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Type 2 and Type 3 Compensator Analysis for Power Supplies

This PLECS demo model analyzes the performance of Type 2 and Type 3 analog compensators used in power supply units (PSUs). The analyzed PSU is a buck converter with modeled-in inductor and capacitor non-idealities. The role of the capacitor and its effective series resistance (ESR) on the plant zero and poles is discussed. Furthermore, the compensators' performance is analyzed with respect to the phase margin, system bandwidth, and rate of change in gain at the crossover frequency.

Single-Phase, Grid-Connected PV Inverter with Partial Shading (Equation-Based PV Cell, P&O and dP/dV MPPT)

This PLECS demo model illustrates a grid-connected solar panel system with a boosted front end and a single-phase inverter back end. The boost converter is designed to operate the panel at its maximum power point (MPP). A maximum power point tracking (MPPT) algorithm is implemented to improve the performance of the solar panel under partial shading conditions. Further, the inverter is operated with an outer voltage loop to control the DC-link voltage and a synchronous regulator to maintain unity power factor.

HVDC Transmission System with MMCs

This PLECS demo model shows a 320 kV, 200 MW high-voltage direct current (HVDC) transmission system with two modular multi-level converters (MMC) interconnecting two 110 kV high-voltage AC grids. MMCs are the prevalent type of voltage-source converter topology for HVDC applications. At high voltages the transmission of direct current can be more efficient than alternating current. The MMC is a bi-directional voltage source converter that interfaces high-voltage AC and DC power systems. It comprises a positive and negative arm for each of the three phases. Each arm further contains a set of switching submodules connected in series, the number of which can be chosen in this model to achieve the desired harmonic performance.

Single-Phase Battery Charger

This PLECS demo model shows a grid-connected battery charger with cascaded AC/DC and DC/DC converters. The AC/DC converter is regulated by a digital PI controller to achieve power factor correction (PFC) and maintain the DC bus voltage at 300 VDC. The DC/DC converter is designed to provide a maximum 120 VDC output at a power rating of 1.4 kW.

STATCOM Cascaded H-Bridge Converter

This PLECS demo model shows a medium-voltage static synchronous compensator (STATCOM) system. Converters with cascaded connections are common in high-power applications such as medium-voltage drives, high-voltage direct current (HVDC) and flexible alternating current transmission systems (FACTS). These types of converters have the advantages of low switching losses and high redundancy, but require sophisticated control, e.g., cell-capacitor voltage balancing. The STATCOM’s purpose is to compensate for the reactive power required by various loads on a power system.

Neutral-Point Clamped Converter

This PLECS demo model illustrates a neutral-point clamped (NPC), three-level voltage-source inverter. The NPC topology has been adopted for high power applications as it can achieve better harmonic reduction than traditional two-level voltage source inverters and the associated control strategies help to minimize semiconductor losses. This model is designed to deliver power to a 50 Hz, 130 VRMS grid from a dynamic DC source.

Three-Phase, Grid-Connected PV Inverter

Three-phase PV inverters are generally used for off-grid industrial use or can be designed to produce utility frequency AC for connection to the electrical grid. This PLECS application example model demonstrates a three-phase grid-connected solar inverter. The PV system includes an accurate PV string model and the strings can be series-parallel connected to scale to a desired array output power. The simulation combines the electrical power circuit, the DC/DC and DC/AC control schemes, and the thermal behavior of the semiconductors.

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