METHOD THEREOF

FIELD OF THE INVENTION

The present invention, in general, relates to the electrical energy generation, storage and supply in the vehicles. Particularly, this invention presents an electrical energy generation and control system and method of photovoltaic road tanker.

DISCUSSION OF BACKGROUND ART

Electric cargo vehicles for long distances are under development today, and in the future electric cargo vehicles are supposed to be commonly present. Electric cargo vehicles consume electric energy, which main source is batteries, chargeable in the charging stations. However, the charging of the electric vehicles takes time, the batteries could be charged at specific places and the charging cost money. Some electrical energy could be produced autonomously while the truck is moving or standing in the parking or even charging in the charging station. In the case when the cargo vehicle is composed from regular truck or tractor, attached to the semi-trailer or regular trailer, which is a road tanker for transportation of liquid products, such tanker has a big surface, which is a perfect place for installation of photovoltaic panels in order to produce electric energy from the sunlight. In most cases, photovoltaic panels are attached to the plain surfaces of the cargo vehicles. It is a need to have a system of photovoltaic electrical energy, which could be mounted on curved surfaces, such as surfaces of road tankers. With the existing technology, this could not be done.

Patent documents W02011046206A1 (published 2011-04-21) and W02011046198A1 (published 2011-04-21) describe a truck vehicle provided with a solar cell panel. The platform of the trailer is connected to the driving vehicle and has a loading platform body for covering a load containing section; and a solar cell panel is attached to the loading platform body and supplies electrical energy. However, such a loading platform could be mounted only on plain surfaces. In addition, the area, covered by the solar panels, is relatively small, so just a small amount of electrical energy could be produced, which could be used as a supplementary energy, such as for the air conditioning device.

Patent document CN 102019857A1 (published 2011-04-20) describes solar electric truck, so that the roof and two sides of the carriage are provided with a solar battery pack. An electric control system is arranged at the carriage, and the solar battery pack is connected with the electric control system of the vehicle. Thus, the electric control system is respectively connected with an electromotor and an illuminating system through leads. However, the solar battery pack could be mounted only on the plain surface of the truck.

Patent document CN101070059B (published 2011-08-31) describes a solar energy generation system for vehicle, which could have a curved shape. The system comprises a vehicle and a plurality of solar panels forming the vehicle body. In such a case, the curved shape of the vehicle could be covered. However, the solar panels themselves are not curved. Each area of the vehicle is covered by small and separate solar panels, which dimensions match the vehicle part’s dimensions. Therefore, such a solar generation system is difficult to produce and assemble, since every single curved surface needs a special solar panel, according to its dimensions. In addition, such a method for mounting solar panels could not be applied for the vehicles, which do not have even small parts of plain surfaces, as in the case for a road tanker for liquid products.

Existing methods don't allow to mount photovoltaic panels on curved surfaces of vehicles, as in the case of a road tanker for liquid or gas products. In addition, there is no solutions, when all cargo vehicle would be covered by the photovoltaic panels, and the solar energy would be fully controlled and integrated into the energy system of the cargo vehicle. Therefore, it is a need for a system and a method where: photovoltaic panels could be mounted on curved surfaces of a cargo vehicle; photovoltaic electrical energy would be controlled and fully integrated into the energy system of the truck; photovoltaic electrical energy system would produce electrical energy in a safe and efficient mode.

Our invention describes a new method and a system, which satisfies above mentioned requirements.

SUMMARY OF THE INVENTION

The present invention solves the task of photovoltaic electrical energy generation on a road tanker surface and the control of generated photovoltaic electrical energy. It could be used for the electrical trucks or for trucks with internal combustion engines. The method has the following components: a truck, a road tanker, photovoltaic panels and an electrical system control mechanism. The photovoltaic panels generate photovoltaic electrical energy, which feeds the road tanker electrical users. The excess electrical energy is stored in the truck batteries, the road tanker batteries or both. Upon demand, the stored photovoltaic electrical energy is used to feed the road tanker electrical users, the truck driving electrical motor or the truck electrical equipment. The electrical system control mechanism ensures the safe regime of the photovoltaic electrical system. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1. A general view of a photovoltaic electrical energy system of a road tanker.

There 1-truck, 2- road tanker, 3- photovoltaic panels, 4- electrical system control mechanism.

Fig. 2. An electrical scheme of the photovoltaic electrical energy generation and control system.

There 1.1- truck batteries, 2.1-road tanker batteries, 2.2- road tanker electrical users, 3- photovoltaic panels, 3.1- photovoltaic modules, 4.1- controller, 4.2- power inverter, 4.3- power and current regulator, 4.4- wires, AC- alternating current, DC- direct current.

DETAIFED DESCRIPTION OF THE INVENTION

The present invention solves the task of photovoltaic electrical energy generation on a road tanker surface and the control of generated photovoltaic electrical energy. The photovoltaic electrical energy generation and control system of a road tanker for liquid or gas products has the following components (Fig. 1): a truck (1) a road tanker (2); photovoltaic panels (3); an electrical system control mechanism (4).

A truck (1) is a motor vehicle designed to transport cargo or to pull a trailer, a semi-trailer or a road tanker (2) (Fig. 1). It could be called a truck, a semitrailer truck or a tractor. In this application it will be called a truck (1). The most common truck (1) has a cabin, a forward engine, one steering axle, two or more drive axles, a platform and a mechanism for connecting and pulling a road tanker (2). The truck (1) could be an internal combustion engine truck (1) or an electric truck (1) powered by the truck batteries (1.1).

A road tanker (2) is a vehicle, pulled by the truck (1), designed to carry liquefied loads or gases on roads (Fig. 1). The road tanker (2) could carry various liquefied goods such as liquid sugar, molasses, milk, wine, juices, water, diesel, gasoline or industrial chemicals. Usually the road tanker (2) has a cylindrical tank upon the vehicle lying horizontally, the platform to carry the tank, two or more drive axles and a mechanism for attaching to the truck (1). The road tanker (2) also has road tanker electrical users (2.1), such as electrical pumps, heating, cooling systems or other. The road tanker (2) could also have road tanker batteries (2.2) installed, which would be used to store photovoltaic electrical energy and to feed the road tanker electrical users (2.1). When the road tanker (2) does not contain the road tanker batteries (2.2), the energy for the road tanker electrical users (2.1) is delivered from additional internal combustion engine, installed on the road tanker (1), which would bum fuel and deliver the energy. Another option of providing energy for the road tanker electrical users (2.1) could be to use a part of energy from the main truck internal combustion engine. Both solutions use energy, generated from the burned fuel, which could be used for the truck (1) and the road tanker (2) transportation. In the case of an electric truck (1), the main truck batteries (1.1) could provide electrical energy for the road tanker electrical users (2.1). but it would reduce the range of the truck (1) per one charge. Photovoltaic panels (3) generate photovoltaic electrical energy, therefore the range of the truck (1) is prolonged.

Photovoltaic panels (3) are devices, which absorb sunlight as a source of energy and generate direct current electricity (DC) by the photovoltaic effect (Fig. 2). The photovoltaic panels (3) are mounted on the surface of the road tanker (2) or on another or another cylindrical or curved vehicle. The photovoltaic panels (3) are composed of separate photovoltaic modules (3.1), which are connected in parallel. Parallel way of connection maximally protects the power of the photovoltaic panels (3) when a single photovoltaic module (3.1) is damaged or broken. Due to the safety reasons, the voltage of the photovoltaic modules (3.1) should operate in a safe voltage range. For example, the voltage of the photovoltaic modules (3.1) should not exceed 12 V. Such an assembly of photovoltaic modules (3.1) allows safe and efficient photovoltaic electrical energy generation by the photovoltaic panels (3). Photovoltaic panels (3) could be of different types and sizes, could have different physical characteristics. Photovoltaic panels (3) are mounted on the road tanker (2) surface by attaching them mechanically or by gluing them (Fig. 1). Flexible photovoltaic panels (3) or flexible panel laminate is used in order to cover the cylindrical road tanker (2) surface. The mounting of the photovoltaic panels (3) should ensure the electrical safety, so that the damage of the photovoltaic panels (3) would not cause danger to the people inside or near the truck (1). The photovoltaic modules (3.1) could be made of multicrystalline or monocrystalline silicon, by thin-film technologies using cadmium telluride, copper indium gallium selenide, amorphous silicon, gallium arsenide or from other known materials.

The electrical system control mechanism (4) connects photovoltaic panels (3) with the road tanker electrical users (2.2), truck batteries (1.1) or road tanker batteries (2.2) and controls the generation, storage and usage of the photovoltaic electrical energy, generated by the photovoltaic panels (3). The electrical system control mechanism (4) comprises the following parts (Fig. 2): controller (4.1); power inverter (4.2); power and current regulator (4.3); wires (4.4).

A controller (4.1) is an electronical device that connects the truck batteries (1.1) with the photovoltaic panels (3) by means of wires (4.4). The controller (4.1) manages the truck batteries (1.1) electrical conditions, such as protection of the truck batteries (1.1) from operating outside its safe operating area, monitors and controls the charging state the state of the truck batteries (1.1), computes maximal charge and discharge levels and other characteristics, ensures safe charging and discharging of the truck batteries (1.1) by protecting from over-current, over-voltage during charging, under-voltage during discharging and other performs other necessary functions. The controller (4.1) prevents the truck batteries (1.1) from overcharging or fully discharging.

A power inverter (4.2) is a power electronical device that changes direct current (DC) into alternating current (AC). The power inverter (4.2) connects the road tanker electrical users (2.1) with the truck batteries (1.1), the road tanker batteries (2.2) or the photovoltaic panels (3). The road tanker (2) electrical users (2.1) are the electrical devices, which use alternating current for their operations. For example, if the liquid or gas product loading pump needs 400 V AC for its operation, and the truck batteries (1.1) or road tanker batteries (2.2) have 24 V (or 48 V) DC, the power inverter (4.2) converts 24 V (or 48 V) DC electrical current into 400 V AC.

A power and current regulator (4.3) is an electronical device that is designed to keep the power and current flowing through the electrical system at a constant rate. The power and current regulator (4.3) ensures that the electrical current through the electrical system is flowing at a constant level.

Wires (4.4) are flexible strands or rods of metal or other conductive material, which are used to carry electricity in the photovoltaic electrical energy system of the truck (1) and the road tanker

(2). Wires (4.4) connect comprising parts of the road tanker (2) photovoltaic electrical energy system.

The most convenient way to store photovoltaic electrical energy is to use both the truck batteries (1.1) and the road tanker batteries (2.2) together with the photovoltaic panels (3). However, in separate embodiments of this invention, it could be that only the truck batteries (1.1), or only the road tanker batteries (2.2) are installed in the system. The truck batteries (1.1) and the road tanker batteries (2.2) are rechargeable, meaning that they could be charged or recharged on demand many times. The truck batteries (1.1) and the road tanker batteries (2.2) usually have 24 V or 48 V voltage due to possibility to accumulate more energy.

The method, described in the proposed invention, employs the above-mentioned system for photovoltaic electrical energy generation. The road tanker (2) is covered by photovoltaic panels

(3). When the sun is shining, the photovoltaic panels (3) generate photovoltaic electrical energy which is used to feed the road tanker electrical users (2.2) or is stored at truck batteries (1.1) or road tanker batteries (2.2). Initially, photovoltaic electrical energy is used to feed the road tanker electrical users (2.1), such as liquid or gas product loading pumps, road tanker (2) heating or cooling system or other devices. When the photovoltaic panels (3) generate more photovoltaic electrical energy than is needed for the road tanker electrical users (2.1), the excess photovoltaic electrical energy could be used to charge the truck batteries (1.1) while the electric truck (1) is mowing or is parked. When the truck batteries (1.1) are fully charged, the photovoltaic electrical energy will be used to charge the road tanker batteries (2.2). Later on, the electrical energy from the truck batteries (1.1) or the road tanker batteries (2.2) will be used to feed the road tanker electrical users (2.1) or the truck (1) driving electrical motor or few motors depending on electric truck drivetrain design. The controller (4.1), which is connected to the truck batteries (1.1), prevents the truck batteries (1.1) from fully discharging.

The photovoltaic electrical energy generation and control method could also be used for trucks (1) with internal combustion engines. In this case, the photovoltaic electrical energy is firstly used to feed the road tanker electrical users (2.1), as in the case of the electrical truck (1). When the photovoltaic panels (3) generate more photovoltaic electrical energy than is needed for the road tanker electrical users (2.1), the photovoltaic electrical energy charge the road tanker batteries (2.2). Later on, the electrical energy from the road tanker batteries (2.2) is used to feed the road tanker electrical users (2.1) or the electrical equipment of the truck (1), such as air conditioning, lighting or other.

Off-grid option of the road tanker (2) is also be possible. In many cases the road tanker (2) is needed to keep at the chocolate factory, dairy or supplier/user of any liquid cold of hot liquid product as a buffer tank. It’s possible to disconnect the road tanker (2) from the truck (1), which could be used for different journeys, and to ensure liquid product heating or cooling inside the tank without connecting it to any energy source. Usually the energy consumption for extra cooling or heating is so low that such photovoltaic system would be able to generate enough energy even during wintertime depending of the geography, where the road tanker (2) would be used. For off- grid application of the road tanker (2), road tanker batteries (2.2) are needed to be installed on the road tanker (2). When the road tanker (2) has road tanker batteries (2.2) installed, sufficient photovoltaic electrical energy would be generated for keeping products, such as chocolate, oil or other at the right temperature regime without using external electrical energy.

The photovoltaic energy could be generated when the truck (1) with the road tanker (2) is moving on the road, is parked or even is charging at the electrical charging station. The most convenient way to store the photovoltaic electrical energy is to use both the truck batteries (1.1) and the road tanker batteries (2.2) together with the photovoltaic panels (3). However, in separate embodiments of this invention, it could be that only the truck batteries (1.1), or only the road tanker batteries (2.2) are installed in the system. The electrical system control mechanism (4) manages, controls, regulates and ensures the safe and optimal regime of the photovoltaic electrical system. The controller (4.1) manages the truck batteries (1.1) electrical conditions, monitors its state, controls the charging and discharging levels and prevents the truck batteries (1.1) from overcharging or fully discharging. The power inverter (4.2) changes direct current (DC) into alternating current (AC), which is needed to feed the road tanker electrical users (2.1). The power and current regulator (4.3) keeps the power and current flowing through the electrical system at a constant level, ensuring that the electrical system is operating in a safe and efficient mode.

In conclusion, the method, described in the proposed invention, has the following steps: the photovoltaic panels (3) generate photovoltaic electrical energy; the photovoltaic electrical energy feeds the road tanker electrical users (2.1); the excess photovoltaic electrical energy is stored at the truck batteries (1.1), the road tanker batteries (2.2) or both; upon demand, the stored photovoltaic electrical energy is used to feed the road tanker electrical users (2.1), the truck (1) driving electrical motor or the electrical equipment of the truck (1); the electrical system control mechanism (4) manages, controls, regulates and ensures the safe and optimal regime of the photovoltaic electrical system.