EV.5 Energy Storage

EV.5 ENERGY STORAGE

EV.5.1 Accumulator

EV.5.1.1 All cells or super capacitors which store the Tractive System energy are built into Accumulator Segments and must be enclosed in (an) Accumulator Container(s).

EV.5.1.2 Each Accumulator Segment must contain:

Maximum static voltage of less than 120 V DC

Maximum energy of 6 MJ

The contained energy of a stack is calculated by multiplying the maximum stack voltage with the nominal capacity of the used cell(s).

EV.5.1.3 No further energy storage except for reasonably sized intermediate circuit capacitors are allowed after the Energy Meter EV.3.1

EV.5.1.4 All Accumulator Segments and/or Accumulator Containers (including spares and replacement parts) must be identical to the design documented in the ESF and SES

EV.5.2 Electrical Configuration

EV.5.2.1 All Tractive System components must be rated for the maximum Tractive System voltage

EV.5.2.2 If the Accumulator Container is made from an electrically conductive material:

a. The poles of the Accumulator Segment(s) and/or cells must be isolated from the inner wall of the Accumulator Container with an insulating material that is rated for the maximum Tractive System voltage.

b. All conductive surfaces on the outside of the Accumulator Container must have a low resistance connection to the GLV System Ground, see EV.6.7

c. Any conductive penetrations, such as mounting hardware, must be protected against puncturing the insulating barrier.

EV.5.2.3 Each Accumulator Segment must be electrically insulated with suitable Nonflammable Material (F.1.18) (not air) for the two:

a. Between the segments in the container

b. On top of the segment

The intent is to prevent arc flashes caused by inter segment contact or by parts/tools accidentally falling into the container during maintenance for example.

EV.5.2.4 Soldering electrical connections in the high current path is prohibited

Soldering wires to cells for the voltage monitoring input of the AMS is allowed, these wires are not part of the high current path.

EV.5.2.5 Every wire used in an Accumulator Container, whether it is part of the GLV or Tractive System, must be rated to the maximum Tractive System voltage.

EV.5.3 Maintenance Plugs

EV.5.3.1 Maintenance Plugs must allow electrical separation of the Accumulator Segments to meet:

a. The separated Segments meet voltage and energy limits of EV.5.1.2

b. The separation must affect both poles of the Segment

EV.5.3.2 Maintenance Plugs must:

a. Require the physical removal or separation of a component. Contactors or switches are not acceptable Maintenance Plugs

b. Have access after opening the Accumulator Container and not necessary to move or remove any other components

c. Not be physically possible to connect in any configuration other than the design intended configuration

d. Not require tools to install or remove

e. Include a positive locking feature which prevents the plug from unintentionally becoming loose

f. Be nonconductive on surfaces that do not provide any electrical connection

EV.5.3.3 When the Accumulator Containers are opened or Segments are removed, the Accumulator Segments must be separated by using the Maintenance Plugs. See EV.11.4.1

EV.5.4 Accumulator Isolation Relays - AIR

EV.5.4.1 Every Accumulator Container must contain minimum one fuse (EV.6.6) and two or more Accumulator Isolation Relays (AIR)

EV.5.4.2 The Accumulator Isolation Relays must:

a. Be a Normally Open type

b. Open both poles of the Accumulator

EV.5.4.3 When the AIRs are open, High Voltage T.9.1.1 must not be external of the Accumulator Container

EV.5.4.4 The Accumulator Isolation Relays and any fuses must be separated from the rest of the Accumulator with an electrically insulated and Nonflammable Material (F.1.18).

EV.5.4.5 A capacitor may be used to hold the AIRs closed for up to 250 ms after the Shutdown Circuit Opens EV.7.2.2

EV.5.5 High Voltage Disconnect - HVD

A High Voltage Disconnect (HVD) must be included to quickly disconnect one or both poles of the Accumulator EV.11.3.2

EV.5.5.1 The High Voltage Disconnect (HVD) must be:

a. A directly accessible element, fuse or connector

b. More than 350 mm from the ground

c. Easily visible when standing behind the vehicle

d. Operable in 10 seconds or less by an untrained person

e. Operable without removing any bodywork or obstruction or using tools

f. Directly operated. Remote operation through a long handle, rope or wire is not acceptable.

g. Clearly marked with "HVD"

EV.5.5.2 An Interlock EV.7.8 must Open the Shutdown Circuit EV.7.2.2 when the HVD is removed

EV.5.5.3 A dummy connector or similar may be used to restore isolation to meet EV.6.1.2

EV.5.6 Precharge and Discharge Circuits

EV.5.6.1 The Accumulator must contain a Precharge Circuit. The Precharge Circuit must:

a. Be able to charge the Intermediate Circuit to minimum 90% of the Accumulator voltage

before closing the second AIR

b. Be supplied from the Shutdown Circuit EV.7.1

c. Not be fused

EV.5.6.2 The Intermediate Circuit must precharge before closing the second AIR. The end of precharge must be controlled by one of the following two options:

a. Feedback by monitoring the voltage in the Intermediate Circuit

b. A conservative time defined by the longer of:

Twice the time to charge to 90%
The time to charge to 90% plus 500ms

EV.5.6.3 The Tractive System must contain a Discharge Circuit. The Discharge Circuit must be:

a. Wired in a way that it is always active when the Shutdown Circuit is open

b. Able to discharge the Intermediate Circuit capacitors if the HVD has been opened

c. Not be fused

d. Designed to handle the maximum Tractive System voltage for minimum 15 seconds

EV.5.6.4 Positive Temperature Coefficient (PTC) devices must not be used to limit current for the Precharge Circuit or Discharge Circuit

EV.5.6.5 The precharge relay must be a mechanical type relay

EV.5.7 Voltage Indicator

Each Accumulator Container must have a prominent indicator when High Voltage T.9.1.1 is

present at the vehicle side of the AIRs

EV.5.7.1 The Voltage Indicator must always function, including when the Accumulator Container is disconnected or removed

EV.5.7.2 The voltage being present at the connectors must directly control the Voltage Indicator using hard wired electronics with no software control.

EV.5.7.3 The control signal which closes the AIRs must not control the Voltage Indicator

EV.5.7.4 The Voltage Indicator must:

a. Be located where it is clearly visible when connecting/disconnecting the Accumulator Tractive System connections

b. Be labeled “High Voltage Present”

EV.5.8 Tractive System Measuring Points - TSMP

EV.5.8.1 Two Tractive System Measuring Points (TSMP) must be installed in the vehicle which are:

a. Connected to the positive and negative motor controller/inverter supply lines

b. Next to the Master Switches EV.7.9

c. Protected by a nonconductive housing that can be opened without tools

d. Protected from being touched with bare hands / fingers once the housing is opened

EV.5.8.2 Two TSMPs must be installed in the Charger EV.8.2 which are:

a. Connected to the positive and negative Charger output lines

b. Available during charging of any Accumulator(s)

EV.5.8.3 The TSMPs must be:

a. 4 mm shrouded banana jacks rated to an appropriate voltage level

b. Color: Red

c. Marked “HV+” and “HV-”

EV.5.8.4 Each TSMP must be secured with a current limiting resistor.

a. The resistor must be sized per the following:

Maximum TS Voltage (Vmax) Resistor Value

Vmax <= 200 V DC 5 kOhm

200 V DC < Vmax <= 400 V DC 10 kOhm

400 V DC < Vmax <= 600 V DC 15 kOhm

b. Resistor continuous power rating must be more than the power dissipated across the TSMPs if they are shorted together

c. Direct measurement of the value of the resistor must be possible during Electrical Technical Inspection.

EV.5.8.5 Any TSMP must not contain additional Overcurrent Protection.

EV.5.9 Tractive System Active Light - TSAL

EV.5.9.1 The vehicle must include a Tractive Systems Active Light (TSAL) that must:

a. Illuminate when the GLV System is energized to indicate the status of the Tractive System

b. Be directly controlled by the voltage present in the Tractive System using hard wired electronics. Software control is not permitted.

c. Not perform any other functions.

EV.5.9.2 The TSAL may be composed of multiple lights inside a single housing

EV.5.9.3 When the voltage outside the Accumulator Container(s) exceeds T.9.1.1, the TSAL must:

a. Be Color: Red

b. Flash with a frequency between 2 Hz and 5 Hz

EV.5.9.4 When the voltage outside the Accumulator Container(s) is below T.9.1.1, the TSAL must:

a. Be Color: Green

b. Stay continuously illuminated

EV.5.9.5 The TSAL mounting location must:

a. Be near the Main Hoop at the highest point of the vehicle.

b. Be inside the Rollover Protection Envelope F.1.13

c. Be no lower than 150 mm from the highest point of the Main Hoop.

d. Not allow contact with the driver’s helmet in any circumstances.

e. Not be in proximity to other lights.

EV.5.9.6 The TSAL must be visible:

a. From every horizontal direction, except small angles which are blocked by the Main Hoop

b. From a point 1.6 m vertically from ground level, inside a 3 m horizontal radius from the TSAL

c. In direct sunlight

EV.5.10 Connectors

Tractive System connectors outside of a housing must meet one of the two:

- Contain an Interlock EV.7.8 which must Open the Shutdown Circuit EV.7.2.2
- Be sealed at Tech Inspection IN.4.7.1

This set of rules outlines detailed requirements for energy storage systems, focusing on safety and operational standards. The accumulator, which comprises cells or super capacitors storing Tractive System (TS) energy, must be housed within specific accumulator segments, each adhering to stringent specifications. These include maintaining a static voltage below 120 V DC and containing a maximum energy capacity of 6 MJ, calculated based on maximum stack voltage and cell capacity. Additionally, no additional energy storage beyond reasonable intermediate circuit capacitors is permitted out of scope of the Energy Meter. Electrical configuration mandates that all components be compatible with the maximum tractive system voltage, and Accumulator Segments must be insulated to prevent arc flashes and accidental contact. Soldering in high-current paths is strictly prohibited, except for voltage monitoring inputs. Maintenance Plugs must allow for safe electrical separation of segments, meeting specified voltage and energy limits, and ensuring easy, tool-free access without altering other components' positions. Additionally, each accumulator container must incorporate isolation relays and fuses, ensuring safe handling and containment of high-voltage elements. A High-Voltage Disconnect (HVD) is required for rapid disconnection of the accumulator poles under emergency conditions, with specific operational and accessibility criteria outlined to ensure safe disconnection. Other critical components include Precharge and Discharge circuits to manage voltage levels safely during system operation and maintenance. Voltage indicators and Tractive System Measuring Points (TSMP's) with appropriate safety features are also mandated, along with a Tractive System Active Light (TSAL) which provides clear indication of Tractive System status. Overall, these regulations ensure that energy storage systems adhere to robust safety and operational standards, emphasizing containment, isolation, and accessibility for efficient maintenance and emergency procedures.

For more specific information about each rule, click the buttons below to navigate to the Sub-Tabs within this section.

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