High voltage components

High Voltage Disconnect - HVD

The HVD is one of the most important parts of the vehicle, it is purpose to disconnect the high voltage between the accumulator and the inverter, and also it open the shutdown circuit which cause the AIRs to be opened as well.

It is important to consider the following when choosing the HVD:

• Voltage and current rating for the high voltage disconnect.

• Voltage and current rating for the low voltage disconnect, since the shutdown circuit powers the AIRs eventually, it is important to know there current consumptions and to choose the HVD according to that.

• mechanical size and weight.

• ease of use.

• what the supplier supplies within it, are all the pins, crimps, wiring included or it has to be bought separately.

In 2022 it was first to be considered to use the TE connectivity HVD yet, although we acquired it free of charge (sample) we found out it is huge and also the latching mechanism is difficult to operate. there for in the 22 after searching in forums we found the HIROSE EM30MSD it is relative smaller than the TE's HVD, and the mechanism is easy to operate, we did found out that the manufacture made small current rating for the interlock in which we got around cause our AIRS for that session used Econizer, and the peak current time duration was short enough to not damage the interlock according to the graphs in the unit datasheet.

In FSS22 we discovered that some teams did not use manufacture build of HVD but they created their own by using high voltage connecter that also have signals pins, those team made the correct shorts in the plug so both the receptacle and the plug behave as proper HVD, the teams also 3D printed a cup for that plug (also with their mascot on), we have seen that Greenteam did their HVD using Souriau connector.

Tractive System Measure Point - TSMP

The TSMPs are 4mm female socket (AKA banana socket or banana jack), while a lot of HV components are required to be fused, the TSMPs must not to be fused, but have instead a resistor in series to their connection. according to table in EV 4.7.6 in FSG rule book 22.

In general, FSG rule book 22 made it relatively clear how the TSMPs should be mounted, and how they should be connected. In 22 we have seen that rated quality sockets are in very limited supply and therefore should be bought at the very beginning of the season.

While it is common to see teams placing they TSMPs in the open air with a proper cover for each one like this cover from Staubli, it is possible to make hole (with cover) in aerodynamic package as long as at least two TSMPs are close to the master switches.

Wires

There are many rules and terms related to vehicle and the charger on both the HV and LV systems. and it required to read in very detail the FSG rule book when a wire or coundactive needs to be installed. some of the important rules:

• ALL wiring inside the accumulator must be rated for the maximum voltage the accumulator capable of.

• EV 4.5.3 the temperature rating for TS wiring, connections and insulation must be at least 85 °C.

• EV 4.5.7 TS wiring must be located out of the way of possible snagging or damage.

• EV 4.5.8 All TS wiring that runs outside of TS enclosures must

  • be enclosed in separate orange non-conductive conduit or use an orange shielded cable. The conduit must be securely anchored to the vehicle, but not to wire, at least at each end.

  • be securely anchored at least at each end so that it can withstand a force of 200 N without straining the cable end crimp.

Body work is not sufficient to meet this enclosure requirement.

• EV 4.5.9 Any shielded cable must have the shield grounded.

• T 11.1.4 [EV ONLY] The LVS must not use orange wiring or conduit.

• T 11.1.5 [EV ONLY] The LVS must be grounded to the chassis.

The FSG allows the use of only approved wires for the TS high current path, a list of those approved wires can be found here, prior to the competition, an item request may be applied here for approval(Login in with account are required). A sample piece of each wire need to be brought in the event for demonstration to the judges.

In 22 we have seen that acquiring wires can be relative hard task because of the price and the shipping time thus it should be bought at the very beginning of the season.

Wire terminals are important to buy at the same time of purchasing the wires, their price at local stores are high and it is hard to find terminal for big cross section wires, also branded terminal, or connectors may requires special size and or shape of crimper die. when choosing a wire terminal it must be considered not only the wire cross section but also the screw hole diameter.