Progress 09/01/18 to 08/31/21
Outputs
Target Audience:
Nothing Reported
Changes/Problems:As mentioned previously and detailed in the final technical report to NIFA staff, some of our research objectives could not be completed primarily due to COVID-19 impact. Federal stay at home orders and instructions from the grant agency to continue to pay staff during that time, depleted our research budget and funds. Research momentum was lost and supply chain disruptions occurred that limited our ability to get the equipment needed in timely manner before the research budget was exhausted. COVID-19 effectively stopped our research at a crucial time for the last six months of our project, just when major advances were culminating. The PI continued the research effort on his own, after the grant funding was depleted. What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Under the proposed goals, most were accomplished but due to COVID-19, funding instructions, and other complications some goals were not reached. The test turbine was constructed and performed well. The test generator was attached and tuned and we tested scalability in both the permanent magnet generator and the induction motor generator. Both scaled equally well in power output range. During testing, the runner (propeller) for the PMG fractured, likely due to repeated testing (significant back torque was applied to the drive train) and age of the equipment. It was cost prohibitive to purchase a new runner (($80 to 100k) and recasting the missing blade was limited because the foundry could not support the repair due to other projects and limited work staff during COVID. Instead, we fashioned a new blade and welded it in place but the geometry of the repaired blade and runner, when compared to the test runner on the test turbine, were now significantly different and enough so that data could not be directly compared. To mitigate this inability to test "head-to-head", we developed a scheme to test turbine power output (measured as electrical output since the scalability of both generators was essentially equivalent), against water consumed. To do this we installed an open channel water flow meter that would allow us to measure the amount of water entering the turbine and then compared the water flow (usage) against the electrical power output. On both test turbines we found that it required approximately 1.5 CFS of water to produce 1 kW of power at peak efficiency. There was no significant difference in either turbine, or either generator topology. The induction generator worked equally as well as the PMG with the caveat that the test induction generator was belt driven and the PMG was direct drive, so total power output was different due to system losses like power loss in the belt drive.Regardless the "efficiency" of both generator topologies scaled nearly equally when the turbines were operating at their peak output. This is not surprising because the shaft power of the turbine directly correlates with the available power available to the generator. Simple propeller turbines are not very efficient when operated outside of the upper operating ranges. We believe the scalability of efficiency would be much improved in a turbine with a flatter operating range, like a full Kaplan or other, and this would be an opportunity for further research. In this case our technology would very likely increase even further the scalability of those systems. Our conclusion is that our technology provides excellent opportunity for scaled operation using either a PMG or induction generator. Secondary goals included mitigating DC bus variants and using a parallel braking chopper scheme. We effectively demonstrated an excellent (and safe and affordable) method to limit DC bus overvoltages and nuisance tripping. Anecdotally, since installing the braking chopper equipment, we have not experienced a DC overvoltage dropout in over a year now whereas without our design, sometimes we experienced DC overvoltage events several times a day, especially in high grid demand periods when the utility was changing transformer taps multiple times a day to regulate grid voltage variance due to consumer demand. With the induction generator, we also programmed a drop out sequence into the VFD so that as the DC bus voltage approached dangerous levels, the VFD reduced back torque allowing the generator to ride through utility grid glitches up to 200 ms. Additon of the braking chopper is a good idea in any generation scheme but adds several thousand dollars in cost and additional engineering/design/construction/maintenance. The induction generator does not absolutely require this equipment whereas the PMG does and it would be very unsafe to operate without our design. Another secondary goal was to test the ability to change the operation of the turbine from generation to pumping mode. From the electrical side of this task, this is very easy to accomplish. Our VFD inverter system can easily and effectively be installed to control a pump as generator scheme or in a pumped storage installation. Other testing that was originally proposed such as tying in other power sources like DC power from PV panels, and such could not be performed due to the effects of COVID-19. COVID-19 and the federal instructions to continue to pay staff during lockdown effectively depleted six months of our research budget when stay at home orders halted our research and work effort momentum. Further complicating the work effort has been supply chain disruption which continue to the time of this report submission. However, we connected a subsystem VFD, that is used to control a cooling motor, to the DC bus. This demonstrates that the DC bus can be the common point of connection, at least for power take off, for other components in a power system so our VFD inverter technology could easily be installed in a factory setting where a generating source is supplying the DC bus while other components are taking power from the bus. Further, our system allows the grid to interact with the DC so that when excess power is produced, it can be exported and when the internal demands exceed generation capacity, power can be pulled from the utility. COVID-19 also resulted in travel restrictions and nearly all industry events and conferences were cancelled including the events where we intended to promote and discuss our research efforts and data. The unfortunate timing of COVID-19 and our developing technology and research have severely limited our ability to commercialize our very promising technology.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
All trade conferences were cancelled due to COVID-19 so we could not present our findings
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Progress 09/01/19 to 08/31/20
Outputs
Target Audience:
Nothing Reported
Changes/Problems:As mentioned previously and detailed in the final technical report to NIFA staff, some of our research objectives could not be completed primarily due to COVID-19 impact. Federal stay at home orders and instructions from the grant agency to continue to pay staff during that time, depleted our research budget and funds. Research momentum was lost and supply chain disruptions occurred that limited our ability to get the equipment needed in timely manner before the research budget was exhausted. COVID-19 effectively stopped our research at a crucial time for the last six months of our project, just when major advances were culminating. The PI continued the research effort on his own, after the grant funding was depleted. What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Under the proposed goals, most were accomplished but due to COVID-19, funding instructions, and other complications some goals were not reached. The test turbine was constructed and performed well. The test generator was attached and tuned and we tested scalability in both the permanent magnet generator and the induction motor generator. Both scaled equally well in power output range. During testing, the runner (propeller) for the PMG fractured, likely due to repeated testing (significant back torque was applied to the drive train) and age of the equipment. It was cost prohibitive to purchase a new runner (($80 to 100k) and recasting the missing blade was limited because the foundry could not support the repair due to other projects and limited work staff during COVID. Instead, we fashioned a new blade and welded it in place but the geometry of the repaired blade and runner, when compared to the test runner on the test turbine, were now significantly different and enough so that data could not be directly compared. To mitigate this inability to test "head-to-head", we developed a scheme to test turbine power output (measured as electrical output since the scalability of both generators was essentially equivalent), against water consumed. To do this we installed an open channel water flow meter that would allow us to measure the amount of water entering the turbine and then compared the water flow (usage) against the electrical power output. On both test turbines we found that it required approximately 1.5 CFS of water to produce 1 kW of power at peak efficiency. There was no significant difference in either turbine, or either generator topology. The induction generator worked equally as well as the PMG with the caveat that the test induction generator was belt driven and the PMG was direct drive, so total power output was different due to system losses like power loss in the belt drive.Regardless the "efficiency" of both generator topologies scaled nearly equally when the turbines were operating at their peak output. This is not surprising because the shaft power of the turbine directly correlates with the available power available to the generator. Simple propeller turbines are not very efficient when operated outside of the upper operating ranges. We believe the scalability of efficiency would be much improved in a turbine with a flatter operating range, like a full Kaplan or other, and this would be an opportunity for further research. In this case our technology would very likely increase even further the scalability of those systems. Our conclusion is that our technology provides excellent opportunity for scaled operation using either a PMG or induction generator. Secondary goals included mitigating DC bus variants and using a parallel braking chopper scheme. We effectively demonstrated an excellent (and safe and affordable) method to limit DC bus overvoltages and nuisance tripping. Anecdotally, since installing the braking chopper equipment, we have not experienced a DC overvoltage dropout in over a year now whereas without our design, sometimes we experienced DC overvoltage events several times a day, especially in high grid demand periods when the utility was changing transformer taps multiple times a day to regulate grid voltage variance due to consumer demand. With the induction generator, we also programmed a drop out sequence into the VFD so that as the DC bus voltage approached dangerous levels, the VFD reduced back torque allowing the generator to ride through utility grid glitches up to 200 ms. Addition of the braking chopper is a good idea in any generation scheme but adds several thousand dollars in cost and additional engineering/design/construction/maintenance. The induction generator does not absolutely require this equipment whereas the PMG does and it would be very unsafe to operate without our design. Another secondary goal was to test the ability to change the operation of the turbine from generation to pumping mode. From the electrical side of this task, this is very easy to accomplish. Our VFD inverter system can easily and effectively be installed to control a pump as generator scheme or in a pumped storage installation. Other testing that was originally proposed such as tying in other power sources like DC power from PV panels, and such could not be performed due to the effects of COVID-19. COVID-19 and the federal instructions to continue to pay staff during lockdown effectively depleted six months of our research budget when stay at home orders halted our research and work effort momentum. Further complicating the work effort has been supply chain disruption which continue to the time of this report submission. However, we connected a subsystem VFD, that is used to control a cooling motor, to the DC bus. This demonstrates that the DC bus can be the common point of connection, at least for power take off, for other components in a power system so our VFD inverter technology could easily be installed in a factory setting where a generating source is supplying the DC bus while other components are taking power from the bus. Further, our system allows the grid to interact with the DC so that when excess power is produced, it can be exported and when the internal demands exceed generation capacity, power can be pulled from the utility. COVID-19 also resulted in travel restrictions and nearly all industry events and conferences were cancelled including the events where we intended to promote and discuss our research efforts and data. The unfortunate timing of COVID-19 and our developing technology and research have severely limited our ability to commercialize our very promising technology
Publications
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Progress 09/01/18 to 08/31/19
Outputs
Target Audience:The target audience reached duing this reporting period is other small scale renewable energy producers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?A technical paper has been submitted to and accepted by Hydrovision 2019. The paper and presentation will be released in July, 2019 What do you plan to do during the next reporting period to accomplish the goals?The test turbine and inverter system are well underway. These systems and components will be complete soon to allow testing of the induction generator as generating source, as a variable speed and flow generating source, and ultimately this test system will be compared against an existing and identical generation system to evaluate and compare the scalability and function of two distinct generation schemes.
Impacts
What was accomplished under these goals?
The test turbine reconstruction and reinstallation is nearly complete. As well, investigation and a solution was developed, tested and installed to address the DC bus transients. Testing on the PM generator has been completed and we have demonstrated a mechanism to both generate and motor the system.
Publications
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2019
Citation:
Demonstration of Variable Speed and Power Generation Using Permanent Magnet Generator and Inverter System
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