Analysis of National Power Grid Structure and Inverter Selection
Later, with the advancement of technology, a 220V alternator was built. Therefore, the European countries that built the power grid directly adopted the most advanced 220V-240V technology at that time, and the countries that have adopted 110V-127V have all replaced 220V power. The system is too expensive, so they have to use it to this day. Objectively speaking, the 220V system is more economical than the 110V. It can also separate 220V single-phase electricity for civilian use from the power 380V without the transformer, which is more advanced than 110V.
The early British voltage was 240V, and later changed to 230V in order to be consistent with EU standards. Most Commonwealth countries and British overseas territories inherit this standard, such as Australia, New Zealand, India, Nigeria, etc. 240V, Malaysia, Singapore, Pakistan, etc. 230V. However, there are exceptions, such as Canada, Jamaica and other countries, because of the impact of the United States is 110V; Hong Kong considers the use of power from the Chinese mainland, so the 220V standard. In the Middle East, from the end of the 19th century to the beginning of the 20th century, most of them belonged to the British sphere of influence. Therefore, most of the voltages also use British standards, around 230-240V.
The voltage in Germany is 230V, which is affected by it. Almost all the voltages in continental Europe are around 220V-230V. They also adopted this standard in the majority of the former colonies of Asia, Africa and Latin America. The former Soviet Union countries are mostly 220V (Russia is now gradually changing to 230V), and China, Mongolia, Vietnam, etc. are also 220V because they implement Soviet standards.
Photovoltaic grid-connected inverters have a wide output voltage and are generally compatible with 220V to 240V, but are not compatible with 110V.
China's three-phase power grid structure includes IT, TT, TN-C and TN-S, among which TT, TN-C and TN-S need to be connected to the zero line, and IT does not need to be connected to the zero line. The TN-C neutral and ground wires can be connected together, and the TN-S neutral and ground wires cannot be connected together and cannot be connected incorrectly.
China's industrial and commercial power grid generally adopts three-phase five-wire TN-S system or three-phase three-wire IT system. The grid-connected inverter output is generally star three-phase five-wire system, or triangular three-phase three-wire system, inverter and grid connection. When the following fault occurs (taking the Guruwatt inverter as an example), the output of the inverter does not match the grid:
1) The inverter shows that the voltages of the AC phases are very different, and the voltages of the phases measured by the multimeter are basically the same.
Reason: The grid is a three-phase three-wire IT system. The inverter output is three-wire and five-wire, but the zero line is not connected, causing the AC voltage sampling to be inaccurate. Solution: Inform Guriwatt after the sale, change the inverter output system to three-phase three-wire system.
2) The inverter displays “ERROR111” zero ground detection fault.
Reason: The power grid is a three-phase five-wire TN-S system, and the inverter output zero line and ground line are reversed. Solution: Remove the neutral and ground wires and connect them as required.
US power grid structure: The US low-voltage grid voltage has two systems, according to the US national standard (ANSIC84-la-1980): First, the SplitPhase system, the voltage is 120/240V: Second, the Delta3Phase system 480/277V and 208 /120V three-phase system.
The average voltage of household appliances in the United States is 110V, but most of the household distribution boxes use the SplitPhase system, that is, there are two fire lines. The US three-phase voltage is 208V and 480V. Shenzhen Guruwatt Company has deepened the US market and introduced various models to adapt to the US market.
The three-phase power grid in the United States has three voltages of 208, 240, and 480V. The 208V and 240V are generally household systems, and the three-phase voltage of the factory is generally 480V/277V. Guruvat has two models that can match a 480V three-phase voltage system. Growatt 10-20KTL3-US, Growatt 30-40KTL3-US.
Summary: Although the voltage level in the United States is not the same as in China, it is still possible to modify the inverter. The key is to obtain the US UL certification.
110-120V: United States, Canada, Jamaica, Mexico, Cuba, Colombia and other North America, Cayman Islands, Japan, Taiwan and other countries and regions
230-240V: UK and most Commonwealth member states, most British overseas territories, most Middle Eastern countries
220-230V: China, Russia, continental European countries, and most of their former colonies; the former Soviet Union, and countries deeply affected by the Soviet Union.
