GOMspace NanoPower P60 ACU 200 User manual

NanoPower
P60 ACU 200
Manual
Software Documentation
Release 2.0.2

Product name: NanoPower P60 ACU 200
Document No.: 1018434
Revision: 2.0.2
Author: Gomspace
Approved by: Gomspace
Approval date: 2023
Confidentiality Notice
This document is submitted for a specific purpose as aggred in writing and contains information, which is
confidential and proprietary. The recipient agrees by accepting this document, that this material will not be
used, transferred, reproduced, modified, copied or disclosed in whole or in part, in any manner or to any third
party, except own staff to meet the purpose for which it was submitted without prior written consent.
GomSpace © 2023

Table of Contents
1 Introduction 1
1.1 Unpacking and Handling Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Overview 2
3 Command Interface 3
3.1 GlobalSettings.............................................. 3
4 Operation 4
4.1 BoardParameters............................................ 4
4.2 ConfigurationParameters........................................ 4
4.2.1 ChargingControl ........................................ 4
4.2.2 Hardwareprotection ...................................... 5
4.3 CalibrationParameters ......................................... 5
4.4 TelemetryParameters.......................................... 6
4.5 Configuration............................................... 6
4.6 GroundWatchdog............................................ 6
5 Client API 8
5.1 CSPPortNumbers ........................................... 8
5.2 Get and Set Configuration Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.3 Retriving Housekeeping Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.4 ResetGroundWatchdogTimer .................................... 10
6 Parameter Tables 12
6.1 Table0:BoardParameters....................................... 13
6.2 Table 1: Configuration Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.3 Table 2: Calibration Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.4 Table4:Telemetry............................................ 14
© 2023 GomSpace A/S. All printed copies, and all electronic copies and versions except the one accessible on
the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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© 2023 GomSpace A/S. All printed copies, and all electronic copies and versions except the one accessible on
the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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1. Introduction
The GomSpace NanoPower P60 EPS is a flexible and modular system to rapidly implement power supply
systems based on customer requirements. The P60 ACU-200 is part of the NanoPower P60 EPS modular
power supply system.
This manual describes the P60 ACU-200 firmware version 2.0.2:
• Command Interface
• CSP Client API
• Parameter Tables
1.1 Unpacking and Handling Precautions
Warning The P60 ACU-200 is an ESD sensitive device. Proper precautions must be observed
during the handling of the device.
Please use an ESD mat and a wrist strap as a minimum. Please wear gloves to avoid fingerprints on the
anodized aluminum parts, as these are particularly difficult to rinse off. If any cleaning of the parts are required
prior to flight, use only ESD safe cleaning methods and a neutral, non-reactive, IPA solvent.
© 2023 GomSpace A/S. All printed copies, and all electronic copies and versions except the one accessible on
the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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2. Overview
The P60 ACU-200 can be operated through the Cubesat Space Protocol (CSP) over CAN, I2C or serial port.
This integrates well with other GomSpace products, and GomSpace provides a client library for commanding
the P60 ACU-200 from other systems running CSP. Refer to the Client API page for documentation of the client
library API.
For integration and testing purposes, a command line interface is also available as explained in Command
Interface. The command line interface uses the client API internally, so command names generally reflects the
API function names.
The block diagram below shows the different P60 ACU-200 modules.
Fig. 2.1: P60 ACU-200 Block Diagram
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the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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3. Command Interface
For testing and debugging purposes, the P60 ACU-200 can be operated using the GomSpace Shell (GOSH)
interface. The console interface is available in the FPC Debug connector. The serial connection is 8 databits, 1
stopbit, no parity at 500000 baud. On Linux, the serial connection can be opened using the minicom or tio tools
(tio was formerly known as gotty).
You can now execute commands in the GOSH command interpreter. An example command is cmp ident
which lists identification info of the current subsystem:
p60-acu # cmp ident
Hostname: p60-acu
Model: NanoPower P60 ACU-200
Revision: v1.0
Date: Jun 10 2016
Time: 09:53:08
A list of available commands can be shown by running the help command in GOSH. Pressing the tab key
automatically completes commands and subcommands, and shows a usage string. Commands specific to
the P60 ACU-200 are assembled under the p60acu command group. These commands are also available in
csp-term for operating the P60 ACU-200 via CSP:
p60-acu # p60acu
node Set P60 ACU node address
timeout Set timeout in milliseconds
hk Retrieve and list all housekeeping parameters
gndwdt_clear Clear GND WDT
Note: All of the p60acu commands run over loopback CSP using GOSH command wrappers around the Client
API
3.1 Global Settings
The P60 ACU-200 command line interface is written such that there are a few global variables that can be set
first. The default values of the variables are:
• The P60 ACU-200 CSP address is set to 2.
• Timeout is set to 5000 ms.
These values can be set using the p60acu node <node> and p60acu timeout <timeout>. To show the
current setting, run each command without an argument.
© 2023 GomSpace A/S. All printed copies, and all electronic copies and versions except the one accessible on
the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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4. Operation
The P60 ACU-200 has three configuration parameter tables:
• Board parameters (table 0)
• Configuration parameters (table 1)
• Calibration parameters (table 2)
P60 ACU-200 telemetry parameters are available in parameter table 4.
See Parameter Tables for details on the individual parameter tables.
4.1 Board Parameters
The Board parameters will normally be configured from factory.
The P60 ACU-200 does not support RS422 USART and rs422 should is set to 0.
CSP address is controlled by the parameter csp_addr. The default CSP address is 2 for the P60 ACU-200. If
multiple P60 ACU-200 modules are included, they will need to use different CSP address.
4.2 Configuration Parameters
The P60 ACU-200 power point tracking can either be Fixed or Tracking mode. This is controlled by the parameter
mppt_mode. To use Fixed mode, set mppt_mode to 2. To use Tracking mode, set mppt_mode to 1.
The P60 ACU-200 module has a total of 6 input channels.
For each input channel, the fixed power point voltage level used for charging the battery can be set by the
parameter vboost[].
In Fixed mode, the voltage is set to the value of parameter vboost[] and is not changed, except if battery
charge is completed.
In Tracking mode, the voltage is initialized to the value of parameter vboost[]. By tracking the power, the input
voltage is regulated to optimize the power generated by the input channels. It is possible to limit how much
the voltage is changed from the initial vboost value. This is controlled by the parameter max_dv. E.g. if the
vboost[] is set to 10000 mV and the max_dv is set to 5000 mV, the minimum voltage allowed will be 5000 mV
and the maximum will be 15000 mV.
In both modes, the lower limit for vboost[] is 4300 mV and the upper limit is 27000 mV.
4.2.1 Charging Control
When the battery becomes fully charged or near to fully charged, the charging will be regulated to avoid over
charging the battery. This is controlled by two parameters, vbat_max_hi and vbat_max_lo. When the
battery voltage exceeds vbat_max_lo, the P60 ACU-200 will regulate the voltage down slowly to reduce the
charging power. If the charging continues, even with reduced voltage, and the vbat_max_hi limit is reached,
the charging will be reduced to a minimum. Charging will not be resumed until the battery voltage drops below
vbat_max_lo. The following table lists the recommended values for vbat_max_hi and vbat_max_lo for 8,
16 and 32 V battery.
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the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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Table 4.1: Recommended settings for vbat_max_hi and
vbat_max_lo
Battery Pack Voltage 8 V 16 V 32 V
vbat_max_hi 8300 mV 16600 mV 33200 mV
vbat_max_lo 8150 mV 16300 mV 32600 mV
The ov_mode defines the photovoltaic converter behavior of the P60 ACU-200 when the battery is fully charged,
i.e. above the vbat_max_hi value.
When the battery voltage is above vbat_max_hi, the charging is minimised by setting the vboost voltage level
to the maximum value (27000 mV) or the minimum value (4300 mV), depending on the parameter ov_mode. If
ov_mode is 1, the vboost voltage level will be set to the minimum value (4300 mV). If ov_mode is 2, the vboost
voltage level will be set to the maximum value (27000 mV).
The default ov_mode is 2, defining that the photovoltaic input is open circuited when the battery is fully charged.
This mode is used on all spacecrafts with 8V, 16V and 32V battery pack, as long as each photovoltaic input
open circuit voltage is guaranteed to be below the maximum operation voltage of the battery pack. E.g. a 8V
battery pack requires an open circuit photovoltaic of no more than 8400 mV.
In special cases it may be desired to have a photovoltaic array with an open circuit input voltage slightly above
the max. battery voltage. If such a case cannot be avoided the ov_mode must be set to 1. When ov_mode
is 1, the photovoltaic input converter set point is as low as possible (4300 mV) when the maximum battery
voltage is reached. Note that in this case, a one-string photovoltaic panel (500 mA) still produces about 2.2 W.
It is recommended to have sufficient amount of subsystems powered ON in normal mode to avoid charging the
battery further.
If the battery is charged further, the P60 Dock will disconnect the battery as a final protection method until the
voltage is within safe operation again. Tripping the P60 Dock overvoltage battery protection may cause the
spacecraft to be power cycled, as the available photovoltaic input power might be insufficient.
4.2.2 Hardware protection
Both the P60 ACU-200 and the P60 Dock has hardware protection circuits to protect the battery. The P60
ACU-200 takes this into account when controlling the charging of the battery. If the battery voltage exceeds the
hardware protection high threshold, the charging will not resume until the battery voltage level has dropped be-
low the hardware protection low threshold. For security reasons, the hardware protection low and high threshold
are not configurable, but are listed here for reference:
Table 4.2: Hardware protection thresholds for battery voltage
Battery Pack Voltage 8 V 16 V 32 V
High threshold 8400 mV 16800 mV 33600 mV
Low threshold 7625 mV 15250 mV 30500 mV
4.3 Calibration Parameters
The P60 ACU-200 module has a set of calibration parameters for voltage and current measurements.
The calibrations parameters are configured from factory and normally don’t need to be changed.
For voltages, there is a gain parameter. The gain is a floating-point number.
For currents, there is a gain and an offset parameter. The gain is a floating-point number. The offset is a signed
16-bit integer that controls the offset in mA.
The following table lists the default nominal values for each calibration parameter:
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the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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Table 4.3: P60 ACU-200 Calibration values
Name Voltage gain Current gain Current offset
V IN channel 0 11.0 1.0 0
V IN channel 1 11.0 1.0 0
V IN channel 2 11.0 1.0 0
V IN channel 3 11.0 1.0 0
V IN channel 4 11.0 1.0 0
V IN channel 5 11.0 1.0 0
VBAT 25.0 n/a n/a
VCC 3.2 n/a n/a
DAC channel 0 11.0 n/a n/a
DAC channel 1 11.0 n/a n/a
DAC channel 2 11.0 n/a n/a
DAC channel 3 11.0 n/a n/a
DAC channel 4 11.0 n/a n/a
DAC channel 5 11.0 n/a n/a
4.4 Telemetry Parameters
The P60 ACU-200 module will provide the measured input voltage and current for each input channel in param-
eters v_in[] and c_in[] respectively. The calculated power is also available in parameter power[]. The
charging voltage is provided in the parameter vboost[].
P60 ACU-200 also measures VCC and VBAT, they available in parameters vcc and vbat. Temperature of the
P60 ACU-200 is measured in three locations on the module and is available in parameter temp[].
The up time measured in seconds is available in the uptime parameter and the number of boots is available in
the bootcnt parameter (see also Parameter Tables for details on the telemetry parameters).
4.5 Configuration
The P60 ACU-200 module has two sets of configuration, the running configuration and the default configuration.
The default configuration is a fallback configuration that will be restored automatically if the ground watchdog is
triggered (see Ground Watchdog)
The P60 ACU-200 has a set of commands to manage the configuration:
p60-pdu # config
status Show FRAM Lock status
lock Lock FRAM upper tables 0x1000 to 0x1800
unlock Unlock FRAM upper tables 0x1000 to 0x1800
gnd_wdt Get or set gnd wdt timeout value
update_default Update default factory settings in FRAM
verify_default Verify default factory settings in FRAM
4.6 Ground Watchdog
The P60 ACU-200 module has a ground watchdog that needs to be activated at least every 48 hours if enabled.
The purpose of the ground watchdog is to enable the P60 ACU-200 to revert to the default configuration if for
some reason the running configuration prevents the P60 ACU-200 from operating.
If the ground watchdog is triggered, the P60 ACU-200 will restore to the default configuration and then do a
reset of the P60 ACU-200.
To enable the ground watchdog and set the timeout value, run the following command form the GOSH terminal:
© 2023 GomSpace A/S. All printed copies, and all electronic copies and versions except the one accessible on
the GomSpace A/S server, are considered uncontrolled copies used for reference only.
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