AC asynchronous motor drives water pump
Larger power (for example, power greater than 10KW or larger) photovoltaic water pump system, drive motor is still a lack of three-phase AC asynchronous motor, of which asynchronous motor usually uses wet sheath winding, due to the low tank full rate of structural characteristics, its efficiency is usually much lower than the same power DC permanent magnet brushless motor, but its structure is relatively simple, the cost is relatively low, oil immersion motor is not suitable for use in the water supply system that provides drinking water for people and livestock 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, essentially the frequency conversion technology and photovoltaic array maximum power point tracking technology and a number of necessary operation protection measures in the same controller, by the central controller to complete all the control functions required in the photovoltaic pump system, the advantage of this is that the system stability is good, compact structure, motor voltage level can be freely optimized according to the array configuration, low manufacturing cost, while fully considering the photovoltaic pump outdoor long-term unattended, The characteristics of fully automatic operation and other characteristics, special consideration are given to heat dissipation, dust protection, lightning protection and various special protection measures (such as dry protection), which is much more economical and reliable than the "patchwork" structure.
DC permanent magnet brushless motor drives water pump
DC motor has been widely used in motion control system with its advantages of good mechanical characteristics, wide speed regulation range, large starting torque, high operating efficiency and simple control, but its brushes and commutators also bring weaknesses such as low reliability and frequent maintenance. In 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 working on the principle of electronic commutation have also been developed accordingly and rapidly. It has rapidly expanded from the initial application of aerospace and military facilities to industrial and civilian fields, and its use is becoming more and more extensive. Mesh low-power brushless DC motors have been widely used in computer peripheral equipment, office automation and audio, film and television equipment, and their applications are becoming more and more widely used in some electric drive systems.
For several years, brushless DC motors began to be used as drive motors in photovoltaic water pump systems, which is because the motor has high efficiency that is not easy to achieve by general AC motors, and it is expected to greatly reduce the amount of relatively expensive solar cells, with significant economy. However, since photovoltaic water pumps usually require the motor to run submerged in the water, the research work in this paper requires that the motor can adapt to the requirements of submersion in addition to the operation drive technology of conventional brushless DC motors, that is, the reliable insulation of the windings must be solved at the same time. From the perspective of mechanical seals, it is certainly an idea to find ways to solve the sealing problem of submersible motors, but it is difficult to overcome the problems of complex structure and corresponding mechanical loss.