In this webinar, Dave Berry, a principal applications engineer at Vicor, explains why most power supplies need to be sized based upon the maximum power demanded by the load, even though it adds size, weight and cost to the system. He then explains the technique of power averaging, which allows power systems to be sized based on the average power requirement, delivering many benefits.

1. 1
Maximum Load: The Wrong Specification for Pulsed Power
David Berry
Principal Applications Engineer

2. 2
› Power Averaging: Definition and Criteria
› Power Configuration: Typical Approach vs. Averaging Approach
› Solution Sizing: Capacitor & Power Supply Selection
› Power Averaging: Configuration Example
› Conclusions
Agenda

3. 3
› Configuring the power supply
to deliver the average power to the load
› A capacitor is used
to deliver the peak power to the load
Power Averaging: Definition

4. 4
› Periodic load
› The load has a wide input range
› The max on-time and min off-time are known
› Space and weight are critical
Power Averaging: Criteria

5. 5
900 Watt Periodic Load 25% Duty Cycle
Power Configuration: Typical Approach

6. 6
Power Configuration: Averaging Approach
900 Watt Periodic Load 25% Duty Cycle

7. 7
Solution Sizing: Capacitor Selection
› Peak load power
› Maximum load on time
› Minimum load off time
› Load input voltage range

8. 8
Solution Sizing: Capacitor Selection
C = capacitor value
T1 - T2 = load ON duration
V1 – V2 = voltage drop at capacitor during load ON
V1
V2
T1
T2

9. 9
Solution Sizing: Power Supply Selection
› Capable of recharging the capacitor to initial voltage
› Must be stable during operation
› Must be capable of operating in current limit
› Must be capable of operating in power limit

10. 10
Solution Sizing: Power Supply Selection

11. 11
Solution Sizing: Power Supply Selection

12. 12
Power Averaging: Configuration

13. 13
Power Averaging: Example
DCM output voltage
DCM output current
Load current

14. 14

15. 15

16. 16
1. Saves system weight
2. Saves system space
3. Saves system cost
Conclusion
Power Averaging

17. 17
Thank You