Power system (pdf file)

The system starts with the generation, by which electrical energy is produced in the power plant and then transformed in the power station to high voltage the electrical energy that is m

Ho Chi Minh City University of Technology and Education

Faculty for High Quality Training

Electrical and Electronic Engineering Technology

POWER SYSTEM

Supervisor

Assoc.Prof Le My Ha

Submitted by Dinh Xuan Tien Bach Quoc Khanh Nguyen Dang Phuong Hua Hong Minh Quan

J anuary 7th

, 2022

1.1 Introducing of standard of power system 2

1.2 Objective of study 3

1.3 On Grid solar system 3

2 Design 5 2.1 Theoretical basis 5

2.1.1 The configuration of a typical power system 5

2.1.2 The working principle of power system 7

2.2 MATLAB design 8

2.2.1 Idea 8

2.2.2 Applications of power system in MATLAB 8

3 Results 18 3.1 MATLAB Simulink 18 3.2 Review 19 3.3 Inclusion 19

4.1 Advantage 20 4.2 Disadvantage 20 4.3 Future work 20

In this final project, we develop the project according to the electricity system in a country.The application is used by Matlab software through the Simulink tool to run simulations Weuse renewable energy and solar energy is used as the main source And is connected to thenational system through loads and power stations Experimental results show that solar cellscan work in different temperature and time conditions

List of Figures

1.1 On grid power system 4

2.1 Configuration of a typical power system 6

2.2 The distribution network in power system 6

2.3 Structure of power system 7

2.4 Converter 8

2.5 Cascading control block diagram 9

2.6 Block diagram of control method V–I 10

2.7 Block diagram Control method V–f 11

2.8 PV block model connected to Boost Converter 11

2.9 MPPT algorithm 12

2.10 System of loads, transformers and grids 13

2.11 Block diagram of 3 phase motor 13

2.12 Block diagram of Rectifier circuit (Diot) 14

2.13 Block diagram of Pulse generator circuit (PWM); Inverter Circuit (IGBT) 14

2.14 Block diagram of the three-phase motor 15

3.1 Our power system via Matlab simulink 18

Assignment of work

Member Private work Work in pairs Work in group

Dinh Xuan Tien

Prepare code for Latexand find informationabout power system

Write report andand complete it

by using LaTex

Discuss reportandassemble hardwareBach Quoc Khanh Code of MPPT and present

Nguyen Dang Phuong Find information about

power system Design powerpointHua Hong Minh Quan Find information about

power system Design powerpoint

Chapter 1

Overview

1.1 Introducing of standard of power system

Electric power systems are real-time energy delivery systems Real-time means that power

is generated, transported, and supplied the moment you turn on the light switch Electricpower systems are not storage systems like water systems and gas systems Instead, gener-ators produce the energy as the demand calls for it The system starts with the generation,

by which electrical energy is produced in the power plant and then transformed in the powerstation to high voltage the electrical energy that is more suitable for efficient long-distancetransportation The power plants transform other sources of energy in the process of pro-ducing electrical energy For example, heat, mechanical, hydraulic, chemical, solar, wind,geothermal, nuclear, and other energy sources are used in the production of electrical energy.High-voltage (HV) power lines in the transmission portion of the electric power system effi-ciently transport electrical energy over long distances to the consumption locations Finally,substations transform this HV electrical energy into lower-voltage energy that is transmittedover distribution power lines that are more suitable for the distribution of electrical energy

to its destination, where it is again transformed for residential, commercial, and industrialconsumption

1.2 Objective of study

We have looked up references on the internet and YouTube, but their make are complicatedsystems we have consulted and re-implemented the process of making an electrical system

- Creation of an electrical system through MATLAB simulink

- Source starts from solar energy

- Transformed through loads to reach the point of consumption

- Monitor the power transmission of the system

- The running process depends on the environmental impact

On Grid solar system is a solar power system connected to the electricity grid The basicstructure of a grid-tied power system includes the following basic components:

+ Solar panel

+ The inverter is capable of synchronizing the frequency of the grid

A grid-tied solar power system allows the AC power produced by the PV system to besupplied to local electrical loads or re-supply to the grid when the output of the PV system isgreater than the demand of the PV system load However, in the event of a grid outage due

to a power failure or maintenance, at this time, the solar power system will be disconnected,the load will no longer have electricity to use Therefore, this system is suitable for customerswho are using electricity from Electricity’s grid without ensuring uninterrupted power supply.The installation of grid-tied solar power system has the following advantages: Low initialinvestment cost; no energy storage is used, so the system life is longer and the operating andmaintenance costs are low; maximum savings on monthly electricity costs; selling excesselectricity to electricity through 2-way meters at preferential prices; Support Electricity inreducing power transmission

Chapter 2

Design

2.1 Theoretical basis

2.1.1 The configuration of a typical power system

The basic structure of a power system is it contains a generating plant, a transmissionsystem, a sub transmission system and a distribution system These subsystems are intercon-nected through transformers T1 , T2 and T3 Let us consider some typical voltage levels tounderstand the functioning of the power system The electric power is generated at a thermalplant with a typical voltage of 22 kV (voltage levels are usually specified line-to-line) This isboosted up to levels like 400 kV through transformer T1 for power transmission TransformerT2 steps this voltage down to 66 kV to supply power through the sub transmission line toindustrial loads that require bulk power at a higher voltage Most of the major industrial cus-tomers have their own transformers to step down the 66 kV supply to their desired levels Themotivation for these voltage changes is to minimize transmission line cost for a given level.Distribution systems are designed to operate for much lower power levels and are suppliedwith medium level voltages

The power distribution network starts with transformer T3, which steps down the voltagefrom 66 kV to 11 kV The distribution system contains loads that are either commercial type(like office buildings, huge apartment complexes, hotels etc) or residential (domestic) type.Usually, the commercial customers are supplied power at a voltage level of 11 kV whereas thedomestic consumers get power supply at 400-440 V Note that the above figures are given forline-to-line voltages Since domestic customers get single-phase supplies, they usually receive230-250 V at their inlet points While a domestic customer with a low power consumption gets

a single-phase supply, both industrial and commercial consumers get three-phase supplies notonly because their consumption is high but also because many of them use three-phase motors.For example, the use of induction motor is very common amongst industrial customers whorun pumps, compressors, rolling mills etc

2.1.2 The working principle of power system

The power system is a network which consists of generation, distribution and sion system It uses the form of energy (like coal and diesel) and converts it into electricalenergy The power system includes the devices connected to the system like the synchronousgenerator, motor, transformer, circuit breaker, conductor, etc The power plant, transformer,transmission line, substations, distribution line, and distribution transformer are the six maincomponents of the power system The power plant generates the power which is step-up orstep-down through the transformer for transmission The power system is the complex enter-prise that may be subdivided into the following sub-systems The subsystems of the powersystem are explained below in details

transmis-Figure 2.3: Structure of power system

2.2 MATLAB design

2.2.1 Idea

In this project, we had a lot of ideas such as designing a power system with solar energy orwind energy After a period of debate, we chose the source as solar energy Then connect thatenergy source into an electricity network through loads, sources, transformers, etc to transmit

to the loads, places of consumption and link to the national grid However, our system alsoincorporates a three-phase electric motor via diodes and IGBT/diots

2.2.2 Applications of power system in MATLAB

Converter (DC – DC)

DC switch - DC is installed between PV array and inverter frequency The main function

of the converter is to create a separation between the two voltage levels by increasing or creasing the PV array output voltage to match the inverter input voltage level The structuralbasis of a converter consists of diodes, capacitors, inductors and switching electronics thatcan be controlled and act as a switch This commonly used component is MOSFET or IGBT.The tool converts each option type, and the way these events are connected is also different

de-Figure 2.4: Converter

Converter control (MPPT)

MPPT (short for Maximum Power Point Tracker) or maximum power point tracker is anelectronic converter to optimize the match between solar panels and solar batteries, or grid.Simply put, they convert the higher voltage DC current from the solar panels to the lowervoltage needed to charge the solar battery

There are a lot of type of MPPT, but in this project, we have consulted and selected P&O(Perturbation and observation), which is a cascaded linear control method, with the outer stagebeing a DC voltage control loop and the inner stage a current control loop This algorithm isapplied to the boost converter This algorithm alters the operating voltage to ensure maximumpower Although there are some more advanced and optimized variations of this algorithm,the basic P&O MPPT algorithm is shown below

Figure 2.5: Cascading control block diagram

Inverter (DC – AC)

Inverters are used to convert DC to AC in PV systems Different types of inverters producedifferent “quality” of electricity Therefore, based on the amount of electricity that the loadrequires, the user must choose the appropriate inverter to achieve the best possible efficiency.Simple storage consists of semiconductor tools such as BJT, IGBT Operates on the fre-quency of the inverter and turns off the switches at the required frequency f However, whenoperating, the harmonic generator can generate overheating in case of no higher dynamic load

as well as uneven magnetic field affecting the overall operation Harmonics can be reduced byusing high frequency tuning techniques to reduce harmonics and provide load voltage testing.Inverter control method

The operation and control of inverters of distributed renewable energy sources, such asPhotovoltaic in microgrids, is a real challenge, especially when it comes to maintaining bothlow grid voltage and frequency within the allowed range There are many methods that havebeen studied, of which three are common: the V–I cascade control method, the V–f voltage-frequency control method and the PQ power control method In this section, two methods

of cascading V-I control and V-f control are introduced Note, the control methods considerthe coordinate system transformation abc-dq and vice versa, which will be analyzed in thefollowing section

Figure 2.6: Block diagram of control method V–I

Modeling a PV system using Simulink

In this section, a stand-alone PV system will be modeled including PV array, MPPT, Boostconverter and inverter

Figure 2.8: PV block model connected to Boost Converter

Pv system is designed to endure with different weather circumstances The parameters areshown in the table below

Parameters IrradianceBaking sun (about 12 a.m) 1000Sunny (7h - 9h a.m / 15h - 17h p.m) 800 - 900

The power system

The PV–converter Block is then connected to the inverter (DC-AC) Then it is connected

to a transformer to increase the voltage (22kv) and directly connected to the transmission line(designated in the form of ) and carries the high voltage power to the loads used ( we use inthis project is the load R) A part is continued to be connected to the national grid

Three-phase motor

Figure 2.11: Block diagram of 3 phase motor

Besides connecting to the system of loads and the power grid, we also connect to a phase motor system to see the operation of solar energy

three-The input source is a three-phase AC source (50Hz)

The structure of a three-phase motor consists of these parts:

+ Rectifier circuit (Diot)

+ Pulse generator circuit (PWM)

+ Inverter Circuit (IGBT)

+ Electric motor

Figure 2.12: Block diagram of Rectifier circuit (Diot)

The operation is as follows: Before the power source enters the motor, it must pass throughthe rectifier circuit (Diot) Then connect to intermediate d.c voltage (L) And continuethrough an inverter circuit (Including 6 IGBT) Through the inverter circuit, the intermedi-ate DC voltage will be converted into AC voltage Finally, current will be supplied to thestator of the 3-phase AC motor.

To control the inverter circuit, we must have a pulse generator (PWM) circuit

Figure 2.14: Block diagram of the three-phase motor

persistent Dprev Pprev Vprev % record values for next recall

to fix it Third, is a three-phase motor system And connect them to the Solar power source.Besides, thanks to the MPPT algorithm and the Intensity Adjustment Block, our system runsnormally and produces numerical and sine results.

3.2 Review

In the process of mounting blocks and running the system is very complicated We oftenhave system errors We were shocked by what we went through We don’t know where tostart over and especially in the process of learning online We are difficult to connect witheach other to solve the problem But thanks to Mr Tu (a graduate student from PolytechnicUniversity) who helped us in installing the loads, sources and even the code for MPPT.Although, we are under the guidance of Mr Tu and the system runs well, but we onlyunderstand part of the MPPT algorithm, still do not fully understand the algorithm, so weneed to study that part more

3.3 Inclusion

Solar power is mainly used to operate residential equipment, commercial equipment, ing and air conditioning for all types of buildings Through stand-alone systems, it is also verysuitable for remote areas where there is no power source PV solar panels can be mounted

light-on the ground, installed light-on the roofs of buildings or installed floating light-on a lake This chapterdiscussed solar PV arrays, converters, inverters and control methods, MPPT techniques alongwith MATLAB/SIMULINK blocks describing PV system components