheoretical conditions the switching frequency based active power is absolutely equal to the well-known activepower definition. In practical applications it approximates the active power but with the advantage of considerationof highly dynamic load changes and transients in voltages and currents. Because of this aspect, it is very useful forreal time applications, especially for active power control.