Conventional Generator vs Inverter – What is the Big Difference?

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Yes, what is the difference between an inverter, a generator and an inverter generator? If you cannot tell the difference, you are not alone. Thousands of people, some of whom use these machines daily, cannot tell the difference. And who can blame them? The terms are similar and some will say that all the three are really one- a trinity! We certainly need to distinguish between the trio and even determine if any is better than others. Let us find out.

Conventional Generator

Conventional generators have existed for a long time. The concepts that led to their invention has largely remained the same. The machines consist of an energy source like diesel, gasoline or propane. This powers a motor which, in turn, is linked to an electricity-generating alternator. The motor is expected to run at a steady speed so as to generate a standard current used domestically. This speed averages at 3600 rpm. Usually, the frequency of electrical output fluctuates according to the engine’s rpm.

What is an Inverter Generator? How does it Work?

As noted, few people understand how an inverter generator differs from a portable conventional generator. The strikingly similar terminology that comes with the latest technology can be confusing. For instance, we’ve not had inverter generators with us for a long time. Many would like to learn more about such a machine. Some questions, therefore, need answers: What really is an inverter generator? How does it work? What advantages and disadvantages does it offer?

Generally, it’s good to know that the key function of an inverter is to convert direct current (DC) into alternating current (AC). You do this simply by using a switch mode. In order to change the polarity of current, the DC power source is usually directed to an opening and closing switch. The switch is connected on each side to a field conductor.

Field conductor

A field conductor is just a circuit that, all around it, generates an electrical field. It is usually made of copper coil. Each field creates a point for the power source to alternate. The power is subsequently distributed to transistors which direct the current as pulse. The current leads to the final output in correct frequency. A frequency is generally created Vis a Vis the speed of the current pulsing. This switching system uses what is abbreviated as MOSFET. Two MOSFETS usually operate in a parallel mode to form a sine wave peak and trough.

A square sine wave is usually created by two points on either sides of the switch. However some equipment fail to work well on this square. When more MOSFETS are added in parallel, the result is multiple square waves or modified sine wave. This enables virtually all AC equipment to run in the normal manner. Higher currents generally require switch modes with larger capacity. There is, however, one major challenge encountered with the modified and square sine waves; it is usually impossible to control the wave’s harmonic distortion. But what is a Harmonic distortion?

What is Harmonic Distortion?

It is notable that alternating currents, just like sound, move in waves. It’s possible for these waves to be distorted. Generally, we know about distortion of sound waves simply because we can hear it. This happens when there is some interference with the signal or the amplifier has been overloaded. Sine waves experience similar distortion. The only difference is that we can neither see nor hear it. Whatever the case, it usually affects the way our electric gadget works.

Electric motors tend to overheat and be less efficient due to the effect of Harmonic distortion. This HD effect is generally exacerbated when it applies to electronic equipment. Such equipment, especially those using a microprocessor, get affected by HD and produces excessive heat besides functioning below par. You need to remember that excessive exposure to HD can damage the equipment circuitry. In the end, it can make them fail.

Clean Power

Many everyday household gadgets including phones, computers and TV’s use microprocessors. For this reason, it’s important to use low HD ‘clean’ power. Remember that all AC power is susceptible to levels of distortion. As a rule, engineers calculate HD as total harmonic distortion (THD). If the THD is less than 3 percent then it’s clean power. Interestingly, even Grid power, on rare occasions, sometimes exceeds that level. A portable generator, however, has less capacity and can greatly fluctuate depending on the load. This can gradually result in damage to equipment. The circuitry of this kind of equipment gets compromised, leading to eventual failure.

Good enough, today you can use IGBT transistor technology that produces a virtually perfect sine wave. The wave produced by IGBT is highly superior to MOSFET inverters. Pulse width modulation is also used to control sine wave and lessen the THD. Ultimately, this results in pure, clean sine wave that can be used to limit the HD and control sine wave. If you want to compensate for changes resulting in DC voltage, you can use capacitors. In this way, you can maintain a stable voltage output.

Double Conversion Factor

The system of double conversion was introduced to work with highly sensitive electronic gadgets. The main reason for this is because today’s inverters have the capacity to create a much better sine wave than the usual grid power. Double conversion is actually a system that converts AC type power to DC. The inverter is then used to convert this power to AC. Eventually, this type of technology results in a more reliable sine wave than what originally existed. Often, this sine wave has less than one percent HD.

The technology first developed in laboratory and aviation industries. These usually require a perfect sine wave. These industries have to maintain set calibrations with accurate measurements. Inverter generators generally use the double conversion system.

What is an Inverter?

We are used to standard generators since we’ve had them for long periods. They use basic technology. For example, a gas engine runs an alternator producing AC power. The amount of fuel in the engine is controlled by a governor. This keeps the machine running at a constant speed. As you increase load, more power is required to maintain the engine’s constant speed. As more power becomes necessary, the governor opens to supply more fuel. This is comparable to a car driver stepping down on the pedal to keep constant speed while approaching a hilly terrain. The changes in alternator speed causes a change in both the frequency and voltage of the current. In order to keep the voltage more stable, most modern generators use the automatic voltage regulator. Because the frequency changes cannot be controlled, generators are usually subject to high degrees of HD.

Advantages of Inverter Generators

It is clear that, when using electronic equipment, the inverter generator is best. It limits the harm occasioned by harmonic distortion. It enables all equipment running on the generator to function efficiently while consuming less power. For this reason, the inverter generator will generally run for a longer time on just one tank of gas compared to the conventional machine.

Additionally, inverter generators allow parallel functioning. It means that you can simultaneously use more than one generator for a higher power output. In the final analysis, the inverter generator protects equipment. It saves on fuel consumption and functions efficiently. Ultimately, you can use more than one generator for higher power output.

Disadvantages

One huge disadvantage with inverter generators is their high price.  Because they offer more sophistication than the conventional types, consumers are forced to pay more for this convenience. Interestingly, for a number of people who are conservatives, the complicated technology that comes with advanced machines may be deemed as a challenge.

For example, inverter machines are generally reliable units that are maintenance-free. However, they cannot be easily repaired by many ordinary technicians. For consumers who are used to repairing their machines, it can be a challenge to adjust to inverter technology. Another disadvantage is that the inverter generator fuel tank is typically designed to be small and light. For this reason, the fuel tank is usually smaller than the ordinary conventional generator tank.

Conventional versus Inverter – What is the Big Difference?

There are some key differences between the conventional and inverter generator types. For one, traditional generators are usually noisier, bigger and heavier. They produce ‘dirtier’ power but are largely more affordable. Inverter generators, in comparison, produce ‘cleaner’ power and are quieter and more portable. However, they are significantly more costly than conventional generators.

Which is preferable, therefore? It all depends. What do you want to do with the engine? How much power do you want to generate? How much money can you pay? You can easily transport and store a modern portable generator. Many conventional machines are comparably bulkier and heavier and therefore more difficult to carry or store. Overall, they are less convenient than the lighter, smaller modern machines. Inverter generators are also more fuel-efficient and therefore saves money while reducing needless exhaust fumes.

Noise Levels – How do they compare?

Considering noise levels, the difference between the two types of machines are glaring. From the word go, inverter generators are designed to be very quiet. They are made with special mufflers and sound-dampening technology that results in amazingly quiet engines with low noise levels.

Conventional generators must run at constant high speed to produce desired power. This also means constant noise. Inverters are able to use special electronics and microprocessors to adjust power levels without impacting on noise levels or quietness of running.

Amazingly, the Yamaha EF2000iSv2 produces only 51.5 decibels while running at a-quarter-load. This noise level is comparable to that of a quiet office. It produces just about 60 decibels running at full load. This is roughly comparable to normal human conversation. In contrast, most conventional generators produce some 65 to 75 decibels. This compares with busy traffic noise levels, being in a noisy restaurant or standing next to a dog barking loudly!

Maximum Power Output

You can get a conventional generator at almost any size desired. This can begin from 500 watts, going up to 50,000 watts or more. On the other hand, inverter generators are designed to operate quietly and be more portable. This means that their maximum power output is limited. Many are available in between the ranges of 1000 to 4000 watts.

Power Quality

How can we define a conventional generator? It similar to an engine that is connected to the alternator that runs at a certain speed. The controlled speed produces a desired frequency at whatever load it carries. This means that when the load increases the engine throttles up and this action maintains the speed of engine. The alternator output is usually connected to the load in a direct manner, with no need for processing.

The inverter generator, on its part, is connected to the alternator. Just like with the conventional generator, the alternator produces AC type of electricity. In this case, however, a rectifier converts this AC power   to DC. Capacitors are then used to make it relatively smooth. The DC power is afterwards inverted back to cleaner AC power. This power comes in the required voltage and frequency.

Such a mechanism results in consistent characteristics of power that does not depend on the speed of engine. Ultimately, the resultant power is cleaner than that produced by a conventional generator. Indeed, the power produced by an inverter may be reasonably compared to clean electricity that we get from electric companies. Why can we say that this last point is this important?

Microprocessor

Remember that most products we use today function with some form of a microprocessor. Be it the TV, your phone, the computer, game consoles, DVD player, printer and even kitchen appliances; all these household tools use a highly advanced system of electronic circuitry. Their microprocessors are quite sensitive to electricity quality. If you use power that may be classified as “unclean,” it is likely to cause your devices to malfunction. They may even be damaged.  For this reason, any application that runs sensitive electronics will benefit a lot from the much cleaner power that is derived from inverter generator.

Parallel Operation

Most inverters can easily be paired with a similar identical unit to produce double power. This is called parallel capability. This means you can use twin smaller and lighter generators to obtain similar wattage and amperage of one larger generator. Happily, this is possible to achieve while still enjoying the advantages of having a smaller, quieter, lighter and more portable inverter machine. Actually, to get a combined power output, you will require a special cable linked to your generator. This cable is usually obtained separately or sometimes may be availed in case you buy two generators at the same time.

Design and Construction – How Simple?

Many consumers of generators generally consider the simplicity of design and construction as an important element. Indeed, it is considered as a key advantage that the conventional generator enjoys over the inverter type. To be sure, conventional generators are basically simple units consisting basically of a motor with an alternator attached. It is simple to maintain, repair and run. There are no complex controls or complicated electronic systems.

From these facts, conventional generators are basically made of a motor together with an attached alternator. They are fundamentally very simple machines. They are significantly simple to run, maintain and repair. The motor usually cranks at a standard rpm going at about 3,600. There are generally no complicated controls, electronics or other things that can easily go wrong.

Even so, inverter generators have been here for a good number of years. And they use technologies that are fairly well-tested. In the final analysis, while deciding what to purchase, it is really a question of personal preference. You can decide whether simplicity of design is actually a big deal before choosing which generator to purchase.

Price Factors

Ultimately, it seems that almost everything in this life comes down to one thing: price! The same applies with generators. One of the greatest disadvantages with the superb inverter generator is the cost. Generally, an inverter generator costs much more than a similar or better capacity conventional machine. The benefits of the inverter generator including fuel efficiency, portability, convenience and lower noise levels, therefore, come at a high cost. It all depends on what applications you have and the budget you can afford. Interestingly, it seems that more people have in recent past bought inverter generators. This means that they consider the benefits to be worth the higher price.

Conclusion

Certainly, both inverter and conventional generators have their pros and cons. As a consumer, it all depends on your priorities. If you just need a simple machine that provides power and costs less regardless of a few drawbacks here and there, then you can go for a conventional machine. Alternately, if you want more conveniences like cleaner power, noiseless operation and easier portability, then you might decide that the inverter generator will give you great value for your money. Eventually, the choice is all yours.

Alexey P. , Qualified Electrician and Website Founder

Alexey P. , Qualified Electrician and Website Founder

My name is Alexey P. I was born in Poland but later moved to the USA in 1998. As a well-qualified and fairly experienced electrician, I love working with generators. After my family, the generator could easily be my next love in life! No wonder, I am constantly working with this widely used and very fascinating machine. As a result of my professional training in the field of electrical engineering, I am well versed with the key elements of the trade. I am generally knowledgeable with all inspecting codes and important regulations governing electrical components and repair. I presently live in Monticello, Minnesota, USA. Want to know a little about my life outside work? It is no wonder. If you encounter any challenges with your portable generator while on that camping expedition, you can count on me to help deal with that decisively. I love life. I love people. And yes, I love generators, of course!

One Response

  1. Avatar Dave November 6, 2019

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