# Power Sharing Control in a Grid-Tied DC Microgrid: Controller Hardware in the Loop Validation
###### Abstract
Furthermore, in [27], the design of an HILP, with a 100 u IT, of a multilevel converter that includes a control system test scheme based on the FPGA OP5607, was presented. Investigations in converters may include other aspects in addition to their electrical characteristics; for example, in [28], an electrothermal model of an interleaved boost converter was developed using an FPGA. The HILP was designed using a graphical programming environment in LabVIEW, embedding the system in the NI-7975R FlexRIO DB with an IT of 25 ns. For the design and implementation of HILPs to emulate DC uGs, various DBs have been used. In [29], the Typhoon 602+ platform was used to emulate the behavior of a DC uG with an IT of 1 u, while for the TMS32028335 DSPC, Spartan 6 XC6 SLX16 FPGA DBs were used to control the different converters, which operate with a modulation frequency of 10 kHz. These implementations were carried out to analyze the effect of the drivers on the transitions of the DC uG converters. In [30], the same platform to emulate a DC uG was used; this time, the objective was to measure the effectiveness of the proposed Adaptive Droop Control; the control systems are embedded in a Texas Instruments DSP DB. In contrast, in [31], a robust control strategy was presented to solve the stability problems caused by constant power loads in a DC uG. To demonstrate the operation of the proposed controller, a simulation in MATLAB was compared with experimental results using an HILP implemented on the DSP (TMS320F28035) DB. National Instruments platforms have also been used. In [32], a DC uG HILP was developed to validate the behavior of a DC bus voltage control system; in this design, the NI-PXIe-1078 DB was programmed with LabVIEW software. In [33], an HILP of a DC uG using an RT-LAB and NI cRIO-9030 emulator was implemented; with this platform, the behavior of the system controllers, as well as their stability, were tested. In [34], an HILP was proposed, with an IT of 20 u, as a new method to develop and test control algorithms and operation strategies in DC uGs; this proposal uses RT-LAB (OP5600) for the implementation of the components of DC uG and an NI cRIO-9025 DB for the control and administration of the DC uG. In [35], the stability of the converters connected in parallel in a DC uG is analyzed; for this, an HILP was developed with the RT-LAB software and an AD7606 data acquisition board. In [36], an OPAL-RT device was used to emulate the behavior of a DC uG, presenting the advantage of considering delays and errors; these considerations allow the characteristics of the fuzzy controller proposed in this research to be strengthened. An HIL simulation is considered control hardware in the loop (C-HIL) when the power elements of a system are emulated in real time, while its controller, or part of it, is embedded in an external hardware device [37]. This technique allows experimentation with real controllers under a wide range of operating conditions without the risk of damaging real components [38] and has been used to validate controllers in PECs. In [39], work was carried out with an i-uG, a C-HIL with an IT less than 1 us to validate the controllers applied to a photovoltaic system, and a storage system using batteries. In [40], a C-HIL platform to validate the control strategies applied to a multifunctional converter was developed. In this platform, the controller was emulated in a dSPACE with a 6 us IT. In [41], the C-HIL technique to validate different control strategies applied to a universal PQ compensator for low-voltage distribution networks was used. The HILP used had an IT of 15,625 us. This article proposes the development of a C-HIL platform for the analysis of controllers aimed at managing the power sharing between a DC uG, with a photovoltaic array (PA) as the main source of energy, and the MG, considered as first-level controllers in the uG's hierarchical control structure.