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MAX 50K-80K TL3 Introduction

MAX 50K-80K TL3 introduction
1. Product appearance
Line voltage of MAX LV model is 400V; Line voltage of MAX MV model is 480V or 500V
MAX LV model and MAX MV model have same boards
2. System Diagram
3. Board Introduction
IO Board

SPD Board

It is used to prevent lighting strike


It is used in BUS circuit and it is function is filtering wave

PID BUS Interface

PID means ” PotenTIal Induced DegradaTIon “, The direct harm of PID is that a large amount of charge accumulates on the surface of the cell, which deteriorates the passivation effect of the cell surface, resulting in a decrease in the fill factor, open-circuit voltage, and short-circuit current of the cell, and the power attenuation of the battery module.

SPS circuit

main SPS circuit

Internal and external fan driving circuit

3OP driving parallel wire

It is used to drive Boost and DC-AC circuit , SPS circuit on mainboard


It has been cancelled in new MAX series.

Left Cover of Max Inverter
Main board
3 Boost modules contain 6 Boost Circuits, Every module has 2 Boost Circuit
BUS Capacitors which are used to filter high frequency wave
3 INV Modules
SPS Circuit on mainboard which is used to supply power for BOOST and DC-AC driving circuit
PV INPUT board
SPD board
Right Cover of Max Inverter
AC Filtering board
AC SPD board
It is installed on AC Filtering board
M3 board
M3 Board in charge of communication, STM32 chip and led light are on it. Inverter S/N etc. is stored in M3 board
Dip switch is prepared for future. Now it is useless. It won’t affect the inverter.
Control board
DSP, CPLD, AD, SPI, Driver Model

DSP Chip called 75 chip , Mainly deal with AC output Sampling data

AD chip called 67 chip, mainly deal with PV Sampling data

CPLD is used to produce wave and drive related circuit.

Communication Switch Board
4. Board Position
5. Electrical Diagram Introdcution

Boost Circuit on mainboard

Driving circuit of Boost Circuit

BOOST. PWM1 is introduced into the main board from the control board through the 30PIN cable of the IO board, and outputs BoostA.PWM after passing through the optocoupler TLP352
As the driver of the BoostA. The other five are the same

INV Driving Circuit

There are 12 routes in total on Inverter drive circuit, PWM through 8286 driver chip output Give to push-pull and then to Vge of IGBT

Full Bridge Circuit

PV String Current Sampling Circuit

String current sampling circuit, the string current passes through the string chip and outputs the sampling voltage, and output of the sampling circuit to the operational amplifier
After scaling, it is given to the AD port of the control board to convert the current.

Boost Current Sampling Circuit

PV current through HCT (Current Sensing device) sampling, HCT voltage type, straightly Connect output sampling voltage. There are 6 routes in total

The PV current (BOOST inductor current) is sampled through the HCT. When a current flows through the HCT, the HCT itself outputs a sample signal. The sample voltage increases linearly (that is, the greater the current flowing, the greater the output voltage),

HCT output sampling After the voltage is transported After zooming to the control panel AD port to read Get real-time PV curren

PV voltage Sampling Circuit

PV voltage sampling sample resistor to
PVA road is the reference test, other five
the same way. Sampling resistor at PVinput
PV voltage sampling with an op-amp
stream to PVA as a reference, The other five Same.op on IO board.

The PV voltage is divided by the resistor and sent to the op amp for scaling, and then sent to the control AD port for operation, so as to sample the PV Voltage.

BOOST OCP Protection Circuit

BOOST OCP Protection Circuit output voltage with an electron and diode via sampling current Op amp

Compare negative output of the comparator and positive voltage

BUS Voltage Sampling Circuit

Negative BUS voltage Sampling Resistance

Sampling Resistance is on IO Board

Negative BUS voltage Sampling op amp The output is divided into Second, give to 075 and 067 control chip

Positive BUS voltage Sampling Resistance

Sampling Resistance is on IO Board

The total BUS voltage is summed by the positive and negative BUS voltages, and the positive and negative BUS voltages are sampled respectively, and then given by the op amp scaling.
The AD port of the control chip performs sampling and calculation to obtain the real-time voltage, and the output of the op amp is divided into two parts, which are respectively given to two different chips for sampling.

AC Current Sampling and OCP Protection Circuit

AC current passes through
HCT Current Sensing sampler
HCT sample output
voltage to the op amp after zooming
is given to control
Board AD port.
OCP is made by
After the sample is taken out separately
given to the comparator

AC Voltage Detecting Circuit

Grid Voltage Sampling Resistance

Grid R phase voltage
Voltage sampling operation
output to
075 Chip
Grid R phase voltage
Voltage sampling operation
output to
067 Chip

The grid voltage is given to the op amp after being divided by the resistor, and then given to the control chip after scaling, and the two chips are sampled separately

The inverter voltage is divided by the resistor and given to the op amp, and after scaling, it is given to the control board for sampling operation.

R phase Relay Circuit

R Phase

S phase Relay Circuit

T phase Relay Circuit

When it is about to be connected to the grid, the relay detection is carried out, and by switching the relay, and control INV Circuit to form wave., so that the inverter output and the grid Voltage at the same frequency and the same volt value, compare the voltage difference between the inverter side and the grid side to judge whether the relay can work normally

Detection logic:

1. Before the inverter produces the wave (before the relay driver works), detect the voltage across the inverter and the grid, if there is a large voltage difference 80V indicates that the first step has passed the test;

2. After the inverter produces the wave, firstly close the inverter relay to detect the voltage across the inverter and the grid.
If there is no voltage difference between the two ends, it means the relay on the grid side is stuck (or on the inverter side).
3. After the inverter produces the wave, firstly disconnect the inverter side relay, and then close the grid side relay to detect the power at both ends of the inverter and the grid. If there is no voltage difference between the two ends, it means that the inverter relay is stuck (the above inverter side is excluded at this time), otherwise there is a voltage difference and is greater than 80V
It means that there is no sticking;

4. At this time, close the relay on the inverter side again, and check the voltage across the inverter and the grid. If there is no voltage difference. It means that the detection is normal, and it is connected to the grid. Otherwise, there is a voltage difference and it is greater than 80V, which means that the relay cannot be closed.

Main SPS Circuit

DC and AC SPS Switch Circuit

Auxiliary power SPS adopts integrated DC SPS and AC SPS, that is, DC SPS and AC SPS share a transformer,
The secondary side outputs are together, and the DC SPS takes power from the BUS, adopts an overlapping flyback topology circuit, and uses 2844 for the control driver chip;
The AC SPS takes power from the ST two-phase uncontrolled rectification, and also uses the overlapping flyback topology circuit, and the control driver chip also uses 2844.
The primary side of the transformer is controlled separately

DC SPS or AC SPS operation is performed by voltage judgment through comparator.
Input voltage range: PV =200-1100v, AC= 210v-615V

Output voltage range: +15V, -15v, 8V, 8v convert to 5V( 2567 Buck chip Degarde ),24V (Fans), 24V converted to 5V( 2567 Buck chip Degarde, for communication ), 100V( PID Input Voltage ), 15V(PID Driving Voltage)

SPS Cirucuit on mainboard ( It is used for Boost and INV Driving Circuit)

The BOOST drive voltage and inverter drive voltage of this model consist of an independent SPS. is a flyback topology, the control
chip is 2843, and there are 6 sets of outputs (the total output voltage of each channel is 22V, and then 15V is clamped by the Zener diode
and -7V. ), input 15V from main SPS output as power supply

PID Circuit( Potential Induced Degradation )

PID working principle: It is to increase the voltage between PE ( ground) and PV+, and optimize the panel at night. actually
The topology of PID boosting is a BOOST circuit. After the main SPS outputs 100V, the voltage is boosted to the set voltage value.

After PID’s BUS
output, go
through the diode
directly after
PV input
positive electrode

FAN Circuit

FAN switching on and off circuit
Fan frequency check circuit

GFCI Circuit (Ground Fault Circuit-Interrupter)

Principle: It is like RCD. When 3 phase in balance, current of Neutral line should be 0

Internal Communication Circuit (Between M3 board and control board)

Between 067 Chip on control board and M3 board

Between 075 Chip on control board and M3 board

ISO Circuit

The ISO detection circuit samples the voltage at both ends through the opening and closing of two relays, and then calculates the impedance between PV+ and PV- to PE. So as to determine whether it is OK.

30PIN Drive Row Wire

1,2 GND Control ground

3 DRV.Fault Driving fault alert


5 T3.PWM T phase G3 IGBT Driving

6 T4.PWM T phase G4 IGBT Driving

7 T1.PWM T phase G1 IGBT Driving

8 T2.PWM T phase G2 IGBT Driving

9 S3.PWM S phase G3 IGBT Driving

10 S4.PWM S phase G4 IGBT Driving

11 S1.PWM S phase G1 IGBT Driving

12 S2.PWM S phase G2 IGBT Driving

13 R3.PWM R phase G3 IGBT Driving

14 R4.PWM R phase G4 IGBT Driving

15 R1.PWM R phase G1 IGBT Driving

16 R2.PWM R phase G2 IGBT Driving

17 BoostE.PWM BOOST E Driving

18 BoostF.PWM BOOST F Driving

19 BoostC.PWM BOOST C Driving

20 BoostD.PWM BOOST D Driving

21 BoostA.PWM BOOST D Driving

22 BoostB.PWM BOOST B Driving

23 TEMp.INV INV Temperature detecting

24 TEMp.BOOST BOOST Temperature detecting

25, 26 GND Control ground

27 +5V Main SPS power Supply

28 -15V Main SPS power Supply -15V

29.30 +15V Main SPS power supply +15V

50PIN Drive Row Wire

1、 2 pin:


PID F Route Voltage Sampling

3、 4 pin:


PID E Route Voltage Sampling

5、 6 pin:


PID D Route Voltage Sampling

7、 8 pin:

PID C Route Voltage Sampling

9、10 pin:

PID B Route Voltage Sampling

11、12 pin:


PID A Route Voltage Sampling

13、14 pin


PV F Route Voltage Sampling

15、16 pin

PV E Route Voltage Sampling

17、18 pin


PV D Route Voltage Sampling

19、20 pin


PV C Route Voltage Sampling

21、22 pin


PVB Route Voltage Sampling

23、24 pin


PVA Route Voltage Sampling

25、26 pin

BoostF.I BoostF.G

PV F Route Inductor current Sampling

27、28 pin

BoostE.I BoostE.G

PVE Route inductor current Sampling

29、30 pin

BoostD.I BoostD.G

PV D Route inductor current Sampling

31、32 pin

BoostC.I BoostC.G

PV C Route Inductor Current Sampling

33、34 pin

BoostB.I BoostB.G

PV B Route Inductor Current Sampling

35、36 pin

BoostA.I BoostA.G

PV A Route Inductor Current Sampling

37 pin


PVF Route String Current Sampling

38 pin


PV E Route String Current Sampling

39 pin


PVD String Current Sampling

40 pin


PV C Route String Current Sampling

41 pin


PVB Route String Current Sampling

42 pin


PVA String Current Sampling

43、44、45、46 pin


Control Ground

47、48、49、50 pin


Main SPS power supply +5V

12 PIN Communication Row Wire

1 pin


SPS power supply +3.3V.S

2 pin


SPS power supply 24V

3、 4 pin


SPS power supply +5V.S

5、 6 pin


Communication control ground

7 pin


067 sending data

8 pin


067 receiving data

9 、10 pin


Communication control ground

11 pin


075 sending data

12 pin


075 receiving data

30 pin Communication row wire

1,2 pin


USB differential signal

3,4 pin


USB output BUS voltage

5 pin


485.B Signal

6, 15, 20,26 pin


Communication control ground

7 pin


485 A signal

8 pin


232B Enable signal

9 pin


232B Receiving signal

10 pin


232B Sending signal

11 pin


232A Receiving data

12 pin


232A Sending data

13 pin


CAN Sending signal

14 pin


CAN Receiving data

16 pin


17、18 pin


Chip output 5V

19 pin


SPS power supply 3.3V.S

21-25 pin

27 pin


28 pin


SPS power supply 24V.S

29 pin


30 PIN


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