Description

The ABB NUIM-62C (also designated as NUIM-62C-64791869) is a specialized voltage and current measurement unit engineered for ABB wind power converters, serving as a critical precision sensing component within the ACS800-67 dual-fed wind turbine converter platform . Unlike a power conversion module, this board performs the essential function of sampling generator stator voltage, grid-side voltage, and two-phase stator current, transmitting this data to the drive control unit via fiber optic link for vector control and protection calculations .

As a key enabler for grid integration, the ABB NUIM-62C ensures that the converter’s control algorithms receive accurate, low-latency electrical data—a prerequisite for stable synchronization and power quality. The module’s importance is underscored by its application in major Chinese wind turbine OEMs including Dongqi, Haizhuang, Mingyang, Shanghai Electric, Yunda, and Huarui, across 1.5MW, 2.0MW, and 3.0MW doubly-fed induction generator (DFIG) models .

 

Application Scenarios

In a 100 MW onshore wind farm operating 50 units of 2.0 MW turbines with ABB ACS800-67 converters, an intermittent fault code “Stator Voltage Meas Fault” began appearing across multiple units during high-wind periods, leading to nuisance grid disconnections. The fault caused 250 MWh of lost production over a two-month period. Maintenance engineers traced the root cause to aging measurement boards on the rotor-side and grid-side converters. By replacing the suspect units with verified ABB NUIM-62C boards, the farm restored clean voltage and current signals to the NDCU-33CX drive control units . The 15-minute board replacement per turbine eliminated the measurement-related faults, and the farm has since operated with 98.5% availability through the subsequent high-wind season. The ABB NUIM-62C now provides reliable sensing for both the INU (rotor-side) and ISU (grid-side) converters, ensuring that the dual-fed topology maintains ±0.5% active power accuracy under fluctuating grid conditions.

 

Parameters

Main Parameters	Value/Description
Product Model	NUIM-62C (order code: 64791869 / L701342)
Manufacturer	ABB
Product Category	Voltage & Current Measurement Unit / Measurement Board
Measurement Type	Stator voltage, grid voltage, two-phase stator current
Communication Interface	Fiber optic serial link to NDCU-33CX/RDCU-12C
Power Supply	Backplane supply (+15V / +24V DC)
Applicable Systems	ABB ACS800-67 wind turbine converters
Compatible Turbine Power	1.5 MW, 2.0 MW, 3.0 MW DFIG turbines
Turbine OEMs	Dongqi, Haizhuang, Mingyang, Shanghai Electric, Yunda, Huarui
Environmental Rating	Industrial-grade for wind turbine environments
Net Weight	0.2 – 0.6 kg (depending on source)
RoHS Compliance	Yes

 

 

Technical Principles and Innovative Values

Innovation Point 1: Precision Measurement for Doubly-Fed Control Architecture
The ABB NUIM-62C serves as the sensory front-end for the ACS800-67 DFIG control scheme. It samples the stator voltage (essential for grid synchronization) and the grid voltage, as well as the two-phase stator current required for vector control . This data is transmitted via optical fiber to the NDCU-33CX (rotor-side converter control unit) and RDCU-12C (grid-side converter control unit), where it is used for real-time torque, speed, and reactive power calculations. Unlike standard industrial measurement devices, the NUIM-62C is optimized for the demanding dynamic response required by wind turbine applications—measurement latency is minimized to support sub-millisecond control loop execution.

Innovation Point 2: Optically Isolated Sensor-to-Control Interface
By using a fiber optic link, the ABB NUIM-62C provides galvanic isolation between the high-voltage power section (up to 690V AC) and the sensitive control electronics . This isolation is critical in wind turbine nacelles, where lightning-induced transients and electromagnetic interference from the generator can corrupt analog signals. The optical interface ensures that measurement integrity is maintained even during grid faults or switching transients, preventing spurious protection trips.

Innovation Point 3: Enabling Grid Code Compliance through Accurate Measurement
The ABB NUIM-62C contributes directly to grid code compliance. Modern grid operators (e.g., E.ON, VDE-AR-N 4110) require wind turbines to inject specified reactive current during grid faults for voltage support—a process known as “Low Voltage Ride Through” (LVRT). The accuracy of the voltage and current measurements from the ABB NUIM-62C determines the precision of the current injection, enabling the turbine to remain connected through voltage dips down to 15% of nominal for up to 625ms. Measurement errors as small as 1% can push the response outside tolerance limits, risking a grid violation.

Innovation Point 4: Application-Specific Design for DFIG Converters
The ABB NUIM-62C is not a general-purpose I/O module—it is tailored for the specific voltage and current ranges encountered in 1.5-3.0 MW wind power applications . This purpose-built design ensures that the measurement scaling, filtering, and protection are optimized for wind turbine control, eliminating the need for external signal conditioners that introduce error and complexity.