Square wave inverters and inverter ladder

Press the 4000w inverter charger output voltage or current waveform can be divided into:
(1) The square wave inverter
Voltage waveform square wave inverter output is a square wave inverter circuit such inverter used are not identical, but the common feature is the circuit is relatively simple, small amount of power used by the switch. Design of power is generally between one hundred watts to kilowatts.
Square wave inverter advantages are: line, easy maintenance, low price.
The disadvantage is that the square wave voltage contains a large number of high-order harmonics generated additional losses in the electrical load with core inductor or transformer in on the radio and some communication equipment interference. In addition, these 500w charge inverter also pressure range is not wide enough, the protection function is not perfect, the noise is relatively large shortcomings.
(2) step wave inverter
Such inverter output voltage waveform is a stepped wave. Inverters achieve stair-step output also has a variety of different lines. The number of stairs output waveform varies greatly.
Advantages step wave inverters are: wave output waveform example, a significant improvement in reducing high harmonic content, when the ladder to reach 17 or more quasi-sine wave output waveform can be achieved, when using transformerless output high overall efficiency .
The disadvantage is that the ladder wave superimposed line use more power switches, which form some lines also require multiple sets of DC power input. This gives the PV array wiring and balanced grouping and rechargeable battery are in trouble. Further staircase voltage radio communications equipment and some are still some high-frequency interference.

Inverter composition

The inverter is a power adjustment device consisting of a semiconductor device, it is mainly used to convert the DC power into AC power. Generally consists of a boost circuit and an inverter bridge circuit. Boosting circuit boosting the DC voltage to the solar cell necessary for controlling the inverter output DC voltage; put the bridge circuit of the 5000w charge inverter DC voltage boosted equivalently converted into the common frequency AC voltage.
Mainly composed of switching elements such as transistors, by regularly make switching element repeat - off (ON-OFF), the DC input into AC output. Of course, this is simply an split phase inverter output waveform generated by the opening and closing of the circuit is not practical. Generally require the use of a high frequency pulse width modulation (SPWM), so close to the sine wave voltage across the width becomes narrow, the center of the sine wave voltage width wider, and in a half-cycle so that the switching element is always in one direction at a certain frequency operation, the thus formed a pulse wave train (quasi-sine waves). Then let the pulse wave formed by a simple sinusoidal filter.

Structure and working principle of photovoltaic inverters

The inverter is a power adjustment device consisting of a semiconductor device, it is mainly used to convert the DC power into AC power. Generally consists of a boost circuit and an Off grid inverters bridge circuit. Boosting circuit boosting the DC voltage to the solar cell necessary for controlling the inverter output DC voltage; put the bridge circuit of the 500w solar inverter DC voltage boosted equivalently converted into the common frequency AC voltage. The inverter is mainly composed of switching elements such as transistors, by regularly make switching element is repeated on - off (ON-OFF), the DC input into AC output. Of course, this is simply an 48v to 220v power inverter output waveform generated by the opening and closing of the circuit is not practical. Generally require the use of a high frequency pulse width modulation (SPWM), so close to the sine wave voltage across the width becomes narrow, the center of the sine wave voltage width wider, and in a half-cycle so that the switching element is always in one direction at a certain frequency operation, the thus formed a pulse wave train (quasi-sine waves). Then let the pulse wave formed by a simple sinusoidal filter.

PV inverter introduction and classification

Typically, the process is called the AC power rectifier, the complete rectification circuit called a rectifier circuit to achieve rectification process or rectifier device called a rectifier equipment. Correspondingly, the direct current can be converted into AC power process is called an inverter, the complete functionality of the 5000w solar inverter circuit is called an inverter circuit, the process of realization of the inverter device called an inverter device or inverter .
At present, China in a small power inverter and international at the same level, according to the PV inverter can be divided into the following macro
1. General Inverter
2. The Car power inverters control one machine
3. Communications Posts and dedicated inverter charger 12V
4. aerospace, military special inverter

Solar inverter design

Solar 3000w home inverter is now widely used, for those who can not support themselves national energy, solar energy and other alternative energy sources has indisputable advantages, we can help them to reduce fossil fuel consumption and achieve energy independence purposes. Replace fossil fuel energy with alternative energy systems will have a significant impact on the global economy and human life. But the problem is the cost of the cost of alternative energy generation with fossil fuel generation to be similar or less, in order to truly reduce oil consumption.
In the development of solar technology, engineers put much attention has been placed on how to improve the efficiency of photovoltaic cells. But another important issue can not be ignored is how to design the direct current generated by the battery into alternating current circuits. In order to compete with the cost of power generation burning coal, oil and other fossil fuels, engineers every one percentage point increase best power inverter efficiency efforts are very important.
Some solar energy conversion system manufacturers to battery power inverter conversion efficiency from 92% to 96%, so their chances of success in the market will increase. One way is to design transformerless DC / DC converter. In the conversion system, the energy loss caused by the transformer is approximately 2% to 3%. So we must use higher voltage transistors.

Brief sine wave inverter

Inverters have square wave inverter and sine wave inverter two categories, square wave inverter although single-cylinder structure, low cost, but due to harmonics too, is not suitable for inductive, capacitive circuit work, and sine wave inverter on the market price is relatively high, so some users difficult to accept, thus limiting its promotion and application. A brief introduction and practical 600w car inverter.
Sinusoidal pulse modulation Solar power inverters is the key, they all require a sine wave generator, use it to generate the sine wave and triangular wave (sawtooth) were compared realize sine wave modulation. Many ways and means to generate a sine wave. Methods commonly employed analog and digital two, through a variety of different ways to achieve. As with a filter circuit with a sine wave oscillator generator and the positive feedback amplifier circuit, which is the most common classic circuit, but the adjustment is more complex, frequency accuracy is not high. There are other methods used to generate a sine wave function generator circuit. With large-scale ASIC and MCU constituted sinusoidal pulse width modulation circuit. Using EPROM and D / A converter reference sinusoidal voltage generation is a common method. DSP processors with high-speed data is the latest of a pulse width modulation method, the introduction of computer technology, we need to increase the number of software development and design work, despite the complexity and cost of the circuit coefficient has increased, but it really is great A good design approach capacity 6000w power inverter.

The development prospects of solar inverter uses and processes

Solar AC power generation system consists of solar panels, charge controllers, inverters and batteries composed. Mainly composed of electronic components, it does not involve machinery parts, thus generating equipment is extremely refined, reliable, stable, long life, easy installation and maintenance. Compared with the conventional thermal power system, solar power system in addition to polluting emissions, but also has short construction period and can be used roofing advantage. Wherein the with bypass inverter is a key component of the entire solar system. Because of the direct solar energy output are generally 12VDC, 24VDC, 48VDC. If you want to 220VAC to provide electrical power, solar power system needs to be issued by the DC energy into AC power, this time on the need to use an inverter. In addition, it can be a variable DC output of photovoltaic cells to convert into a clean sinusoidal current at 50 or 60Hz, it is also ideal for providing power to the commercial power grid or local grid. With the development of the solar PV market, solar inverter market will inevitably bring a new spring.
Generally speaking, there are step-up transformer and two types of isolation transformer is applied in the 5000w inverter charger electronic transformers. Since the input DC voltage than AC output voltage level is higher, but the solar panels provide input source voltage is usually not so high, so the system to the AC output side of the step-up transformers to boost voltage. At the same time, both sides need to isolate the circuit transformer isolation to prevent flow AC DC side, improved circuit protection, but also increase the safety of users.
Power inverter can be divided by converting frequency conversion and high-frequency transformation. Frequency transformation is the use of discrete devices or manifold generate 50Hz square wave signal, and then use the signal to push the power switch, the use of frequency step-up transformer to generate 220V AC. As a result of frequency transformer, bulky, heavy, high prices, currently used in large-scale solar photovoltaic power plants. But as the technology matures and the magnetic power MOSFET improving the quality, high-frequency inverter transform it to market. High-frequency 12v car inverter is converted by high-frequency DC / DC conversion technology, the first low-voltage DC power to high-frequency low-voltage AC, after the pulse transformer and then rectified high voltage DC boost.