Zhejiang SHUYI Electric Co., LTD

The soft starter is mainly composed of a voltage regulating circuit composed of three pairs of anti-parallel thyristors connected in series between the power supply and the controlled motor, with a microprocessor as the control core, and the entire starting process is automatically carried out under the control of digital program software. The soft starter utilizes the electronic switching characteristics of the three pairs of thyristors, and controls the timing of the trigger pulse through the microprocessor in the starter to change the size of the trigger delay angle, and the size of the trigger delay angle of the thyristor can also change the conduction of the thyristor. time, thereby ultimately changing the magnitude of the three-phase voltage applied to the stat winding. The characteristic of the soft starter is that the motor torque is approximately proportional to the quadratic of the stat voltage, and the current of the motor is proportional to the stat voltage. Therefore, the...

1) The higher the operating frequency, the larger the duty cycle of the voltage wave and the smaller the current high-order harmonic component, that is, the higher the switching frequency; 2) The smoothness of the current waveform is better; 3) The higher the switching frequency, the less current the inverter allows to output; 4) The higher the switching frequency, the smaller the capacitive reactance of the wiring capacitor (because Xc=1/2πfC), and the greater the leakage current caused by the high frequency pulse. www.shuyitop.com; Tel/Fax: 0086-577-62840011 WhatsApp: 008613355775769 #inverter #forfrequencydrive #ACvfd #frequencyinverter #variablefrequencydrive #threephaseacinverter #ZJSHUYI #variablefrequencyinverter #3phaseinverter #chinashuyi #achotsalefrequencyinverter #highvoltageacinverter #SHUYITOP

According to the function of the soft starter, it is suitable for the following occasions: 1. Where it is required to reduce the starting current of the motor. 2. During normal operation, the motor does not need to have a speed regulation function, and only solves the working state of the starting process. 3. During normal operation, the load is not allowed to step down or slow down. 4. The power of the motor is large (such as greater than 100kW), which will cause adverse effects on the operation of the main transformer during startup. 5. The equipment is precise, and the start-up shock is not allowed when the equipment is started. 6. The starting torque of the equipment is not large, and it can be started with no load or light load. 7. Medium and large motors need energy-saving starting. From the initial investment point of view, it is more economical to use an auto-decompression starter for motors with a power below 75kW, and it is more cost-effective to use a soft starter for motors...

1. Overload protection function: The soft starter introduces a current control loop, so it can track and detect the change of motor current at any time. By increasing the setting of overload current and the inverse time limit control mode, the overload protection function is realized. When the motor is overloaded, the thyristor is turned off and an alarm signal is issued. 2. Phase loss protection function: When working, the soft starter can detect the change of the three-phase line current at any time. Once the current is cut off, it can make a phase loss protection response. 3. Overheating protection function: The temperature of the thyristor radiator is detected by the internal thermal relay of the soft starter. Once the temperature of the radiator exceeds the allowable value, the thyristor is automatically turned off and an alarm signal is issued. 4. Other functions: Through the combination of electronic circuits, various other interlocking protections can also be realized in the sy...

The inverter uses vector control in the occasions that require torque control, occasions that require low-speed and high-torque output, and occasions that require a wide speed regulation range beyond the rated speed, and require good control characteristics, etc. In fact, as long as it is V/F control, vector control can be used. The debugging requirements of vector control are a little more complicated than V/F control, and he is more strict in determining the motor model. That's all. The biggest feature of multi-machine parallel drive is that the load torque of each motor at the same time will not be the same. If it is a large vector control at this time, the ghost knows how the excitation component and torque component of each motor are distributed. . Judging from the sum of the power supply of the motor, it is a vector model of the motor, but it is not clear when it is converted to each motor. Although the equivalent model of the motor is the same, the control will change due to...

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Our cooperation with every customer starts with some samples. From sample order to trial order to mass production, our service aim is to do our best for every order. Provide all the information customers want, including product pictures, packaging pictures, packing lists, invoices. Thanks to our customers for their recognition and continuous orders, we will have more far-reaching and long-term cooperation. www.shuyitop.com; Tel/Fax: 0086-577-62840011 WhatsApp: 008613355775769 #softstarter #motorsoftstar #softstarters #softstartechnology #solidstatesoftstarter #acmotorstarter #singlephasesoftstarter #24monthswarrantysoftstarter #voltagerampstartsoftstarter #15-400kwintelligentsoftstarter #3phasesolidstatesoftstarter

The soft starter is only used for starting, continuous use is not allowed, so a bypass contactor should be used after starting. The bypass soft starter must be used together with the contactor to work normally. After the soft starter starts, the main current is switched to the bypass contactor, and the current during normal operation does not go inside the soft starter, but this does not mean that this is the case. When the soft starter is useless. There is a high-precision transformer inside the soft starter, the main current will pass through it, and the soft start detects the current and voltage during operation through the transformer. The contactor will command the coil of the bypass contactor to de-energize, and the contactor will disconnect the main current, thus playing a variety of protection functions. How to wire the control circuit between the soft starter and the external contactor? First, first understand the secondary control loop of soft start. Generally, soft start ...

1. The motor can't get up There are two reasons why the motor cannot start. One is that one of the six thyristors is unreliable or non-conductive, the one-phase circuit passes half-wave DC, and the two-phase winding of the motor passes through the DC to start the motor. When the braking effect is reached, not only the motor cannot be started, but also the motor and the thyristor will be burned in serious cases. The second is that the motor cannot be started due to improper starting parameters or starting curve, which is the most common fault problem. 2. The thyristor is burnt The thyristor is destroyed or exploded. This kind of failure has nothing to do with domestic and foreign brands, but the failure rate is lower than that of the contactor. The main problem appears in the installation technology of the pie-type thyristor. 3. Controller burnout Compared with the soft starter, the controller burns the most seriously. Some manufacturers have this failure with repair rates in exce...

How to control soft start with buttons 1. First understand the secondary control loop of soft start. Generally, soft start has bypass contactor output node. 2. Know the load start-up time again. The best time to cut the bypass contactor is after the start-up process is completed. 3. The main circuit of the bypass contactor should be connected in parallel with the soft starter. 4. String the output node of the bypass contactor into the control loop of the bypass contactor, preferably a self-locking loop. Among them, the external contactor is used for direct starting, which is in a parallel relationship and requires electrical interlocking. How to measure the quality of soft starter 1. Visual observation. Through visual inspection, we can observe whether the soft starter has the following phenomena: The soft starter has strong damage, and the damage is usually caused by collision, fire, water, dust, load short circuit, etc. Treatment method: It can be sent back to the manufacturer for re...

1. Startup Curve - Set the time for voltage boost at startup Description: Ramp boost soft start. This starting method is the simplest, it does not have current closed-loop control, and only adjusts the conduction angle of the thyristor to increase it as a function of time. The disadvantage is that, due to the unrestricted current, when the motor is started, sometimes a large inrush current is generated to damage the thyristor, which has a great impact on the power grid and is rarely used in practice. Start-up time can be adjusted within 1-30 seconds. 2. Stop curve - set the speed of voltage drop at stop time Description: When the motor stops, the traditional control method is completed by instantaneous power failure. But there are many applications where momentary shutdown of the motor is not allowed. For example, if the pump system of high-rise buildings and buildings is stopped instantaneously, it will produce a huge "water hammer" effect, which will damage the pipes and ev...

1. Selection of overload protection device Thermal overload relay with overload protection, phase break protection and temperature compensation function shall be selected for the overload protection device of soft start device. Specific selection, to make the working current of the motor within the range of setting current of the thermal element. The rated current value of the motor should be close to the lower limit of the setting current range of the thermal element for equipment that is prone to overload when working. 2. Electrical wiring and component arrangement of low-voltage soft starter cabinet Electrical wiring of low-voltage soft starter cabinet is shown in Figure 2. The electrical components in the cabinet are arranged in the order shown in the diagram, so that the main wiring is short and not crossed, which is convenient for copper bar connection. The soft starter is installed on the right side of the contactor and is not affected by the heating of other components. The d...

11. When the IGBT is connected through, the dead time becomes narrower (the temperature increases, the inverter tube is aging), and the inverter tube enters the amplifying area (the drive power voltage drops, and the inverter tube ages). 12. The output current of the inverter determines the output torque of the inverter. If it is a constant torque load, the current has nothing to do with the frequency drop. The DC part of the inverter will decrease as the frequency decreases, and the input current will decrease as the frequency decreases. 13. The inverter plus the output reactor can effectively suppress the change of DU/DT, because the inverter output is all PWM wave, and there is also distributed capacitance at a long distance, so there may be a large leakage current. 14. Adding capacitors can't change the power factor of the motor. It just means that the capacitor can provide part of the reactive current to the motor without the need for the motor to obtain it from the circuit...

Zhejiang Shuyi Electric Co., Ltd. talks about the necessity of soft start cabinet in power system 1. The soft start cabinet can slow down the impact on the power grid The impact of the large current started by the large motor on the power grid is almost similar to the impact of a three-phase short circuit on the power grid, which often causes power vibration and the power grid loses stability. In addition, the starting current contains a large number of high-order harmonics, which will cause high-frequency resonance with the power grid circuit parameters, resulting in malfunction of the relay protection. Therefore, if the soft start cabinet is involved, the starting current will be greatly reduced. 2. Influence on the motor. The large current produces a great impact on the stator coil and rotor squirrel cage bar of the motor, which will cause the coil to deform and the squirrel cage bar to break. 3. Influence on motor insulation and life. Excessive starting current will increase the...

In industrial applications, the speed control and torque control are not very demanding for general use of frequency converters, and in the occasions with strict position control requirements, the intelligent use of AC servo drives is used to achieve, and the response speed of the servo is much greater than Frequency conversion, some occasions that require high speed accuracy and response are also controlled by AC servo drives. That is to say, almost all occasions that can be controlled by frequency conversion can be replaced by AC servo drives. AC servo drives and inverters can be said to be a pair of brothers, both of which are drives of AC motors. According to the order of appearance, the inverter should be called the elder brother, and the AC servo drive should be called the younger brother. The frequency converter drives the frequency conversion motor, and also drives the ordinary AC motor. The main function is to adjust the speed of the motor. The AC servo driver drives the AC s...

(1) Selection of overload protection device The overload protection device of the soft start device should choose a thermal overload relay with overload protection, phase failure protection and temperature compensation functions. When selecting, the working current of the motor should be within the range of the setting current of the thermal element. For equipment that is easy to be overloaded during operation, the rated current value of the motor should be close to the lower limit of the setting current range of the thermal element. (2) The electrical wiring and component arrangement of the low-voltage soft-start cabinet The general electrical wiring of the low-voltage soft-start cabinet is shown in Figure 2. The electrical components in the cabinet are arranged in the order shown in the figure, so that the main wiring is short and does not cross, which is convenient for the connection of copper bars. The soft starter is installed on the right side of the contactor and is not affected...

The digital display time relay is an important period that can control the electrical system. It is generally divided into two types, one is an electrical appliance that can be powered on and delayed, and the other is an electrical appliance that can be powered off and delayed. The working principle of the digital display time relay includes electronic and mechanical actions. In the electronic action principle, the combination of capacitors and electronic components is often used to achieve the effect of delay. The mechanical action is to use the airbag and spring. The digital time relay is a single-pole, double-throw switch with a rod wall with an active point, just like the knife switch we see in our daily life, it can move up and down, especially the 8th position, this is a Active point, and position 5 is a normally closed point, when the digital time relay does not move, connect these two together. But in the action state, it is necessary to connect the 8th interface and the 6th in...

Soft starter is a kind of motor control equipment with various protection functions, and various faults will also occur in the application. , Due to the variety of operation methods, the maintenance method of soft start is also more complicated. You should know that a complete soft starter is a standard motor starter controller that can be used to protect and control medium and high voltage AC motors. Its operation process can be divided into four processes: starting preparation, starting process, running and stopping process. The following will introduce you one by one. The first is the preparation of the soft starter operation process. In this process, control and power have been added to the starter, and its protection includes short circuit to SCR, bypass clutch, and contact melting short circuit. Other detection and protection features, whether the soft starter temperature rise fuse indicator light is in the correct sequence (if selected), the power input frequency tripping range,...

MCC is shorted for Motor Control Center. Soft starter MCC control cabinet consists of the following components: (1) input circuit breaker, (2) Soft starter (including electronic control circuit and three phase thyristor), (3) soft starter bypass contactor, (4) secondary-side control circuit (for manual start, remote start, soft start and direct start functions selection and operation), and voltage, current display, fault, running and working status indicators. We can achieve various complex functions with combinations of soft starter MCC control cabinet. For example: add logic controller to two control cabinets to form a "alternative solution" for building's fire protection system, sprinkler pumps etc. Couple with PLC (programmable logic controller), we can achieve automatic detection (eg half a month) and shutdown of the fire pump system; couple with corresponding logic controller to make the pump running at low speed and low pressure in setting time when we mainten...

In principle, the selection of the #softstarter should be larger than the capacity of the motor being driven. The rated capacity of the soft starter usually has two kinds of nominal: one is nominal according to the power of the corresponding motor; the other is nominal according to the maximum allowable current of the soft starter. The following two points should be noted: 1) Based on the nominal rated capacity of the motor, the rated current of products with different voltage levels is different. 2) It is nominally based on the maximum allowable working current of the soft starter, and the rated capacity of products of different voltage levels is different. In addition, comprehensive consideration should be given, such as the load capacity of the soft starter, working system, environmental conditions, cooling methods, etc. www.shuyitop.com; Tel/Fax: 0086-577-62840011 WhatsApp: 008613355775769 #softstarter #motorsoftstar #softstarters #softstartechnology #solidstatesoftstart...

Debug sequence of soft starter: 1. Selection of starting mode and starting time of soft starter: ① For soft starters of general power, the larger the load, the longer the starting time; ② When the quality of power supply of the power grid is relatively high, the current limit start can be selected, and the same load The larger the value, the longer the startup time should be. 2. Check whether the motor can rotate normally and flexibly, otherwise it will never start. 3. Check the parameters of the fan, motor and soft starter. Parameters checked include voltage, current, power, and the number of poles of the motor. 4. The commissioning sequence is manual cranking, air-dropping control loop, motor idling, and running with load. 5. Check the insulation resistance of the motor. This work must be done before the motor is connected to the soft starter, because the starting circuit is composed of thyristor components. When the motor and the soft starter are connected, if the motor insulat...