Never Do this activity in Solar PV Plant

 

Battery Selection Electric Vehicles

An electric-vehicle battery (EVB) or traction batteryis a battery used to power the propulsion of battery electric vehicles (BEVs). Vehicle batteries are usually a secondary (rechargeable) battery. Traction batteries are used in forklifts, electric golf carts, riding floor scrubbers, electric motorcycles, electric cars, trucks, vans, and other electric vehicles.
Electric-vehicle batteries differ from starting, lighting, and ignition (SLI) batteries because they are designed to give power over sustained periods of time. Deep-cycle batteries are used instead of SLI batteries for these applications. Traction batteries must be designed with a high ampere-hour capacity. Batteries for electric vehicles are characterized by their relatively high power-to-weight ratio, specific energy and energy density; smaller, lighter batteries reduce the weight of the vehicle and improve its performance. Compared to liquid fuels, most current battery technologies have much lower specific energy, and this often impacts the maximal all-electric range of the vehicles. However, metal-air batteries have high specific energy because the cathode is provided by the surrounding oxygen in the air. Rechargeable batteries used in electric vehicles include lead–acid ("flooded", deep-cycle, and VRLA), NiCd, nickel–metal hydride, lithium-ion, Li-ion polymer, and, less commonly, zinc–air and molten-salt batteries. The most common battery type in modern electric cars are lithium-ion and Lithium polymer battery, because of their high energy density compared to their weight. The amount of electricity (i.e. electric charge) stored in batteries is measured in ampere hours or in coulombs, with the total energy often measured in watt hours.
The battery makes up a substantial cost of BEVs, which unlike for fossil-fueled cars, profoundly manifests itself as a price of range. As of 2018, the few electric cars with over 500 km of range such as the Tesla Model S are firmly in the luxury segment. Since the late 1990s, advances in battery technology have been driven by demands for portable electronics, like laptop computers and mobile phones. The BEV marketplace has reaped the benefits of these advances both in performance, energy density. The batteries can be discharged and recharged each day.

Types of Motors used in Electric Vehicles ELECTRONICS

  

Types of Motors used in Electric Vehicles

ELECTRONICS

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Types of Motors used in Electric Vehicles

Electric vehicles are not something new to this world, but with the technological advancement and increased concern on controlling pollution has given it a tag of future mobility. The core element of the EV, apart from Electric Vehicle Batteries, which replaces the Internal Combustion engines is an Electric motor. The rapid development in the field of Power electronics and control techniques has created a space for various types of electric motors to be used in Electric Vehicles. The electric motors used for automotive applications should have characteristics like high starting torque, high power density, good efficiency, etc.

Various types of Electric Motors used in Electric Vehicles

1. DC Series Motor
2. Brushless DC Motor
3. Permanent Magnet Synchronous Motor (PMSM)
4. Three Phase AC Induction Motors
5. Switched Reluctance Motors (SRM)

1. DC Series Motor

High starting torque capability of the DC Series motor makes it a suitable option for traction application. It was the most widely used motor for traction application in the early 1900s. The advantages of this motor are easy speed control and it can also withstand a sudden increase in load. All these characteristics make it an ideal traction motor. The main drawback of DC series motor is high maintenance due to brushes and commutators. These motors are used in Indian railways. This motor comes under the category of DC brushed motors.

2. Brushless DC Motors

It is similar to DC motors with Permanent Magnets. It is called brushless because it does not have the commutator and brush arrangement. The commutation is done electronically in this motor because of this BLDC motors are maintenance free. BLDC motors have traction characteristics like high starting torque, high efficiency around 95-98%, etc. BLDC motors are suitable for high power density design approach. The BLDC motors are the most preferred motors for the electric vehicle application due to its traction characteristics. 

BLDC motors further have two types:

i. Out-runner type BLDC Motor:

In this type, the rotor of the motor is present outside and the stator is present inside. It is also called as Hub motorsbecause the wheel is directly connected to the exterior rotor. This type of motors does not require external gear system. In a few cases, the motor itself has inbuilt planetary gears. This motor makes the overall vehicle less bulky as it does not require any gear system. It also eliminates the space required for mounting the motor. There is a restriction on the motor dimensions which limits the power output in the in-runner configuration. This motor is widely preferred by electric cycle manufacturers like Hullikal, Tronx, Spero, light speed bicycles, etc. It is also used by two-wheeler manufacturers like 22 Motors, NDS Eco Motors, etc.

BLDC Hub Motor

Bosch’s BLDC Hub motor used by 22 Motors

ii. In-runner type BLDC Motor:

In this type, the rotor of the motor is present inside and the stator is outside like conventional motors. These motor require an external transmission system to transfer the power to the wheels, because of this the out-runner configuration is little bulky when compared to the in-runner configuration. Many three- wheeler manufacturers like Goenka Electric Motors, Speego Vehicles, Kinetic Green, Volta Automotive use BLDC motors. Low and medium performance scooter manufacturers also use BLDC motors for propulsion.

BLDC Motor In-runner type

BLDC In-runner type used in Ather Scooter

It is due to these reasons it is widely preferred motor for electric vehicle application. The main drawback is the high cost due to permanent magnets. Overloading the motor beyond a certain limit reduces the life of permanent magnets due to thermal conditions.

3. Permanent Magnet Synchronous Motor (PMSM)

This motor is also similar to BLDC motor which has permanent magnets on the rotor. Similar to BLDC motors these motors also have traction characteristics like high power density and high efficiency. The difference is that PMSM has sinusoidal back EMF whereas BLDC has trapezoidal back EMF. Permanent Magnet Synchronous motors are available for higher power ratings. PMSM is the best choice for high performance applications like cars, buses. Despite the high cost, PMSM is providing stiff competition to induction motors due to increased efficiency than the latter. PMSM is also costlier than BLDC motors. Most of the automotive manufacturers use PMSM motors for their hybrid and electric vehicles. For example, Toyota Prius, Chevrolet Bolt EV, Ford Focus Electric, zero motorcycles S/SR, Nissan Leaf, Hinda Accord, BMW i3, etc use PMSM motor for propulsion.

Permanent Magnet Synchronous motor of Toyota Prius 2004

4. Three Phase AC Induction Motors

The induction motors do not have a high starting toque like DC series motors under fixed voltage and fixed frequency operation. But this characteristic can be altered by using various control techniques like FOC or v/f methods. By using these control methods, the maximum torque is made available at the starting of the motor which is suitable for traction application. Squirrel cage induction motors have a long life due to less maintenance. Induction motors can be designed up to an efficiency of 92-95%. The drawback of an induction motor is that it requires complex inverter circuit and control of the motor is difficult.

Induction Motor (Image Source: OrientalMotor)

Three Phase Induction Motor Characteristic

Three Phase Induction Motor Characteristic Under Flux Oriented Control

In permanent magnet motors, the magnets contribute to the flux density B. Therefore, adjusting the value of B in induction motors is easy when compared to permanent magnet motors. It is because in Induction motors the value of B can be adjusted by varying the voltage and frequency (V/f) based on torque requirements. This helps in reducing the losses which in turn improves the efficiency.

Tesla Model S is the best example to prove the high performance capability of induction motors compared to its counterparts. By opting for induction motors, Tesla might have wanted to eliminate the dependency on permanent magnets. Even Mahindra Reva e2o uses a three phase induction motor for its propulsion. Major automotive manufacturers like TATA motors have planned to use Induction motors in their cars and buses. The two-wheeler manufacturer TVS motors will be launching an electric scooter which uses induction motor for its propulsion. Induction motors are the preferred choice for performance oriented electric vehicles due to its cheap cost. The other advantage is that it can withstand rugged environmental conditions. Due to these advantages, the Indian railways has started replacing its DC motors with AC induction motors.

5. Switched Reluctance Motors (SRM)

Switched Reluctance Motors is a category of variable reluctance motor with double saliency. Switched Reluctance motors are simple in construction and robust. The rotor of the SRM is a piece of laminated steel with no windings or permanent magnets on it. This makes the inertia of the rotor less which helps in high acceleration. The robust nature of SRM makes it suitable for the high speed application. SRM also offers high power density which are some required characteristics of Electric Vehicles. Since the heat generated is mostly confined to the stator, it is easier to cool the motor. The biggest drawback of the SRM is the complexity in control and increase in the switching circuit. It also has some noise issues. Once SRM enters the commercial market, it can replace the PMSM and Induction motors in the future.

Switched Reluctance Motor

 

Insights for Selecting the Right Motor for your EV

For selecting the appropriate electric vehicle motors, one has to first list down the requirements of the performance that the vehicle has to meet, the operating conditions and the cost associated with it. For example, go-kart vehicle and two-wheeler applications which requires less performance (mostly less than 3 kW) at a low cost, it is good to go with BLDC Hub motors. For three-wheelers and two-wheelers, it is also good to choose BLDC motors with or without an external gear system. For high power applications like performance two-wheelers, cars, buses, trucks the ideal motor choice would be PMSM or Induction motors. Once the synchronous reluctance motor and switched reluctance motor are made cost effective as PMSM or Induction motors, then one can have more options of motor types for electric vehicle application

How to Calculate Solar Plant PR% Performanse Ratio

1  What is the performance ratio? 
The performance ratio is a measure of the quality of a PV plant that is independent of location and it therefore often described as a a quality factor. The performance ratio (PR) is stated as percent and describes the relationship between the actual and theoretical energy outputs of the PV plant. It thus shows the proportion of the energy that is actually available for export to the grid after deduction of energy loss (e.g. due to thermal losses and conduction losses ) and of energy consumption for operation. The closer the PR value determined for a PV plant approaches 100 %, the more efficiently the respective PV plant is operating. In real life, a value of 100 % cannot be achieved, as unavoidable losses always arise with the operation of the PV plant (e.g. thermal loss due to heating of the PV modules). High-performance PV plants can however reach a performance ratio of up to 80 %. 2  


What is the function of the performance ratio?
The performance ratio informs you as to how energy efficient and reliable your PV plant is. With the performance ratio you can compare the energy output of your PV plant with that of other PV plants or monitor the status of your PV plant over a prolonged period. The determination of the performance ratio at fixed regular intervals does not provide an absolute comparison. Instead, it provides the operator with the option of checking performance and output: if it is assumed that the PV plant is running optimally on being commissioned, and hence that the initial value for the performance ratio is 100%, then taking of further PR values over time enables the identification of deviations, meaning that appropriate countermeasures can be promptly initiated. Deviations in the PR value in the form of values below the normal range therefore indicate a possible fault in your PV plant at an early stage.

Weather Monitoring System #SustainableEveryDay

Weather Monitoring System

SCADA Compatible ALL – IN – ONE WMS Systems – Surya

Precise weather monitoring system for assessment and system operations are a requirement for Renewable projects and other Industrial applications. In Solar Plants, Weather Monitoring stations are the key in the initial assessment to finding optimal locations for solar radiation and improving plant efficiency.

MBCS provides end-to-end solutions in hardware and software for Renewable Plants and other Industrial applications. One our offering is “Surya”, high precision weather monitoring stations with long term stability for the most critical parameters of power plants along with collecting information, transferring it back to the control site, carrying out necessary analysis and control, and then displaying this data to a central database. These stations are permanently installed as a part of the control system for each wind and solar energy project by feeding data into the SCADA System.

These sensors can be procured standalone or as an all-in-one WMS solution :

• Solar irradiation (W/m2) as per ISO 9060:
  • Second Class Pyranometer SR05(Analogue Output & RS-485 Modbus Output)
  • Secondary Standard PyranometerSR20-T1 (Analogue Output) and SR20-D2 (4-20mA & RS-485 Modbus Output)

• Wind Speed & Direction as per MEASNET Compliance: MeteoWind (4-20mA & RS-485 Modbus Output)
• Relative Humidity, Temperature, Barometric Pressure, Dew Point & Frost Point as per WMO Compliance:
  • MeteoTemp RH+T (4-20mA & RS-485 Modbus Output)
  • MeteoTemp RH+T with Pressure (4-20mA & RS-485 Modbus Output)

• Radiation Shield: MeteoShield
• Soil Moisture and Temperature Sensor (4-20mA Output)
• Solar PV Module Temperature Sensor (PT100 Output, 4-20mA Output & RS-485 Modbus Output)
• Rain Gauge Sensor SEB-200 (Pulse or RS-485 Modbus Output)
• Datalogger: EasyLog GSM (RS-232/ RS-485 Modbus or ETH Output)
• WMS Solar Power Supply: Includes Solar Panel, Charge Controller & Battery
• WMS Junction Box: UV Resistant and IP65
• WMS Mast: Tripod Stand with necessary mounting

Features :

DC string Monitoring Box #SustainableEveryDay

DC string Monitoring Box

smoothly with the Modbus RTU protocol and the provided RS485 interface. The SMU is compatible with meteocontrol data loggers.

Features

• Measurement of 8 to 24 individual strings, 16 to 48 strings with double assignment
• Error recognition in the PV generator on the string level
• Precise, real-time measured value recording
• Compatible with system voltage levels of up to 1,500 V DC
• Manufacturer-independent, open Modbus RTU protocol
• Comprehensive status monitoring
• Preconfiguration for easy connectivity to the data loggers WEB’log and blue’Log X-Series

Your benefits

• Highly flexible system design
• Detection of even small yield losses – assurance of yields on the string level
• Cost-efficient monitoring of the direct current side of your PV system
• Future-proof hardware also for system designs with 1,500 V DC
• Effortless connection to any SPS or data logger
• Time and cost savings through simplified commissioning process

DIY dual axis solar tracker #SustainableEveryDay

DIY dual axis solar tracker

Arduino Solar Tracker Dual Axis

In modern solar tracking systems, the solar panels are fixed on a structure that moves according to the position of the sun.

Let us design a solar tracker using two servo motors, a light sensor consisting of four LDRs and Arduino UNO board.

Circuit Diagram

The circuit design of solar tracker is simple but setting up the system must be done carefully.

Four LDRs and Four 100KΩ resistors are connected in a voltage divider fashion and the output is given to 4 Analog input pins of Arduino.

The PWM inputs of two servos are given from digital pins 9 and 10 of Arduino.

Components Required

• Arduino UNO  - https://amzn.to/2RguMc4
• Servo Motor - https://amzn.to/32ZvFZv
• LDR - https://amzn.to/3nLzP0J
• Resistors - https://amzn.to/3e5Bbjt

Working

LDRs are used as the main light sensors. Two servo motors are fixed to the structure that holds the solar panel. The program for Arduino is uploaded to the microcontroller. The working of the project is as follows.

LDRs sense the amount of sunlight falling on them. Four LDRs are divided into top, bottom, left and right.

For east – west tracking, the analog values from two top LDRs and two bottom LDRs are compared and if the top set of LDRs receive more light, the vertical servo will move in that direction.

If the bottom LDRs receive more light, the servo moves in that direction.

For angular deflection of the solar panel, the analog values from two left LDRs and two right LDRs are compared. If the left set of LDRs receive more light than the right set, the horizontal servo will move in that direction.

If the right set of LDRs receive more light, the servo moves in that direction.

Project Code

	#include <Servo.h>
	//defining Servos
	Servo servohori;
	int servoh = 0;
	int servohLimitHigh = 160;
	int servohLimitLow = 20;
	Servo servoverti;
	int servov = 0;
	int servovLimitHigh = 160;
	int servovLimitLow = 20;
	//Assigning LDRs
	int ldrtopl = 2; //top left LDR green
	int ldrtopr = 1; //top right LDR yellow
	int ldrbotl = 3; // bottom left LDR blue
	int ldrbotr = 0; // bottom right LDR orange
	void setup ()
	{
	servohori.attach(10);
	servohori.write(0);
	servoverti.attach(9);
	servoverti.write(0);
	delay(500);
	}
	void loop()
	{
	servoh = servohori.read();
	servov = servoverti.read();
	//capturing analog values of each LDR
	int topl = analogRead(ldrtopl);
	int topr = analogRead(ldrtopr);
	int botl = analogRead(ldrbotl);
	int botr = analogRead(ldrbotr);
	// calculating average
	int avgtop = (topl + topr) / 2; //average of top LDRs
	int avgbot = (botl + botr) / 2; //average of bottom LDRs
	int avgleft = (topl + botl) / 2; //average of left LDRs
	int avgright = (topr + botr) / 2; //average of right LDRs
	if (avgtop < avgbot)
	{
	servoverti.write(servov +1);
	if (servov > servovLimitHigh)
	{
	servov = servovLimitHigh;
	}
	delay(10);
	}
	else if (avgbot < avgtop)
	{
	servoverti.write(servov -1);
	if (servov < servovLimitLow)
	{
	servov = servovLimitLow;
	}
	delay(10);
	}
	else
	{
	servoverti.write(servov);
	}
	if (avgleft > avgright)
	{
	servohori.write(servoh +1);
	if (servoh > servohLimitHigh)
	{
	servoh = servohLimitHigh;
	}
	delay(10);
	}
	else if (avgright > avgleft)
	{
	servohori.write(servoh -1);
	if (servoh < servohLimitLow)
	{
	servoh = servohLimitLow;
	}
	delay(10);
	}
	else
	{
	servohori.write(servoh);
	}
	delay(50);
	}