Diagram of the motor control unit icons and symbols

There were various prices for motor control units. For example, some models of motor control units under the brand of Abbott were priced in different price ranges such as 3723.00 - 3950.00 yuan, 5900.00 yuan, 6800.00 yuan, 7418.00 yuan, 86.00 yuan, etc. There were also cases where the price of the engine hydraulic control unit for the Dodge Challenger 15 - 21 cars was not specified. There was also a price of 1.0 yuan. 10.0 yuan, 12.0 yuan, and other control units for different purposes. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The motor control unit was shortened to MCUs, which meant the module that controlled the motor's actions. It could also be referred to as EMCUs, which stood for the Electric Motor control unit. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The following is a circuit diagram of a motor reverse rotation time control: As for the physical connection diagram, there was a problem with the control of the two AC contactors. The control requirement was to press the self-locking button SSS, and the motor would run clockwise (forward) for 35 seconds, counterclockwise (reverse) for 30 seconds, and then the motor would run forward for 35 seconds, and so on. Press the button SSS again, and the motor would stop running. A simple loop control circuit could be controlled by a relay. In the teaching materials, the symbol of an energized delay relay could be used to replace the double delay time relay, and a pulse counter (its function was the same as the double delay time relay) could also be used to replace the simulation. The double delay loop interlocked time relay used two independent time relay T1 and T2 to be interlocked to form a loop closing and opening working mode. The delay time of T1 and T2 was set independently. With the choice of time base, it could be set freely within a certain range. In a three-phase induction motor control system, KM1 and KM2 were AC contactors that controlled forward and reverse operation respectively. In the ladder diagram, two start-stop circuits were used to control the forward and reverse rotation of the motor. Pressing the start button for forward rotation, the corresponding input point X0 turned ON, and its normally open contact was connected. The coil of Y0 was "energized" and self-protected, so that the coil of KM1 was energized, and the motor began to rotate forward. Press the stop button, and X2 will turn ON, and its normally closed contact will be disconnected, causing the Y0 coil to "lose power" and the motor to stop running. In the ladder diagram, the normally closed contacts of Y0 and Y1 were connected in series with each other's coil (this was called "interlocked" in the relay circuit). At the same time, a "button interlocked" was also set, which was to connect the normally closed contact of the reverse start button X1 in series with the coil of Y0 that controlled the forward rotation, and connect the normally closed contact of the forward start button X0 in series with the coil of Y1 that controlled the reverse rotation. This setting can achieve positive and negative rotation control and ensure that the coil of KM1 and KM2 will not be energized at the same time. For the positive and negative transfer wires of the three-phase motor, press the forward rotation button circuit control button SP2, the KM1 coil, and the KM2 normally closed contact. The power is connected, and the forward rotation coil is energized to start the motor. At the same time, the normally closed contact of the KM1 is disconnected, and the KM2 coil connected in series cannot be connected. Press the reverse rotation button circuit control button SSB3, the KM2 coil, and the KM1 normally closed contact. The power is connected, and the reverse coil is energized to start the motor. At the same time, the normally open contact of the KM2 is disconnected, and the KM1 coil connected in series cannot be connected. These were part of the circuit diagram principles involved in the motor's forward and reverse rotation time control circuit. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The drive unit consisted of a drive device and a motor. The selection of the motor drive unit mainly depended on the choice of the drive device, because the motor was a common component, and the performance difference mainly depended on different manufacturers and models. Taking the stepping motor as an example, there were three types of single-voltage power drive units: single-voltage drive, dual-voltage drive, and high-low-voltage power drive. The single-voltage drive is to connect a resistance in the motor winding circuit to reduce the time constant of the double-voltage power drive interface of the motor circuit. At high frequency, the motor can produce a large electromagnetic moment and alleviate the low-frequency resonance phenomenon, but it will cause additional losses. High and low voltage drive was to use high voltage power supply to increase the current front of the conducting phase winding regardless of the operating frequency of the motor, and then use low voltage to maintain the winding current. There was also the ACM6763, a high-current three-phase Brushless Inductive Direct Current Drive Chip. The operating voltage was between 4.5V and 32V, with a peak phase current of 5A and a withstand voltage of 45V. It integrated the three-phase Brushless Drive algorithm, power tube, and current/voltage detection. It only needed six resistor-tolerant components and one resistance to drive a three-phase Brushless Direct Current motor. In the design of robots, the motor was an important driving unit. According to whether there was a brush transformer, the direct current motor could be divided into brushed motor and brushed motor. The brush motor has a simple structure, and it is reversed by a transformer. However, due to the long-term friction between the brush and the transformer, it causes mechanical wear, noise, short life, and needs regular maintenance. The structure of the Brushless motor is slightly more complicated, and it uses electronic phase reversal. Brushless motor's motor was a permanent magnet, and the rotating magnetic field generated by the winding of the motor drove the motor to rotate. According to the different back EMF waves, square-wave back EMF was usually driven by square-wave current, and sine-wave back EMF was usually driven by sine-wave current. Brushless motor drive requires a motor driver (electronic regulator), through the control of A, B, C three input to make the motor rotate and control its speed and direction, speed regulation can be used pulse width regulation (Pulse width regulation). In addition, there were also high-performance servo-axis drive units such as the MDS-D/HH series, which could improve the performance of the drive system (high gain control); MDS-D-LVJ3/SPJ3 series and MDS-D/HH series had ultra-compact drive units with built-in power supply, which could reduce the size of the operation panel; MDS-EM series, which could drive up to three servo-axes and one main axis; The MDS-EJ/EJH series of integrated compact drive units came with a built-in power supply. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The symbol of the transformer is C. In the international system of units, the unit of capacity was farad, or French for short, and the symbol was F. Because the unit Farad was too large, the commonly used units of capacity were millifarad (mF), microfarad (pF), nanofarad (nF), and picofarad (pF). The conversion relationship was: 1 Farad (F)= 1000 milliFarad (mF)=1000000 microFarad (uF);1 microFarad (uF)= 1000 nanofarad (nF)= 1000000 picofarad (pF). An example of how to read a voltage is as follows: 105 = 1000000pF = 1000nF = 1 pF;104 = 100000pF = 100nF = 0.1 pF;103 = 10000pF = 10nF = 0.01 pF;102 = 1000pF = 1nF = 0.001 pF;224 = 22×10 pF = 220000pF = 220nF = 0.22uF. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The following is an explanation of the principle of alternating forward and backward rotation of the motor: ##I. Explanation of the principle analysis diagram based on the relay control circuit 1. * * Main circuit part ** - Main switch QF: It is the main switch of the main circuit and the control circuit, mainly used to isolate the power supply and short-circuit protection. - AC contactors KM1 and KM2 main contacts: connected in series in the main circuit, switched on and off to control the positive and negative rotation cycle of the motor. For example, when the KM1 main contact is closed, the motor receives a power input of a phase sequence and turns forward; when the KM2 main contact is closed, the motor receives a power input of a changed phase sequence and turns backward. 2. * * Control circuit part ** - "Relay KC: After pressing the start button, the KC coil is energized, and its normally open contact is closed and locked in the closed position. This is the start of the entire control circuit. - Time Relays KT1 and KT2: - When the KC normally open contact is closed, the KT1 and KM1 coil circuits are connected. The main contact of KM1 is closed to make the motor rotate forward, and the normally closed contact of KM1 is opened (in the coil circuit of KM2) to prevent the reversing contactors from getting electricity when the motor is rotating forward. KT1 was connected in series to the delay contacts of the KM1 and KM2 coil circuits, and the timer started. - When the KT1 delay contact reaches the set time, the delay break contact is opened to cause the KM1 coil to lose power (the main contact of the forward rotating contactors is opened), and the delay close contact is closed. At this time, the KM2 coil and the time relay KT2 coil are energized, the KM2 main contact is closed, and the motor is reversed. The KM2 normally closed contact is opened (in the KM1 coil circuit) to prevent short circuit. - Then, KT2 was connected in series with the time relay delay break contact of the KT1 coil circuit to start timing. When the KT2 delay break contact reached the set time, the KT1 coil lost power, and the two delay contacts of KT1 were reset. Then, the KM2 and KT1 coil lost power, and the KM2 main contact was disconnected. After the relevant contacts were reset, the AC contractor coil KM1 and the time relay KT1 coil were energized again, and so on. ##II. Explanation of the principle analysis diagram of the control system (ladder diagram) 1. * * Forward Rotation Control ** - Press the forward start button, SSB2 (in the ladder diagram, the corresponding X0 turns on), and its normally open contact is connected. The coil of Y0 is "energized" and self-protected, which makes the coil of KM1 energized and the motor starts to rotate forward. Here, the normally closed electric shocks of Y0 and Y1 were connected in series with each other's coil to form an interlocked loop, ensuring that the coil of KM1 and KM2 would not be energized at the same time. 2. * * Reverse Control ** - When the motor is rotating forward (Y0 is on), if you directly press the reverse start button SSB3 (X1 becomes on), the normally closed contact of X1 will be disconnected, causing the Y0 coil to "lose power". At the same time, the normally open contact of X1 will be connected, causing the Y1 coil to "gain power", and the motor will turn from forward to reverse. 3. * * Interlocking mechanism ** - In the ladder diagram, in addition to connecting the normally closed contact of Y0 and Y1 to the coil of the other party in series (called "electrical interlocked "), there was also a" button interlocked ". The normally closed contact of the reverse start button X1 was connected in series with the coil of Y0 that controlled the forward rotation, and the normally closed contact of the forward start button X0 was connected in series with the coil of Y1 that controlled the reverse rotation. This double interlocked ensured the safety and reliability of the forward and reverse rotation control. ##III. Explanation of the principle analysis diagram based on the double interlocked positive and negative rotation control circuit (double interlocked contactors and buttons) 1. * * Forward Rotation Start ** - Press the start button of the SSB1 forward rotation, and its break contact will first break the reverse circuit to realize the button interlocked, and then its contact will close, and the KM1 coil will be energized. The KM1 break-off auxiliary contact first breaks the reverse circuit to realize the mutual locking of the contactors, then the KM1 break-on auxiliary contact and the KM1 main contact are closed at the same time to realize the self-locking, and the motor is energized to rotate forward. 2. * * Reversal activated ** - Directly press the reverse start button of the SK2, and the break contact will first break the forward circuit to realize the button interlocked, and then the contact will be closed, and the KM2 coil will be energized. The KM2 movable break auxiliary contact first breaks the forward rotation circuit to realize the mutual locking of the contactors, then the KM2 movable close auxiliary contact and the KM2 main contact are closed at the same time to realize the self-locking, and the motor is energized to reverse. 3. * * Stop Operation ** - Press the stop button of the SSB3, and the motor will stop running. The double-interlocked circuit overcame the shortcoming that the stop button needed to be pressed when the positive and negative reversing control circuit of the interlocked contactors switched over. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The principle of the three-phase induction motor's forward and reverse swing: The three-phase induction motor has three-phase winding, and the voltage of each phase winding is 120° different. When three-phase symmetrical alternating current is introduced into the three-phase winding of the stators, a rotating magnetic field is generated, and an induced current is generated by cutting the winding of the rotators. Under the effect of the rotating magnetic field of the stators, the conductor of the current carrying rotators generate electromagnetic force to form an electromagnetic moment to drive the motor to rotate, and the direction of rotation of the motor is the same as the direction of the rotating magnetic field. To achieve positive and reverse control, you only need to switch any two phases in the power supply phase sequence (such as keeping phase B unchanged and switching phase A and phase C), and make the connection on the top port of the contactors consistent, and phase adjust the lower port of the contactors. For the single-phase motor, the principle of positive and negative rotation swing: Single-phase motor is generally powered by single-phase AC power supply (AC220V). There are two-phase winding on the stators, and the rotor-type is ordinary squirrel cage. The starting winding is added to the stators. The starting winding and the main winding are separated by 90° in space. The starting winding is connected in series with a suitable capacity, so that the current of the starting winding and the main winding are separated by approximately 90° in phase, thereby generating a rotating magnetic field to make the rotor-to-start operation automatically. When the direction of rotation needs to be changed, the L wire ends of the main and auxiliary winding can be reversed to realize reverse operation. In terms of the motor reverse rotation control circuit schematics: - In the relay control circuit, such as the three-phase induction motor forward and reverse control circuit, KM1 and KM2 are AC contactors that control forward and reverse operation respectively. Two start-stop protection circuits are used to control the forward and reverse rotation of the motor respectively. When the forward rotation start button is pressed, the corresponding contactors coil is energized and the motor is rotated forward. The forward and reverse contactors will not be energized at the same time through the interlocked (including the interlocked contact of the normally closed contact of the contactors and the interlocked button). It was the same for reversal. - In the control system of the PC, the external connection diagram and the ladder diagram achieved similar functions. There was also a start-stop circuit to control the positive and negative rotation, and there were interlocked measures to prevent simultaneous output. In addition, in order to avoid the instantaneous short-circuit fault caused by the delay of the induction, the delay during the forward and reverse switching can be used (but it will increase the programming workload and cannot solve all short-circuit accidents). At the same time, in order to prevent the three-phase power short-circuit accident caused by the electric arc fusion welding when the main contact of the contactors is cut off due to the excessive current of the main circuit or the quality of the contactors, a hardware interlocked circuit composed of the auxiliary normally closed contacts of the contactors should be set outside the PC. The thermal relay was used for overload protection. The thermal relay with different reset functions (manual reset or automatic reset) had different contact connection methods. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The electronic fuel injection system used the electronic control unit as the control center. It used various sensors installed on the engine to measure the operating parameters of the engine, and then accurately controlled the fuel injection amount of the fuel injection according to the pre-stored control program in the computer, so that the engine could obtain the best air-fuel ratio of the flammable mixture under various working conditions. In the entire system, the Electronic Control Unit (CPU) played a key role. For the control of the fuel injection amount, the CPU will collect the engine speed signal and load signal for analysis to determine the basic fuel injection amount (fuel injection pulse width), and correct it according to the cooling liquid temperature signal and other signals to obtain the total fuel injection amount. In terms of fuel injection timing control, for an engine with multi-point sequence injection, the CPU controls the fuel injection time at the best time according to the ignition sequence of each cylinder of the engine to ensure that the gasoline injected into the cylinder is fully burned. In addition, the CPU also played a role in fuel cut-off control, which included normal deceleration fuel cut-off control (when the vehicle suddenly released the accelerator pedal, the CPU automatically cut off the fuel injection control circuit and stopped the fuel injection. When the engine speed dropped to the critical speed, the fuel supply was resumed) and overrun fuel cut-off control (when the engine reached the critical speed or the set maximum speed, the CPU cut off the control circuit of the electric fuel pump and stopped the fuel injection to prevent the vehicle from speeding). For the fuel pump control, after the ignition switch is turned on, the CPU will make the fuel pump work for 2 - 3 seconds to establish the oil pressure when the engine starts. The fuel pump will maintain normal operation during the engine starting and running process. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The electronic control unit in the electric control system of the new energy vehicle was the core component, which was mainly composed of sensors, control units, and actors. In hybrid vehicles, the electronic control unit needed to go through various complicated adjustments before it could be applied. This process was similar to the adjustment between the engine and the transmission of a fuel car. It required long-term experience to achieve obvious results. Toyota had done in-depth research on the electronic control management system of hybrid vehicles. For example, in the charging and discharge of the battery pack and kinetic energy recovery, Toyota divided the battery structure and controlled the charging capacity in the area that was not easy to age; The battery pack was equipped with a battery temperature control system that inhibited battery aging; The upper limit of the charging range was limited to 90%, so that when the kinetic energy recovery system was used, there was sufficient capacity to collect the kinetic energy brought by the brakes and increase the safety of driving downhill on long slopes. These were the manifestations of the hybrid vehicle's electronic control unit in the research and development results of different car companies. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>