System Description
CND series, 400-1500kW
This series of converters are composed of high-performance modular units, different combinations of which can be used for various applications.
Convert connected with three-phase grid
Inverter connected with DC bus supplies power for the bus through the front-end unit.
As a system module, they can provide suitable solutions for single drive or multi-motor drive.
Converter
Single quadrant operation, 6/12 pulse
Four quadrant operation, 6 pulse, self-commutation with AFE
Front-end unit
The front-end unit can convert AC voltage and current on the input side into DC voltage and current on the common DC bus, thus transferring energy from the power side to the common DC bus (under certain circumstances, energy can be transferred reversely).
AFE (active front-end) is a bidirectional (regenerative energy) rectifying device in the common DC bus system. It should be fitted with an external LCL filter on the input side for application in power grids with low harmonics. AFE can be connected to the same field bus system with converter for control and monitoring by field bus, and be individually ordered.
NFE (non-regenerative front-end) is a unilateral (motor direction) rectifying device in the common DC bus system. It uses diode or thyristor, works under the mode of diode bridge rectifier, is fitted with a dedicated reactor, and can charge the DC bus, thus available for applications without higher requirements for harmonic quantity and any requirement for energy feedback.
Inverter unit
INU (inverter unit) is a bidirectional DC converter, which is used in power supply for motor or controlled by INU for power supply by the common DC bus system. If required to be connected with DC bus, it should be fitted with a charging circuit. INU can be ordered individually.
Brake unit
BU (brake unit) is a unidirectional energy transfer unit used for transfer of excess energy on the DC bus in the common DC bus system and conversion into heat for exhaustion, which should be used in combination with
energy-consuming resistor. BU can be individually ordered, while the energy-consuming resistor should be ordered in company with BU.
Model Number
Segment 1: 01066 pulse power converter, 011212 pulse power converter
0200AFE, four-quadrant converter , 110 inverter
A: Grid voltage (3AC380V~480V) (converter and AFE) or DC510V~650V (inverter)
C: Grid voltage 3AC660V~690V (converter and AFE) or DC890V~930V (inverter)
D: DC670/770V (for BU only)
F: DC1065/1155V (for BU only)
The final 3 bits represent the rated power.
Segment 3:
Segment 4:
Options
Common DC Bus Applications
CND devices provide the common DB bus products complying with various complex requirements, including front-end units, INU and BU within the power range from 400kW to 1500kW and voltage range from 380VAC to 690VAC. The whole system is completely based on advanced vector control technologies.
The common DC bus products offer various combinations. In the common DC bus system, electric energy generated by the braked unit can be directly utilized by the motorized unit.
