[0001] The present disclosure relates to solar power integrated bi-directional non-isolated DC-DC converter for use in e-rickshaw. The bi-directional DC-DC converter integrated with a solar panel can improve the battery's performance in both forward and regenerative operation modes, thereby improving efficiency and extending the driving range.
BACKGROUND OF INVENTION
[0002] The lack of public transportation is a major constraint in hilly areas. People from these areas still cannot get to facilities for their ever-increasing transportation needs to ensure civic engagement and other types of employment in community life. Access to safe and reliable transportation services impacts the health and well-being of rural populations.
[0003] The transport sector in hilly area is predominantly based on the combustion of fossil fuels, making it one of the largest sources of urban and regional air pollution, which is the dominant cause of global warming.
[0004] Electric vehicles (EVs) have zero tailpipe emissions because they employ electric-drive technologies and are much better for the environment. As one of the emerging technologies for e-mobility, the electric rickshaw has faced essential and demanding concerns like sustainability, accountability, and responsibility. The current e-rickshaw uses up to 1.2 kW motor driven by 48 volts. Because of this motor's size and voltage level, the battery voltage drops significantly during high torque requirements, especially in hilly areas, which affects the vehicle's motor and battery life.
[0005] In hilly terrain, the distance between passenger stations typically has undulating roads. This situation results in vehicle having repeated acceleration and braking cycles, resulting in considerable regenerative energy. Regenerative braking technology can increase the driving range possible in electric vehicles. Still, in research, it has been observed that the benefits are not always as great as expected because of inefficiencies in the power conversion processes.
[0006] At the same time, there is a need to provide energy access to rural areas and reduce dependence on fossil fuels and electricity consumption. Solar energy has vast potential, and the availability of solar insolation is higher in hills, which are close to being mostly cold and sunny.
[0007] Thus, it is desired to address the above-mentioned disadvantages or other shortcomings or at least provide a useful alternative.

OBJECTIVE OF INVENTION
[0008] The principal object of the embodiments is that a non-isolated bidirectional converter is designed to drive an up to 1.5 kW BLDC motor through a conventional voltage source inverter (VSI) to maintain a wide range of constant voltage operation up to 60 volts. In a highly inertial load driven by a BLDC motor during the motoring mode, the converter operates in boost mode to meet torque requirements and reduce stress on the motor by efficiently utilizing battery power.
[0009] Another object of the embodiments herein is to provide a bi-directional power flow using a bidirectional dc-dc converter for maximizing the extraction of regenerative power efficiently from the motor to the battery with appropriate digital control on undulating roads.
[0010] Another object of the embodiments is improving efficiency and extending the driving range of the battery by integrating monocrystalline flexible solar panels on the rooftop of the e-rickshaw. The above configuration with an integrated buck converter provides the MPPT control used to charge the batteries of the e-rickshaw with up to 15% of their capacity throughout the day. It promotes sustainable development principles empowering renewable energy resources in cold and sunny regions with high solar insolation.
[0011] Still, another object of the embodiments herein is to facilitate public transportation and enhance employment opportunities in hilly terrain by implementing these e-rickshaws in public transport sector properly.
SUMMARY OF INVENTION
[0012] The following presents a simplified summary to provide a basic understanding of some aspects of the disclosed invention. This summary is not an extensive overview, and it is not intended to identify key/critical elements or delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description given later.
[0013] Accordingly, a solar power integrated bi-directional non-isolated DC-DC converter in e-rickshaws is provided. The bi-directional DC-DC converter is integrated with a buck converter to extract power from a flexible monocrystalline solar panel configured on the e-rickshaw, improving power management, lowering running costs, and enhancing the battery's performance in both forward and regenerative operation modes.
[0014] In accordance with an embodiment of the present invention relates to integrated converter which is interconnected with the solar panel and the electronic speed controller (ESC) of the BLDC motor, and its connection with the battery.
[0015] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. However, it should be understood that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the scope thereof, and the embodiments herein include all such modification
BRIEF DESCRIPTION OF FIGURES
[0016] In order to describe how features and other aspects of the present disclosure can be obtained, a more particular description of the subject matter will be rendered by reference to specific embodiments, which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments and are not, therefore, to be considered to be limited in scope nor drawn to scale for all embodiments, various embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
[0017] According to the present invention, figure 1 illustrates a schematic circuit diagram of solar charging battery operation.
[0018] According to the present invention, figure 2 illustrates a schematic circuit diagram of motoring mode operation with a solar and battery energy source.
[0019] According to the present invention, figure 3 illustrates a schematic circuit diagram of regenerative mode operation.
DETAILED DESCRIPTION OF INVENTION
[0020] The embodiments herein and the various features and advantageous details are explained more fully in the non-limiting embodiments illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term "or" as used herein refers to a non-exclusive or otherwise indicated. The examples used herein are intended merely to understand how the embodiments herein can be practiced and enable those skilled in the art to practice the embodiments further herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0021] The accompanying drawings are used to help easily understand various technical features, and it should be understood that the accompanying drawings do not limit the embodiments presented herein. The present disclosure should be construed to extend to any alterations, equivalents, and substitutes in addition to those particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited. These terms are generally only used to distinguish one element from another.
[0022] Accordingly, embodiments here are provided for a bi-directional non-isolated DC-DC converter integrated with buck converter of solar panel in e-rickshaws. The bi-directional DC-DC converter can improve the battery's performance in forward and regenerative operation modes, efficiency and extending the driving range.
[0023] In an embodiment of the present subject matter, it is generally concerned with non-isolated bidirectional DC-DC converters for high current applications that keep a constant voltage level across an e-rickshaw motor. Further, the invention also includes a flexible monocrystalline PV panel with a buck converter integrated with a bidirectional converter. Therefore, the above arrangement increases the battery life and reduces the running costs of the e-rickshaw in hilly terrain.
[0024] Referring Figure 1 shows a schematic circuit diagram of solar charging battery operation according to the present invention. The integrated non-isolated DC-DC converter (10) comprises a photovoltaic (PV) panel buck converter (10 A) integrated with the bidirectional non-isolated DC-DC converter (10 B); a flexible monocrystalline solar panel (20) configured to be placed on top of the e-rickshaw (100) to improve power management and lower running costs, and a 1.5 kW BLDC motor (30) configured to be placed on rear wheel of the e-rickshaw (100). The circuit of integrated converter (10 A) charge the battery through the solar panel (20), and it will significantly reduce overall energy consumption when charging the e-rickshaw battery.
[0025] According to the present invention, the reference Figure 2 shows a schematic circuit diagram of motoring mode operation with a solar charging and battery energy source. The power comes from a battery to the BLDC motor (30) while running the e-rickshaw 100 in a forward motoring mode. The proposed integrated converter (10) will contribute to the current distribution from both solar panels and batteries. The current distribution from both sources has been demonstrated in the motoring mode of operation.
[0026] Referring Figure 3 shows a schematic circuit diagram of regenerative mode operation according to the present invention. The regenerative power of the BLDC motor (30) contributes to battery charging during a regenerative mode of operation. Integrating the bidirectional non-isolated DC-DC converter (10 A) with the PV panel buck converter (10 B) can improve the battery's performance. Therefore, the integrated converter (10) controls the power flow from both solar panels and the regenerative action of the BLDC motor (30) to charge the battery of the e-rickshaw (100).
[0027] The advantages of the present subject matter related to the bidirectional DC-DC converter integrated with the solar panel can improve the battery's performance in both forward and regenerative operation modes, improving efficiency and extending the driving range. This invention can limit the battery current drawn and meet high torque requirements on hills in the voltage boosted mode of the converter.
[0028] The preceding description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and adapt for various applications of such specific embodiments without departing from the generic concept. Therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for description and not for limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We claim:

1. A non-isolated bidirectional DC-DC converter (10 A) with an integrated buck converter (10 B) for solar powered e-rickshaw (100), comprising of:
a constant voltage embedded control (40B) is connected to the BLDC motor input voltage-side and the second constant voltage/constant current embedded control for battery charging (10A);
a high frequency, high current rating inductor (10 C) with reduced size and current ripple to increase power density connected to the input-output circuit (10B); and
a controlling circuit (40) that controls multiple operations of switching elements in BLDC (40) motoring mode, regenerative mode, and MPPT power tracking (40A).
2. The solar powered e-rickshaw bidirectional non-isolated DC-DC power converter (10A) circuit is also integrated with a unidirectional buck converter (10B) to control power management from the PV panel (20) to the battery, as recited in claim 1, wherein said set of integration designs for electric vehicle applications.
3. The solar power integrated bidirectional non-isolated DC-DC converter (10) as claimed in claim 1, wherein the calculated structure size with a maximum power rated occupancy flexible solar panel (20) mounted on a rooftop on an existing e-rickshaw has much less weight than other panel structures.
4. The solar power integrated bidirectional non-isolated DC-DC converter (10) as claimed in claim 1, wherein the first variable is the high voltage in the input/output terminal (10), and the second variable is the low voltage in the input/output terminal (10).
5. The solar power integrated bidirectional non-isolated DC-DC converter (10) as claimed in claim 1, wherein the bidirectional non-isolated DC-DC converter (10) is open to mounting a high power-rating BLDC motor (30) on an existing e-rickshaw (100), to improve performance for high torque conditions in hilly areas.
6. The solar power integrated bidirectional non-isolated DC-DC converter (10) according to claim 1, wherein the high-power BLDC motor (30) is coupled in existing differential and conventionally suitable with an integrated converter for e-rickshaw (100).

7. The solar power integrated bidirectional non-isolated DC-DC converter (10) is recited in claim 1, wherein the integrated bidirectional non-isolated DC-DC converter (10 A) controls the power flow from both solar panels and the regenerative action of the BLDC motor (30) to charge the battery of the e-rickshaw (100) for hilly areas.
8. The solar power integrated bidirectional non-isolated DC-DC converter (10) recited in the claim1, wherein the integrated non-isolated DC-DC converter (10) is used to extract effective solar insolation and regenerative power utilized towards a reduction in running cost and an increment of driving range in hilly areas.