GoodWe Smart Meter Solution with 2 CTs

Author: Jeffery

2024-10-11 10:24

 

As we know, there are different solar energy storage solutions for different house electricity systems and requirements like hybrid system, coupled system, and also SPLIT etc. Here we talk about the new GoodWe solutions in energy storage systems for AC coupled energy storage system and SPLIT phase electricity system.

 

Solutions

Except for normal single-phase and three-phase smart meters, GoodWe also have 2 other different smart meter systems with 2 CTs attached for different GoodWe products:

1.GMK110D for single phase AC coupled energy storage inverters

2.GMK120 for SPLIT phase electricity system

Note: Do not worry that you might mess them up, because these smart meters will be together with the specific energy storage inverters as a default components. Namely you do not have buy them separately

 

GMK110D Solution

GMK110D is a smart meter with 2 CTs attached on it, used for single phase AC coupled energy storage system with GoodWe AC coupled inverters like SBP series, SBP G2 series and BH series.

Because AC coupled solar inverters does not have connection to PV strings, so it has to work with grid-tied solar system. As a result, AC coupled inverters cannot detect PV production, thus cannot give a complete system data monitoring like PV power and load power. GMK110D is a good solution for this situation, system wiring diagram as below:

In the system,

CT 1 is a bidirectional CT clamp that detects the real-time up-flow or down-flow current through it, which will be a basic data for inverter system to decide charge or discharge battery.

CT 2 is a one-way CT clamp, which detects only the output current (Ia) from grid-tied system. Power Cable both powers up GM1000D and detects AC voltage (Va) of the electricity system. 

By this way, GM1000D is able to calculate grid-tied solar system production: Pa = Ia * Va And further being able to calculate real-time consumption of loads:

Thanks to CT 2 to make the monitoring data complete, as below:

 

GMK120 Solution

GMK120 is a smart meter with 2 CTs attached on it, a solution for split phase A-ES and ES-US series hybrid energy storage systems, which is used in SPLIT phase system, mainly in North America. In SPLIT phase system, there are two line cable and neutral (L1/N/L2) and phase voltage is 120V (North America) and in the system, there are consumption requirement for both 120V and 240V. Thus the data detection in SPLIT system becomes more complicated. For North American SPLIT phase house electricity system, GoodWe provides GMK120 as a solution with 2 CTs attached and special control logic inside. System wiring as below: 

CT#1 and CT#2 are both bidirectional CT clamp that detects the real-time up-flow and down-flow current through it on phase A and phase B, which will be a basic data signal for inverter system to decide charge or discharge battery.

Power Cable supply both powers up GMK120 and detect AC voltage of the electricity system.

By this way, GMK120 is able to know the detailed system reaction with utility and calculate the general load power in the system.

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