1. University of Texas at Dallas
REVT |
Renewable Energy and Vehicular Technology Lab
Recent Advances in Distributed Monitoring of HVAC Systems and the Impact on Modern Power Grids
Babak Fahimi, PhD
University of Texas at Dallas

2. Renewable Energy & Vehicular Technology Laboratory
REVT |
Renewable Energy and Vehicular Technology Lab
Renewable Energy & Vehicular Technology Laboratory

3. Renewable Energy & Vehicular Technology Laboratory
REVT |
Renewable Energy and Vehicular Technology Lab
1 post-doctoral scientist, 11 PhD, 3 MS, 2 Undergraduates, 3 visiting scholars
2017 Research Expenditure: $1.2M
2017 publications: 12 journal articles, 25 conference papers, 2 invention disclosures
Scientific Staff
Renewable Energy & Vehicular Technology Laboratory

4. Areas of Research: REVT | Transportation Electrification
Renewable Energy and Vehicular Technology Lab
Areas of Research:
Transportation Electrification
Electric and hybrid vehicle propulsion
Fault tolerant drives
Mobile wireless charging
Maglev and linear drives
Electric aircraft propulsion
Electric marine propulsion
Electric auxiliary drives
Distributed Power Generation
Solar energy systems
Wind energy systems
Energy management
Smart micro-grids
Reliability analysis and life time monitoring
Grid integration
Fuel cell based hybrid power systems
Energy Storage, Management and Harvesting
Remote charging of portable electronics and biomedical devices
Energy scavenging from vibration and solar sources
On-chip power supplies
Prognostics, health management, and control
Battery and ultracapacitor management
Hydrogen harvesting and storage
Power electronics, Motors & Drives
Electric machine design
Permanent Magnet
Switched Reluctance
Induction
Electric drive optimization
Sensor elimination
Noise, vibration reduction
Efficiency maximization
Cost minimization
Fault tolerance
Resonant and multi-level converters
PWM strategies
High freq. dc-dc converters
High and low temperature power converters
GaN, SiC utilization
Low power electronics

5. Corporate Engagement Strategy
REVT |
Renewable Energy and Vehicular Technology Lab
Corporate Engagement Strategy
Industrial Advisory Council
Internships and Entry Level Jobs
UTDesign
Unrestricted Gift
Company Sponsored Research
Institute and Center Projects
Federal Research Grants
Fellowships, Endowed Chairs, Buildings
Your
Company

6. REVT |
Renewable Energy and Vehicular Technology Lab
Modern Grid

7. Evolution of Grid REVT |
Renewable Energy and Vehicular Technology Lab
Evolution of Grid
Source:

8. Integrated Energy Systems
REVT |
Renewable Energy and Vehicular Technology Lab
Integrated Energy Systems
Combined Heat & Power
Heatling Grid
Turbines
Electricity Grid
Hydrogen
Electrolysis
Transportation Fuel
Nat. Gas Pipelines and Storage
Storage
Biogas
Natural Gas Hydrogen
Variable mixing
Gasoline
Diesel
Biofuel

9. Modern Power Systems Challenges
REVT |
Renewable Energy and Vehicular Technology Lab
Modern Power Systems Challenges
Reliability for contingency and uncertainty
Quick dynamic response in the event of a failure
Cyber security
Seamless integration of renewable energy sources
Poor efficiency for end users
Capacity enhancement

10. By 2030 DOE predicts that 20% of US electricity should
REVT |
Renewable Energy and Vehicular Technology Lab
Opportunities
Potential Solar energy map
Potential Wind energy map
By 2030 DOE predicts that 20% of US electricity should
be generated in wind farms

11. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Features:
Distributed generation
Economic dispatching
Reliability
Disaster mitigation
Power quality improvement
Communication
Cyber security protocols

12. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)

13. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Base Power Management – Intelligent hybrid microgrid

14. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Base Power Management – Intelligent hybrid microgrid
Multi-Port Electronics Interface (MPEI)
Solar-Expansion
Generator-Expansion
Wind Turbine-Expansion
Battery-Expansion
Expansion Slot
Minimal Storage
Solar Array
Diesel Generator
Wireless Communication
Expansion potential includes:
Solar Module(s)
Diesel Gen-set Module(s)
Wind Turbine Module(s)
Fuel Cell Module(s)
Energy Storage Unit(s)
Battery
Flywheel
Others
Scales from Watts (for electronic loads) to kW (Forward Operation units) to MW (Base Systems)
Wind Turbine
Battery Storage System

15. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Base Power Management – Intelligent hybrid microgrid

16. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)

17. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Remote computation and Data analytics
Transferring computational resources to a remote location
reduces hardware requirements
provides access to unlimited computational capability
allows long term field data collection and analysis
Applications:
Supply-demand management
Economic dispatching
Disaster mitigation
Remote fault diagnosis
Fault prediction/prevention
Improvement of grid reliability

18. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Remote computation and Data analytics
Source: Calculation of Voltage Sag Indices for Distribution Networks. Juan A. Martinez-Velasco, Jacinto Martin-Arnedo
Change in Frequency spectrum

19. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Remote computation and Data analytics
Feature 1
Feature 2
Feature 3
Feature 4
Feature 5 …
Example1
Time
Weather
Voltage 1_1
Current 1_1
Voltage 1_2
Example2
Voltage 2_1
Current 2_1
Voltage 2_2
X =
Example solution: The voltage sag experienced in Richardson around 6pm during bad weather usually leads to an outage!

20. Multi-port Power Electronic Interface (MPEI)
REVT |
Renewable Energy and Vehicular Technology Lab
Multi-port Power Electronic Interface (MPEI)
Availability of variable output ports
Critical
Sub-critical
Normal load
Capability of variable output signals
Normal load
Variable load – Integrated adjustable speed drives: pool pumps, AC compressor
Modularity

21. HVAC Concentration REVT |
Renewable Energy and Vehicular Technology Lab
HVAC Concentration

22. REVT |
Renewable Energy and Vehicular Technology Lab
HVAC systems
HVAC is the largest source of residential energy consumption in the United States, 47% of total household energy requirements (source: U.S. Energy Information Administration)
-Value
Market size
Rate of increase of HVAC equipment = 6.8% annually
HVAC equipment market size, year 2019 = $20.4 billion
(Source: “HVAC Equipment” - Freedonia)

23. REVT |
Renewable Energy and Vehicular Technology Lab
Value
Environmental impact – Out of the total household energy consumption, Central AC is responsible for around 30%. Presented in the figure below is the total and residential energy breakdown (source: “Energy savings potential and opportunities for high-efficiency electric motors in residential and commercial equipment US Dept. of Energy).
Total energy consumption breakdown of US in 2012
Residential energy consumption breakdown of US in 2012

24. REVT |
Renewable Energy and Vehicular Technology Lab
Typical System
Current HVAC systems, mostly residential units, utilize line start induction motors.
Compressor
Evaporator
Condenser

25. REVT |
Renewable Energy and Vehicular Technology Lab
-Current Technology
HVAC system can play a substantial role in providing a flexible load in the utility network. This flexibility , in the form of a commitment, is equivalent to that of distributed generation and will potentially allow small consumers of electricity to play an active role in setting the market prices and overall stability of the distribution system. However, to effectively exploit this opportunity, a hybrid (cyber-physical) layout is necessary. The main elements of such systems include:
An adjustable speed driver.
A bi-directional communication platform supported by cloud computing and machine learning algorithms.

26. Conventional Variable Frequency Drives
REVT |
Renewable Energy and Vehicular Technology Lab
VFD
The current HVAC compressor motors are mostly line start induction machines without drive electronics, allowing only binary configuration of “On” or “Off”. To satisfy the government set regulations and to gain the market edge, the HVAC manufacturers are continuously trying to improve efficiency (SEER ratings). Hence, inevitable shift of industry trend towards VFDs is apparent. VFDs reduce energy consumption by matching the heating/cooling load with the HVAC system output. However, introduction of drive electronics alters the efficiency, reliability, and cost of the overall system. The typical topology utilized by VFDs are rectifier – inverter circuits with DC bus capacitors, as shown in figure 1 (for single phase inputs).
VFD market size for = $1.08 billion.
Conventional Variable Frequency Drives

27. Monitoring system Aggregator REVT | 11230 Btu/h – 3290 W Sensor array
Renewable Energy and Vehicular Technology Lab
Monitoring system
11230 Btu/h – 3290 W
1125 W (Input Power)
Sensor array
VFD
Aggregator
Sensor Cluster
Some Data filtering
Communication Channel
Data Parsing
DB Storage
Computation
Analytics

28. Hardware Specifications: Power level – Up to 3kW. Input – Grid.
REVT |
Renewable Energy and Vehicular Technology Lab
Hardware
Sensor Type
Location
Voltage
Machine Phase input, Electronics
Current
Machine T.
Machine frame, Electronics
Grid input/User behavior
Ambient T.
Aggregator
Humidity
Pressure
Vibration
Aggregator/Machine Frame
Specifications:
Power level – Up to 3kW.
Input – Grid.
Output – Up to 3 motors control outputs.
MCU – TMSF28335
Sensors – Voltage, Current, on boards Temperature and Humidity sensors
Peripherals – Analog interface, I2C and SPI communication.
Current Sensors
Voltage Sensors
Temp. & Humidity Sensors
Sensor Outputs, I2C, SPI

29. Communication REVT | Services
Renewable Energy and Vehicular Technology Lab
Communication
Services

30. Communication Data Base REVT |
Renewable Energy and Vehicular Technology Lab
Communication
Data Base
Data is stored with a node identifier (3) followed by a time stamp ( :58:36) for query purposes.

31. Induction Motor Fault classification using neural networks
REVT |
Renewable Energy and Vehicular Technology Lab
Software/Algorithm
Induction Motor Fault classification using neural networks
Training the Neural Network: requires a set of data for which the result is known to deduce a model/feature weights depending on this data. This data is then used to predict future outcomes.

32. Based on collected, 3 tier filtered data.
REVT |
Renewable Energy and Vehicular Technology Lab
Software/Algorithm
Characteristics of the compressor motor:
Single speed operation.
Multiple on-off cycles.
High inrush current.
Main Faults
Based on collected, 3 tier filtered data.
Inter Turn Winding Fault - Temperature and Current.
Bearing Fault - Vibration signature.
Output: classes, where each class represents the category of interest
Inter Turn Fault
Bearing Fault
Additional Fault
Depending on the prediction accuracy of the model, a time function will be used (based on DB data – run the algorithm few seconds before the fault occurs) for fault Protection

33. REVT |
Renewable Energy and Vehicular Technology Lab
Thank you!!