Study of dual control electronic loads for spacecraft electrical power system tests

In the article the possible topologies of electronic loads consisting of linear regulator and switched-mode converter are studied. During developing and testing of spacecraft power supply systems, there is a need for devices that simulate various electrical characteristics of the spacecraft payload. This problem can be solved using specialized electronic loads that allow reproducing static and dynamic characteristics of the simulated payload with required accuracy. In addition, using electronic loads it is possible to return unused electrical energy into a DC or AC power supply network, which, in turn, makes it possible to improve the quality of power supply system tests. The development of a device that simultaneously provides both specified accuracy of reproduction of payload electrical characteristics and the recovery of surplus electric power is associated with a number of technical difficulties that can be solved by using an electronic load that includes two controllable stabilizers: a high-speed linear regulator and a switched-mode converter which limits the dissipated power of the linear regulator and provides recovering an excess electrical energy to the supply network. Various properties of dual control electronic load topologies were considered, the most promising topologies that can be used as electronic loads for spacecraft power systems tests were highlighted. A mathematical description of the electronic load used in the test setup was developed, an analysis of the admittances and the quality of noise suppression for various topologies was performed. The aspects of the electronic load operation related to the input current interfer- ing mode, the parameters determining the frequency range of the interfered noise, and the conditions for the possibility of the interference were determined for four topologies under the same conditions.