A design technique of ARCP matrix converter using circuit simulator Nagasaki University Yuichiro Nakazawa

Contents Design and evaluation of ARCPMC prototype system ・ Introduction ・ Power conversion system ・ Conventional voltage source inverter (VSI) topology ・ Conventional voltage source inverter (VSI) topology ・ Matrix converter topology ・ Matrix converter topology ・ ARCP matrix converter (ARCPMC) topology ・ ARCP matrix converter (ARCPMC) topology ・ Determination of specification & hardware parameters ・ Evaluation of design parameters ・ Outline of ARCPMC prototype system ・ Conclusion

Necessity of power conversion Now, disruption of environment such as global warming by energy consumption and exhaustion of energy resources are serious problem In the industry application, power conversion technology is effective for energy saving In the field of AC motor drive, inverter is widely used as AC adjustable speed drive ⇒ Inverter can generate variable voltage and variable frequency output from AC voltage source ⇒ Inverter can generate variable voltage and variable frequency output from AC voltage source Energy saving technology is strongly demanded

・ AC-DC-AC power conversion ・ Indirect power conversion device ・ Necessity of energy storage components Conventional VSI topology Converter circuit Inverter circuit Energy storage components AC DC AC

Conducted Emission Power Converter Power Source Motor Surge Voltage Input Current Harmonics Leakage Current Motor Shaft Voltage Conventional PWM Inverter Switching loss Influence on Power Source Influence on Power Source ・ Influence on other devices by conductive noise ・ Influence on other devices by conductive noise ・ Stress to power source by input current harmonics ・ Stress to power source by input current harmonics Influence on Power Converter Influence on Power Converter ・ Switching loss ・ Switching loss Influence on Motor Influence on Motor ・ Insulation deterioration of motor winding by surge voltage ・ Insulation deterioration of motor winding by surge voltage ・ Bearing degradation by high dv/dt of motor shaft voltage ・ Bearing degradation by high dv/dt of motor shaft voltage Fig.1. Conventional PWM Inverter

Matrix converter topology AC ・ AC-AC direct power conversion ・ No large energy storage components ・ Regeneration ability & Displacement factor control ・ Reduced input harmonic current

Higher switching frequency for higher performance power conversion ･ Increasing of switching loss ･ Increasing of switching loss ･ Destruction of switching device by dv/dt or di/dt ･ Destruction of switching device by dv/dt or di/dt ･ Development of switching noise ･ Development of switching noise Availability of soft switching technology ZVS (zero voltage switching), ZCS (zero current switching) One of the solution of these problem The soft switching technology ⇒ The soft switching technology One of the technique to realize soft switching ⇒ Auxiliary Resonant Commutated Pole ( ARCP ) technology ⇒ Auxiliary Resonant Commutated Pole ( ARCP ) technology Soft switching is realized by resonance using auxiliary circuit

Matrix converter ARCP technology ・ AC-AC direct power conversion ・ AC-AC direct power conversion ・ No energy storage components ・ No energy storage components ・ Soft switching ・ Soft switching ・ Reduced switching loss ・ Reduced switching loss ARCP technology which is one the soft switching technology is applied to Matrix converter Soft switching technology ARCP matrix converter

ARCP Matrix converter topology AC ・ Auxiliary switches & resonance components ・ Soft switching ( ZVS & ZCS ) ・ Reduced switching loss & switching noise & dv/dt, di/dt Auxiliary circuit L r = Resonance Inductor Main circuit C r = Resonance Capacitor Input Filter Composing of switch ( = Bi-directional switch)

Design of ARCPMC prototype system Determination of hardware parameters and resonance components Evaluation of design parameters using circuit simulator Construction of ARCP prototype system Hardware parameters and resonance components are determined, depend on evaluation system specification A study purpose

Fig.2. The two-phase modulated PWM method The two-phase modulated PWM method 1.Base voltage (V base ) is determined, according to the input three-phase voltage and output voltage command 1.Base voltage (V base ) is determined, according to the input three-phase voltage and output voltage command Condition ② Condition ① e mid < 0 ・・・ V base = e max Control method 2. Two other phases carry out PWM modulation 2. Two other phases carry out PWM modulation e mid > 0 ・・・ V base = e min

Fig.3. The two-phase modulated PWM method The two-phase modulated PWM method Control method 1.Base voltage (V base ) is determined, according to the input three-phase voltage and output voltage command 1.Base voltage (V base ) is determined, according to the input three-phase voltage and output voltage command Condition ② Condition ① Condition ① e mid < 0 ・・・ V base = e max 2. Two other phases carry out PWM modulation 2. Two other phases carry out PWM modulation e mid > 0 ・・・ V base = e min

Fig.4. firing time where Average of output voltage (S 1 ) : Input current distribution factor Firing time Average of output command voltage (S 2 ) In the switching period ( Ts )

Fig.5. Commutation method ARCP commutation ARCP commutation realizes ZVS ( Zero Voltage Switching) by LC resonance Capacitive commutation Capacitive commutation realizes ZVS by charging and discharging action of resonance capacitor These commutation methods realize soft switching ： ARCP commutation ： Capacitive commutation Commutation method e max e mid e min TCTC

Fig.6. Switching pattern Switching pattern

Calculation equation Capacitive commutation Charging or discharging duration ARCP commutation Boost duration Resonance duration Current decreasing duration Commutation time calculation equation e 1 : Voltage before Commutation e 2 : Voltage after Commutation

Specification of prototype system Input Voltage200Vrms Frequency50/60Hz Output Power11kW Voltage Vrms frequency Hz Switching frequency 20kHz Specification of prototype system Resonance component parameters are decided from specification of prototype system and commutation time calculation equation which is shown in the preceding slide

of prototype system Specification of prototype system Capacitive commutation time is set at 5  sec or less, and ARCP commutation frequency is set at 200kHz to achieve in 20kHz switching frequency Parameters of prototype system Input filter Inductor0.18 mH Capacitor 90  F Resonant component Inductor 5  H Capacitor50 nF Resonant capacitor Cr = 50 [nF] Resonant inductor Lr = 5 [  H] Input filter Lf = 0.18 [mH] Cf = 90 [  F] The resonant capacitor value is selected to change maximum commutation voltage within the selected capacitive commutation time for output current 10% of rated The inductance value of the resonant inductor is decided from the resonance frequency Parameters

Fig.7. System configuration of ARCPMC Host PC System configuration

・ Calculation of firing time ・ Calculation of commutation time ・ Phase distinction Fig.8. System configuration of ARCPMC Host PC System configuration DSP TMS320C31

Host PC Generation of PWM signal Fig.9. System configuration of ARCPMC System configuration FPGA EPF10K50RC-240-4

Necessity of simulation Evaluation by experiment without simulation ・ Experiment environment and hardware conditions such as wiring impedance participate in a result ・ Validation of software is difficult ・ Experiment environment and hardware conditions 00 0 such as wiring impedance participate in a result ・ Validation of software is difficult Evaluation by simulation Simulation model contains the control system which is equivalent to an experiment machine Simulation model contains the control system which is equivalent to an experiment machine

Simulation model Fig.10. ARCPMC simulation model ARCPMC Model DSP&FPGA Model

Simulation model DSP Main circuit Auxiliary circuit Load Fig.11. ARCPMC simulation model FPGA Input filter

Simulation parameter The two-phase modulated PWM method Input line voltages 200 V Power frequency 60 Hz Output voltage command 100 V Output frequency command 30 Hz Switching frequency 10 kHz Analysis precision 0.4  sec

Input lines voltage Vrs [500V/div] Input current Ir [50A/div] Filtered Output line voltages (Filtered) V UV [500V/div] Output current I U [10A/div] Simulation result The two-phase modulated PWM method [20msec/div]

Output phase voltage V U [500V/div] Output line voltages V UV [500V/div] Simulation result The two-phase modulated PWM method Output phase voltage V V [500V/div] [2.5msec/div]

Prototype system Fig.12. ARCPMC prototype system Main circuit Gate drive circuit Resonance capacitor Resonance inductor IGBT switch

Prototype system Equivalent circuit ・ The resonant circuit layout is decided to fix design layout ・ The resonant circuit layout is decided to fix design layout Accurate resonance for ARCP commutation ・ A resonant path impedance each phase is equal ・ A resonant path impedance each phase is equal

Future development ・ Drive of ARCPMC prototype system ・ Determination of specification and hardware parameters ・ Evaluation of design parameter using circuit simulator ・ Construction of prototype system Design of ARCPMC prototype system Conclusion

Thank you for your attention !! The END ARCP matrix converter