E Kretzschmar motor, German E Kretzschmar model, E Kretzschmar price

E Kretzschmar motor is a type of motor that can be used in flammable and explosive environments without generating electrical sparks during operation. Explosion-proof motors are mainly used in coal mines, oil and natural gas, petrochemical, and chemical industries. In addition, they are widely used in textiles, metallurgy, urban gas, transportation, grain and oil processing, papermaking, pharmaceuticals, and other sectors. As primary power equipment, explosion-proof motors are typically used to drive pumps, fans, compressors, and other transmission machinery.

E Kretzschmar motor protection device

Motor differential protection devices are mainly used in large high-voltage motors in power plants, chemical plants, and similar facilities. If a severe fault causes the motor to burn out, it will seriously disrupt normal production and cause significant economic losses; therefore, comprehensive protection must be provided. Existing integrated motor protection devices mainly target small and medium-sized motors, providing protection functions such as instantaneous current cutoff, thermal overload inverse-time overcurrent, two-stage definite-time negative sequence, zero-sequence current, rotor stall, excessive start time, and frequent starting. However, for extra-large capacity motors above 2000KW, these devices cannot meet the requirements for protection sensitivity and speed during internal faults. Therefore, this device was developed to work in conjunction with integrated protection devices, providing more reliable and sensitive protection measures for high-voltage motors. This device is designed as a three-phase longitudinal differential protection because the 3KV, 6KV, and 10KV power grids where extra-large capacity motors above 2000KW are located may have transformer neutrals grounded via high resistance. Three-phase longitudinal differential protection serves not only as the main protection against phase-to-phase short circuits in the motor stator windings and lead wires but also as the main protection against single-phase ground faults, triggering instantaneous tripping.

E Kretzschmar motor control principle

When the motor rotates, the control unit compares the speed composed of commands based on the speed and acceleration/deceleration rates set by the driver with the speed of hall-sensor signal changes (or via software calculation) to determine which next set of switches (AH, BL or AH, CL or BH, CL or ...) conducts and for how long. If the speed is insufficient, the conduction time is lengthened; if the speed is too high, it is shortened. This part of the operation is completed by PWM. PWM determines whether the motor speed is fast or slow; how to generate such PWM is core to achieving precise speed control. High-speed control must consider whether the system's CLOCK resolution is sufficient to handle software instruction timing. Additionally, the data access method for hall-sensor signal changes affects processor performance, judgment accuracy, and real-time response. For low-speed control, especially low-speed starting, the return hall-sensor signal changes more slowly, making the signal capture method, processing timing, and appropriate configuration of control parameters based on motor characteristics critically important. Alternatively, speed feedback can reference encoder changes to increase signal resolution for better control. Smooth motor operation and good response also depend heavily on proper P.I.D control. As previously mentioned, brushless DC motors use closed-loop control, so the feedback signal indicates to the control unit the difference between the actual motor speed and the target speed, which is the error.

E Kretzschmar motor classification

Embedding short-circuit copper rings or short-circuit coils (groups) into part of the stator poles forms a shaded-pole single-phase motor. Shaded-pole single-phase motors include salient-pole and non-salient-pole types. When the stator winding is supplied with single-phase AC current, most of the pulsating magnetic flux generated couples directly to the rotor through the air gap, while a small portion of the flux induces magnetic flux when passing through the shaded-pole copper ring. This induced flux combines with the original flux and enters the rotor magnetic circuit through the air gap. According to Lenz's law, the induced flux always opposes changes in the original flux and lags behind it in phase. This creates two magnetic fluxes spatially displaced by a certain angle and with a phase difference, resulting in a rotating magnetic field with high ellipticity. The rotation direction of a shaded-pole motor is fixed, moving from the unshaded part to the shaded part. These motors have low power, low starting torque, simple structure, low cost, and easy maintenance. Shaded-pole motors are generally used in small blower motors and fan motors.

Weidou Intelligent Technology specializes in selling German E Kretzschmar motors, E Kretzschmar motors, E Kretzschmar drives, E Kretzschmar synchronous motors, E Kretzschmar servo motors, E Kretzschmar DC motors, E Kretzschmar AC motors, E Kretzschmar stepper motors, E Kretzschmar synchronous motors, E Kretzschmar asynchronous motors, E Kretzschmar single-phase motors, E Kretzschmar three-phase motors, E Kretzschmar drive motors, E Kretzschmar geared motors, E Kretzschmar electric motors. E Kretzschmar products are original imports from Germany. Customers are welcome to inquire and order.