Energy Meter and Current Transducer Assembly Manual 2017 1
The energy meter assembly is made of two separate boxes and associated accessories, as follows: Energy Meter (EM) Box, with two cables feeding directly out from the box Current Transducer (CT) Box USB Flash Memory 50cm Male Micro-USB to USB Memory Stick cable (supplied as one assembly including custom adapter PCB) Current Transducer (CT) Box Fig.1 shows a picture of the CT box. Each CT box has a center hole of 20mm diameter through which the main current carrying conductor from the high voltage battery must pass. Figure 1: Current Transducer Box Each CT box is marked with an arrow symbol which indicates its positive electrical current flow orientation. Find the arrow on the CT box and install it with its arrow pointing in the direction of positive current flow from the battery under motor drive conditions. The CT box can be installed on either the outgoing (positive) connection from the battery, or the return (negative) connection to the battery. However, the direction of current flow through the CT box for a driven motor must be positive in the direction of the arrow. 2
The CT box connects to the EM box via an EM-CT Cable that is permanently wired into the box, and pre-terminated with a Mini-USB plug at the free end as shown in Fig. 1. The cable length is preset, and cannot be modified. Fig. 2 shows a guidance picture of the installation of the CT box for a positive battery terminal connection. Battery Positive Terminal Battery Negative Terminal Energy Meter (EM) Box Figure 2: Orientation of CT Box Fig.3 shows the picture of the Energy Meter box. Each box has four mounting feet, two directly connected cables, one Mini-USB socket and one micro-usb socket, as follows: EM-CT Mini-USB cable socket HV Battery Voltage Connections LV Power Supply Connections Figure 3: Energy Meter Box High Voltage Measurement Cables (1.5 m long): These orange cables come directly out of the EM box, and are used to connect to the main battery (0V to 800V) for the high voltage measurement. They are to be connected to the non-battery side of the current limiting resistors that connect between the external voltage measurement test points and the main DC bus voltage. 3
Connect the negative voltage measurement point to the cable core with the black heatshrink sleeving fitted to the cable, and the positive measurement test point to the other cable core. If you shorten these cables before connection, make sure you maintain the correct voltage polarity connection the EM box will not operate correctly if the HV voltage measurement polarity is reversed. Fig. 4 shows the heatshrink polarity sleeving fitted to the HV cables. Figure 4: HV Cable Connections EM-CT Cable connection: The Mini-USB plug end of this cable plugs into the EM box at the TOP RIGHT socket shown in Fig. 3. Note that this is the only Mini-USB socket used for the EM box the two lower sockets shown in Fig. 3 are Micro-USB sockets and will not accept the EM-CT cable plug. Power Connection Cable: This cable comes directly out of the EM box as shown in Fig. 3, and is to connect the low voltage power supply (9V to 36V). Connect the low voltage supply positive terminal to the WHITE cable core, and the low voltage supply negative terminal to the BLACK cable core. USB Port: This port is to connect flash memory for logging energy data via the cable supplied to you. The cable plugs into the lower left hand socket as shown in Fig. 5. If required, this cable can be unplugged from the EM box for installation. However, make sure you re-insert it in the correct orientation, and properly plug into the correct Micro- USB socket as shown in Fig. 5. 4
Micro-USB socket for USB Cable Figure 5: USB Port Cable Connection Micro USB Cable This cable is used to connect the flash memory to the EM box. The cable has a length of 1m, and plugs into the USB port on the EM box. The other end of the cable must be mounted to allow free external access to the USB memory stick by the race scrutineers. Typically it can be taped to a car frame strut, using the (supplied) foam backing to minimize vibration. The memory stick assembly is shown in Fig. 6. Figure 6: Male Micro-USB to USB Memory stick (connector wrapped in tape) 5
If you have any questions, please do not hesitate to contact Prof. Grahame Holmes at grahame.holmes@rmit.edu.au. NOTE: The energy meter recording is written as a text file to the USB memory stick, which can be readily read using a standard PC to confirm correct installation. This memory stick MUST be handed to the race officials on Saturday 9 th of the competition to be re-initialised in preparation for the endurance event on Sunday 10 th. 6