KEB motor, German KEB model, KEB price

KEB motors refer to electric motors with a rated voltage above 1000V. Commonly used voltages are 6000V and 10000V; due to differences in foreign power grids, there are also voltage levels of 3300V and 6600V. High-voltage motors were developed because motor power is proportional to the product of voltage and current. Therefore, when the power of low-voltage motors increases to a certain level (such as 300KW/380V), the current is limited by the allowable carrying capacity of the wires, making it difficult to increase further or resulting in excessive costs. High voltage is required to achieve high-power output. The advantages of high-voltage motors are high power and strong shock resistance; the disadvantages are high inertia, making starting and braking difficult.

KEB motor control principle

Motor control principle: To make the motor rotate, the control unit must first determine the rotor position based on signals sensed by the hall-sensor. It then determines the switching sequence of the power transistors in the inverter (inverter) according to the stator winding configuration. This involves the AH, BH, and CH (known as upper-arm power transistors) and the AL, BL, and CL (known as lower-arm power transistors) within the inverter. This causes current to flow through the motor coils in sequence, generating a forward (or reverse) rotating magnetic field that interacts with the rotor magnets, thereby causing the motor to rotate clockwise or counter-clockwise. When the motor rotor rotates to a position where the hall-sensor senses another set of signals, the control unit activates the next group of power transistors. This cycle allows the motor to continue rotating in the same direction until the control unit decides to stop the rotor by turning off the power transistors (or only turning on the lower-arm power transistors). To reverse the rotor direction, the activation sequence of the power transistors is reversed. Basically, the activation of power transistors can be exemplified as follows: AH and BL as a pair → AH and CL as a pair → BH and CL as a pair → BH and AL as a pair → CH and AL as a pair → CH and BL as a pair. However, AH and AL, or BH and BL, or CH and CL must never be turned on simultaneously. Furthermore, since electronic components always have switching response times, the response time must be considered during the transition between off and on states. Otherwise, if the lower arm (or upper arm) turns on before the upper arm (or lower arm) has completely turned off, it will cause a short circuit between the upper and lower arms, burning out the power transistors.

KEB motor performance

The circuit driven by transistors, resistors, and diodes achieves adjustable speed, forward, and reverse drive for DC motors. The four diodes protect the transistors by preventing the negative induced electromotive force generated by inductive components (the motor) from impacting the transistors. When the 74LS00 output is low, Q2 and Q4 are cut off, while Q1 and Q3 conduct, resulting in a high output. When the 74LS00 output is high, Q2 and Q4 conduct, while Q1 and Q3 are cut off, resulting in a low output. The supply voltage is 15–30v, with a maximum continuous output current of 500mA per motor. For short durations (10 seconds), it can reach 700mA. The maximum PWM frequency can be up to 30kHz (typically 1–10kHz). High-current traces should be as short and thick as possible, and vias should be avoided. If vias are necessary, they should be made larger (>1mm), and a ring of small vias should be placed on the pad and filled with solder during welding to prevent burnout. Additionally, if voltage regulator diodes are used, the wires connecting the transistor emitter and collector to the power supply and ground should be as short and thick as possible. Otherwise, under high current, the voltage drop across these wires may pass through the diodes and conducting transistors, causing them to burn out. The PWM signal can be generated by a timer. However, since the 51 internally provides only two timers, repeatedly setting the timer to output signals with different duty cycles to three or more DC motors is complex. We adopt a simpler method that not only provides different duty cycle input signals to more DC motors but also occupies only one timer resource. This method can be simply described as follows: Store the duty cycle information required by each DC motor in a specific memory space. If the duty cycle is 1, save 0FFH (11111111B); if the duty cycle is 0.5, save 0F0H (11110000B) or any binary number containing 4 0s and 4 1s. That is, Duty Cycle = Number of 1s / 8. The specific binary number selected depends on the output frequency requirements. To output the PWM signal to this DC motor, simply shift once per time slice to extract a fixed bit (implemented using bit addressing or the carry flag C) and send it to the motor port. Additionally, since the shift algorithm depends on previous results, it is best to regularly check or reset the shifted number to prevent persistent errors caused by incorrect shifting. The advantage of this algorithm is that it is an independent process capable of controlling multiple motors; the disadvantage is that it consumes more resources and results in a lower PWM frequency.

KEB motor classification

General DC motors share the same working principles and application characteristics, but their compositions differ. In addition to the motor itself, the former includes a commutation circuit, with the motor and commutation circuit closely integrated. Many low-power motors have the motor body and commutation circuit integrated into a single unit; visually, brushless DC motors appear identical to DC motors. The motor body of a brushless DC motor is the electromechanical energy conversion part. In addition to the armature and permanent magnet excitation, it includes sensors. The motor body is the core of the brushless DC motor, affecting performance indicators, noise and vibration, reliability, service life, manufacturing costs, and product costs. The use of permanent magnet fields allows brushless DC motors to break away from the traditional design and structure of general DC motors, meeting various market application requirements and developing towards copper saving, material efficiency, and simplified manufacturing. The development of permanent magnet fields is closely related to the application of permanent magnet materials. The application of third-generation permanent magnet materials has promoted brushless DC motors towards high efficiency, miniaturization, and energy savings. Electronic commutation requires position signals to control the circuit. Early systems used electromechanical position sensors to obtain position signals; now, electronic position sensors or other methods are gradually used. The simplest method is to use the electromotive force signal of the armature winding as the position signal. Motor speed control requires speed signals. Speed signals are obtained using methods similar to those for position signals. The simplest speed sensor combines a frequency-measuring tachogenerator with electronic circuits. The commutation circuit of a brushless DC motor consists of drive and control parts, which are difficult to separate. Especially for low-power applications, these two parts are often integrated into a single dedicated integrated circuit. In higher-power motors, the drive circuit and control circuit can be separate entities. The drive circuit outputs electrical power to drive the motor armature winding and is controlled by the control circuit. Drive circuits have transitioned from linear amplification to pulse-width modulated switching states, and their composition has shifted from discrete transistor circuits to modular integrated circuits. Modular integrated circuits consist of power bipolar transistors, power field-effect transistors, and insulated-gate bipolar transistors (IGBTs). Although IGBTs are more expensive, they are more suitable in terms of reliability, safety, and performance. The control circuit controls motor speed, direction, current (or torque), and provides protection against overcurrent, overvoltage, and overheating. These parameters are easily converted into analog signals for simpler control. However, from a development perspective, motor parameters should be converted into digital quantities and controlled via digital control circuits. Currently, control circuits are composed of dedicated integrated circuits, microprocessors, and digital signal processors (DSPs). For applications with less stringent motor control requirements, dedicated integrated circuits are a simple and practical solution. Using DSPs for control circuits is the future direction; DSPs will be discussed further in the section on AC synchronous servo motors. Brushless DC motors are a rapidly developing new type of motor in the micro-power range. Since various application fields require unique brushless DC motors, there are many types. These generally include flat coreless motor structures for computer external storage drives, VCD, DVD, and CD spindle drives; outer rotor motor structures for small ventilators; multi-pole magnetic field structures and internal mounting structures for home appliances; and multi-pole, outer rotor structures for electric bicycles. In the aforementioned brushless DC motors, the motor body and circuit are integrated, making them very convenient to use, and their production volume is very large. To meet the market demand for large volumes and low costs, brushless DC motor production must achieve economies of scale. Therefore, the brushless DC motor industry is characterized by high investment and high output. Meanwhile, we must consider continuous market development. For example, motors for household air conditioners are shifting from 3A to 3D, creating a demand for a large number of medium and low-power brushless DC motors. Research and development of medium and low-power brushless DC motors have become urgent tasks.

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