Solar water pump (also known as photovoltaic water pump) is the most attractive water supply method in the sun-rich areas in the world, especially in remote areas lacking electricity and no electricity. It is an ideal green energy system that integrates economy, reliability, and environmental benefits.
It mainly converts the light energy of the sun into electric energy and provides working power to the load pump motor.
Photovoltaic pumping inverter or controller
The operation of the solar water pump is controlled and adjusted, the water pump is driven by the electric energy emitted by the solar array, and the output frequency is adjusted in real-time according to the change of the sunlight intensity so that the output power is close to the maximum power of the solar battery array.
Motor (drive motor)
The drive motors used in different systems are also different. In photovoltaic water pump systems with a power level of less than 10 Np, in order to obtain the highest possible system efficiency, DC brushless permanent magnet motors are mostly used to drive. With the continuous development of modern control technology, in order to further increase the water lift provided by the unit peak watt, it has begun to be replaced by the multi-machine group control technology that realizes flexible control of multiple pumps.
water pump
For the photovoltaic pump system, the selection of the pump type is also very important. In a system with low power, if the user requires a high lift but a small flow rate, a positive displacement pump should be selected. In other cases, a centrifugal or axial flow pump may be used. The selection and consideration of pump types for photovoltaic water pump systems.
Water towers and water storage facilities
If the photovoltaic water pump system is used in cold winter regions (such as the vast western region of my country), it is advisable to use antifreeze water storage facilities, such as intermediate vacuuming or double-layer water tanks or water towers with thermal insulation materials. For antifreeze treatment. [1]
Category Features Edit Broadcast
AC asynchronous motor drives water pump
In the photovoltaic water pump system with high power (for example, when the power is greater than 10KW or more), there are still many drive motors that use three-phase AC asynchronous motors. Among them, the asynchronous motors usually use wet sheathed windings. Features, its efficiency is usually much lower than that of the DC permanent magnet brushless motor of the same power, but its structure is relatively simple, the cost is relatively low, the oil-immersed motor is not suitable for use in the water supply system that provides drinking water for humans and animals at the same time, so there is still a certain demand. . The core of its drive control is a dedicated frequency conversion and control integrated power supply, which is essentially a combination of frequency conversion technology, maximum power point tracking technology of photovoltaic arrays and several necessary operation protection measures in the same controller, and the central controller completes the photovoltaic system. All control functions are required in the water pump system, the advantages of this are good system stability, compact structure, motor voltage level can be freely optimized according to the array configuration, low manufacturing cost, and can fully take into account the long-term unmanned outdoor photovoltaic pump. On duty, fully automatic operation, and other characteristics, special consideration is given to heat dissipation, dustproof, lightning protection, and various special protection measures (such as dry protection), which is much more economical and economical than the “patchwork” structure. reliability.
DC permanent magnet brushless motor drives the water pump
DC motors have been widely used in motion control systems due to their good mechanical characteristics, wide speed range, large starting torque, high operating efficiency, and simple control. Weaknesses such as low performance and frequent maintenance. Over the past 20 years, with the rapid development of high-power switching devices, analog and digital integrated circuits, computer technology, and high-performance magnetic materials, brushless DC motors that operate on the principle of electronic commutation have also developed rapidly. It has rapidly expanded from the initial application of aerospace and military facilities to industrial and civil fields, and its use has become increasingly widespread. The low-power brushless DC motor has been widely used in computer peripheral equipment, office automation and audio and video equipment. In the electric drive system, its application is more and more extensive.
For several years, brushless DC motors have been used as drive motors in photovoltaic water pump systems. This is because this type of motor has high efficiency that is not easily achieved by ordinary AC motors. It is expected to reduce the relatively expensive solar The amount of battery used has significant economical benefits. However, since the photovoltaic water pump usually requires the motor to run submerged in water, the research work in this paper not only needs to solve the operation and drive technology of the conventional brushless DC motor but also requires the motor to adapt to the requirements of submersion, that is, the reliable insulation of the winding must be solved at the same time. question. It is an idea to find ways to solve the sealing problem of submersible motors from the perspective of mechanical sealing, but it is difficult to overcome the problems of complex structure and corresponding large mechanical loss. [2]
How it worksEdit Broadcast
Brushless DC Solar Water Pump (Motor Type)
The motor-type brushless DC water pump is composed of a brushless DC motor and an impeller. The shaft of the motor is connected to the impeller. There is a gap between the stator and the rotor of the water pump. After a long time of use, water will penetrate into the motor and increase the possibility of the motor burning out.
Brushless DC Magnetically Isolated Solar Water Pump
The brushless DC water pump adopts electronic components for commutation, no need to use carbon brushes for commutation, and uses high-performance wear-resistant ceramic shafts and ceramic bushings. The bushing is integrated with the magnet through injection molding to avoid wear and tear. The life of the pump is greatly enhanced. The stator part and the rotor part of the magnetically isolated water pump are completely isolated, the stator and the circuit board part are encapsulated with epoxy resin, 100% waterproof, the rotor part uses permanent magnets, the pump body is made of environmentally friendly materials, low noise, small size, high performance Stabilize. Various required parameters can be adjusted through the winding of the stator, and it can operate with a wide range of voltages.
Editing and broadcasting of own advantages
(1) Reliable: The photovoltaic power supply rarely uses moving parts and works reliably.
(2) Safe, no noise, no other public hazards. Does not produce any solid, liquid, and gaseous harmful substances, absolutely environmentally friendly.
(3) Simple installation and maintenance, low operating cost, suitable for unattended operation, etc. In particular, it has attracted attention for its high reliability.
(4) Good compatibility, photovoltaic power generation can be used in conjunction with other energy sources, and the photovoltaic system can be easily expanded according to needs.
(5) The degree of standardization is high, and the components can be connected in series and parallel to meet the needs of different electricity consumption, and the versatility is strong.
(6) Solar energy is everywhere and has a wide range of applications.
However, the solar system also has its shortcomings, such as: energy dispersion, large intermittent, strong regional. The upfront cost is higher.
System Outlook Edit Broadcast
It is difficult for the efficiency of silicon solar panels to be greatly improved in a short period of time. Although the second-generation thin-film solar cells and the third-generation organic solar cells have obvious advantages in cost, compared with the large-scale production of silicon solar panels Not yet competitive. In the future, silicon solar panels will still occupy a large share of the market. Therefore, in the future, the research and development direction of solar water pump systems should focus on the following three aspects:
(1) Research and develop high-efficiency pumps and motors to improve the high-efficiency range of motors and pumps under a wide range of rotational speeds and flow changes and reduce the threshold power of the system to lift water. Develop low-cost, high-reliability intelligent controllers to improve performance matching between components and cope with changing weather conditions, thereby improving system dynamic quality and overall efficiency. At the same time, improve the development and promotion of comprehensive technologies for complementary utilization of small and medium-sized wind-light-heat energy sources;
(2) A general method for long-term performance prediction of solar water pump systems under the changes of climate, light, water level, water demand, and other factors and a system design method based on dynamic changes, establish databases in different regions, and gradually replace the method of using static average estimation ;
(3) With the decrease in the price of solar panels and the development of small and medium-sized solar energy systems, in the future, on the basis of optimizing the power of solar panels, the evaluation of the reliability of system operation should be increased to improve the long-term operation reliability of the system and the stability of water supply.
