In order to measure stable harmonics, it is necessary to meet the following two conditions:
At the top of the list, the signal is a stable periodic signal.
Second, it is necessary to perform harmonic analysis according to the integer multiple of the period of the stable periodic signal.
The switching frequency of the traction motor inverter is low, and its switching frequency is often not an integer multiple of the fundamental frequency, so that the output of the inverter is actually not a strict periodic signal (of course, there is no strict periodic signal in the objective world, which refers to the meaning of a large error). For example, each signal period contains 8.2 switching pulses, so that 5 cycles account for a total of 41 pulses, but the pulses contained in each cycle are not integers, and the waveforms of these 5 cycles must be different. When the switching frequency increases, the same number of pulses may not be guaranteed. However, synchronization is not an integer multiple, and the higher the switching frequency, this effect is correspondingly smaller. For example, if each cycle contains 24.2 pulses, although it is not an integer, the effect of these 0.2 pulses on the 24 pulses is necessarily less than that of the previous 8 pulses due to the 0.2 pulses. Harmonic analysis equipment often takes the period of the fundamental content of the output voltage of the inverter as the analysis cycle, because the signal of each cycle is different, and its harmonics are naturally different.
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Inverter dust handling – Reynolds inverters
1. Plan a special inverter room: When the power of the inverter used is large or the number is large, a special inverter room can be planned. The doors, windows and cable holes in the room should be sealed to prevent dust from entering; It is necessary to plan air filtration equipment and circulation channels to adhere to the normal circulation of indoor air ...
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The cause of the heating of the inverter of the special machine
1. Problems of the inverter and the motor itself;
After the motor has been used for a long time, it cannot be ruled out that the insulation function is not good, or the bearing is stuck, and it may show a large current and heat. The coupling between the motor and the load may also be worn, or the motor is unbalanced in three phases, and the fixtures of the motor are loose.
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Characteristics of isolation transformer at the input end of AC power supply - Reynolds
a。 When the third harmonic and disturbance signals are severe, a barrier transformer can be used to eliminate the third harmonic and disturbance signals.
b。 The use of barrier transformers can generate new neutrals and avoid the abnormal operation of equipment due to defective neutrals in the grid.
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Introduction and features of Reynolds soft starters
Reynolds soft starters include soft starters for high, medium and low voltage motors, including JJR1000 series, JJR2000 series, JJR5000 series, and RNB3000 series frequency converters. Reducing the starting power supply avoids voltage drops and voltage dips in the power supply. Smooth start-up avoids product damage. ...
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Safety precautions for low-voltage soft lift - Reynolds
Precautions for low-voltage soft starters
For cooling purposes, the soft starter must be installed in a straight direction.
In order to ensure excellent heat dissipation, there should be room for the soft starter device.
Main circuit selection ...
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Frequency converter overcurrent problem treatment - Reynolds
General treatment methods for inverter overcurrent problems:
The output side of the inverter is a PWM voltage waveform, and after passing through the motor winding, the output current is approximately a sine wave, and lags behind the voltage by a phase viewpoint, which is determined by the power factor of the motor. The output current of the inverter passes through ...
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Tips for using reducers - Reynolds
1. After 200-300 hours of operation, the first oil change should be carried out, and the quality of the oil should be checked regularly in the subsequent use, and the oil mixed with impurities or deteriorated oil must be replaced in time. Under normal circumstances, the reducer for long-term continuous operation should be replaced after 5000 hours of operation or once a year.
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Fault analysis of short circuit of inverter motor – Reynolds
According to the different degrees of short circuit, the inverter can display the short circuit of the SCF1 motor; SCF2 has an impedance short circuit; SCF3 is short-circuited to ground.
Causes of the problem: insulation problems with the cable from the motor or inverter to the motor; current transformer fault; ...
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Inverter composition and various functions - Reynolds
Rectifier circuit: rectify 50HZ communication power into direct current.
Frequency conversion circuit: The rectified direct current is inverted into a variable frequency communication current.
Control part: control the frequency of communication electricity output by the inverter circuit.
Maintenance circuit: maintenance and blockage of overcurrent and phase loss ...
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DCS and PLC and other control cabinets are inspected before leaving the factory
1. Test preparation:
1. It is necessary to remove all power switches before powering on the PLC control cabinet or IO cabinet.
2. It is necessary to completely cut off the connection between the PLC or DCS card and the outside. All front adapters are to be loosened and raised.
3. Check the power terminal wires and connectors.
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The cause of damage to the inverter brake unit - Reynolds
The inverter motor is equipped with a mechanical brake, is the inverter motor in the power generation condition when parking? Is the brake unit of the inverter working at the moment? What are the causes of brake unit damage?
Answer: 1. The inverter motor is equipped with a mechanical brake, and when parking...
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Basic characteristics of inverter transmission - Reynolds
Compared with the motor driven by the inverter, the power factor and efficiency of the motor will deteriorate and the temperature rise will increase because the output waveform of the inverter contains the influence of higher harmonics. On the other hand, when the frequency conversion is driven, the same torque should be obtained as when the power frequency power supply is driven, ...
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Reynolds inverter parameter problem
1. What are the factory recovery parameters of Reynolds inverter?
N600 = 100 (often press the WR button for 3-5 seconds), it is necessary to be in the shutdown state to be effective.
2. In the parameters of the N308 motor of the inverter, is the [motor leakage inductance reactance] specified sub-leakage inductance or rotor leakage inductance react?
Decide...
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Reynolds EPS emergency power supply routine maintenance
1. EPS the first use of the emergency power supply, the battery pack should be charged continuously for 48 hours after discharging protection;
2. EPS emergency power supply to keep the whole machine dry, clean, free of dust and foreign objects, wipe with a soft cloth after shutting down, and strictly ...
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PLC and inverter communication mode
1. The switching signal of PLC controls the inverter
The PLC can control the start, stop and reset of the inverter through the program; It can also control different combinations of high-speed, medium-speed and low-speed terminals of the inverter to achieve multi-stage speed operation. However, because it is controlled by switching ...
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Reynolds drives RNB1000 series fault code resolution
Reynolds inverter fault codes:
E.bC
Reynolds inverter fault phenomenon/type:
Brake unit failure
Reynolds inverter failure may be caused:
1. Brake line failure or brake ...
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Reynolds-5G empowers the paper industry to improve quality and efficiency of the industrial IoT control system
From September 23rd to September 25th, 2020, the 2020 China International Paper Technology Exhibition was held in Hall D1 of Suzhou International Expo Center.
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Features of the unit tandem inverter - Reynolds
(1) The multi-pronged PWM control method is selected, and the output voltage waveform is close to the sine wave.
(2) The rectifier circuit is multiplied, the number of pulses is as high as 36, the power factor is high, and the input harmonic is small.
(3) Modular design, compact structure ...
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The inverter has no short-circuit protection for the reason – Reynolds
Short-circuit maintenance is a function of equipment connected between the power supply and the load, which can effectively disconnect the short-circuit point from the power supply when the load side is short-circuited. If an equipment has a short-circuit maintenance function, it must have a certain short-circuit breaking ability; And a device with the ability to break in a short circuit ...
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Precautions for the use of frequency converters - Reynolds
In order to ensure the safe, efficient and reliable operation of the inverter, the following keys should be grasped when using the inverter:
1) It is necessary for the grounding terminal of the inverter to be firmly grounded, so as to effectively press the radio frequency disturbance and enhance the reliability of the system: the frequency conversion speed regulation system is best to use independent grounding, grounding resistance...
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