Challenges and Opportunities in Implementing a Distributed Parallel MLPE Power Regulation Topology

1. Simply More Energy
Challenges and Opportunities in Implementing a
Distributed Parallel MLPE Power Regulation
Topology
Tim Johnson

2. tenKsolar Worldwide Installations
Bloomington, MN (HQ)
Shanghai, China

3. Value of Module Electronics
• What is MLPE really meant to do?
–Remove serial limitations in infrastructure applications
–Enable Faster Growth in PV by making it foolproof to install
• Solve Serial DC
–Module Mismatch, Stringing, MPPT, etc….
• Make DC “Plug and Play”
– It’s easy to install Serial DC incorrectly
– Hard to diagnose
– Difficult to maintain

4. • Navigant Research reports that annual installations of global module-level power
electronic (MLPE) capacity will grow from 1,185 MW in 2013 to 12,844 MW by 2020.
• IHS Research The worldwide market for module-level power electronics (MLPEs),
including PV microinverters and power optimisers, is expected to reach US$1 billion
by 2019, according to IHS.
Market Value of MLPE

5. • MLPE is not a coherent market, creating some misidentification
– Add on Optimizers
– Micro Inverters
– System Integrated
– Others….
• Barriers to Entry to “Bankability”
– Not as high as they used to be
• How to address?
– Design – Manage component failure so system performs above required service levels.
– Quality Assurance Systems – IECRE will be a critical standard to enable overall faster growth in the
industry.
– Do specific MLPE types need specific IEC standards?
Challenges of MLPE

6. 3/6/2016 tenKsolar Confidential 6
The tenK Topology
Parallel/Serial
Cell Matrix Within
Each Module
All Modules in Parallel
DC Bus Delivers Energy to Group of Inversion Units
Energy From Any Cell Can Go Through Any Inversion Unit
15VDC
Non-PV Source:
<57VDC
480VAC
• Utilize modular, low cost components to create an easy to
install, highly reliable, zero maintenance PV system
Embedded
DC:DC Boost
Charge Controller

7. RAIS PV Module
Onboard LED
aids installation

9. 9

10. 3/6/2016 tenKsolar Confidential
10
Logical Construction of a tenK PV module
PV+
PV (-)
BAT+
BAT-
Parallel Matrix
Controller
Ultra-Low Cost Aluminum Backsheet
(Very Low Impedance Current Return Path)
Serial Cell Connections (Red)Parallel Cell Connections (Green)

11. 3/6/2016 tenKsolar Confidential 11
tenK – Dual Listed to UL1703 + UL1741
CSA Listing to UL1703 + UL1741
No Other Module Listed This Way
UL1703 Covers Panel Portion
UL1741 Covers Charge Controller
Grounding Tested to UL2703

12. RAIS® Parallel Matrix Controller (RAIS® = Redundant Array of Integrating Solar)
• Contains six DC:DC converters operating off of selectable, parallel
buses internal to the module.
• The energy available the module at STC conditions can be produced
by four of the six converters operating, thus two are fully redundant.
Each converter is internally fused and fully isolated from each other.
• Each DC:DC converter operates only as needed, is virtualized to wear-
level across each.
• All electronic boards repeat functionally tested during a continuous
module light test where the electronics runs a full diagnostic on the
module.

13. RAIS® Parallel Matrix Controller (RAIS® = Redundant Array of Integrating Solar)
• Self-starting and used to self-charge the circuit to begin operation when
illumination is present on the PV cells.
• Only produce energy when connected to a pre-qualified circuit (circuit
cannot be shorted, open or purely resistive), and has an embedded
ground fault detection circuit.
• It can also detect arc-fault failures by continuously monitoring the line
for voltage fluctuations over a very narrow range of limits.

14. RAIS® Parallel Matrix Controller (RAIS® = Redundant Array of Integrating Solar)
• The Parallel Matrix Controller tracks and stores all performance
information over the lifetime of module.
• An LED is used on the circuit board to present both visual and binary
information to the user.
• A power-line carrier based digital communication routine allows all
modules to be transmit information to a receiving device

15. 3/6/2016 tenKsolar Confidential 15
The tenK Topology
Parallel, Un-Interrupted
DC Bus
Parallel (Fault Tolerant)
Inversion Units
All Modules in Parallel
DC Bus Delivers Energy to Group of Inversion Units
Energy From Any Cell Can Go Through Any Inversion Unit
Non-PV Source:
<57VDC
480VAC
• Utilize modular, low cost components to create an easy to
install, highly reliable, zero maintenance PV system
DC Coupled Energy Storage

16. tenKsolar RAIS Inverter Bus
pv
dc
distribution
box
pv
to specific
Service
pv
dc
distribution
box
pv
Multiple Inverters Operating Off DC Bus (Fault Tolerant)
No Digital Communication Between Units
All Operate Based Off DC Setpoint Targets
Only Operate as Needed
Randomized DC Setpoint Process
Daily Wear Leveling Across All Units
If One Fails or is Damaged
No Impact on Others (Fused)
Extremely Simple Repair
Changing Failed Units is a Very Simple Swap-Out
All Units are Inter-operable

17. 3/6/2016 tenKsolar Confidential 17
Simplified System Block Design (33.6 kWAC)
Modules
RIB RIB
Modules
Modules Modules
RIB RIB AC Box
(4 RIB’s)
AC Subpanel
8.4KW 8.4KW8.4KW
8.4KW 8.4KW

18. Improved System Longevity – Redundant Inversion
18
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
tenK RIB String
50% Fewer Annual hours
operating
Inversion Units All Come On at Different Times
Note: Total Power Curve is Smooth
Also – Repeats AM and PM
Randomized Each Day
Net Required On-Time: 25% vs. 50% For Module Dedicated Inversion

19. Benefit of Redundant Inversion

20. Electronic Failures Grouping in Time
MLPE Availability Inverter Bus AvailabilityXc-Si Degredation X = Output
tenK RAIS PV Module

21. 3/6/2016 tenKsolar Confidential 21
Zero Energy Loss With No Maintenance
In Year 25, 13% Additional Loss in Total AC
Power is Compenstated for with redundant
bus. Results in Zero lifetime Energy Loss
versus Expected with No Maintenance or
Corrective Actions for Inversion.
As failures are distributed among
redundant buses, remaining
functioning boost converters on
the module and inverters on RIB
ensure no effective

22. Simply More Energy
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