1. 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

2. 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;

3. Multi-objective model predictive control
Generalised model predictive control:

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

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

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

7. 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%.

8. 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

9. 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

10. 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

11. 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

12. 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

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

14. 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;

15. Case 1: Single-stage single-phase battery charger
Experimental results
Parameters
Value
Vin
90-120V AC
Vdclink
V DC
Vout
24.0V
Inductor (L1)
20µH, 0.01Ω
DC link capacitors (C1 & C2)
100µF
Output capacitor (Co)
220µF
Switching frequency
kHz
Switches
C2M D
250W Prototype

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

17. 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.

18. 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

19. 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;

20. 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
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

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

22. Case 2: LED drive without electrolytic capacitor
Circuit design
Input voltage (Vin)
120V 60Hz
Output voltage (Vout)
24.0V
Switches
C3M D
Diodes
VB30202C
Inductance (L1)
120µH,16mΩ
DC bus capacitor(C1)
66µF/500V
Output capacitor (C2)
150µF/100V
Switching frequency
300-kHz

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

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