List of contents Introduction Topology derivation with switch multiplexing Multi-objective model predictive control Case 1: Single-stage single-phase battery charger Case 2: LED drive without electrolytic capacitor Case 3: Advanced switched reluctance motor drive Conclusions

Multi-objective model predictive control Conventional control method with one input and one output is not suitable for MPEI Model predictive control Easy to expand; Non-accurate modeling; System stability; Constraints to be considered; Require parameter tuning;

Multi-objective model predictive control Generalised model predictive control:

Multi-objective model predictive control Predictor In order to embed the control method into the microprocessor, it is necessary to optimize the prediction step.

Multi-objective model predictive control Optimizer/control law Stability analysis Control law Steady state estimation:

Multi-objective model predictive control Case study Parameters Value Vin 160-200V Vdclink 350V Vout 200V Inductor (L1) 1.5mH, 0.1Ω Inductor (L2) Capacitor (C) 2200µF Switching frequency 20-kHz Control frequency Switches STGIPS30N60

Multi-objective model predictive control Simulation results Output current Input current Dc link voltage Duty cycle 1 Duty cycle 2 The dynamic response time is 28ms, the overshoot of the Dc link voltage is less than 7%.

Multi-objective model predictive control Experimental results Prototype Using two PI controllers According to the experimental waveforms, the method based on MPC can control both the dc link voltage and output current with 6% overshoot and 40ms dynamic response time. Using generalized MPC

List of contents Introduction Topology derivation with switch multiplexing Multi-objective model predictive control Case 1: Single-stage single-phase battery charger Case 2: LED drive without electrolytic capacitor Case 3: Advanced switched reluctance motor drive Conclusions

Case 1: Single-stage single-phase battery charger The requirements for battery charger: High efficiency; High power density; Grid harmony; A new single-stage single-phase isolated AC-DC converter is proposed by combining LLC resonant unit and T-type multi-level unit based on switch multiplexing. Output voltage doesn’t change much Achieve soft-switching for all switches Small inductor with discrete conduction mode

Case 1: Single-stage single-phase battery charger Mode analysis Mode 1: S1 is on S1 is automatically turned on during dead time Mode 2: S1 and S3 are on There is no current through S3 when it is turned on

Case 1: Single-stage single-phase battery charger Mode analysis Mode 3: S2 and S3 are on S2 is automatically turned on during dead time Mode 4: S2 is on There is no current through S3 when it is turned off

Case 1: Single-stage single-phase battery charger Steady state analysis Peak current rise time=t2-t1 Average current Input power Imax tr tf

Case 1: Single-stage single-phase battery charger Control method The inductor current is discontinues and the grid voltage is easy to detect, thus it is easy to predict the required duty cycle and start angle/time. Control method: To use predictive control to achieve inductor current regulation; To use linear controller to keep the dc link voltage constant;

Case 1: Single-stage single-phase battery charger Experimental results Parameters Value Vin 90-120V AC Vdclink 300-400V DC Vout 24.0V Inductor (L1) 20µH, 0.01Ω DC link capacitors (C1 & C2) 100µF Output capacitor (Co) 220µF Switching frequency 150-250kHz Switches C2M0080120D 250W Prototype

Case 1: Single-stage single-phase battery charger Experimental results Input current Input current THD

Case 1: Single-stage single-phase battery charger Experimental results Transformer waveform Experimental efficiency Experimental results reveal that the proposed topology can achieve above 87.6% efficiency and 91.4% maximum efficiency in the power range [50, 250]W with less than 5.5% input current THD.

List of contents Introduction Topology derivation with switch multiplexing Multi-objective model predictive control Case 1: Single-stage single-phase battery charger Case 2: LED drive without electrolytic capacitor Case 3: Advanced switched reluctance motor drive Conclusions

Case 2: LED drive without electrolytic capacitor The specific requirements for LED drives: high power density high temperature operation current balancing By multiplexing switches with one H-bridge rectifier and one LLC unit, the topology is simplified to be a single-stage single-phase AC-DC power converter. Features: Only 4 switches are used; No electrolytic capacitor is necessary;

Case 2: LED drive without electrolytic capacitor Why should we reduce capacitance? Large capacitance(6800uF) Voltage limitation(450V) Expensive Short Lifetime $60.0 $180.0 Elec cap(2200uF) $7.9 $23.7 electrolytic capacitor Elec cap(220uF) $4.8 $9.6 Data from www.mouser.com Theoretical lifetime of electrolytic capacitor is only about 30,000h at high operating temperature(85ºC) Film cap(20uF) Long lifetime High voltage(1200V) Low ESR Small capacitance(20uF) Reducing the capacitance can help to reduce the cost, the size and improve the lifetime. film capacitor

Case 2: LED drive without electrolytic capacitor Capacitance calculation Assuming DC bus voltage ripple Minimum capacitance

Case 2: LED drive without electrolytic capacitor Circuit design Input voltage (Vin) 120V 60Hz Output voltage (Vout) 24.0V Switches C3M0065090D Diodes VB30202C Inductance (L1) 120µH,16mΩ DC bus capacitor(C1) 66µF/500V Output capacitor (C2) 150µF/100V Switching frequency 300-kHz

Case 2: LED drive without electrolytic capacitor Experimental results 5.3V 1.2V Using conventional control method Using dual one-cycle control

Case 2: LED drive without electrolytic capacitor Experimental results Output ripple distribution System efficiency