创建自定义组件和库

该示例对车辆暖通空调 (HVAC) 系统中的湿空气流动进行建模。车辆座舱表示为与外部环境交换热量的湿空气体积。湿空气流经再循环风门、鼓风机、蒸发器、混合门和加热器，然后返回座舱。再循环风门选择从座舱或外部环境流动进气。混合门引导加热器周围的气流来控制温度。

Models an aircraft environmental control system (ECS) that regulates pressure, temperature, humidity, and ozone (O3) to maintain a comfortable and safe cabin environment. Cooling and dehumidification are provided by the air cycle machine (ACM), which operates as an inverse Brayton cycle to remove heat from pressurized hot engine bleed air. Some hot bleed air is mixed directly with the output of the ACM to adjust the temperature. Pressurization is maintained by the outflow valve in the cabin. This model simulates the ECS operating from a hot ground condition to a cold cruise condition and back to a cold ground condition.

此示例展示如何使用自定义 Simscape™ 模块对质子交换膜 (PEM) 燃料电池电堆进行建模。PEM 燃料电池通过消耗氢气和氧气并产生水蒸气来发电。该自定义模块代表膜电极组件 (MEA)，并连接两个独立的湿空气网络：一个用于阳极气体流，一个用于阴极气体流。

此示例展示如何使用自定义 Simscape™ 模块对质子交换膜 (PEM) 水电解槽进行建模。PEM 电解槽消耗电能将水分解成氢气和氧气。该自定义模块代表膜电极组件 (MEA)，并连接到一个热液体网络和两个独立的湿空气网络：热液体网络对供水进行建模，阳极湿空气网络对氧气流进行建模，阴极湿空气网络对氢气流进行建模。

Use the Simscape™ example library Capacitors_lib. The model is constructed using components from the example library. The circuit charges an ultracapacitor from a constant 0.05 amp current source, and then delivers a pulse of current to a load. The ultracapacitor enables a much higher current to be delivered than is possible directly from the current source. The library contains capacitor models with different levels of fidelity to allow exploration of the effect of losses and nonlinearity.

此示例展示了一个集总参数传输线模型。它由一个自定义 Simscape™ 组件构建而成，该组件定义了单个 T 形段。该模型将 50 个段连接起来，每段长度为 0.1m，从而实现了对长度为 5m 的同轴电缆的建模。从仿真结果可以观察到传输延迟。

Model a basic engine cooling system using custom thermal liquid blocks. A fixed-displacement pump drives water through the cooling circuit. Heat from the engine is absorbed by the water coolant and dissipated through the radiator. The system temperature is regulated by the thermostat, which diverts flow to the radiator only when the temperature is above a threshold.

Models a gas turbine auxiliary power unit (APU) based on the Brayton Cycle. The Compressor and Turbine blocks are custom components based on the Simscape™ Foundation Gas Library. The power input to the system is represented by heat injection into the combustor; actual combustion chemistry is not modeled. A single shaft connects the compressor and the turbine so that the power from the turbine drives the compressor. The APU is a free turbine that further expands the exhaust stream to produce output power.

此示例基于朗肯循环对汽轮机系统进行建模。该循环包括过热和再加热，以分别防止高压涡轮和低压涡轮中发生冷凝。该循环还通过将抽取的蒸汽传递到闭环式给水加热器来实现再生，以加热水并提高循环效率。

Use the Simscape™ example library ElectroChem_lib. In the model Fe3+ ions are reduced to Fe2+, and Pb is oxidized to Pb2+, thereby releasing chemical energy. The molar flow rate of lead ions is half that of the iron ions as two electrons are exchanged when Pb is oxidized to Pb2+. The chemical potential of the Pb source is by convention zero as it is a solid.

Model a lead-acid battery cell using the Simscape™ language to implement the nonlinear equations of the equivalent circuit components. In this way, as opposed to modeling entirely in Simulink®, the connection between model components and the defining physical equations is more easily understood. For the defining equations and their validation, see Jackey, R. "A Simple, Effective Lead-Acid Battery Modeling Process for Electrical System Component Selection", SAE World Congress & Exhibition, April 2007, ref. 2007-01-0778.

此示例展示如何使用 Simscape™ 语言对锂单元进行建模，以实现具有一个 RC 支路的等效电路模型的元件。有关定义方程及其验证，请参阅：T. Huria, M. Ceraolo, J. Gazzarri, R. Jackey."High Fidelity Electrical Model with Thermal Dependence for Characterization and Simulation of High Power Lithium Battery Cells," IEEE International Electric Vehicle Conference, March 2012.

此示例展示如何使用 Simscape™ 语言对锂单元进行建模，以实现具有两个 RC 支路的等效电路模型的元件。有关定义方程及其验证，请参阅：T. Huria, M. Ceraolo, J. Gazzarri, R. Jackey."High Fidelity Electrical Model with Thermal Dependence for Characterization and Simulation of High Power Lithium Battery Cells," IEEE International Electric Vehicle Conference, March 2012.

Simulate a battery pack that consists of multiple series-connected cells. It also shows how you can introduce a fault into one of the cells to see the impact on battery performance and cell temperatures. The battery pack is modeled in Simscape™ language by connecting cell models in series using arrays. You can represent the fault by defining different parameters for the faulty cell.

Use Simscape™ to model a variable transport delay. The Transport Delay block models signal propagation through media moving between the Input and the Output terminals. The media velocity may vary, thus it is specified through the block port. The distance between the terminals as well as the initial output are constant and they are specified as block parameters.

How the Simscape™ Foundation Library PS Asynchronous Sample & Hold block can be used to build components with more complex behaviors. The model implements a controllable PWM voltage source where the PWM on-time (the duty cycle) is proportional to the physical signal input u.

How the discrete-time Simscape™ Foundation Library PS Counter block can be used to build components with more complex behaviors. The model implements a controllable PWM voltage source where the PWM on-time (the duty cycle) is proportional to the physical signal input u.

Model a controlled actuator using simplified custom pneumatic components. There are two across variables, defined as pressure and temperature, and two through variables, defined as mass flow rate and heat flow rate. The simplified approach means that every node in the circuit must have a volume of gas associated with it. This physical volume of gas in the circuit is represented by the Constant Volume Pneumatic Chamber blocks, the Pneumatic Piston Chamber blocks, and the Pneumatic Atmospheric Reference block. Conversely, the Foundation Library gas components require no such connection rules at every node. See the Pneumatic Actuation Circuit example for a more capable way of modeling pneumatic systems using Foundation Library gas components.

Write Simscape™ functions to compute numerical values with Simscape expressions and how to use Simscape functions to improve code reuse across components. The top two Simscape component blocks ( inside the "Use no Simscape functions" box ) are respectively created using two Simscape component files. Comparing these two component files, similar Simscape expressions can be observed on the right hand side of the equation to compute numerical values, which is essentially a modification of exp(i) to provide protection for large magnitude of i. Such expressions are common in standard diode modeling. Using Simscape functions, such expressions are abstracted out into a Simscape function file, and their usages inside the component files are replaced by calls to such Simscape functions. The bottom two Simscape component blocks ( inside the "Use Simscape functions" box ) are created using component files using Simscape functions.

A cart bouncing between the two ends of an ideal hard stop, while a mass slides freely on top of it. The friction between the mass and cart is modeled using an ideal, modechart-based friction block, while the hard stop is modeled using instantaneous modes and entry actions. When the cart hits the bounds of the hard stop, the impulsive force is propagated to the mass above, causing it to be displaced as it transitions from static to dynamic friction modes.