Even before the rising prices of fuel, hybrid and electric vehicles (EVs) were already becoming popular both in the United States (US) and Europe. It’s not only the environmentally conscious who’ve been convinced to shift to EVs. People who want to save on fuel and prefer to drive zero-emission vehicles are all shifting to hybrid or EVs.
A hybrid or EV uses an auxiliary inverter and converter tandem to manage its power supply and electric motor drive system. This is necessary because the power supply from the grid is in alternating current, but car batteries store electricity in direct current. To complicate things even more, most hybrid or EVs use electric motors that run on AC. This article would discuss how inverters work in hybrid and electric vehicles.
What An Inverter Does
There are two critical elements that work in tandem to manage the power supply and recharge batteries and circuits in hybrid and electric vehicles. These key elements are the inverter and the converter. These two always work together to manage the power supply. This isn’t quite the same as the device used to manage the power supply for computers and routers.
The principal function of an inverter is to convert electricity, which comes from a direct current (DC) power source to an alternating current (AC) power supply. Most of the motors designed to drive home appliances and devices run on an AC power supply. The reason for this is that AC motors are considered to be generally more powerful than DC motors. They can generate a higher torque with the use of a more powerful electrical current.
Here are some of the other advantages of an AC motor:
- AC motors require a lower startup power
- They have a more controllable level of starting current and acceleration, which is highly suitable for controlling the acceleration of electric vehicles
- VFD and VSD can be added to AC motors, which can provide better control of torque and speed at different stages of operation
- They’re considered to be more durable and have longer lifespans, making them more suitable for the wear and tear that comes with road travel
- AC motors are suitable for multiphase configurations
AC And DC Power Supply Charging
Keep in mind that the power supply from the grid is in AC. This means that charging the batteries of an electric car has to be done by converting the AC power supply from the grid to DC so the car batteries can be recharged. The power supply is converted from AC to DC at the charging station itself. The power supply running from the grid is in AC because it can transmit more powerful and efficient electric power.
The output power supply that comes from solar power panels and is stored in electric car batteries is usually in DC. Car batteries work with DC. Electric batteries can also be charged using DC chargers. There’s a thick wire that comes from the charging station. The thick wires are designed for DC charging. This is what you use to plug into your hybrid or EV car for charging.
In Europe, DC chargers can deliver between 50 kW to 100 kW. There are some chargers that can charge up to 350 kW. At around 90kW, an electric car’s battery can be recharged up to 80% in just around 30 minutes.
How Inverters Work
The technical term for an inverter is a voltage converter. It’s called a converter because it’s an electrical device that converts the voltage from the power supply from AC to DC. The two common types of voltage converter are the step-up converter (this is used to increase voltage) and the step-down converter (used to decrease voltage). Converters are commonly used to step-up voltage from a low voltage source to a higher voltage, which can be used for heavy-duty equipment.
An inverter works in a hybrid or electric vehicle as part of an inverter/converter tandem unit. The two main components are contained in a single housing unit, which you won’t be able to distinguish unless you open the housing. Most hybrid and EVs use these two important devices to manage the power supply to their electric drive systems.
The inverter functions by supplying electricity to the electric motor, which drives the shaft for vehicle propulsion. Both hybrids and EVs typically make use of low-voltage DC batteries. These batteries typically have only around 210 volts. They’re designed that way so they won’t be too heavy and won’t take up too much space in the vehicle.
The electric current that comes out of the inverter becomes AC and is used to power the electric motor or generator. These motors typically use approximately 650 volts. This is already considered a relatively efficient high voltage. In other words, the primary function of an inverter is to convert the DC power supply from the battery to AC, which is the power configuration of the electric motor.
Conclusion
Hybrid or electric vehicles run through a tandem unit of inverter and converter. The converter is needed because power from the grid is in AC but the car battery stores electricity in DC. Then it becomes necessary to convert the DC power again to AC because electric motors use AC as a power supply. In other words, the main function of an inverter is to convert the power supply from DC to AC since electric motors operate using AC as a power supply.