Modeling and Simulation of a Piezoelectric Vibration Energy Harvester Using Matlab Simulink

This example shows how to model a device that harvests energy from a vibrating object by using a piezo bender.

This example shows how to model a device that harvests energy from a vibrating object by using a piezo bender.

The device uses this energy to charge a battery and power a load.

These devices are common in low-power applications that require energy autonomy, such as wearable devices or sensors in vehicles.

This energy harvester consists of a piezo bender, a rectifier, and a DC-DC converter. The left end of the piezo bender is clamped to a vibrating object, forcing the motion.

The right end of the piezo bender is connected to an extra mass.

Due to the elasticity, mass, and inertia of the piezo bender, the motion of the right end is not synchronous to the left end.

The deformations produce then a charge and voltage across the electrical terminals of the piezo bender, that are harvested into power.

The full-wave rectifier transforms the AC power generated by the piezo bender into DC power. It comprises four diodes and a capacitor that acts as a filter to smooth the DC voltage.

The buck converter regulates the voltage to transfer the maximum possible power to the load and ensures that the transfer of power is unidirectional.

In this example a pulse generator controls the converter in open-loop with a fixed switching frequency and duty cycle.

If the vibration source does not have a constant frequency or it contains harmonics, you can design a more sophisticated closed-loop controller to optimize the transfer of power and improve the efficiency of the energy harvester in different conditions. Initially, the energy harvester charges a battery.

Then both the energy harvester and the battery power up a constant power load.

Simulation & Analysis of Grid Connected Photo Voltaic Residential System with MPPT Controller

This example shows the operation of a photovoltaic (PV) residential system connected to the electrical grid.

Run the simulation and observe the resulting signals on the various scopes. 1) At 0.25s, with a solar irradiance of 1000 W/m2 on all PV modules, steady state is reached. The solar system generates 2400 Watts and the DC link is maintained at 400 volts with a small 120-Hz ripple due to the single-phase power extracted from the PV string. The Utility meter indicates that the system takes almost no power from the grid to supply the home total load. 2) At 0.3s, a partial shading condition is created by reducing the irradiance on some PV modules. When steady-state is reached at 0.35s, the MPPT controller has set the boost duty cycle at 0.44, generating a PV string voltage of 225 V. With this voltage, 920 W is extracted from the PV string. As you can see on the PV curve characteristic, the system is operating at a local maximum power point but not at the global maximum power point. 3) At 0.4s, a duty cycle scan of 0.25 seconds is performed by the MPPT controller to find the GMPP point. 4) At 0.7s, the MPPT controller has set the boost duty cycle at 0.58 generating a PV string voltage of 168 V. With this voltage, 1364 W is extracted from the PV string which is the GMPP value. The Utility meter indicates that it takes now around 1100 W (2500 W residential load - 1364 W supplied by PV) from the grid to supply the home total load.

Modeling and Control of PMSG-Based Energy System With Battery Charging

This example shows how to use a permanent magnet synchronous generator (PMSG) to charge a battery.

An ideal angular velocity source is used to maintain the rotor speed constant.

The Control subsystem uses Field Oriented Control to regulate the torque of the PMSG.

The torque reference is obtained as a function of dc-link voltage.

The initial battery state of charge is 25%.

The Scopes subsystem contains scopes that allow you to see the simulation results. The plot below shows the generator torque and the battery voltage and state of charge. Click here to download the simulink File: https://drive.google.com/file/d/1jydEGkk18Qfq-WIfU-HVu5SePWtRUY4V/view?usp=sharing

Modeling and simulation of Automotive Battery Pack for Electric vehicle DC Fast Charging Tasks

The example models a battery pack connected to an auxiliary power load from a chiller, a cooler, or other EV accessories.

This example shows how to model an automotive battery pack for DC fast charging tasks.

In this example, a battery pack is created by connecting three battery modules in series.

A resistance models the cable connection between individual modules.

A DC current source models the charger current and it is connected to the battery pack using a cable modeled as a resistance.

A power load across the battery terminals models the power consumption due to the chiller or the heater for coolant circuit. 

This example uses the parameters defined in the ee_lithium_pack_DCFC_ini.m file. 

Three cases are considered:

Case 1: The vehicle is parked in the parking area for a long time. The initial cell temperature is the same as the ambient temperature. The battery is heated during charging, with the initial battery state of charge equal to 20%. Case 2: The vehicle is driven and immediately charged. The initial battery cell temperature is equal to 285 K. The battery is heated during charging, with the initial battery state of charge equal to 20%. The cellInitialTemp workspace variable, defined in the ee_lithium_pack_DCFC_ini.m file, is changed to a value equal to the value of the Amb port plus 15.  Case 3: The vehicle is driven and immediately charged. The initial battery cell temperature is 285 K. The battery is not heated during charging (no auxillary power consumption), with the initial battery state of charge equal to 20%. The cellInitialTemp workspace variable, defined in the ee_lithium_pack_DCFC_ini.m file, is changed to a value equal to the value of the Amb port plus 15 and auxLoad is set to a low value equal to 1e-4. The coolant flow rate FlwR is set to zero by turning off the coolant flow inside the Controls/Flow_Control subsystem, setting NoFlow to 0. Click here to download the simulink file: https://drive.google.com/file/d/1EDdBN9WU1bcp6rogdQZcJyhyCrjZiKRZ/view?usp=sharing Kindly Subscribe My YouTube Channel... Please like, share and comments on My Videos 🙏 Please click the below links to Subscribe/Join & View my Videos https: //www.youtube.com/c/DrMSivakumar Telegram : t.me/Dr_MSivakumar website : drmsivakumar78.blogspot.com https://www.paypal.com/paypalme/DrMSivakumar?locale.x=en_GB

PPT_Modeling and Simulation of an Electric Vehicles using Matlab Simulink