Circuit principle of inverter classification of in

  • Detail

Inverter is a device that converts DC electric energy (battery, storage battery) into current (generally 220 V 50Hz sine wave or square wave). Our common emergency power supply generally reverses the DC battery into 220V AC. In short, inverter is a device that converts direct current into alternating current

inverter, also known as converter and inverter, is a device that can convert DC into AC. it is composed of inverter bridge, logic control and filter circuit, and can be divided into half bridge inverter, full bridge inverter, etc. At present, it is widely used in air conditioners, home cinemas, computers, televisions, range hoods, fans, lighting, video recorders and other equipment. Next, I will introduce the circuit principle of inverter and the classification of inverter

inverter circuit principle

first, the whole process of main circuit

input from AC power grid and DC output, including:

1. Input filter: its function is to filter the clutter existing in the power grid, and also prevent the clutter generated by the machine from being fed back to the public power grid

2. Rectification and filtering: the AC power supply of the power grid is directly rectified into smoother DC for the next level of transformation

3. Inverter: convert the rectified DC into high-frequency AC, which is the core part of high-frequency switching power supply. The higher the frequency, the smaller the ratio of volume, weight and output power

4. Output rectification and filtering: provide stable and reliable DC power supply according to the needs of the load

second, the control circuit

on the one hand, samples from the output end, compares it with the set standard, and then controls the inverter to change its frequency or pulse width to achieve stable output. On the other hand, according to the data provided by the test circuit, through the identification of the protection circuit, the control circuit is provided to provide various protection measures for the whole machine

III. detection circuit

in addition to providing various parameters in operation in the protection circuit, it also provides various display instrument data

IV. auxiliary power supply

provides different power requirements for all single circuits

classification of inverters

1. Centralized inverter: its main characteristics are high power of single machine, small number of maximum power tracking (MPPT) and low cost per watt

2. Series inverter: the power of a single machine is between 3-60kw. Mainstream models have a single machine power of 30-40kw, single or multiple mppts, generally 6-15kw and one MPPT. This kind of inverter has a high cost per watt and is mainly used in small and medium-sized power stations. The selection rate of power stations with a capacity of less than 1MW in the world is more than 50%

3. Micro inverter: the power of a single machine is less than 1kW, a single MPPT. In application, it is mostly 0.25-1kw one-way MPPT. Its advantage is that it can carry out independent MPPT control on each or several battery boards, but the cost per watt of this kind of inverter is very high. At present, it is widely used in household photovoltaic power stations below 10kW in North America

characteristics of photovoltaic inverter

1. It is required to have high efficiency

due to the high price of solar cells at present, in order to maximize the use of solar cells and improve system efficiency, we must try to improve the efficiency of the inverter

2. It is required to have high reliability

at present, the photovoltaic power station system is mainly used in remote areas, and many power stations are unattended and maintained, which requires the inverter to have a reasonable circuit structure, strict component screening, and various protection functions, such as input DC polarity reversal protection, AC output short circuit protection, overheating, overload protection, etc

3. The input voltage is required to have a wide adaptation range

because the terminal voltage of the solar cell changes with the load and sunshine intensity. Especially when the battery is aging, its terminal voltage changes widely. For example, for a 12V battery, its terminal voltage may change between 10V and 16V, which requires the inverter to ensure normal operation within a large DC input voltage range

editor's summary: that's all for the inverter circuit principle and inverter classification. I hope it will be helpful to you. If you want to know more about it, you can pay attention to the information




Copyright © 2011 JIN SHI