Most people don’t understand the difference between an inverter generator and a conventional portable gas generator, which isn’t a criticism. Most people don’t care until they want to buy a portable generator. We begin this article by answering this common question : What is an inverter generator?We understand it can be confusing to make sense of the technical aspects of generators.
We also discuss : Advantages and disadvantages of an inverter generator, how an inverter generator works, and more.
With any new technology, people can become easily confused with the terminology and applications associated with them. Inverter generators haven’t been around very long so, understandably, people want to know more about them. This article is intended to answer all your questions surrounding this relatively new technology.
What is an inverter generator? How does an inverter generator work? What are the advantages and disadvantages of an inverter generator? We’ll provide the answers to all these questions and more. After reading this, you’ll have no doubts left about inverter generators and will be able to decide with certainty whether it’s worth getting one.
Difference Between Inverter Generator and Conventional Generator:
With this in mind, we’ll go on to review some of your best options when buying an inverter generator. VIDEO | from Champion : What is an inverter generator?
The basic function of an inverter is to change Direct Current (DC) into Alternating Current (AC).
The simplest way to do this is by using a simple switch mode. A DC power source is directed to a switch that opens and closes in order to change the polarity of the current. Each side of the switch is connected to a field conductor, simply put, this a circuit (usually a copper coil) that generates an electric field around it.
Each of these fields creates a point to which the power can alternate and is then supplied to transistors that direct the current as a pulse to a final output at the desired frequency. The speed at which the current pulses creates a frequency, in other words, how many times the power is switched per second. Standard US power operates at 60HZ and therefore the transistor will swap polarity 60 times per second.
This system of switching uses what is called a Metal Oxide Semiconductor Field Electric Transistor (MOSFET).
Standard generators run at a constant speed of 3,600 rpm, but inverter generators run at a slow rpm rate, providing the same power output at a high frequency.
The inverters reduce up to 40 percent fuel consumption because the engine doesn’t run at full speed all the time.
These generators can also be connected to another identical generator unit. By pairing two units, the power is doubled. Through parallel capability, you can use two small, lightweight inverter generators instead of bulky and loud standard type of generators.
Inverters come in all shapes and sizes and each has its own specifications. If you're asking yourself "what size inverter do I need? Like with many things, it depends.
This type of sine wave is not very efficient and some equipment will not function properly on a square wave. By adding more MOSFETs in parallel, multiple square waves are produced to create a stepped square or modified sine wave. While this is not a true sine wave, it works very similarly to one and allows almost all AC equipment to operate normally, though not always as efficiently as a true sine wave.
Larger capacity switch mode inverters will use thyristors to handle the higher current. The problem with square and modified sine waves is that one cannot control the harmonic distortion of the wave. Difference between a conventional generator & inverter generator. Just like sound, alternating current moves in waves and both of these wave types can become distorted. We are familiar with sound wave distortion because we can hear it when the amplifier becomes overloaded or there is interference with the signal.
Electric sine waves experience the same distortion, only we cannot see or hear it. It does, however, affect the way electric equipment functions. Harmonic distortion can cause electric motors to be less efficient and overheat.
HD is most detrimental when it comes to electronic equipment. Electronic equipment that uses a microprocessorare affected by HD in that it changes the way they perform and it generates excessive heat.
Repeated exposure to HD will damage the circuitry of this type of equipment. Eventually causing them to fail. Microprocessors are common in many household devices from computers, phones, and TVs to many kitchen and other household appliances. It is, therefore, becoming increasingly important to ensure that we use “clean” power with low HD. All AC power will experience some degree of distortion.
Engineers measure the amount of harmonic distortion over a continuous sine wave as Total Harmonic Distortion (THD). A THD of less than 3% is considered to be clean power. Even grid power can sometimes exceed the 3% threshold but this happens very seldom because grid power uses large generating capacity.
A portable generator does not have the same capacity and the THD can fluctuate greatly as the load demand changes. As a result, standard gas generators will cause damage to electronic equipment over time. Modern inverters use Insulated Gate Bipolar Transistor (IGBT) technology to create a near-perfect sine wave. The sine wave produced by IGBTs is far superior to MOSFET inverters as they create many more points or steps.
In addition to this, pulse width modulation is used to control the sine wave and limit the THD. The result is a clean pure sine wave, suitable for use with the most sophisticated electronic equipment. Capacitors are also used to compensate for changes in DC voltage, thereby maintaining a stable output voltage.
- Video | Inverter Generator vs Conventional Generator (Read our indepth article). Double Conversion. Because modern inverters are able to produce a sine wave that is even better than standard grid power, the double conversion system was introduced for very sensitive electronic equipment.
- Double conversion refers to a system that converts an AC power supply to DC and then uses an inverter to convert the power back to AC. The point of using this technology is to produce a sine wave that is more reliable than the original source, with very low THD (sometimes less than 1%).
- This technology was originally developed for use in laboratory and aviation equipment that require a perfect sine wave to maintain calibrations set for very accurate measurement. The double conversion system is what is used in inverter generators.
- Standard gas generators have been around for a long time and use very basic technology. A gas engine is used to run an alternator that produces AC power.
- A governor controls the amount of fuel supplied to the engine to keep it running at a constant speed (usually 3600 RPM). As the load is increased, more power is needed to keep the alternator running at the same speed. The governor will open to supply more fuel as more power is needed, very much like pressing down on the accelerator pedal of a car to keep the speed constant when you approach a hill.
A governor is not 100% accurate and there will be changes in alternator speed causing both the voltage and frequency of the current to change. Many modern generators use an Automatic Voltage Regulator (AVR) to keep the voltage relatively stable. They cannot, however, control the frequency changes and generators are therefore prone to quite high levels of harmonic distortion. By using a double conversion system, an inverter generator is able to correct this and the inverter produces a very clean sine wave with low HD.