The High Power Synchronous Generators Application, "AEL-HPSG", has been designed to study the procedure and the maneuversrequired for the synchronization of synchronous generators with the grid, with the aim of delivering the generated energy as done in actualpower plants.

The "AEL-HPSG" application allows the user to go deeper into the working principles and control of synchronous generators to show thestep-by-step synchronization process with the electrical grid. For this, the applicationincludes a synchronous generator coupled to a motor (which will act as drivingforce, simulating a turbine) along with a series of modules such as a single-phasetransformer, an AC/DC converter and a voltage regulator which form the generatorexcitation circuit. It is also included an analog overcurrent relay as grid protectiondevice and a network analyzer to monitor the generation electrical parameters suchas the active and reactive powers generated, frequency, voltage, current, power factor, etc.

This application offers two possibilities regarding the generation group control. The first option, the manual control of synchronousgenerators kit, includes modules for the motor speed control (turbine) and a PWM signal generator module for the control of the synchronous generator excitationcurrent (and therefore the output voltage). This enables the user to carry out theno load, under load and short circuit test aimed to obtain the characteristic curvesand the equivalent circuit of the synchronous generator. This kit also includes asynchronization module which will allow the user to monitor and carry out manually the synchronization process. For that, the synchronization module has two analog voltmeters (grid and generation voltage), two frequencymeters (grid and generator frequency), a digital synchroscope and two push-buttons for closing and opening the synchronization switch.

The second option, the synchronous generator automatic control module, offers the possibility to control automatically every electricaland mechanical parameters of the generator-turbine group. The most signifcant control parameters are the turbine speed, the generator frequency, the excitationcurrent, the voltage at the generator output and the active, reactive and apparentpowers. Moreover, this control module is at the same time an advanced protectionfor generators and turbines. It meets the ANSI standards regarding the protection parameters for generators and turbines (ANSI 81O, ANSI 81U, ANSI 59, ANSI 27,ANSI 50/51, ANSI 32R/F, ANSI IOP 32, ANSI MOP 32, ANSI 46, Voltage Asymmetry, Generator Ground Fault, Phase Rotation, ANSI IEC255 , Generator Lagging Power Factor, among others). It is required to acquire at least one of the two previously described options to be able to work with the modules included in the base unit.

In order to acquire a greater experience with the study of synchronous generators, it is recommended to acquire a set of resistive andinductive loads with the aim of studying the stand-alone operations of synchronous generators (isolated from the national grid). Theseloads will allow the user to go deeper into the basic concepts about the behaviour of synchronous generators working under load, suchas generation and demand in isolated systems, voltage drops or the output voltage control by means of the excitation current regulation.

It is also recommended to acquire a kit for the study of faults in synchronous generators, consisting of an advanced differential protectionrelay with configurable numerical programming which allows showing the features of three-phase differential protection, two power switchmodules as interrupting devices, a fault injection module for the injection of single-phase, two-phase or three-phase, to earth, faults anda module with three-phase inductances as buffering element for the faults at the generator induced side.

In addition, it is recommended as well a rotor protection module for the study of faults at the synchronous generator excitation side and athree-phase harmonic filter for the reduction of the harmonics resulting from the regulation of the generator excitation current.

The "AEL-HPSG" is one of the most complete and versatile applications regarding the in-depth study of synchronous generators, both inisland and parallel to grid operations. Furthermore, it is compatible with any type of energy transmission line which makes it possible tostudy the impact of synchronous generators on real grids, analysing events such as power transfer among several machines working inparallel, sudden decouplings and its consequences and endless meanuevers related to electric generators.

Finally, for the most optimal management of the application, it is recommended the Energy Manager and Data Acquisition Software. Thisawesome tool allows the user to monitor all the curves for the grid and generator electrical parameters, watch the voltage drops, energy losses in transmission lines and voltage drops. In addition, it allows saving all the acquired data to watch and compare it later. It is possibleo see clearly and with accuracy the effects of reactive power compensation on the monitored power curves, maximum and minimumenergy demand, load unbalances and the variation of the power factor in the nodes of the system.