O.M.B srl motors Germany O.M.B srl models O.M.B srl prices

O.M.B srl motors are a commonly used type of AC motor. The synchronous motor is the heart of the power system; it is a component that integrates rotation and stasis, electromagnetic changes and mechanical motion, to achieve the conversion between electrical and mechanical energy. Its dynamic performance is highly complex, and its dynamic performance has a significant impact on the dynamic performance of the entire power system. A key feature is that during steady-state operation, there is an invariant relationship between the rotor speed and the grid frequency: n=ns=60f/p, where f is the grid frequency, p is the number of pole pairs of the motor, and ns is called the synchronous speed. If the grid frequency remains constant, the speed of the synchronous motor during steady state is always constant and independent of the load magnitude. Synchronous motors are divided into synchronous generators and synchronous motors. AC machines in modern power plants are primarily synchronous generators.

O.M.B srl motor performance

Common lubrication methods for motor spindle bearings include grease lubrication, oil mist lubrication, oil-air lubrication, jet lubrication, and under-ring lubrication. Grease lubrication requires no additional equipment and is widely used for low-speed spindles. Oil mist lubrication atomizes lubricating oil (such as turbine oil) using compressed air to lubricate the bearings. This method is easy to implement and uses simple equipment; the oil mist provides both lubrication and cooling. However, oil mist is difficult to recover and causes serious environmental pollution, so it is gradually being replaced by the newer oil-air lubrication method. Oil-air lubrication delivers a small amount of lubricating oil directly along the walls of dedicated oil-air pipes to the bearing lubrication zone using compressed air at regular intervals and quantities, without atomization. The lubricating oil provides lubrication, while the compressed air drives the oil movement and cools the bearings. The oil and air remain separated, which facilitates oil recovery and prevents environmental pollution. When implementing oil-air lubrication, each bearing generally requires a separate oil-air nozzle, with strict requirements for the injection position; otherwise, effective lubrication is difficult to ensure. The effectiveness of oil-air lubrication is also influenced by the compressed air flow rate and oil-air pressure. Generally, increasing the air flow improves cooling, while increasing the oil-air pressure not only enhances cooling but also helps the lubricating oil reach the lubrication zone, thereby helping to increase the bearing speed. Experiments show that increasing the pressure for oil-air lubrication can increase the bearing speed by 20% compared to using conventional pressure. Jet lubrication directly uses high-pressure lubricating oil to lubricate and cool the bearings, resulting in high power consumption and high costs.

O.M.B srl motor operating principle

The motor control system mainly consists of a permanent magnet brushless DC motor, DC voltage source, inverter, position sensor, and controller, adopting a "three-phase six-step 120° square wave" drive. The permanent magnet brushless DC motor operates by turning the inverter power transistors on and off according to a specific pattern, generating a magnetic potential in the motor stator armature that advances continuously by 60° electrical degrees, thereby driving the rotor to rotate. Under ideal conditions, the back EMF and current of each armature phase correspond to each power transistor conducting for 120° electrical degrees, with a phase difference of 60° electrical degrees. When power transistors V3 and V4 are conducting, the motor's V and -U phases are connected (current flowing into the winding is defined as positive). The resultant stator armature magnetic potential is Fa5 as shown in Figure 1; if power transistor V3 turns off and power transistor V5 turns on, the motor's W phase and -U phase are energized, and the resultant armature magnetic potential becomes Fa5. Fa5 has advanced clockwise by 60° electrical degrees compared to Fa4. Thus, the magnetic potential generated by the stator armature rotates continuously clockwise by 60° electrical degrees as the power transistors switch on and off in sequence. There are six commutation states for the inverter power transistors. Each commutation state must correspond to a specific rotor position or back EMF waveform to produce the maximum average electromagnetic torque. The interaction force is greatest when the angle between the two magnetic potential vectors is 90°. Since the magnetic potential generated by the electronic armature advances by 60° electrical degrees, the angle between the rotor magnetic potential and the stator magnetic potential must vary within the range of 60° to 120° in each commutation mode to produce the maximum average electromagnetic torque. As shown in Figure 1, suppose at time t1, the rotor's Fj is within the plane of coils U and X, causing the rotor to rotate clockwise. At this moment, power transistors V5 and V4 should be turned on, making the angle between the stator's resultant magnetic potential Fa5 and Fj equal to 120°. The rotor rotates clockwise under the electromagnetic torque generated by the interaction between Fa5 and Fj. At time t3, the angle between Fa5 and Fj becomes 60°. At this point, power transistor V4 is turned off, and power transistor V6 is turned on. The stator's resultant magnetic potential becomes Fa6, forming an angle of 120° with Fj. The electromagnetic torque generated by both further rotates the rotor. Based on steady-state models, scalar control was the initial operating method for AC motors, characterized by uncontrolled operation. Its control functions were limited to switching on and off, and in some cases, auxiliary starting, braking, and reversing. To meet certain variable-speed drive requirements, several control methods with inferior performance emerged, such as voltage reduction speed control for squirrel-cage asynchronous motors, rotor resistance insertion speed control for wound-rotor asynchronous motors, electromagnetic slip clutch speed control, cascade speed control for wound-rotor asynchronous motors, variable voltage variable frequency (VVVF) speed control for squirrel-cage asynchronous motors (VVVF), pole-changing speed control, and variable voltage variable frequency speed control for synchronous motors. Among these speed control methods, except for variable voltage variable frequency control, most are open-loop controls that do not require inverters. They feature simple equipment but suffer from low efficiency and poor performance. Slip frequency closed-loop control based on constant voltage-to-frequency ratio for squirrel-cage asynchronous motors offers relatively better performance. However, since they are all based on steady-state models, their dynamic performance is poor, and they are generally used only for energy-saving speed control and general speed regulation applications with low dynamic performance requirements, such as water pumps and fans. Vector control theory advances AC motor control from external macroscopic steady-state control to transient control of the internal electromagnetic processes of the motor. This has led to a qualitative leap in the control performance of permanent magnet synchronous motors. The essential characteristic of vector control is the use of coordinate transformations to convert the complex, coupled, nonlinear variables inside the AC motor into DC variables relative to a stationary reference frame (such as current, flux linkage, voltage, etc.), identifying constraints to obtain the optimal control strategy for a given objective.

O.M.B srl motor speed control

Motor speed control: Pole-changing speed control achieves speed regulation by changing the wiring configuration of the stator windings to alter the number of stator pole pairs in squirrel-cage motors. Its characteristics are as follows: 1 It has stiff mechanical characteristics and good stability; 2 There is no slip loss, resulting in high efficiency; 3 Simple wiring, convenient control, and low cost; 4 Stepwise speed control with large steps, preventing smooth speed regulation; 5 Can be used in combination with voltage regulation speed control and electromagnetic slip clutches to achieve efficient smooth speed control characteristics. This method is suitable for production machinery that does not require stepless speed control, such as metal cutting machine tools, elevators, lifting equipment, fans, and water pumps. Variable frequency speed control changes the frequency of the power supply to the motor stator, thereby altering its synchronous speed. The main equipment in a variable frequency speed control system is the inverter, which provides the variable frequency power. Inverters can be categorized into AC-DC-AC inverters and AC-AC inverters; AC-DC-AC inverters are predominantly used domestically. Their characteristics are: 1 High efficiency with no additional losses during speed regulation; 2 Wide application range, suitable for squirrel-cage asynchronous motors; 3 Wide speed regulation range, stiff characteristics, and high precision; 4 Complex technology, high cost, and difficult maintenance and repair. 5 This method is suitable for applications requiring high precision and good speed control performance. Cascade speed control involves inserting an adjustable additional electromotive force (EMF) into the rotor circuit of a wound-rotor motor to change the motor's slip, thereby achieving speed control. Most of the slip power is absorbed by the inserted additional EMF and then returned to the grid or converted for useful energy via additional devices. Depending on how the slip power is absorbed and utilized, cascade speed control can be classified into motor cascade, mechanical cascade, and thyristor cascade speed control. Thyristor cascade speed control is commonly used, with the following characteristics: 1 Slip losses during speed regulation can be fed back to the grid or production machinery, resulting in higher efficiency; 2 The device capacity is proportional to the speed regulation range, offering cost savings. It is suitable for production machinery with a speed regulation range of 70% to 90% of the rated speed; 3 In case of speed control device failure, the system can switch to full-speed operation, avoiding production stoppages; 4 Thyristor cascade speed control has a low power factor and significant harmonic impact. 5 This method is suitable for use in fans, water pumps, steel rolling mills, mine hoists, and extruders.

Weidou Intelligent Technology specializes in selling German O.M.B srl motors, O.M.B srl motors, O.M.B srl drives, O.M.B srl synchronous motors, O.M.B srl servo motors, O.M.B srl DC motors, O.M.B srl AC motors, O.M.B srl stepper motors, O.M.B srl synchronous motors, O.M.B srl asynchronous motors, O.M.B srl single-phase motors, O.M.B srl three-phase motors, O.M.B srl drive motors, O.M.B srl geared motors, O.M.B srl electric motors. O.M.B srl products are original imports from Germany. Customers are welcome to inquire and place orders.