Frequency inverter

Frequency inverter is a DC / AC converter, using high-frequency pulse width modulation technology and microcomputer control technology design, the battery pack DC power is converted to an output voltage and frequency stability of AC power. And it has a high conversion efficiency (at full load conditions up to 80%). At the same time there is a strong nonlinear load drive capability. The 8000w high frequnency inverter also on the input voltage, current and output voltage, current inspection and monitoring, in order to achieve guarded maintenance-free features.
Frequency 800w power inverter has many applications, such as the use of inverters in the aviation industry to provide a 400Hz frequency conversion, in general, according to the application needs to change the input voltage, which use the inverter.

Future development trend of solar inverters

Solar AC power generation system consists of solar cell panels, charge controllers, inverters and batteries composed; Solar solar inverter DC power inverter system are not included. The inverter is a power conversion apparatus according to incentives inverter can be divided into self-excited oscillation inverter and he excited oscillation electric inverters. The main function is to reverse into a DC battery AC. By full-bridge circuit, generally use the SPWM processor through modulation, filtering, boost, etc., to obtain the lighting load frequency, rated voltage sinusoidal AC matches for system end users. With the inverter, you can use a DC battery to provide AC electrical appliances.
First half of 2011, market development of solar inverter as expected, but showed sluggish situation. Suggesting the possible for two reasons: first, in 2010 Q2 to Q3 market demand, so that a large number of repeat customers orders, which led to excessive production of 1000w with charger inverter main reason, but also the start of the fourth quarter of 2010, the solar inverter the stock continues to climb. To the first half of 2011, distributors are still trying to clear the 2010 inventory dilemma. Second, the cost of solar energy subsidies continue to reduce the major European markets, resulting in a substantial decline in end-market demand, but also to relative demand for solar inverter greatly reduced.

From the current development of the market, it can be observed five trends of solar inverter:

1 solar inverter appearance continued diversification. In order to match the appearance of new buildings, DC AC power inverters color and style are becoming more and more fashion sense.
2 smart grid management functions become a trend, but also the direction of a number of the industry's positive efforts in product development. But want to add network management capabilities to the solar inverter is not easy, unless you have extensive experience in electric power network, it will easily have lost.
3 power storage device and the 1000w car inverter combination of new products have also become the focus of market attention. Power storage device included in PV systems, sustainable cost reduction, without affecting reliability, which many system operators want to be able to break through the bottleneck.
4 solar inverter output power will continue to break records. Future through modular or master-slave (Master-Slave) mechanism, a 5000w pure sine wave inverter output power will rise.
Development of 5 solar micro-inverter and power optimizer, although slowly, but the market acceptance is gradually increased.

Inverter features:

The main features of the inverter requirements include
1) requires a high efficiency
Due to the current high price of solar cells, in order to maximize the use of solar cells, improve system efficiency, we must try to improve the efficiency of the 3000w solar inverter.
• (2) requires a high reliability
Currently PV power plant system is mainly used in remote areas, many power plants unattended and maintenance, which requires an inverter circuit has reasonable structure, rigorous component selection, and requires the inverter with a variety of protection features, such as: input DC reverse polarity protection AC output short circuit protection, thermal overload protection and so on.
• (3) requires a wide input voltage range of adaptation
Since the terminal voltage of the solar cell with the load and sunlight intensity changes. Particularly when the aging battery terminal voltage variation range is large, such as a 12V battery, the terminal voltage between 10V ~ 16V may change, which requires the 4000w charge inverter to ensure the normal work in a wide DC input voltage range .

Advantages sine wave inverter

Sine wave inverter output voltage waveform is a sine wave
Advantages sine wave inverter is: an output waveform is good, low distortion, interference to radio and communications equipment, low noise. In addition, protection function, high overall efficiency.
Disadvantages are: the line is relatively complex, high technical requirements for maintenance expensive.
By isolation mode PV inverter can be divided into:
(1) Independent 12v car inverter for photovoltaic systems
Individual inverter power supply system includes villages in remote areas, household solar power systems, communications signal power, cathodic protection, solar lights and other independent power systems with batteries.
(2) grid-connected photovoltaic systems Inverter
• grid system is connected to the power transmission grid photovoltaic system to power. By the PV module to the solar radiation received, after the high-frequency energy into high voltage DC-DC converter, the 300w solar inverter after the conversion with an 4000w inverter charger output frequency to the grid and the grid voltage, a sinusoidal AC current in phase.

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.