📝 Description
Used product consisting of an AC-side power arm for an approximately 100 kW Sungrow central photovoltaic inverter, complete with electronic power stage, DC-Link circuit capacitors, power connections and busbars, resistors, forced-air cooling system, and SEMIKRON SKYPER32 PRO IGBT driver board.
The driver board visible in the photographs bears code L5042700, as well as identifier P1009213069.
The assembly configuration is compatible with the architecture of the Sungrow SG100K3, a 100 kW three-phase inverter using a three-phase full IGBT bridge to convert photovoltaic DC current into AC current, followed by the output filter and transformer. The model documentation also indicates 400 V AC nominal voltage, 100 kW rated power, and forced-air cooling.
⚙️ Main Specifications
- AC-side power arm
- Application: approximately 100 kW Sungrow photovoltaic inverter
- Architectural compatibility with Sungrow SG100K3
-
IGBT conversion technology
-
SEMIKRON SKYPER32 PRO driver
- PCB code: L5042700
- Assembly identifier: P1009213069
- High-current power circuit with busbars
- DC-Link power capacitors
- Power resistors
- High-voltage connections and insulators
- Centrifugal fan for forced cooling
- Complete mechanical power-arm structure
- Industrial configuration for central inverter
The SG100K3 is documented as a 100 kW inverter with 400 V three-phase output, AC rated current in the range of 145–158 A depending on the documented revision, and a three-phase IGBT bridge.
🔧 Main Functions
The power arm constitutes a fundamental part of the inverter's DC/AC conversion bridge.
The IGBTs are controlled by the SKYPER32 PRO board, which manages the gate-drive signals of the electronic power switches.
Controlled IGBT switching generates the alternating waveform, which is subsequently processed by the AC filter and sent toward the transformer and grid.
In practice:
DC-Link → IGBT → power arm → AC filter → transformer → grid
This configuration is consistent with the documented electrical diagram for the SG100K3.
🔌 Purpose and Operation
The AC-side power arm participates in the conversion of energy supplied by the photovoltaic field.
The SKYPER32 PRO board is the control circuit that drives the IGBTs. The presence of two drive channels is consistent with a high-side / low-side configuration of a power half-bridge.
The power circuit must operate in perfect synchronization with the other arms of the three-phase bridge.
Correct operation therefore depends on the integrity of:
- IGBTs;
- driver;
- driver power supplies;
- capacitors;
- busbars;
- resistors;
- insulation;
- cooling system;
- control and protection signals.
🧩 Role Within the Inverter
In the Sungrow SG100K3, the conversion path is essentially:
DC input → DC EMI filter → three-phase IGBT bridge → L filter → transformer → AC contactors/filter → grid
The model documentation explicitly identifies the 3-phase full bridge (IGBT) and the subsequent L Filter.
For this reason, the photographed product should be considered a power component of the conversion stage, not simply an electronic board.
⚡ SKYPER32 PRO Driver
The most important electronic section visible in the photographs is the PCB marked:
SKYPER32 PRO
L5042700
The SKYPER32 PRO driver is designed for applications with IGBT modules and provides functions such as:
- high-side/low-side driving;
- interlock;
- undervoltage protection;
- dynamic short-circuit protection;
- fault management;
- soft turn-off;
- isolated driver power supply.
These characteristics are consistent with the role performed by the board within the power arm.
⚠️ Typical Faults and Symptoms
A fault in the power arm may cause:
- inverter failure to start;
- DC/AC conversion shutdown;
- overcurrent;
- short circuit in the IGBT stage;
- DC bus overvoltage;
- IGBT drive anomaly;
- power-stage protection activation;
- phase imbalance;
- overtemperature;
- system shutdown;
- upstream fuse/protection damage;
- abnormal noise or overheating.
An inverter error does not automatically prove that the power arm is faulty: diagnosis must be performed on the individual power stage.
🚨 Possible Causes of Failure
The most frequent causes on a stage of this type may include:
- IGBT short circuit;
- open IGBT;
- damaged SKYPER32 PRO driver;
- loss of driver power supply;
- deteriorated DC-Link capacitor;
- open power resistor;
- overheated connection/busbar;
- insulation loss;
- insufficient cooling;
- failed fan;
- overvoltage or overcurrent during operation.
🔍 Diagnosis
To check the power arm, it is advisable to inspect:
- IGBTs and their power terminals;
- insulation to the structure;
- busbar continuity;
- capacitors;
- resistors;
- SKYPER32 PRO power supplies;
- gate signals;
- protection circuits;
- fan;
- temperature and mechanical condition of the assembly.
For a sale as working, an instrumented electrical test would preferably be carried out.
🛠️ Common Services in Case of Failure
The assembly may undergo:
- IGBT diagnostics;
- SKYPER32 PRO driver diagnostics;
- capacitor inspection;
- insulation testing;
- busbar inspection;
- IGBT replacement;
- driver replacement;
- capacitor replacement;
- resistor inspection and replacement;
- cooling-system overhaul;
- power-arm functional testing.
🛠️ Applications
- Central Sungrow photovoltaic inverters
- Industrial PV systems
-
100 kW generation inverters
- Applications with three-phase IGBT bridges
- Sungrow inverter maintenance and refurbishment
- Spare part for AC power stages
🛡️ Product Condition
Used product, as shown in the photographs.
The assembly includes the complete power-arm structure, fan, capacitors, power bars, resistors, and driver board.
Electrical operation cannot be verified from the photographs alone.
Before installation, code, configuration, insulation, and condition of the IGBT stage must be verified.
📦 Package Contents
- 1 × AC-side power arm
-
SKYPER32 PRO driver board
- PCB L5042700
- DC-Link circuit/capacitors present on the assembly
- Busbars and power connections
- Power resistors
- Centrifugal fan
- Metal structure and components as shown in the photographs.
🟢 Summary
Used AC-side power arm for a 100 kW Sungrow inverter, consisting of a complete IGBT conversion assembly with capacitors, busbars, resistors, cooling system, and SEMIKRON SKYPER32 PRO – L5042700 driver board.
The architecture is strongly consistent with the Sungrow SG100K3, whose power circuit uses a three-phase IGBT bridge, L filter, transformer, and AC section. The SG100K3 model is documented as a 100 kW / 400 V three-phase inverter.
