The high voltage network within an electric vehicle (EV) will typically comprise of different energy sources such as fuel cells, batteries and ultracapacitors integrated together through the use of both unidirectional and bidirectional DC-DC converters. Given the multitude of feasible high voltage (HV) network designs, there are obvious advantages in having a unifying control architecture that facilitates the energy management (EM) control task. Within this paper, a control reference architecture (RA) is proposed that can be employed as a template for the design of the energy management control function. The RA exploits the object orientated principles of inheritance and encapsulation in order to achieve the desired non-functional attributes of modularity and control function reuse. Example EM control systems are presented each derived from the same RA, but relating to a different physical configuration of HV network. Simulation results are presented to verify the functional performance of the control systems. In each case, the design trade-offs associated with the functional performance of the EM strategy and the non-functional requirements of modularity and reusability are discussed.