Resolute is a module-level power electronics provider, including microinverters, module-level shutdowns and energy storage systems. This time, the charging head network found a photovoltaic grid-connected microinverter YC250A launched by Yunergy, which has a maximum output power of 250W and an output voltage of 220V. The maximum input voltage of DC is 55V, supports 22-45V maximum power tracking, and the maximum input current is 12A.
The inverter housing is made of metal and has IP65 protection. There are screws on the side of the inverter to fix the mounting bracket. The bottom of the inverter is the DC input wiring, and there are connecting wires on both sides for AC output and communication functions. There is also an indicator light on the side of the fuselage for working status indication. Let's bring the dismantling of this photovoltaic microinverter, and take a look at the internal design and materials.
Yuneng 250W photovoltaic grid-connected microinverter YC250 adopts an all-metal shell, and the connector terminals are also designed with cables, and the overall external style is very different from the Yuneng YC240 model that has been disassembled before by the charging head network.
The fuselage tends to be square-shaped, with rounded edges, and the surface of the shell is all sprayed with black protective paint.
There is an L-shaped metal fixing plate on the top of the fuselage, which is connected and fixed with the fuselage through hexagon tamper-proof screws.
There is a product nameplate on the back of the fuselage.
Close-up of product parameters.
Name: Photovoltaic grid-connected microinverter.
Model: YC250A
Maximum DC input voltage: 55VDC
Rated AC voltage: 220VAC
Rated AC current: 114a
Rated AC frequency: 50Hz
Output Power Factor: >099
Maximum AC output power: 250W
Maximum DC input current: 12A
Maximum power point tracking range: 22-45VDC
Maximum conversion efficiency: 955%
Total current harmonic distortion: 3%.
Protection level: l
Overvoltage Category: III
Degree of protection: IP65
Operating ambient temperature: -40 to +65
Zhejiang Yuneng Technology***
The side of the fuselage is equipped with a blind rivet for fixing, and there is also an indicator light on this side.
Close-up of the indicator.
The connecting terminals on both sides of the fuselage tend to be cylindrical, and they are fixed when connected by knobs at the ends.
A set of connection terminals under the fuselage is a classic snap style that fits suit.
The measured length of the product is 15896mm。
The width is 15299mm。
The thickness is 294mm。
The length of the connecting wire and terminal on one side of the fuselage is about 30cm.
The length of the connecting wire and terminal on the other side is about 80cm.
Finally, the weight of the product was about 1707g.
After reading the appearance display of Yuneng's photovoltaic inverter, let's disassemble it and take a look at the internal workmanship and materials.
First of all, the blind rivet on the side of the fuselage is cut, the cover plate is opened, and the internal PCBA module is filled with thermal conductive glue.
The PCBA module is fixed inside the housing with screws.
Remove the PCBA module from inside the aluminum case.
The front of the PCBA module is at a glance, with the input filter capacitor at the top, two step-up transformers at the bottom, the output filter circuit at the bottom right, and the auxiliary power supply circuit on the left.
The back side is soldered with the main control chip, switch tube, feedback optocoupler and rectifier tube.
Close-up of filter inductor at the input end, chip soldering. On the left side of the inductor is the solar cell input terminal, which is also soldered.
The two filter capacitors are from Chemi-Con and are sized at 63V2200 F.
The other set of filter capacitors has the same specifications.
The current transformer is used to detect the switch current.
The Texas Instruments UCD7100 low-side driver is used for switch tube drives.
Close-up of another current transformer.
Close-up of the Texas Instruments UCD7100 driver.
The step-up switch is from Infineon, model BSC190N15NS3, NMOS, withstand voltage 150V, conduction resistance 19M, and is available in a PG-TDSON-8 package.
The other switch tube is of the same type.
A 5m sampling resistor is used to sense the input current.
Close-up of two step-up transformers.
The capacitor size of the film is 0022μf。
The other film capacitor has the same specifications.
The silicon carbide diode is from Cree, model number C4D02120E, withstand voltage of 1200V, and is available in a TO-252-2 package.
The other SiC diode is of the same model.
The programmable gate array chip is from Lattice, model number LFE2-12SE-5TN144C.
Close-up of external 50MHz clock crystal oscillator.
The memory is from Winbond, model W25Q32BVSIG, with a capacity of 4MB.
The filtered tantalum capacitor is specified at 330 F10V.
One MCU from Silicon Labs, model C8051F850, is a mixed-signal 8-bit MCU with a built-in 8051 core, a main frequency of 25MHz, and a built-in 8KB Flash and 512B RAM on the chip. The chip has a built-in ADC, DAC and two comparators.
The power main control chip is from onsemi, model NCP1377, which is used for auxiliary power control.
The LDO regulator chip is from Texas Instruments, model LP2981, the input voltage is 16V, and the output voltage is 33V with an output current of 100mA.
Three optocouplers are used to isolate communication.
Close-up of two other 3053 isolated optocouplers.
One MOS tube from STMicroelectronics, model STB18nm80, NMOS, withstand voltage 800V, conduction resistance 250M.
The other MOS tube is of the same model.
The two thyristors are from STMicroelectronics, silkscreen TN815800, the actual model number is TN815-800B-TR, the specification is 800V 8A, and it is in a DPAK package.
The safety x2 capacitor is from Xiamen Farah Electronics, and the specification is 047μf。
Close-up of a blue varistor.
The filter inductor core is wrapped with tape insulation.
The safety x2 capacitor is from Xiamen Farah Electronics and has a specification of 1 F.
The two fuses are from SCHURTER and have a size of 63a 250v。
The other filter inductor has the same specifications.
Close-up of the varistor at the output.
The outputs are connected via connectors.
The blue varistors are of the TDK S14 series.
The safety x2 capacitor specification is 022μf。
The common mode inductor is wound with insulated wire.
Close-up of auxiliary power transformer.
One MOS tube is from Vishay, model SI4848, withstand voltage 150V, conduction resistance 70M, and is packaged in SOP8.
Close-up of the F817A feedback optocoupler.
One transistor type BD238.
Close-up of the two-color LED indicator used to indicate the working status.
One MOS tube from STMicroelectronics, model STD10nm65N, is a 650V NMOS with a conduction resistance of 430M, and is available in a DPAK package.
The other MCU has the same model, which is Silicon Labs' C8051F850.
The inverter, from Texas Instruments, model CD40106B, is a 6-channel inverter chip with a Schmidt trigger input.
The isolation chip from Silicon Labs, model SI8610EC, is a dual-channel digital isolator.
IMP706 watchdog chip, with power-down detection and power monitoring functions.
The powerline communication chip is from Risecond, model RISE3501, which is used for communication between the inverter and the host.
External 10Close-up of 000MHz SMD crystal oscillator.
A list of all dismantling and a family photo.
The YC250A PV grid-connected inverter adopts a metal shell, has IP65 protection level, and supports -40 65 operating temperature to meet outdoor applications. The maximum output power of the inverter is 250W and the output voltage is 220V. The maximum input voltage of DC is 55V, supports 22-45V maximum power tracking, and the maximum input current is 12A.
Through dismantling, the charging head network learned that the YC250A inverter of Yuneng Technology adopts a potting process to improve heat dissipation performance, and the internal PCBA module is screwed inside the aluminum alloy shell. The DC input of the inverter is filtered by Chemido electrolytic capacitors, boosted by Infineon's BSC190N15NS3-G MOS, and rectified by Cree C4D02120E silicon carbide diode at the boost output, and modulated by MOS transistors and thyristors.
Internally, Silicon CCU and Lattice LFE2-12SE-5TN144C programmable gate array chip are used for the whole machine control, the auxiliary power supply adopts the NCP1377 main control chip, and the Risecomm power line communication chip is also used to communicate with the host. The internal materials are reliable in workmanship and can meet the operation of outdoor harsh environments.