Bi-directional meters are used to calculate both export and import of the energy. It is majorly used to calculate when there is an alternative source of energy like solar, wind, biomass etc is installed along with the main grid supply. In households, meters could be either single phase or three phase. To know more about single phase bidirectional meter, click here.
The figure (Fig. 2) shown is the LCD display of Three Phase Bi-Directional Meter. The top part is for indicating numbers, which basically denotes the value of the electric parameter. Right bottom corner part is to indicate the unit of the electric parameter. All parameter of our electric grid can be possible to store in a smart electric meter. But for the easiness of meter reader and customer, meters are coming with a presetting display.
Fig. 2: LCD Display of the meter
On the right top corner of the LCD display, there is a circle divided equally into four parts (Basically, four quadrant) and consists of a different symbol. This indicates the type of energy being displayed which can be basic import or export, inductor and capacitor for reactive lag and reactive lead respectively.
There are approximately 300 displays are there in the secure meter. Displays are categorized in a different page. With the help of push button, we can change the display and read the required value – Voltage, Current, Import Power, Export Power, etc.
Press the “Scroll Push Button”, a Different value of the parameter will be displayed in the LCD display.
By pressing scroll push button in first time LCD display indicates its unique serial number for the purchased Bi-Directional Meter
When you are pressing push button for the second time. LCD displays indicates the current time in the meter in HH:MM:SS format
At the next Press, Displays shows the current date in the meter in DD: MM: YY format.
Next and the following press will indicate Present Voltage, Current status and Phase sequence and Current sequence (Always have a look on the top bottom corner to understand the unit). When you are pressing each time, the four-quadrant circle will be in the invisible state.
After displaying the value of Voltage, Current of each Phase, Instantaneous Active, Reactive & Apparent Load, Frequency and Power factor in your continuous press. You are going to get a display as given below
which is your total active import energy. Quadrant 1st and 4th are visible at this stage. So, the first display which shows 1st and 4th quadrant is your total import energy in kWh. In this case (First Image) total import energy is 360.9 unit.
On the next press of push button, LCD display gives the value of total active export energy.
Here, 2nd and 3rd quadrant is visible. In this case total export energy is 381.7 unit (First Image). We can stop our reading process at this stage as we got our reading.
Total Imported energy = 360.2 unit
Total Exported energy = 381.7 unit
Total savings for this customer by exporting solar energy to the grid is = 381.7 – 360.2 = 21.5 unit.
Feed in Tariff at the time of Commissioning of the project is = 7.08