7.1. 4. 6 CONDUCTOR MASS FACTORS There appear to be several promising design approaches for reducing the power conductor mass of the 20 kV system, although the system engineering required to evaluate the approaches was not attempted in most cases. Factors contributing to conductor mass can be listed as follows: 1. Array Shape — Conductor mass and power loss are functions of length. If length is doubled, both mass and power loss are doubled. The shortest conductor length is obtained from a split circular array with the antenna located at the center. The large reduction in mass and power loss possible for a circular array is shown in Table 7-5. TABLE 7-5. CONDUCTOR MASS AND LOSS 2. Antenna Location — Power is collected from a distributed solar array source and concentrated at the transmitting antenna. Therefore, conductor size increases near the antenna. When the antenna is located at the extremities of the solar array, the major portion of the conductor mass is likewise located at the extremities. The result is increased structure mass, less opportunity to utilize conductive structure, and increased conductor length. The increase in conductor mass and loss is shown in Table 7-5 for a case where two antennas are located on the long axis of an elliptical solar array. 3. Conductor Structure Axis — For the waffle type structure of the SPS, it is considered overly complex to route power in both X- and Y-directions. A parametric comparison of combined conductor and structural mass for several possible options is as follows: (a) no conducting structure, 34 x 106 kg, (b) conducting structure for X-axis only, 29 x 106 kg, (c) Y-axis only, 26 x 106 kg, and (d) X- and Y-axis, 21 x 106 kg. Option (c) was selected, although some studies have indicated that it is possible to approach the ideal condition of option (d) through a deliberate basic design approach with the goal of reducing conductor mass.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==