Power Grids
Learn how to model power system networks and perform loadflow and harmonic analysis.
Featured Examples
IEEE 39-Bus System
Model a 39-bus three-phase power system network. This example is based on the IEEE benchmark test case. For more information, see "IEEE PES Task Force on Benchmark Systems for Stability Controls" by Hiskens [1].
Model Static Var Compensator Using Thyristor-Switched Capacitor and Thyristor-Controlled Reactor
Models a static var compensator (SVC) using thyristor-switched capacitors (TSC) and a thyristor-controlled reactor (TCR).
Model Static Synchronous Compensator Using Voltage Source Converter
Models a hybrid var compensator that includes a static synchronous compensator (STATCOM) and a thyristor-switched capacitor (TSC).
Design, Operate, and Control Remote Microgrid
Develop, evaluate, and operate a remote microgrid. You also evaluate the microgrid and controller operations against various standards, including IEEE® Std 2030.9-2019, IEC TS 62898-1:2017 and IEEE Std 2030.7-2017. The planning objectives in the design of the remote microgrid include power reliability, renewable power usage, and reduction in diesel consumption. The key indices for economic benefits for the remote microgrid include life-cycle cost, net revenue, payback period, and internal rate of return. You can download this model in MATLAB® or access it from MATLAB Central File Exchange and GitHub®.
Design and Analyze Grid-Forming Converter
Design and analyze the performance of a grid-forming (GFM) converter under 13 predefined test scenarios. You can then compare the test results to the grid code standards to ensure desirable operation and compliance. The GFM converter in this example provides an alternative inertia emulation technique, configurable control loops, different current limiting methods, and is suitable for a wide range of network strengths. You can download this model in MATLAB® or access it from MATLAB Central File Exchange and GitHub®.
2-Bus Loadflow
A model of a two-bus three-phase power system network. The model uses three instances of the Load Flow Source block from Simscape™ Electrical™, one configured to be the swing bus, one configured to be the PV bus, and one configured to be the PQ load. The PV bus regulates its output to be at a voltage of 1.025 times rated voltage and to deliver 80MW active power to the network. The Swing bus regulates voltage at the other end of the transmission line to be one times rated voltage, and it delivers the requisite power to the network so that overall active and reactive powers balance. The Simscape initialization solver determines the required internal initial voltage amplitudes and phases in both the PV bus and the Swing bus so as to start in steady state.
AC Cable with Bonded Sheaths
A three-phase cable model comprised of multiple pi-sections. Each phase is enclosed in a conductive sheath. The conductive sheath is connected to ground at either end of the cable through a simple resistance. A high-voltage source provides power to an unbalanced resistive load through the power cable. You can configure the sheath to be either series-bonded or cross-bonded. You can also configure the number of pi-sections. Increasing the number of pi-sections improves the accuracy but slows down the simulation. To facilitate convergence, the voltage source includes an internal impedance.
Earthing Effects with Unbalanced Load
The effects of three different types of earthing connections on network voltages and currents.
IEEE 9-Bus Loadflow
A model of a 9-bus three-phase power system network. This example is based on an IEEE® benchmark test case, further details of which can be found in "Power System Control and Stability" by P. M. Anderson and A. A. Fouad (IEEE Press, 2003). Simscape™ initializes two of the generators to the specified powers and terminal voltages, and initializes the remaining swing bus generator to meet just the specified voltage. The resulting load flow solution is appended to each of the busbars post-simulation. The four rows correspond to per-unit voltage, phase, active power, and reactive power respectively. Looking at Bus 1, it can be seen from the annotation that the swing generator delivers 76.4MW of active power and 27.5MVAr or reactive power to the network. Differences to the original benchmark are due to the transmission line models and transformer configurations used.
Induction Motor Initialization with Loadflow
Initialize a three-phase induction motor as part of a load flow analysis. When initializing an induction machine that is directly connected to an AC network, in steady state there is one degree of freedom which you can set by any one of shaft torque, shaft power, motor speed, or electrical power.
Phasor-Mode Simulation Using Simscape Components
Configure your model to use frequency-time equation formulation.
Synchronous Machine Initialization with Loadflow
Initialize synchronous machine as part of a load flow analysis. When initializing a synchronous machine there are two degrees of freedom which can be set by any two of rotor angle, active power, reactive power and terminal voltage. The pair of variables that are constrained is set by the source type drop-down menu, this having options of Swing bus, PV bus and PQ bus. Here the machine is configured for a swing bus with a 1.02 per-unit voltage and zero degrees phase.
Input Admittance Response of RLC Ladder Network with Mutual Coupling Between Multiple Coils
Model a four-section ladder network that comprises RLC components with mutual coupling between multiple coils. You can use this ladder network representation to model the disc winding of a transformer. The number of sections of a ladder network depends on the number of discs in the winding. Each section can model two or three discs in the winding.
Distance Relay Protection in AC Microgrid
Model a distance relay in an AC microgrid. The relay block comprises impedance relay characteristic and mho relay characteristic. You can use this example to study the performance of impedance relay and mho relay in various fault conditions. Both the relays have two types of relays for ground fault and phase-phase fault.
Overcurrent Relay Protection in AC Microgrid
Model an overcurrent relay in an AC microgrid. You can use this example to study overcurrent relay coordination in a microgrid. The Relay block comprises two protection units, phase protection and earth protection. The phase protection unit protects the microgrid from high phase currents. The earth protection unit protects the microgrid from high earth currents. In this example the relay2 block protects the distribution_line2 block. The relay1 block protects the distribution_line1 block and also acts a back-up for the relay2 block. If a fault occurs on the distribution_line2 block and the relay2 block doesn't operate, the relay1 block operates after a specified time and isolates the system. To avoid tripping of the system, the relay1 and relay2 blocks operate such that only one relay operates at any given time. You can specify either time multiplier setting or the desired operating time of relay2 block.
Mixed AC/DC System Loadflow
Use the Load Flow Analyzer to review the load flow results of a mixed AC/DC system. The model to which this analysis is applied includes an AC load flow source, a three-phase rectifier, and three loads. One of the loads is AC, one is permanently connected on the DC side, and one is switched on the DC side.
Marine Power System Deployment to HIL
A marine power system model suitable for multirate Hardware-In-the-Loop (HIL) deployment. The example uses the Simscape™ Network Couplers Library to split the model into separate Simulink® subsystems that you can deploy at different sample rates. This allows you to run parts of the system (here, for example, the turbines) with a slower sample time and reduce overall computational cost.
Microgrid Resynchronization with Main Grid
Resynchronize an islanded microgrid with the main grid by using a battery energy storage system (BESS). The model in this example comprises a medium voltage (MV) microgrid model with a battery energy storage system, a photovoltaic solar park (PV), and loads. The microgrid can operate both autonomously (islanded) or in synchronization with the main grid. In this example, the microgrid is first in islanded mode. The resynchronization function then synchronizes the microgrid to the main grid. Finally, the breaker closes to connect the microgrid to the main grid. After the resynchronization, the battery system performs a power dispatch and the loads are changed.
Microgrid Planned Islanding from Main Grid
Execute a microgrid planned islanding from the main grid by using a battery energy storage system (BESS). The model in this example comprises a medium voltage (MV) microgrid model with a BESS, a photovoltaic solar park (PV), and loads. The microgrid can operate both autonomously (islanded) or in synchronization with the main grid. In this example, the microgrid initially is in grid-connected mode. The planned islanding function controls the point of common coupling (PCC) power flow to zero. Finally, the breaker opens to disconnect the microgrid from the main grid. After the islanding, the battery system performs a power dispatch, and the loads are changed.
