# A Low-Cost Evaluation Tool for Synchronization Methods in Three-Phase Power Systems
## 1 Introduction
electrical grid and the second for the execution of the synchronization algorithms. The work compared the response time, the accuracy, and the computational efficiency in an ideal electrical system and a grid with harmonics distortion. The grid emulation and execution methods were implemented in digital systems with real-time simulation capability using a compact development environment based on a field-programmable gate array (FPGA) and/or digital signal processors. The platform also generated emulated signals for an external platform. In [25], an unbalanced electrical system with voltage harmonics was experimentally evaluated considering the OS and steady-state (ST) estimation of frequency ripple. Moreover, the work evaluated the algorithms using computational simulations, considering balanced and unbalanced grid and voltage variations such as sag, phase step change, and direct current (DC) offset. In [26], several algorithms used in distributed generation systems were evaluated for disturbances such as amplitude and frequency variations, unbalance, and harmonics. In [27], due to their hardware and software characteristics, these platforms were also used to evaluate distributed systems. The works that use AES require the equipment to acquire, process, and generate three-phase alternating current voltages. In [28], a converter connected to a single-phase electrical system was used. In [29], disturbances such as unbalance and harmonics, frequency and phase changes, and sag voltage were programmed in the output voltages of a three-phase inverter. The algorithms were implemented on the Infineon XMC 4500-based platform and were evaluated by analyzing the root-mean-square error (RMSE), mean error (ME), OS, settling time (\(t_{s}\)), and process time. In [30], a programmable alternating current source was used. The paper evaluated the performance of synchronization algorithms when changing the phase in a grid with the presence of sag, frequency deviations, and DC offset. The work compared the frequency ripple, \(t_{s}\), and implementation complexity. Finally, Ref. [31] emulated the voltages with an inverter converter connected to a programmable DC source and used frequency estimation, phase estimation, and \(t_{s}\) to compare the algorithms used. The cost of implementing the different evaluation tools depends on the prices of the equipment or devices used (Table 1). In particular, the cost of the tools based on computational simulation is in the upper-low (from USD 100 to USD 1000) to medium (from USD 1000 to USD 10,000) price range, depending on the type of software license. The micro-computerized systems have a low price range of implementation (less than USD 100). The cost of implementation of the real-time simulation systems and the AES tools is in the range of medium to high (over USD 10,000). Figure 2: Classification of evaluation tools. The real-time simulation systems stand out from other methods without grid connection of their computational capacity. Examples of real-time simulation systems include PLECS RT Box, Typhon HIL404, RT-LAB, and Micro-LabBox. However, when considering accessibility, the methods based on computational simulation and micro-computerized systems stand out for their versatility and lower cost (see Table 1). This way, microcontroller-based systems allow for the implementation of an accessible experimental tool for evaluating and validating synchronization methods. This work proposes a new evaluation tool for synchronization algorithms implemented in digital devices. The proposal is based on the emulation of the electrical grid using the Texas Instruments LAUNCHXL-F28379D development platform, and it describes the required peripherals and the methodology of its use for both validation and performance evaluation. The main objective is to provide a tool for engineers and researchers for the experimental validation and evaluation of digital synchronization algorithms before their implementation in grid-connected equipment.