Embedded System Development – Power Grid Condition Monitoring

Client – Power Distribution Grid Monitoring – Smart Grid Equipment Manufacturer

Capabilities Demonstrated

Challenge

The client was experiencing backplane-based serial communication problems within their early/initial production units. The Design Services provider that had completed the subsystem hardware design had become progressively less responsive. They were unable to provide the necessary level of engineering support to diagnose the root cause issues.

The client approached AppliedLogix to critically assess the entire embedded system design, summarize our findings and recommendations, and then update the design as needed to meet their operational reliability level targets.

The entire effort was deemed time-critical as it was imperative that the client resolve the system reliability issues that their end-customers (key early adopters) were experiencing.

The AppliedLogix team needed to:

1. quickly and comprehensively evaluate the failure modes,
2. brainstorm and nail-down the root causes of failure, and then
3. develop a series of design updates/improvements to eliminate the reliability issues.

Solution

The AppliedLogix team completed what is best described as a complete refresh of the embedded hardware platform combined with targeted software updates. The project was completed in 3 sequential phases:

1. Detailed assessment/analysis coupled with system design modifications recommendations.
2. Design execution of the full set of “production intent” HW and SW updates.
3. Supported the client’s functional and environmental testing (within their test facilities) followed by “final production” design updates.

Benefits

• The updated hardware and software design eliminated the reliability issues, enabling the client to retain their early adopters and grow their customer base.
• Delivering the flexible backwards compatibility enabled a mixture of new/old board revisions, thereby enabling the customer to avoid scrapping their entire PCBA inventory.

System Overview

The client’s embedded system deploys novel sensor technologies for the real-time / continuous condition monitoring of power transmission lines. Each three-phase sensor system provides high precision, simultaneous 3-phase measurements of voltage and current (from ~ 5kV to 35kV).

The measurement system capture/compute/comm node comprises (5) unique board types:

• Custom Backplane board – 6-slot with hot swap support (6-layer, controlled impedance).
• Main Processor board with TI OMAP processor, LP DDR2 memory, Spartan6 FPGA, 10/100 Mbit ethernet, NAND Flash, Micro-SD, USB 2.0 (10-layer, via-in-pad, controlled impedance).
• Power Board.
• Analog Input Board.
• Analog Sensor Board.

To achieve the reliability goals, AppliedLogix updated/enhanced the circuit design and PCB layouts for each of the (5) unique board types. The design updates included optimizations for DFM and DFT as mandated by the high-volume production targets.

The hardware and software were modified in a manner to support “flexible backwards compatibility”, i.e., a mixture of new/old board revisions (new backplane with old processor and sensor boards, new backplane with new processor and old sensor boards, etc.). The new software supported all valid permutations from a single binary installation package – obviating the need for the user to customize their software installation procedures based on what combination of hardware boards were installed.