New Industry Products

Grid Monitor Offers Improved Power Quality Measurements

April 20, 2024 by Mike Falter

Bachmann's upgraded GMP232 grid measurement and protection module improves frequency measurement accuracy for measuring current and voltage in grid-scale power applications.

Bachmann Electronic GmbH has launched a revamped version of its GMP232 controller-integrated grid measurement and protection module with more accurate frequency measurement capabilities for protection against common grid faults.  

The improved module boasts a frequency measurement accuracy of less than 1 MHz, with a maximum deviation of 0.1% for grid-scale voltage and current measurements. With a re-engineered isolation scheme, the GMP232/x2 module variant can support rated voltage measurements up to 1000 VRMS, a significant increase over the 690 VRMS rating of prior models.   


GMP232/x2 grid measurement and protection module.

GMP232/x2 grid measurement and protection module. Image used courtesy of Bachmann


The GMP232/x2’s added capabilities make it suitable for grid operators' most challenging requirements. It provides highly dynamic and accurate three-phase data to support safe and reliable power distribution operations.   


Power Grid Monitoring

Power grids are the infrastructure distributing high-voltage power from energy generation sources to commercial and residential customers. These grids must be capable of safely transmitting high-voltage electricity in large quantities over long distances to power homes and businesses. 

Power generation and grid distribution operators must have real-time data measurement, monitoring, and protection capabilities to ensure safe, reliable operation of this critical infrastructure.


Power grid power distribution.

Power grid power distribution. Image used courtesy of Bachmann


GMP232/x2’s Measurement Capabilities

The GMP232/x2’s basic function is to measure current, voltage, frequency, and power parameters in grid power and distribution systems. For current and voltage parameters, the module uses a true RMS measurement to capture harmonics up to 3 kHz and a fundamental RMS measurement for the fundamental only. The sample rate used for measurements depends on the grid frequency, but it is typically about 10 kHz.

The GMP232/x2 series consists of ten models rated to either 120 VRMS, 690 VRMS, or 1000 VRMS and have a voltage measurement accuracy of +/-0.1% of rated voltage. Current measurement levels (from the current transformer) are rated to 1 ARMS or 5 ARMS, also with an accuracy of +/-0.1% of rated current. 


GMP232/x2 series of grid monitoring modules

GMP232/x2 series of grid monitoring modules. Image used courtesy of Bachmann


According to Bachmann, the GMP232/x2's 1000 VRMS rated measurement capability allows for 45% more power transmission capacity than prior models limited to 690 VRMS, with no increase in line transmission widths. The result is less copper and reduced costs for transformers and other system installations.      

Based on the three-phase measurement information the GMP232/x receives, the module can trigger up to two circuit breakers via relay outputs for system protection. Grid harmonics can be monitored continuously up to the 50th harmonic to prompt intervention or for power quality monitoring. An integrated real-time data recorder allows high-resolution recording of key measurement data captured during alarm or protection events.  

The GMP232/x2 is configured to fully integrate with the Bachmann SolutionCenter, a complete software package designed to manage all aspects of a power generation and distribution system, including configuration, control/regulation, and communication. 


Measuring High Voltage Currents With Current Transformers

Current transformers measure high-voltage currents in utility-grade applications. 


Current transformer construction.

Current transformer construction. Image used courtesy of EE Power


They use magnetic coupling to induce an AC current in their secondary windings proportional to the primary current (grid) being measured. The current transformer performs the important function of isolating and stepping down the line current so it can be monitored by meters like the GMP232/x2.