Synchronous motor microcomputer excitation system
1、 System Overview
The microcomputer excitation system for synchronous motors is mainly suitable for brushed and brushless (increased or non increased) synchronous motors of 50MW and below, as well as brushless synchronous motor excitation systems that can adapt to variable frequency starting.
2、 Application scope
It can be widely used in various loads of industrial and mining enterprises such as petroleum, chemical, metallurgical, mining, water conservancy, power, gas, medicine, light industry, textile, as well as various synchronous motor applications with power frequency, frequency conversion, and soft start methods.
3、 Model and meaning
4、 Suffix Details Table
5、 Product Features
Fully digitized
From the AC sampling of input channels to the output of control pulses, all are digitized, with a graphical human-machine interface (touch screen) and complete functions for testing, manual operation, and automatic fault recording and analysis.
Main control unit
We use our company's latest EC-5000 excitation regulator, which is powered by a 32-bit digital signal processor (DSP) from TI in the United States, with a maximum speed of up to 150MHz.
The hardware adopts surface mount technology and a four layer printed circuit board. The chips are all mature products from well-known domestic and foreign enterprises. The software is programmed using C language or ladder diagram (PLD), instruction list (IL), Basic, structured text (ST), sequential function diagram (SFC), data module editor, data type editor, etc.
Dual regulator (optional)
Equipped with dual sets of excitation regulators, the two sets are completely independent and have 100% software and hardware redundancy. When the fault level of the main excitation regulator is worse than that of the backup excitation regulator, it will automatically switch to the backup excitation regulator without shaking.
HMI
Adopting a 7-inch (built-in) or 10 inch industrial grade touch screen, a larger size touch screen (optional) can also be selected, with a resolution of 800 * 600 or 1024 * 768. The operation interface supports the selection of Chinese and English.
Rectifying unit
Select high-quality thyristors or IGBTs (brushless) and use heat pipe cooling technology. Each power component is equipped with resistance capacitance absorption, and each rectifier unit adopts pulse detection function, which can perform intelligent judgment and fault alarm.
Demagnetization unit
The demagnetization method adopts inverter demagnetization+linear or nonlinear resistors and magnetic field circuit breakers to achieve demagnetization and overvoltage protection of the generator. It has the advantages of easy operation, fast demagnetization speed, and large capacity.
Exciter transformer
Adopting indoor epoxy dry-type transformer with metal casing, insulation level of F or H, and protection level of IP20 or above. Temperature detection signal components are embedded in the coil, equipped with temperature display and control devices and alarm signal devices.
Dual power supply
Adopting dual power supply of AC 220VAC and DC 220VDC, the two power supplies operate in parallel and are mutually redundant.
Adjustment method
It has manual (constant excitation current), automatic (constant terminal voltage, constant reactive power, constant power factor), and open-loop (constant trigger angle) adjustment excitation functions, and can switch between each other without disturbance.
Limitations and Protection
It has out of step protection, automatic re stepping without load reduction, false demagnetization protection, low voltage strong excitation, over excitation reverse time limit, under excitation, PT disconnection, and motor starting time exceeding the limit BJMRCT.com 09 limit, overcurrent, overvoltage/undervoltage limit, external startup strong excitation (applicable to ball mills), comprehensive software and hardware detection and protection functions.
Power frequency frequency conversion switching
It has automatic adjustment functions such as power frequency, frequency conversion switching adaptation, and power factor during power frequency operation. Suitable for on-site operation requirements such as variable frequency start-up and variable frequency operation.
Communication interface
Provide open communication interfaces with standard RS485-RTU or fieldbus CANBUS for on-site communication, facilitating connection with other devices.
Rotating diode detection (brushless)
Equipped with a rotating diode detection function, it can monitor the rotating components in real time through multiple harmonics in the armature and issue an alarm in case of faults.
Wave recording and oscilloscope
Can record all analog data and switch status for 20 seconds before and 80 seconds after the fault. It can be uploaded to the upper computer through the serial port for display, processing, waveform storage, analysis, and printing.
It can display real-time waveforms of various physical quantities during operation, covering all analog quantities. It can display communication values, effective values, and operating switch status, and can set the sampling resolution and display resolution for each cycle, as well as the time period and range.
Event Memories
It is able to record 1000 faults, event action values and fault times (accurate to seconds) according to the first in, first out principle, and record the current operating parameter values, covering basically all analog quantities.
Anti-interference ability
·Anti static discharge interference: compliant with GB/T14598.14; Test level 3, test voltage ± 6kV.
·Attenuation oscillation wave pulse group interference: compliant with GB/T14598.13; Test level 3, with frequencies of 1MHz and 100kHz respectively. The common mode is 2.5kV and the differential mode is 1.0kV.
·Fast transient pulse group interference: compliant with GB/T14598.10; Test level 3, positive and negative polarity peak pulses, frequency 5KHz, common mode 2.0kV.
·Radiated electromagnetic field interference: compliant with GB/T14598.9; Test level 3, conducted in a shielded room with a field strength of 10V/m and a scanning speed of 1.5 × 10-3 times per second, with one test in both horizontal and vertical directions.
System structure
The excitation system can adopt single cabinet or multi cabinet structure according to on-site requirements, and multi cabinet structure can adopt parallel cabinet or separate cabinet method. When dividing cabinets, signal transmission is carried out through remote transmission modules, which have a long transmission distance and strong anti-interference ability, and can save on-site engineering costs.
Cabinet size and protection level
·Cabinet size: 2260mm (height) * 800mm (width) * 600/800 (depth), can also be customized according to customer needs.
·Cabinet color: RAL7035, It can also be customized according to customer needs.
·Protection level: IP31。