Properties | GridTrak Open Source PMU (GTosPMU) | OpenPMU |
Technology | Voltage reference crossings converted to digital and directly timed |
ADC and DSP (FFT) |
Hardware | dsPIC30F3013 Micro Controller based Open Source PMU Sensor Kit |
National Instruments NI-DAQ, Sound Card, or other DAQ with custom OpenPMU GPS Clock & Sampling Trigger |
Firmware |
Microchip C30, 16bit, open source code provided |
GPS Clock – Microchip C18 |
Software |
Open Source C# .NET host PC application for sensor configuraiton and local observation and data recording, compatible with openPDC and IEEE C37.118-2005 compliant software |
Open Source Python code library |
GPS | Optional - Integration testing scheduled for March 2011 |
GPS or other UTC 1PPS source required |
Availability | Available February 2, 2011 as Kits and Assembled Sensors |
Summer 2011 (expected) |
Project Life Cycle | R&D work in progress for at least 3 years from Jan 2011 |
Continuous development |
Cost | Kit = $150, Assembled = $500 (USD) (GPS not included at this time) |
~ $400 (less if using existing NI-DAQ) |
More Info Contact | Arnold Stadlin | clockdoctor |
Performance | ||
Signal Input | 9-12 V AC/AC Linear Transformer, Adapters work for foreign conversions |
3-phase & neutral voltages and currents |
Measurements | AC Voltage, single phase per sensor, Voltage Reference Crossings |
14-bit, +/- 10 V |
Measurements Rate | Measurements are made each AC cycle |
240 samples / cycle at 50 Hz (200 at 60 Hz) |
Minimum Sample Time | 1.2 AC Cycles, consecutive cycles overlap by about 20% |
FFT uses minimum 2 cycles, sliding window |
Nominal Frequency and Range | 50Hz or 60Hz +/- 1.0% |
50 Hz / 60 Hz +/- 1.0% |
Packet Transmission Rate | Design Maximum = 60, Reliably Tested = 20 packets per second |
50 / 60 Hz, 25 / 30 Hz, 10 Hz |
Data Connectivity | RS232 115200 bps over Serial Port or Serial/USB adapter |
UDP/IP using NMEA style plain text |
Power Requirement | 9-12V AC/AC Linear, non-Switching, Transformer is shared between input signal and circuitry. Optional +9V DC backup battery. Optional +5V DC. Jumper for isolating the signal input from the circuit power supply. |
30 W auxiliary mains supply |