MARINE POWER SYSTEMS
Marine electric propulsion power systems provide an environmental-friendly alternative to traditional propulsion methods. These systems use electric motors to drive the propellers, replacing conventional steam engines. By harnessing electricity from various sources, such as generators, batteries, or renewable energy sources like solar and wind, marine electric propulsion systems offer cleaner and flexible operation.
Fig 1. Marine Propulsion Power Systems
The Fig. 1. depicts the marine propulsion power systems. One of the benefits of marine electric propulsion is its potential to reduce carbon emissions. Unlike traditional engines that burn fossil fuels and release pollutants into the atmosphere, electric propulsion systems produce minimal emissions at the point of use. This makes them an alternate option for vessels looking to minimize their environmental impact and comply with emissions regulations.
Apart from being environmentally friendly, marine electric propulsion systems are also known for their better energy efficiency. Electric motors offer control over speed, power, allowing marine vehicles to optimize their energy consumption. This can result in fuel savings and lower operating costs for ship owners. Moreover, the flexibility of electric propulsion systems enables hybrid configurations, where different power sources can be used together to maximize efficiency and performance.
Also, marine electric propulsions offer other advantages like vibration reduction. Electric motors run more quietly and smoothly compared to traditional engines, providing a quieter and more comfortable environment for crew and passengers. This is very important for ships like ferries, where passenger comfort is a top priority.
Hence, marine electric propulsion power systems can revolutionize the maritime industry by providing a cleaner and more efficient propulsion method. In future, these systems will play an important role in shaping the future of sustainable maritime transportation. In this blog, we will explore how a marine power systems simulation is done and how the same could be extended to carry out a real-time emulation at full power level using Impedyme’s CHP.
WHY MARINE POWER SYSTEMS EMULATION?
Marine power real-time emulation is an essential for testing and validating the performance and safety of marine propulsion systems in a controlled and efficient manner. By creating an environment that mimics the real-world conditions of marine vessels, we emulate different scenarios and operational conditions without the risks and costs associated with field trials.
One of the main reasons for using real-time emulation in marine power systems is to assess the behavior and performance of the system under various conditions and loads, including normal operation and potential faults. This allows us to test different designs and control strategies to ensure the system operates safely and efficiently, even in situations such as rough seas or sudden changes in power demand.
Real-time emulation also provides a valuable platform for optimizing system performance. By experimenting with different power sources, energy storage options, and control algorithms, we can identify the effective configurations for marine electric propulsion systems. This leads to improved fuel efficiency, reduced emissions, and lower operating costs.
Another benefit of real-time emulation is its ability to support the integration of renewable energy sources and advanced technologies into marine power systems. By simulating the effects of solar, wind, or other renewable energy sources, we could explore hybrid propulsion systems that combine traditional and renewable power sources for greater efficiency and sustainability.
Hence, marine power real-time emulation plays a crucial role in advancing the development of efficient marine propulsion systems. It enables thorough testing and optimization, thereby contributing to a cleaner and more efficient technology for the maritime industry.
SIMULINK MODEL OF MARINE POWER SYSTEMS
The power system model is designed to replicate the behavior and operation of a modern marine power system. It consists of synchronous generators and LC filters that help maintain power quality and stability in the system. Additionally, there are 30 breakers and 20 loads of various types, providing a realistic representation of the various electrical demands in a marine environment. The inclusion of two electric propulsion drives and two shore power sources represents the multi-functionality of the model, as it can mimic different operating scenarios and power sources found in marine vessels.
The shipboard power system model provides a representation of how electrical power is generated, distributed, and managed on a marine vessel. In this model, there are two main zones, each equipped with power generators and approximately four switchboards to handle the distribution of electrical power throughout the ship.
The propulsion motor present in Zone 2 of the marine power systems model is modeled as a permanent magnet synchronous machine with field-oriented control. This design allows for a control over the ship's propulsion system, ensuring navigation and stability in various marine environments.
The power generators (PG units) within the system are modeled using synchronous machines powered by gas turbines. These machines are equipped with governor models to regulate engine speed and maintain stable power output. Auto voltage regulators and exciters are also included to ensure consistent voltage levels across the system, which is crucial for the operation of various electrical components on the ship.
The system also employs AC to DC conversion, enabling the power system to accommodate different electrical needs across the vessel. This conversion is particularly necessary because it allows the system to introduce a droop in the DC voltage, which helps control power sharing between the generators; this ensures that each generator contributes its appropriate share to the overall power supply.
Fig 5. Generator Model
IMPEDYME’S CHP TECHNOLOGY
Fig 6. Impedyme’s CHP Cabinet
The Impedyme’s emulation solutions mimic your MATLAB Simulink models that can be used for high power tests, up to a few Mega Watts scale, for bandwidths up to 20 kHz. Simply connect the optical links to our cabinets and deploy your models to begin the testing. The cabinets have multiple optical links each up to 12.5 giga-bits per second. For simulations with ultra-low step-times, the equipment supports FPGA-based tests, that allows you to have time steps as low as a few nanoseconds. Moreover, the FPGA brings in a better performance for your real-time emulation since the processing speed of an FPGA is much higher than that of a CPU.
Also, for high-speed emulations, the individual FPGAs of the drawers can communicate among them. The testing using Impedyme’s CHP is straightforward as it uses Simulink designs. Our products come with a wide range of pre-designed models, which you can customize the designs according to your needs and requirements. Furthermore, if we were to emulate both the input and the output side of the power systems, we can have a circulating power flow. Since the power is recirculated, we only must feed in power losses from the grid. By having such a technology can reduce the power requirements of your lab for testing large power systems. Moreover, during the real-time emulation of your models, our integrated thermal management utilizes an advanced liquid + air cooling technology that ensures that does not require any additional chiller for cooling. Thus, we use Impedyme’s CHP to emulate the developed marine power systems models in real-time.
Now that we have developed the full powertrain model, let us see how the connections are given to kickstart the testing process.
Fig 7. Marine Power Systems Emulation: Impedyme’s CHP Connection Diagram
We allocate the first two drawers, that is the two top-most drawers, for the Zone 1 model and the two subsequent two drawers for the Zone 2. The last two, that is the two bottom-most drawers are dedicated for the Active Front end Converters that provide the DC coupling for the emulation.
Now, let’s see how the connections are made to allocate these drawers. the power connections are given on the backside of the cabinets. The DC supply from the active front end drawer is given to the Zone 1 drawer and the voltages from Zone 1 are coupled with those of Zone 2. The subsequent drawers below emulate the action of Zone 2 (with propulsion motor model). Finally, the DC coupling is given back to the active front end drawer from Zone 2 to have a circulating power flow. Since the connections are complete, we are now ready to test.
Fig 2. Marine Power Systems Simulink Model
By balancing the power distribution between generators, the shipboard power system can operate efficiently and reliably. This level of control is essential for maintaining the vessel's electrical stability and optimizing its performance, whether it is for propulsion, onboard systems, or other operational requirements. Now that the marine power systems models are built using Simulink, let’s get introduced to Impedyme’s CHP technology to emulate and test the developed models in real-time.
REFERENCES
-
Graham Dudgeon (2024). Shipboard Power System in Simscape (https://github.com/mathworks/Two-Zone-MVDC-Electric-Ship), GitHub. Retrieved April 17, 2024.
-
D. Park and M. Zadeh, "Dynamic Modeling, Stability Analysis, and Power Management of Shipboard DC Hybrid Power Systems," in IEEE Transactions on Transportation Electrification, vol. 8, no. 1, pp. 225-238, March 2022, doi: 10.1109/TTE.2021.3119231.
Fig 3. Zone 1 Model
Fig 4. Zone 2 Model
Fig 8. Generators’ Startup
Fig 9. Generators’ Load Step Change
Fig 10. Propulsion Motor Response
SIMULATION RESULTS
CHP seamlessly integrates hardware-in-the-loop (HIL) and power hardware-in-the-loop (PHIL) capabilities, offering unparalleled accuracy and efficiency in EV development. With CHP, engineers can simulate real-world scenarios with precision, testing EV components and systems under dynamic conditions. From battery management systems to motor controllers, CHP empowers manufacturers to optimize performance, enhance reliability, and accelerate time-to-market for their EVs. Its modular design ensures flexibility to adapt to evolving testing needs, while its intuitive Simulink interface streamlines the testing.
Some of Impedyme CHP’s features include: