Is it possible to accurately test Electric Vehicles?

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There is no doubting the importance of testing setups in production and service facilities if the electric vehicle (EV) sector is to succeed.

But can an exhaustive EV test be performed?

The answer is a resounding yes, all thanks to Su-vastika’s Automatic Testing Setup.

Let’s use an electric scooter as an example to explain this point in more detail.

What exactly has to be tested, and what tools are needed to check those components?

The battery, controller, and motor are the three main parts of an electric scooter or three-wheeler.

Each of these parts needs to be examined separately as well as together. 

Everyone who is curious about the electric scooter or 3-wheeler mileage should understand that it is only calculated based on the efficiency of the complete scooter, which makes it necessary to check all their components for synchronization.

So even the efficiency will be checked on different loads so that we are clear that the mileage will differ on different loads.

The quality of the power supplied to the motor must be the next thing that needs to be assessed by determining whether the controller has a square wave or a sine wave.

Moreover, as you may already observe in certain scooters when moving, there is absolute silence. But in other scooters, a tiny motor noise can be heard due to the controller’s waveform. This is because cheap controllers are fitted in these scooters’ 3-wheelers and 2-wheelers, generally imported from China.

Another crucial aspect that needs to be examined is how much the motor’s THD increases once the load is applied. Remember, more THD will result in more wear and tear on the motor and lower the life of the motor because more THD raises the heat within the motor as the power from the battery is transferred to the motor through the controller of the

Electric Scooter.

Then, we also need to determine the controller’s overload as well as the wattage at which the controller signals the motor to stop. The load is applied to the controller by loading the motor with the load. In order to prolong the life of the battery and motor, it is essential to determine the wattage at which an overload occurs and how quickly the controller responds. The motor’s life may face significant difficulties if the overload is improperly adjusted in the controller since it will repeatedly overload the motor and risk damaging it.

This can be understood in terms of how many people a scooter can carry while still being able to move.

You must have frequently seen images of electric scooters with three, four, or even five people seated on them, and they still run properly. However, it presents a very big risk for electric scooters as the controller permits the engine to run at a specific load while drawing current from the battery. If the limit is not set correctly, the scooter overloads the motor and discharges the battery at a specific current, reducing the life of the motor and battery.

What percentage of load is considered a short circuit in an electric vehicle, say 200 percent or 300 percent, and what happens if the short circuit occurs?

Can the battery still provide power after drawing as much electricity from the battery, and how much load is applied to the motor where it can take that much load?

Another crucial competent is the short circuit. 

How long does the controller take to shut down the system so that any eventuality can be stopped in milliseconds? This is a crucial parameter to verify because the scooter could fall into the water or go through another unplanned occurrence.

These threshold limits need to be reviewed since each lithium battery bank has a unique BMS that specifies the overload and short circuit threshold limits. The overload and short circuit capacity tests for each controller have the same threshold limits. Thus, they are typically not synchronized, leading to many problems over time.

Therefore, the controller must have a distinct set of overload and short circuit tests in the event that a battery bank’s BMS fails and no longer has control over the battery bank. In that instance, the battery will continue to discharge at that certain threshold, causing some cells to be damaged without the user being aware of it. We must also understand how the overload will issue a warning and manage the circuitry to comprehend this function effectively.

The scooter’s speed will automatically decrease if an overload occurs if the operator drives it at a specific speed, such as 100 km/h or whatever the manufacturer’s manual specifies. 

That is the overload threshold limit, and the controller is built in such a way that when an overload occurs, it warns the user, and if the user doesn’t drop the speed at a certain point, the overload function kicks in, reducing the speed automatically to protect the motor and battery.

Since you risk the motor failing if you utilize it beyond its design capability, utilizing extra power from the battery to operate the motor will surely shorten its lifespan.

The next essential component is breaking. 

In this case, we need to note down the timing of breaks, and the current taken through the controller becomes zero.

How long does this process take? 

How long does it take to stop the current because the controller must verify when it receives the break signal? 

If you remove the breaks, it restarts. Therefore the timing between the various instances of breaking is paramount to determining the function of the controller. It starts by gradually reducing the current and eventually stops the top current entirely.

The effectiveness of the controller, battery bank, and motor must also be evaluated. These components’ efficiency varies depending on the load factor. Therefore, we need to check the efficiency of these components at each load, say 10% to 100% load. This specifies the electric vehicle’s life and mileage. Another consideration is the amount of current the scooter draws from the battery while it is turned on but not in use. Thus, the term “idle current” refers to the efficiency of the motor and controller when there is no load. Since some controllers have a lesser efficiency in that state when there is no load applied, the electric scooter’s range will be reduced.

Check the low battery reserve setting for battery testing parameters. 

If the BMS or controller sets the battery reserve at a lower level than the allowed limit, you will receive better mileage, but the battery life will be impacted. 

As the battery reserve must be maintained at, say, 48 V DC, the system should be at about 44 V, extending the battery life to its fullest. 

However, if the EV maker keeps this at 40 volts, the customer will get better mileage, but the battery may also experience severe drain, in which case they will need to perform specific battery charging.

The battery life will dramatically increase if the manufacturer maintains a low battery level higher than the battery reserve. Still, in a cutthroat market, everyone prefers to rate the EV on the basis of mileage rather than other factors. 

Mileage and torque have historically been valued highly in the automotive industry. However, the comparison changes depending on the type of engine being used. 

It is important to note that the motor and battery available in EVs work together, and both components must balance to function properly.

RPM

If we overload the engine, the RPM automatically decreases to reduce the speed. Still, in an electric vehicle, everything is minutely controlled, such that we can decrease the torque time and increase the vehicle’s speed in just under a minute, much faster than mechanical engineering. As we are drawing the current from the battery, which can be very fast, and it depends upon the speed of the motor, which is again a mechanical part controlled electrically.

The motor specification is also an important component that needs to be checked to determine whether the motor is meeting its performance requirements.

Electric scooters and 3-wheelers typically employ BLDC motors, which generally range from 250 watts to 2,000 watts and above in terms of watt capacity. 

The faster the wattage, the more current it will draw from the battery, so the same size of battery will give more mileage if the wattage is less since the motor’s consumption will increase with the size of the motor.

Another crucial factor is the motor’s peak power, which must be used when climbing, traveling quickly, or off-roading. 

If climbing or driving faster is done for longer than a few seconds or minutes, the motor will become overheated and may suffer damage. 

The controller takes care of this since it has a mechanism that cuts the current if the higher current is pulled from the battery for a specified amount of time. As a result, the device automatically slows down until it can handle the additional load. 

Another significant factor is the motor’s RPM, or rotations per minute. 

The amount of power drawn from the battery increases with RPM. 

So, if you run the engine quickly, more current will be pulled from the battery. 

The motor voltage, which is utilized in electric scooters and three-wheelers, is also defined, such as 48V or 60V. 

The current drawn decreases as the voltage rise, but the wattage stays constant. 

Therefore, a 48V BLDC motor will require 20.83 Amps of current to produce 1,000W of output, while the same 60V BLDC motor will require 16.66 Amps of current. However, the main difference will be that the motor’s efficiency will increase if it runs on 60V rather than 48V DC, and its life will also lengthen, and wear and tear will be reduced compared to a 48V DC motor.

As you might have already understood, all features of an electric scooter and a 3-wheeler can be tested by using various testing equipment, and Su-vastika’s focus is on designing the Automatic Testing Equipment for testing Electric Vehicles so that we are able to help the Electric Vehicle Industry to test all the parameters to ensure the reliability of Electric Vehicles.

Learn more about Automatic Testing Setup system by Su-vastika and discover the most accurate way of testing EVs.