The basic principle of a high-voltage inverter
There are two categories of frequency conversion process of frequency converter: AC-AC form and AC-DC-AC form. Now it is mostly in the form of AC-DC-AC, and the following is a brief introduction to the working principle of this form.
The three-phase high-voltage electricity enters the high-voltage switchgear, and is powered by the power unit in the power cabinet after the input step-down and phase-shifting equal processing; Secondly, when the control unit contained in the main control cabinet passes through the optical fiber, the power unit in the power cabinet is rectified, inverted control, detected and other processing, so that the frequency can be given through the operation interface according to the need; Finally, the control unit in the control cabinet sends the control information to the power unit for rectification, inverter and other adjustments, and outputs the voltage of the required level.
Electricity: induced draft fan, supply fan, primary fan, dust collection fan, booster fan, powder discharger, feed pump, circulating water pump, condensate pump, slurry pump
Metallurgy: dust removal fans, ventilators, mud pumps, descaling pumps
Petrochemical: water injection pumps, electric submersible pumps, oil pumps, pipeline pumps, exhaust fans, compressors, descaling pumps
Water: water supply pumps, water intake pumps
Environmental protection: sewage pumps, purification pumps, clean water pumps
Cement: kiln induced draft fan, pressure supply fan, cooler vacuum cleaner, raw meal mill, air supply fan, cooler exhaust fan, sorter fan, main vacuum fan
Papermaking: Pulping machine medicine: cleaning pump, primary fan, secondary fan
Mining: Drainage pumps, exhaust fans, media pumps, slurry pumps
Pump loads, which are widely used in metallurgy, chemical industry, electric power, municipal water supply and mining, account for about 40% of the energy consumption of the entire electrical equipment, and the electricity bill even accounts for 50% of the cost of water production in the waterworks. This is because: on the one hand, the equipment is usually designed with a certain margin; On the other hand, due to changes in operating conditions, the pump needs to output different flow rates. With the development of market economy and automation, the improvement of intelligence, the use of high-voltage inverter to control the speed of pump load, not only to improve the process, improve product quality is beneficial, but also the requirements of energy saving and economic operation of equipment, is the inevitable trend of sustainable development. The benefits of speed control of pump loads are numerous. From the application examples, most of them have achieved good results (some energy saving as high as 30%-40%), greatly reducing the cost of water production in the waterworks, improving the degree of automation, and is conducive to the pressure reduction operation of pumps and pipe networks, reducing leakage and pipe bursts, and prolonging the service life of equipment.
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Megmeet drives – how should high-voltage drives be maintained after they are shut down?
1. Check the surrounding situation - carefully check the ventilation and lighting of the inverter and the surrounding environment. It is necessary to ensure that the ventilation equipment is functioning properly and that the lighting equipment is in working order.
2. Check the internal cable - open the inverter cabinet door and check whether the internal cable is damaged, the cable ...
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Megmeet PLC maintenance and processing methods
1. CPU abnormality: When the CPU is abnormally alarmed, check the device connected to the internal line of the CPU unit. The specific method is to replace the units that may cause failures in turn, find out the faulty units, and deal with them accordingly.
2. Memory abnormality: When the memory is abnormal alarm, if it is a program ...
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Megmeet inverter - 5 precautions for the use of inverter
1. The circuit board inside the inverter belongs to precision electronic components, which needs to be moisture-proof and dust-proof, and the temperature and humidity are not too high, and cannot be installed on the bare wall, so the inverter should be installed in the middle of the control cabinet; The inverter should be installed vertically, and the installation should be avoided directly above and below ...
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Introduction to Megmeet welding machine
The EhaveCM350AR is a fully digital inverter melting multi-functional industrial heavy-duty Megmeet welding machine launched by Megmeet for global metalworking manufacturing. It brings customers higher quality and higher efficiency welding experience and value with excellent arc characteristics, reliability and high efficiency, and helps customers ...
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Megmeet PLC - the hardware composition of PLC control
1. Power components
The power supply assembly is used to provide the power required for the operation of the PLC, and the external power supply can be converted into a power supply for the PLC internal and applicable to the case.
2. Microprocessor CPU and memory components
Microprocessor CPU is the core device of PLC, and CPU is different from each manufacturer.
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Megmeet PLC – the maintenance steps of the PLC control cabinet
1. Data backup
When carrying out maintenance, we must cut off the power, data backup between power outages is an important link, for the data that needs to be archived for a long time, you can back up the historical trend data to the mobile hard disk, and then turn off the Windows-based operating system (Note...
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Megmeet Inverter - Summary of Common Faults of High Voltage Inverter (21-32)
21。 The unit is overheating
The radiator in the unit is equipped with a temperature switch (normally closed point), and when the temperature exceeds 85°C, the normally closed point of the temperature relay is disconnected, and the unit is overheated and faulty.
Check whether the cabinet top fan is working properly, whether the unit cabinet fan switch is tripped, and whether the filter screen is blocked.
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Megmeet Inverter - Summary of Common Faults of High Voltage Inverter (1-10)
1。 How do you distinguish between heavy and light failures?
When the fault is light, the system sends out an alarm signal, and the fault indicator flashes. When a major fault occurs, the system issues a fault indication, and the fault indicator is always on. At the same time, a command is issued to break the high voltage and close the prohibition, and the fault information and high voltage are instructed.
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Megmeet Inverter - Precautions for the Use of Inverter (11-21)
11. For the occasion when the inverter drives the ordinary motor for constant torque operation, long-term low-speed operation should be avoided as much as possible, otherwise the heat dissipation effect of the motor will become worse and the heating will be serious. If long-term operation at low speed constant torque is required, a variable frequency motor must be selected.
12. For the promotion of negative ...
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Megmeet PLC - What are the steps to complete PLC commissioning?
1. Check the circuit according to the drawing (without power transmission)
The drawings of the general PLC system include two parts: the drawings in the cabinet and the drawings outside the cabinet; The drawing in the cabinet refers to the wiring diagram inside the cabinet; The out-of-cabinet drawings are the wiring diagrams of all electrical cabinets.
This part needs to be checked for;
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Megmeet inverter - inverter braking mode and advantages and disadvantages introduction
What are the braking methods of the inverter? Generally speaking, braking refers to the technical measures taken during the operation of the motor due to fault protection or man-made active shutdown, and the commonly used inverter braking methods include energy consumption braking, feedback braking, DC braking and DC feedback braking. ...
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What are the characteristics of Megmeet PLC - PLC working process?
(1) The PLC adopts the working mode of centralized sampling and centralized output, which reduces the influence of external interference.
(2) The working process of PLC is the process of cyclic scanning, and the length of cyclic scanning time depends on the speed of instruction execution, the length of the user program and other factors.
(3) Output ...
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Megmeet inverter - precautions for inverters at high temperatures
1. Carefully monitor and record the display parameters on the man-machine interface of the inverter, and reflect the abnormality immediately;
2. Carefully monitor and record the ambient temperature of the frequency conversion room, and the ambient temperature should be between -5 °C and 40 °C. The temperature rise of the phase-shifting transformer should not exceed 130°C;
3. Summer ...
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Megmeet drives – what are the components of a drive?
The inverter is composed of a main circuit, a rectifier, a flat wave circuit, and an inverter.
1) Main circuit:
The main circuit is the power conversion part that provides voltage regulation and frequency regulation power supply for the asynchronous motor, and the main circuit of the inverter can be roughly divided into two categories: the voltage type is the DC ...
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Megmeet inverter - the selection principle and precautions of the inverter
1. Select the inverter according to the load characteristics
A: Fans and pumps are the most common loads: the requirements for the inverter are the simplest, as long as the inverter capacity is equal to the capacity of the motor (air compressors, deep water pumps, sediment pumps, and fast-changing music fountains need to increase their capacity).
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Analysis of the fault code of Megmeet welder
1. E1: indicates sensor failure. In this case, it is necessary to check whether the sensors of Megmeet are damaged or whether the wiring is loose.
2. E2: Indicates overweight load. At this point, it is necessary to check whether the load of Megmeet exceeds the set maximum load.
3. E3: Indicates battery ...
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Megmeet inverter - introduction to the control method of low-voltage inverter
1. Sinusoidal pulse width modulation
Sinusoidal Pulse Width Modulation (SPWM) is characterized by simple structure of control circuit, low cost, good hardness of mechanical characteristics, and can meet the smooth speed regulation requirements of general transmission, and has been widely used in various fields of the industry.
However, this control ...
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Megmeet inverter - the fault handling method of low-voltage inverter
Before using the inverter, the inverter parameters should be carried out from the following aspects:
First, confirm the motor parameters, the inverter sets the power, current, voltage, speed, and maximum frequency of the motor in the parameters, and these parameters can be directly obtained from the motor nameplate.
Clause...
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Megmeet PLC common faults
1. External equipment failure. Such faults come from external devices such as various sensors, switches, actuators, and loads. The failure of this part of the equipment will directly affect the control function of the system. This type of failure is usually caused by the quality and longevity of the equipment itself.
2. System failure ...
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Megmeet Inverter - Precautions for the Use of Inverter (1-10)
1. The inverter must be selected correctly.
2. Read the product manual carefully, and wiring, installation and use in accordance with the requirements of the manual.
3. The inverter device should be reliably grounded, and the radio frequency interference should be suppressed to prevent the inverter from causing electric shock due to leakage.
4、 ...
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