The Next Generation of the intelligent PDU

Rongwangmq@gmail.com   412-400-2105

  I have been developing the core architecture for next-generation intelligent PDU and switchgear products, aiming to reduce hardware costs by 5 to 10× while decreasing communication latency and heat dissipation 

Background

 As of today, more than 95% of AC loads are not monitored in most facilities— even in data centers the coverage is far below 50% —primarily due to the prohibitive cost of AC power monitoring devices ($1500 - $3500).It should be lowered, and can be lowered by 5-10 times.  

Proposal:
  My hardware core architecture is using a $10 newly released ARM Cortex-M7 MCU model,such as STM32H753ZI to design a 24-48+ channel PDU/Switchgear, replacing groups of (MCU+Meter IC) in today's design, to cut the hardware cost by a factor of 5 to 10, also reducing communication latency and heat dissipation.

  The new type of ARM Cortex-M7 MCU itself contains 60- 90 SAR ADC input channels. By adding an analog multiplexer such as the ADG732 ($5/per), additional 32 ADC channels can be monitored by the same MCU. 

  In recent years, Renesas, NXP, STMicroelectronics, Microchip, and Infineon... all introduced this type of MCU.

  Without meter IC, the general purpose SAR ADC only provides sampled V's, I's. I have my new numerical algorithm to accurately compute RMS voltage,RMS current,Active Power,Reactive Power,Apparent Power,Power Factor,Period,and Total Harmonic Distortion (THD) ....for each load channel. 

  By using DSP DMA,the DSP sampling and the numerical computing can happen simutanously. The M7 MCU has enough power to do many other things.

  My firmware with my PC GUI software has been successfully running in the STM32H753ZI evaluation board (Nucleo-H753ZI).The error due to my algorithm itself is less than 0.1% when inputting the accurate data.It can be placed into a mechanic PDU to form a prototype Intelligent PDU with connected CTs to test, to debug, to certify. 

  The SAR ADC generates more noise than Sigma-Delta ADC, which can be taken care by the hardware configurations hardware work. 

  Vertiv Inc has released this new type of PDU products using the MCU made by NXP.But they have to use dual core version MCU (Expensive!) to reach 0.5% accuracy since their algorithm is not good enough. Their single core version PDU's accuracy is 1%. 

  If you are interested in continuing the task, I would be happy to provide my firmware and PC software to support the further development work. 

  Thank you very much!