전력망

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 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 desiderable 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®.

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.

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.

The effects of three different types of earthing connections on network voltages and currents.

이 예제에서는 9-버스 3상 전력 시스템 네트워크의 모델을 보여줍니다. 이 예제는 IEEE® 벤치마크 테스트 케이스를 기반으로 합니다. 자세한 내용은 "Power System Control and Stability" by P. M. Anderson and A. A. Fouad(IEEE Press, 2003)에서 확인할 수 있습니다. Simscape™는 2개의 발전기를 지정된 전력과 단자 전압으로 초기화하고, 남아 있는 스윙 버스 발전기는 지정된 전압만 충족하도록 초기화합니다. 결과로 생성된 부하 흐름 솔루션은 각각의 부스바 사후 시뮬레이션에 추가됩니다. 4개 행은 각각 per-unit 전압, 위상, 유효 전력, 무효 전력에 대응됩니다. Bus 1을 살펴보면, 스윙 발전기가 76.4MW의 유효 전력과 27.5MVAr의 무효 전력을 네트워크에 전달하고 있음을 주석에서 확인할 수 있습니다. 원래 벤치마크와의 차이는 사용된 전송선로 모델과 변압기 구성으로 인한 것입니다.

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.

Configure your model to use frequency-time equation formulation.

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.

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.

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.

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.

이 예제에서는 Load Flow Analyzer를 사용하여 혼합 AC/DC 시스템의 부하 흐름 결과를 검토하는 방법을 보여줍니다. 이 분석이 적용되는 모델은 AC 부하 흐름 소스, 3상 정류기, 3개의 부하를 포함하고 있습니다. 3개의 부하 중 하나는 AC이고, 다른 하나는 DC 측에 영구적으로 연결되고, 나머지 하나는 DC 측에서 스위치에 의해 켜집니다.

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.

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.

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.