Air Compressor Control for Industry 4.0
We are in the midst of the fourth industrial revolution, or, as it is known in Germany, Industry 4.0. In broad terms, the concept describes manufacturing facilities where all of the machines — including the air compressors, along with their corresponding sensors and air treatment equipment — communicate with each other autonomously, recording performance metrics to a local controller, a wireless network, and an external database. These communicative abilities are enabled by the Industrial Internet of Things (IIoT), in which intelligent, networked devices link everything back to a main data hub.
A factory with that type of machine-to-machine communication and real-time data analysis has the foundation for two essential future-oriented capabilities: Predictive maintenance, and continuous energy efficiency optimization.
Perhaps the most important aspects of an Industry 4.0 compressed air system are its master controller, and the ability of the units to collect and communicate data. As the central hub of intelligence, the controller constantly monitors compressed air system performance and displays vital parameters in real-time. In addition, these comprehensive system controls have the ability to use that information to efficiently and reliably guide compressor performance, and provide the information to management.
Earlier this year, Kaeser Compressors introduced its new master control system, Sigma Air Manager 2 (SAM 2), which boasts a bevy of upgrades geared for Industry 4.0. The team at Compressed Air Best Practices® Magazine was fortunate enough to speak with Kaeser’s Werner Rauer and Michael Camber about SAM 2. During our conversation, they discussed the development of the controller, its new capabilities, and how it fits within the context of Industry 4.0.
Kaeser’s newly introduced SAM 2 master control system. - Click here to enlarge
Future-Oriented Capabilities, Years in the Making
In 1998, Kaeser put an industrial PC inside a standard air compressor. The PC provided the basics: analog and digital inputs and outputs, connectivity, and some memory, enabling Kaeser personnel to evaluate the compressor, using both historical and current data. Two years later, the company developed the first Sigma Air Manager (SAM), an improved “watch dog” for compressed air systems.
During the following years, SAM’s software evolved on a frequent basis to provide the customer with the latest in technology — until the hardware could no longer support additional functions. SAM 2 is the required next step in development, and provides a dramatic improvement in hardware to allot for the complex computing capabilities required by Industry 4.0.
“When looking at the next 10 to 15 years, you need to lay the foundation today,” Werner Rauer, Compressors Product Manager at Kaeser, explained. “So at this time, we have put a highly capable processing unit in this industrial PC.”
The boost in computing power allows SAM 2 to communicate with the compressor room much faster — gathering more details at more data points (10 to 18 million data points per day per compressor). This provides three things:
- More energy-efficient and reliable supply of compressed air
- Remote monitoring and data extraction for making management decisions
- Predictive maintenance capabilities
“[The] predictive maintenance capabilities could — if the customer chose the option — activate an automated service response,” said Michael Camber, Marketing Services Manager, Kaeser. “So, if there is a problem with one of the units, the system would know which compressor, which parts to pull, create a service order, and have someone dispatched to the location — before the customer knew there was a problem.”
SAM 2’s newest core feature, the 3Dadvanced Control scheme, helps optimize energy efficiency on a continuous basis. The 3Dadvanced Control provides real-time analysis of how the compressed air system worked in the recent past, how it is operating now, and — in similar fashion to a chess computer — the controller then calculates thousands of possible operating scenarios. After running the numbers, the controller selects the best configuration and acts accordingly — all within a split second.
Touch Screen, Automated Reporting and Advanced Networking
Many end users requested a color touch screen for simple navigation (think iPad). Now integrated into SAM 2, the touch screen provides a live piping and instrumentation (P&I) schematic of the compressed air system, displaying each component and its status.
Pictured is a screen shot of the P&I schematic provided by SAM 2. - Click here to enlarge
Built-in, automated reporting capabilities are in high demand, so SAM 2 — like its predecessor —can send email alerts as part of a preventative maintenance schedule, or for emergency situations. It also provides added security, leveraging radio frequency identification (RFID) technology on equipment cards to prevent unauthorized personnel from gaining access.
SAM 2’s advanced networking capabilities run through industrial Ethernet. With that connectivity, you can examine your system’s performance directly from your laptop (and eventually your smartphone). Additionally, SD and CF cards are no longer necessary, as the control system features a large internal memory capable of storing system data as far as one year back, depending on the system.
Connecting to the Cloud
While end users can store data locally, they get the most out of SAM 2 by connecting to the cloud. The automatic and continuous energy optimization and predictive maintenance functions are dependent on analyzing and acting on the massive amounts of data collected by SAM 2. By constantly uploading operational data to the secure Kaeser Data Center, located at Kaeser’s headquarters in Coburg, Germany, end users can benefit from in-depth analysis and performance recommendations.
“It’s one thing to have the data, but you also need the processing power and the algorithm to actually do something with the data,” Rauer explained. “So it’s not just a matter of storing it, but you have to actually crunch the numbers, and that’s what the Kaeser Data Center is doing.”
Let’s say, hypothetically, the Kaeser Data Center had a two-year history of your compressor’s operation. If you were monitoring motor temperatures, the logic would compare ambient temperatures with motor temperatures. If it is the same ambient temperature for three days in a row, but the motor increases in temperature on the third day, SAM 2 would detect the issue and send an alert.
“All of these algorithms will be there in the future, and it will automatically raise the flag,” Rauer said. “Then, either with or without human interaction, the Data Center will spit out a report, a recommendation, or it will send a service tech on his way. That is the future when you are talking about the massive amount of data that the controllers in the compressors and the individual sensors will provide to the data center.”
Installation and Integration
To account for the ever-changing demand of modern manufacturing facilities, SAM 2 is modular, allowing the end user to easily adapt the controller to changes in the plant equipment.
“It used to be that we had the SAM 4, SAM 8, and the SAM 16, and every time you matured from four compressors to six, you had to remove the old hardware and put new hardware on the wall,” Rauer explained. “With today’s technology, you do the upgrades pretty much with software only.”
“Plug-and-play” capability has reduced physical integration time compared to the older version of SAM. Industrial Ethernet cables are much easier to install than cumbersome relays, and the controller arrives pre-programmed using information from an extensive customer questionnaire.
“It used to be that you had to program the SAM once you installed and connected it,” Camber explained. “Now, given the correct parameters of the equipment that is going to be connected, we do the programming here so that when it arrives it is ready to connect and run. That’s something new and cost-effective for the customer.”
Even with plug-and-play capability, the controller still takes some time to acquire enough historical data for the controller to manage the compressed air system optimally.
“When you start it up for the first time, [SAM 2] doesn’t even know where it is, and it has no history,” Rauer explained. “Based on our experience, it takes a minimum of twenty minutes, maybe an hour. SAM is looking at what is going on with your pressure, what is going on with your supply, and it calculates how the pressure is reacting to different compressor configurations and fluctuations in the system.”
What Types of Systems Can SAM 2 Control?
Compatibility is an important topic, not only in regards to brands, but in terms of the size and type of compressor system. SAM 2 can control compressor, blower, and vacuum systems with up to 16 machines, along with the auxiliary equipment. According to Rauer, it can monitor “dryers, drain traps, dew point meters, and flow meters.” Whatever it is, you just have to add I/O modules.
The most robust monitoring capabilities come naturally with modern Kaeser compressors. However, SAM 2 is capable of monitoring most any brand compressor, along with older units, so long as you provide the I/O.
“We can certainly also hook up 1984 Kaeser units, and competitive units,” explained Rauer. “But in order to do that, you need to have a compressor that allows remote control and provides some feedback in terms of motor running, load/unload, and whether it has a malfunction or not.”
SAM 2 can also distinguish and properly apply three differently sized variable speed drive units — in particular with a Kaeser system where everything from the SAM and the onboard Sigma Control 2™ compressor controller all the way to the Siemens Sinamics drive is understood and monitored.
Managing Important System Metrics
SAM 2 has the ability to monitor nearly every aspect of a compressor system. The real trick is to evaluate the most important metrics.
During our conversation, Rauer explained what a sample report would include: “I can pick a day, and [SAM 2] tells me how many hours the compressor was either loaded or unloaded (total hours), how many kW-hours it consumed, the energy cost based on how much I pay for it, and then it spits out the total volume for the timeframe — how many millions of cubic feet it was. And then, the most important one, the specific power, which will be in kW/100 cfm.”
The real-time charts on SAM 2 help put compressor performance into context. - Click here to enlarge
According to Rauer, the most important metrics to monitor are: pressure, flow, power, cost, and, most importantly, system dynamics.
“System dynamics is probably the most important, but it’s never talked about other than by some experts on LinkedIn,” he explained. “When people have a very flat average use over the whole day, it is way different than when you have a facility that routinely uses a ton of compressed air all at once. You have two choices to manage it: You either have lots of compressors that you need to turn on just to do this, or you store the compressed energy in a dedicated storage receiver tank. Both of those have a different solution in terms of energy savings.”
In regards to optimizing energy efficiency, the team at Kaeser had another important message: SAM 2, or any other master controller, will not be the ideal solution every time.
“Without studying the system dynamics, and doing an air demand analysis, it’s very difficult to just simply say: ‘Yes, SAM 2 will help,’” Rauer told us. “I say the same thing about flow controllers: ‘No it’s not always the best solution.’ SAM can only employ what you give it to deal with. If you give it four identically sized compressors, you cannot expect a miracle in improved power performance if none of them has a good specific performance to begin with, in particular in part-load.”
Only a comprehensive system analysis will help determine what will help improve your facility’s energy efficiency and reliability.
“It’s really about overall best practices, and a lot of it has to do with pressure,” Camber explained. “There are certain physical facts that if you are running at higher pressures, your specific power will not be able to get as low as if you were running at a lower pressure, generally speaking. So, it’s really about looking at a particular system and optimizing it.”
Energy Management and Quantifying Results
While SAM 2 provides detailed analysis, it does not provide, or quantify, energy savings. Instead it gives end users a “continual energy audit,” which is a major advantage over a one-time, weeklong audit.
SAM 2 provides end users with energy costs in real time. - Click here to enlarge
As part of the continuous energy auditing, SAM 2 generates simple and easy-to-read graphs and charts. Data collection is a major part of Industry 4.0 and IIoT, but understanding the data is not always an easy task. SAM 2’s reports help end users understand exactly what is going on with the compressed air system, and they make that information available to everyone. This facilitates data analysis and simplifies finding trends in power consumption, system performance, and energy efficiency.
Laying the Groundwork for Industry 4.0
Laying the foundation for the future-oriented capabilities of Industry 4.0 is important, and that is exactly what Kaeser has done with SAM 2. While the compressor control system currently only monitors the supply side of a compressed air system, the hardware and intelligence is now in place to start branching out to every facet of the system — including countless end-use applications.
As tighter energy management regulations — like ISO 50001 — become more commonplace, it will be vital to have a firm grasp on how and where compressed air is used. In addition to providing comprehensive oversight of the supply side, SAM 2, in the future, will be able to report on where, when and how much compressed air is used at any given point of use, along with the the amount of energy required.
“The Department of Energy is looking into ISO 50001 as well,” Rauer told us. “Every company needs to be responsible for knowing what type and the amount of energy they are using in each part of their plant.”
SAM 2, with its ability to determine the best way to control a compressed air system, and its energy monitoring features, could help adhere to that standard. Depending on the system, it could also provide a significant ROI — especially for facilities with fluctuating system dynamics.
To read more about Compressor Controls, please visit www.airbestpractices.com/technology/compressor-controls.