How to use Sun Path Finder

Sun path diagrams can tell you a lot about how the sun will impact your site and building throughout the year. Stereographic sun path diagrams can be used to read the solar azimuth and altitude for a given location. Sun path finder is a device that helps you to read the Stereographic Sun Path Diagrams ans shading analysis.

Azimuth Lines - Azimuth angles run around the edge of the diagram.

Altitude Lines - Altitude angles are represented as concentric circular dotted lines that run from the centre of the diagram out.

Date Lines - Date lines start on the eastern side of the graph and run to the western side and represent the path of the sun on one particular day of the year.

Hour Lines - Hour lines are shown as figure-eight-type lines that intersect the date lines and represent the position of the sun at a specific hour of the day. The intersection points between date and hour lines give the position of the sun.

Step by Step Guide to use Sun Path Finder:

1. Locate the required hour line on the diagram. 

2. Locate the required date line, remembering that solid are used for Jan-June and dotted lines for July-Dec. 

3. Find the intersection point of the hour and date lines. Remember to intersect solid with solid and dotted with dotted lines. 

4. Draw a line from the very centre of the diagram, through the intersection point, out to the perimeter of the diagram. 

5. Read the azimuth as an angle taken clockwise from north. In this case, the value is about 62°. 

6. Trace a concentric circle around from the intersection point to the vertical north axis, on which is displayed the altitude angles. 

7. Interpolate between the concentric circle lines to find the altitude. In this case the intersection point sits exactly on the 30° line. 

8. This gives the position of the sun, fully defined as an azimuth and altitude.

Battery Management System

A battery management system (BMS) is an electronic system that controls the charging and discharging of a rechargeable battery (cell or battery pack) by protecting the battery from operating outside its safe operating area monitoring its state, calculating secondary data, reporting that data, controlling its environment, and balancing it.

Basic Features of BMS:

Overcharge Protection: Protects the cells as well as the battery from overcharding beyond its safe limit.

Deep Discharge Protection: Protects the cells as well as the battery from deep discharding while powering a load.

Cell Balancing: When a cell is fully charged bypass that cell to let the other cells to be charged.

Types of BMS depend upon the type of cells as well as the number of cells in series. As per the number of cells in series, BMS is classified as

1S: Only one cell

2S: 2 number cells in series

3S: 3 number cells in series

and so on...

The voltage of BMS depends upon the cell type like for Li-Ion 1S BMS its rated voltage is 3.7V. For 2S it would be 7.4V. On the other hand for lithium ferro-phosphate cell (LiFePO4), 1S BMS would be 3.2V and 2S would be 6.4V, and so on...

 Every BMS has it's terminal marked connection needs to be done as per marking. 

 

 

For this lithium ferro-phosphate 1S BMS
B- Terminal is for Battery Negative
B+ Terminal is for Battery Positive
P+ is for Power Positive
P- is for Power Negative 

B+ and B- connects with the battery and P+ and P- go to the load or charger.

For the above Round type Li-Ion BMS also B+ and B- connects with the battery and P+ and P- go to the load or charger.

 This lithium ferro-phosphate 2S BMS has five terminals apart from B+, B-,  P+, P- it has one extra terminal that is BM. This BM terminal goes to the middle terminal of the battery series.

 The Li-Ion 2S BMS also has the same pin configuration.

 For 3S Li-Ion BMS, the Connection diagram is shown above. The lithium ferro-phosphate does not come with a 3S configuration.

Instead lithium ferro-phosphate BMS comes with 4S configuration. The connection diagram is shown.

Surge Protection Device

A voltage spike is a transient event, typically lasting 1 to 30 microseconds, that may reach over 1,000 volts. Lightning that hits a power line can give a spike of over 100,000 volts and can burn through wiring insulation and cause fires, but even modest spikes can destroy a wide variety of electronic devices, computers, battery chargers, modems and TVs etc, that happen to be plugged in at the time. However, lightning and utility power anomalies only account for 20% of transient surges. The remaining 80% of surge activity is produced internally. Although these surges may be smaller in magnitude, they occur more frequently and with continuous exposure can degrade sensitive electronic equipment within the facility.

A Surge Protector or a spike suppressor, surge suppressor, surge diverter, Surge Protection Device (SPD) or transient voltage surge suppressor (TVSS) is an appliance or device intended to protect electrical devices from voltage spikes in alternating current (AC) circuits. 

Typically the surge device will trigger at a set voltage, around 3 to 4 times the mains voltage, and divert the current to earth. Some devices may absorb the spike and release it as heat. They are generally rated according to the amount of energy in joules they can absorb.

There are three types of power surge protectors:

• Type I: This Power surge protector is installed at the origin such as the main distribution board.

• Type II: It is installed sub-distribution boards.

• Type III: This power surge protector is installed at the protection load.

Reference:
[1] https://en.wikipedia.org/wiki/Surge_protector
[2] https://new.abb.com/low-voltage/products/surge-protective-devices
[3] https://www.se.com/in/en/product-subcategory/1615-acti-9-surge-protection-devices-spds/