What are common types of inverters?

An inverter is a key power electronic device that converts DC power into AC power. The design and performance of an inverter depends heavily on the characteristics of its input source.

Classification by input source

1. DC to AC Inverters:

DC to AC inverter is mainly used to convert DC power into AC power. This type of inverter is widely used in applications such as solar panels and battery energy storage systems. The following are the main features and applications of DC to AC inverters:

1.1 Features:

Input power: DC power source, such as solar panel output or battery system.

Conversion method: Convert from DC to AC to generate AC power waveform.

Control technology: Pulse width modulation (PWM) technology is usually used to ensure high quality output AC waveforms.

1.2 Application areas:

Solar power generation system: Converts the DC power generated by solar panels into AC power for use in the power grid or for home use.

Battery energy storage system: In the battery system, the stored DC power is converted into AC power to be used by power equipment.

2. AC to AC Inverters:

AC to AC inverter is mainly used to change parameters such as frequency, phase number or voltage of AC power supply to adapt to different power systems or special requirements. The following are the main features and applications of AC to AC inverters:

2.1 Features:

Input power: AC power, the frequency, number of phases, or voltage may need adjustment.

Conversion method: Adjusts between input and output to meet specific power system needs.

Control technology: Use different control technologies according to needs, such as phase modulation control, etc.

Classification by output phase

1. Single-Phase Inverters:

1.1 Features:

Output Phase: The output of a single-phase inverter contains a single AC phase.

Wide range of uses: Suitable for household purposes, small commercial buildings, etc., and its output is closer to the needs of general household appliances.

1.2 Working principle:

Input conversion: The input is taken from the DC power source and converted into single phase AC power through the inversion process.

Control technology: Pulse width modulation (PWM) technology is usually used to ensure the quality of the output waveform.

1.3 Application areas:

Home Solar System: Used to convert DC power generated by solar panels into single-phase AC power for home use.

Small commercial buildings: Suitable for small commercial places to meet the electricity needs of general electrical equipment.

2. Three-Phase Inverters:

2.1 Features:

Output Phases: The output of a three-phase inverter contains three AC phases.

Industrial application: Mainly used in industrial power systems, large commercial buildings, etc., suitable for situations with higher power and more complex power requirements.

2.2 Working principle:

Input conversion: The input is taken from DC power and converted into three-phase AC power through the inversion process.

Control technology: Adopt advanced control technology to ensure the balance and quality of the three-phase current output.

2.3 Application areas:

Industrial power system: used to supply industrial equipment, motor drives, etc., suitable for high power and high-efficiency power requirements.

Large commercial buildings: Suitable for large commercial or office buildings to provide efficient and reliable power conversion.

Classification by commutation technology

1. Pulse width modulation inverters (PWM Inverters):

1.1 Features:

Working principle: The pulse width modulation inverter controls the amplitude and frequency of the AC power supply by adjusting the width of the output pulse.

Output waveform: Produces an output waveform close to an ideal sine wave, with high quality and few harmonics.

High efficiency: High-efficiency capability due to precise control of pulse width.

1.2 Application areas:

High-performance requirements: Suitable for applications that require high output waveform quality, such as medical equipment, precision instruments, etc.

Motor drive: widely used in fields that require precise control of motors.

2. Phase-Controlled Inverters:

2.1 Features:

Working principle: The phase modulation inverter adjusts the parameters of the output power supply by controlling the phase of the AC voltage.

Output Waveform: Produces an adjustable output waveform, but often with harmonics and lower quality.

Lower cost: Compared with PWM inverter, the cost of phase modulation inverter is lower.

2.2 Application areas:

General household use: Common in some general household appliances and occasions with low precision requirements.

Cost Sensitive Applications: Used in some cost sensitive applications where waveform quality is not the primary consideration.

3. Multilevel Inverters:

3.1 Features:

How it works: Multi-level inverters generate an output that is closer to a sinusoidal wave by switching at different voltage levels.

Output waveform: Produces higher quality output waveform, reducing the generation of harmonics.

Strong adaptability: It has strong adaptability when dealing with different loads and working conditions.

Classification by connection method

1. Unidirectional Inverters:

Features: Only one-way energy flow is possible, from DC to AC.

Application fields: Solar power generation systems, battery energy storage systems, etc., suitable for scenarios where DC power needs to be converted into AC power.

2 Bidirectional Inverters:

Features: Allows bidirectional energy flow, converting AC power to DC power.

Application fields: Battery energy storage systems, electric vehicle charging systems, etc., suitable for scenarios that require energy flow in different directions.

Classification by operation modes

1. Stand-Alone Inverters:

Features: Does not depend on the power grid and operates independently.

Application areas: Independent solar power systems in remote areas, outdoor mobile power supplies, etc.

2. Grid-Tied Inverters:

Features: Connected to the power grid, enabling two-way energy flow.

Application fields: Home solar system, which returns excess electric energy to the power grid to realize energy sharing.

Classification by output waveform

1. Pure Sine Wave Inverters:

Features: The output waveform is close to the ideal sine wave.

Application fields: Medical equipment, precision instruments and other occasions that require high power supply quality.

2. Modified Sine Wave Inverters:

Features: The output waveform is modified and the cost is lower.

Application areas: Household use, power tools, etc., suitable for general household appliances.

Classification by the number of output levels

1. Two-Level Inverters:

Features: Output is generated by switching between two levels.

Application areas: General industrial and commercial applications, providing basic inverter functions.

2. Multilevel Inverters:

Features: Reduces harmonics by switching across multiple voltage levels to produce output.

Application areas: High-performance power systems, motor drives, etc., providing higher quality output waveforms.

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