Maximum Power Point Tracker

In collaboration with the U.S. Naval Research Lab (NRL), developed power management for extended endurance, portable, hand-launchable solar-soaring UAS

• Providing efficient Power Management and Delivery (PMAD), energy dense smart battery, and high-performance solar Maximum Power Point Tracker (MPPT)
• NRL delivering expertise in advanced optoelectronics/photovoltaics and thermal soaring algorithms
• Test flights at Aberdeen Proving Ground and Cape Canaveral: aircraft flew 11 hours from sunrise to sunset
• Advance to OECIF project targeting a larger airframe and longer, multi-day flights

Kraus Aerospace, a developer of long-endurance Unmanned Aerial Systems (UAS), integrated Packet Digital’s MPPTs into their solar-covered wings to provide high-efficiency solar power management for their fixed-wing aircraft.

“We consider the Packet Digital Maximum Power Point Tracker to be a key technology component of our aircraft. We have 100s of hours of flight time using the MPPT and it has been bulletproof for us”. – Kraus Aerospace

Status LED

CAN Communication

Broadcasted Data Types

The following data types are broadcast once per second.

• NodeStatus – Link
• Stream
  • Default data type ID: 20009
  • This is a non-standard UAVCAN datatype, the dsdl definition is included below:

#
# MPPT streaming data, transmitted at 1Hz
#

uint8 OV_FAULT = 1 # over-voltage
uint8 UV_FAULT = 2 # under-voltage
uint8 OC_FAULT = 4 # over-current
uint8 OT_FAULT = 8 # over-temperature
uint8 fault_flags

int8 temperature # [Celsius]

float16 input_voltage # [Volt]
float16 input_current # [Amp]
float16 input_power # [Watt]

float16 output_voltage # [Volt]
float16 output_current # [Amp]
float16 output_power # [Watt]

Supported Service Requests

• GetNodeInfo
• ExecuteOpCode
• GetSet
• RestartNode

OutputEnable

Full name: uavcan.thirdparty.mppt.OutputEnable

Default data type ID: 240

This is a non-standard UAVCAN datatype, the dsdl definition is included below:

#
# Service to enable or disable the mppt output
#

void6

# If both enable and disable are true then no change is applied
bool enable
bool disable

---

void7

# The new enable state after applying the reqeust
bool enabled

Node Parameters

uavcan.node_id

This parameter sets the node ID for this MPPT. If set to 0 dynamic ID allocation will be used. Requires restart to take effect.

Default value: 0
Minimum value: 0
Maximum value: 127

mppt.dcdc_en

This parameter controls whether the MPPT output is enabled automatically when powered on.

Default value: 1
Minimum value: 0
Maximum value: 1

mppt.dcdc_algorithm

This parameter selects which maximum power point tracking algorithm is used. This does not take effect until the next time the output is turned on.

0: Perturb and Observe
1: Reserved
2: Constant voltage test mode – the MPPT maintains a fixed output for stable conversion efficiency measurements. There is no maximum power point tracking in this mode, however all of the sensors and software functions remain active for accurate measurements. This is intended to be used with a controlled load on the output – do not use in a live system.
3: Integrated Adaptive Step Search (default)
4: Reserved

Default value: 3
Minimum value: 0
Maximum value: 4

mppt.vout_set

Sets the maximum output voltage when the battery is fully charged. This does not take effect until the next time the output is turned on.

Default value: 47.0
Minimum value: 12.0
Maximum value: 54.0

mppt.cvt_set

Sets the output voltage when operating in constant voltage test mode. This does not take effect until the next time the output is turned on.

Default value: 45.0
Minimum value: 12.0
Maximum value: 54.0

mppt.impedance_comp

This parameter sets the resistance value used for impedance compensation on the output voltage. This does not take effect until the next time the output is turned on.

Default value: 0.0
Minimum value: 0.0
Maximum value: 1.0