Modelng and Control of a Cascaded Boost Converter for a Battery Electrc Vehcle A. Ndtoungou, Ab. Hamad, A. Mssandaand K. Al-Haddad, Fellow member, IEEE EPEC 202 OCTOBER 0-2
Introducton contents Comparson between boost and cascade boost Modelng and control of cascade boost converter Space average model of the system Control law for output voltage control Desgn of the Proportonal Integral (PI) controller Control Scheme of cascade boost for voltage control Smulaton results Control of Battery current Smulaton results Cascade boost converter used as non pollutng converter Control scheme Smulaton results Concluson EPEC 202 OCTOBER 0-2
INTRODUCTION I s a new modelng technque of a cascade Boost converter; The nonlnear control s appled and gves good performances n grd sde and n dc sde. PI controller elmnates effcacy the steady state error of the dc bus voltages; The confguraton proposed may be used to fast chargng electrcal vehcle battery by controllng the tme chargng; The confguraton connected to the grd compensates current harmoncs, reactve power, the THD of the grd current s less than 5%. EPEC 202 OCTOBER 0-2
Comparson between Boost and cascade Boost Characterstcs of boost converter and cascade boost converter The boost converter provdes hgh currents, whle the cascade boost converter acheves hgh voltage. The advantageof the hghvoltage of the cascade boost converter maketvery sutable for hgh battery voltage chargng current. EPEC 202 OCTOBER 0-2
Modelngand control of cascade boost converter D 2 L L D L 2 v L 2 D 3 o V C Q C2 R vo n ON OFF L L2 o v L L v L2 v L2 o V n L C v L v C C2 C v L 2 v L2 v C2 C2 R vo Vn L C v C C2 L 2 C v C2 C2 R vo EPEC 202 OCTOBER 0-2
Space average model of the system ( ) dl d = vc + V dt L L dl ( ) 2 d = v C v 0 dt L2 L2 dvc ( d ) = L L2 dt C C dv o ( d ) = L 2 dt C RC 2 2 v o n EPEC 202 OCTOBER 0-2
Control law for output voltage control : The dynamcs of the output voltage s gven by dv0 C + v = ( d ) = u 2 o L dt R 2 The control law s u u d = L 2 The rght term of ths equaton whch s lnear uses PI controller to regulate the voltage v0 and we extract the control law from ths equaton Where: L2 s the output of the controller PI s the current n nductance L 2 EPEC 202 OCTOBER 0-2
Desgn of the Proportonal Integral (PI) controller k k + = + = p s k G(s) k p s s v0ref k s + k v p u R 0 s RC s + Closed loop output voltage regulaton 2 G F + Rk RC2 k ( k p s + k ) G 0 C 2 = = + G + R k k s + s + R C C p 0 2 p 2 2 = ω 0 k = ω0 C 2 C2 2 2 = 2ξω0 k p = 2ξω0C2 R G C ( k p s + k ) 2 F = 2 2 s + 2 ξ ω 0 s + ω 0 The choce of the PI controller s based on the desred performance of The dampng factor ζ and pulsaton ω 0 to gve best response. EPEC 202 OCTOBER 0-2
Control scheme of cascade boost for voltage control Output voltage d u v 0 L2 v 0 ref Output reference voltage s chosen by user EPEC 202 OCTOBER 0-2
Cascade boost converter s able to regulate the output voltage The best choce of nductance L2 can gve L2 postve Smulaton results For the hgh voltage, the boost converter s not able to regulate the output voltage Smulaton results wth cascade boost converter Smulaton results wth boost converter EPEC 202 OCTOBER 0-2
CONTROL OF BATTERY CURRENT L D 2 D L2 We test the cascade boost converter to charge the battery and to compare t wth the boost converter L v L 2 D 3 0 V n C Q C 2 v 0 Control law: d = + u V ( ) n vc Control scheme of cascade boost for current control EPEC 202 OCTOBER 0-2
Smulaton results The both system gves the same performance to charge the battery The slght dfference s observed n the boost converter that the current flowng n the nductance presents the hgh rpple current compared of the cascade boost converter Smulaton results of cascade boost wth battery current control Smulaton results of boost wth battery current control EPEC 202 OCTOBER 0-2
CASCADE BOOST CONVERTER USED AS NON POLLUTING CONVERTER D 2 L D L 2 L v L 2 D 3 o L f D a D c Vn C Q C2 R vo D b D d Cascade boost Spectrum of the grd current EPEC 202 OCTOBER 0-2
Control law Control Scheme Reference current : Lref eq. 3 d = + ( u Vn ) v eq. 29 C v u V 0 n Lref = v + C V n v0 EPEC 202 OCTOBER 0-2
Grd current and grd voltage are n phase The THD of the grd current s less than 5% Smulaton results Durng the output reference voltage varaton we see that the output voltage well regulated, that the grd voltage and the grd current are n phase and snusodal Steady state response of a non pollutng converter: upper -voltage and current source, lower- output voltage Dynamc response of a non pollutng converter: upper- voltage and current source, lower-output voltage and ts reference EPEC 202 OCTOBER 0-2
CONCLUSION The modelng of the cascade boost converter and the nonlnear control technque are presented. The smulatons results have shown good performances of the cascade Boost compared to the classcal Boost converter. The cascade Boost converter s sutable for hgh voltage battery. The cascade Boost converter used as non pollutng converter gvesathd lessthan5% nthegrdsde. The control of the battery current wll help to control the chargng tme whch may be used to fast chargng electrcal vehcle battery. EPEC 202 OCTOBER 0-2
THANK YOU? EPEC 202 OCTOBER 0-2