The copper and the inverter manufactured by IGBT applied in the internal feedback chopped wave speed regulating device are the intellectual property solely owned by Shanghai Nanzheng Electrical and Electronic Equipment Co., Ltd. with the patent number ZL 200520039244.7. The patent technical products of our company are protected under national laws and any individual or organization is prohibited from making imitations. The patent technical characteristics of SN6100 internal feedback chopped wave speed regulating device are listed as follows:
Mode of speed regulating: automatically change the motor current and lower the motor revolutions based on actual load requirements to conduct stepless speed regulating. The speed regulating system can be operated locally to be in speed regulating operation or can be operated remotely by DCS system operation, and can also be directly changed into full speed operation. The soft-startup device is provided with functions of independent, individual and continuous start.
Scope of speed regulating: 0-100% and 50%-100% of rated revolutions of motor, which, according to the designed scope of speed regulating by customers, can also require stepless speed regulating, with high precision of speed regulation.
Mode of soft startup: the specially controlled liquid soft-startup device has its starting current smaller than 1.5 times of the rated current of motor. The starting torque is large and the starting action is stable, which, therefore, makes the device can realize smooth stepless continuous startup without any impacts on motor, electric network and unit transformer. After being started to any revolutions, the motor then will directly enter the state of speed regulating.
Mode of automatic soft bypass: a special control mode, even if the speed regulating device is suddenly in failure, the device can be automatically changed into operation with power frequency to ensure the normal operation of motor without any shutdown and production halts; besides, it can make the rotating speed of motor rise to the highest value and the transition time lasts about 10-30 seconds for available regulation, so as to satisfy the responses of air door and valve regulator, thus making the motor operation with load changed from the revolutions of original speed regulating gradually raising to the full speed. The conversion has no impact and will not burn out the motor and blow out the boiler.
Mode of chopper and pulse control: a unique IGBT technology on parallel connection, which is also the core patent technology of electronic circuit of the system. IGBT is an element provided with functions of self switching off and self recovery. Since the speed of switching off of IGBT is much higher than SCR or IGCT and its capacity of self switching off for protection and self recovery is extremely effective, the impact current and electromagnetic interference produced due to current consolidation during network wave or instant blocked motor can be thoroughly removed. After the pulse, its self-recovery capacity is extremely high with special capacity of resisting disturbance to ensure absolute reliability of chopper’s work.
Mode of inverter and synchronized-signal control: when adopting the inverter composed by IGBT, if the synchronized signal is in failure, the inverter will never be overturned or in overcurrent. IGBT is an element provided with functions of self switching off and self recovery, and its capacity of self switching off for protection and self recovery is extremely effective which can effectively remove the failure of overcurrent. The inverter applied in the system adopts bimodular IGBT, and when one circuit of synchronized signal is lost, it can be automatically switched to spare module of another circuit to ensure the normal operation of inverter.
Control mode of operational power supply: the speed regulating is provided with three-protection – power supply control loop switch. When the control power supply of 380V or 220V is lost, it can be automatically switched onto the additional winding of the motor for power supply. The normal operation can be maintained only if the motor is equipped with the electrically speed regulating device. Besides, it can also be switched into the UPS direct current supply of customers for power supply so as to avoid damage to devices due to electrical breakdown of control, thus ensuring the reliable operation of the control system.
Coping capacity to power failure and bypass performance: when the motor power is in failure such as undervoltage, default phase and short circuit, the chopper will not lose control to the failure and the inverter will not overturn the failure. The power voltage will wave for 0.5 second and the device will not be affected. The device will be automatically and smoothly transited to the full speed operation of motor with transition time of 10-30 seconds for available adjustment so as to guarantee the response of air door and valve regulator. The trouble hunting will not influence the full speed operation of motor.
Protection of speed regulating device and control mode of DCS system: the speed regulating device adopts the control technology taking all-digital DSP and programmable PLC as the core to realize the two-ring control of the system including open-loop control and closed-loop control, which is provided with functions of short-circuit protection, direct connection protection of chopper circuit, power-off protection of auxiliary circuit, overload protection, overvoltage protection, power-off protection, overcurrent protection, over-temperature protection, high-voltage instant power-off protection, wave lost protection, phase failure protection, inversion protection, etc. The given speed is fast, the precision of speed regulating is high and the system is reliable, which is also in seamless connection with DCS system on any bases of owners. The speed regulating device can automatically adjust the rotating speed of motor by comparing the rotating speed output: the ratio between the two is given by industrial general-purpose interface of 4-20mA and the SCS speed, to realize automatic speed regulating operation of fan and water pump. When the signal given by DCS on site of customers is offline, the speed regulating device can provide warning signals, and the device will work on at the original revolutions without change on operating condition of the machine set.
Control mode: adopt imported LCD touch screen with menu in Chinese language, which can correctly conduct the velocity measurement to display the motor parameters, and realize display and local operation of ON/OFF of breaker, rotor current and voltage, change from speed regulation to full speed, variation from full speed to speed regulation, startup, shutdown, duty ratio, malfunction alarm and recovery for once, twice and three times, 1,000-time record of historical events and printing, etc. It can also conduct control with operation of DCS system in central control room to realize remote display operation, with the selective options of open loop and closed loop controls, which can conveniently realize the closed-loop control on pressure and flux.
Power factor: the power factor of the speed regulating device shall not be lower than 0.9 lag to guarantee that the operating power factor of motor is not lower than the rated power factor of motor.
Harmonic: the harmonic distortion of the system: less than 4%.
|
