Title: On the conversion of three-phase alternating current and direct current - practical application analysis of 7.5 kW kW motor With the continuous development of electric power technology, the application of electric motors in industrial production is becoming more and more extensive. The power, efficiency and conversion mode of the electric motor are directly related to the efficiency and cost of industrial production. In this paper, we will discuss the topic of "conversion of three-phase alternating current and direct current", and take a typical case, a 7.5 kW three-phase AC motor, as an example to discuss its practical application in the process of direct current conversion. 1. The basic concept of three-phase alternating current and direct current Three-phase alternating current is a power supply method in the power system, which has the advantages of high transmission efficiency and stable voltage. Direct current, on the other hand, is a form of current in which the direction of the current remains unchanged, and is widely used in electronic equipment, battery power supply and other fields. In practical applications, it is sometimes necessary to convert three-phase alternating current to direct current to meet the power supply needs of specific equipment. The difference and connection between two-phase and three-phase AC motor and DC motor Three-phase AC motors and DC motors are two different types of motors, which differ in structure, working principle, and application field. However, in some specific cases, the electrical energy of a three-phase AC motor needs to be converted to direct current to drive certain devices. This requires us to carry out the conversion of three-phase alternating current to direct current. 3. The conversion process of three-phase alternating current to direct current In order to achieve the conversion of three-phase alternating current to direct current, rectifier equipment is required. Rectifiers can convert alternating current to direct current. In the conversion process, it is also necessary to consider the stability of the voltage and the smoothness of the current to ensure the quality of the direct current. For a 7.5 kW three-phase AC motor, the conversion process needs to ensure efficient energy conversion and low heat loss. 4. Case study: Practical application analysis of 7.5 kW motor Take the 7.5 kW three-phase AC motor as an example, which is widely used in industrial production. In practical applications, it may be necessary to convert the electrical energy of the motor into direct current to drive certain equipment, depending on the actual demand. This necessitates the use of power conversion equipment such as rectifiers. When making conversions, factors such as power, efficiency, and heat loss of the motor need to be taken into account to ensure the normal operation and long service life of the motor. In addition, it is necessary to select the appropriate rectifier and conversion scheme according to the specific application scenario to meet the specific power supply needs. V. Conclusions In summary, the conversion of three-phase alternating current and direct current is of great significance in practical applications. For the practical application of 7.5 kW motors, power conversion is required according to the actual demand to meet the power supply needs of specific equipment. When conversion, it is necessary to consider factors such as the power, efficiency and heat loss of the motor and select the appropriate power conversion equipment and scheme. In the future, with the continuous development of power technology, new power conversion technologies will continue to emerge to meet the needs of more complex application scenarios.