Overview of SINAMICS S120 Series Power Modules
SINAMICS S120 series drive system, as an ideal match for SINUMERIK828D/840Dsl CNC products, has been widely used in the field of machine tools. Among them, the “Book-Size” module has become the focus of users with its unique size and function. In this issue, we will explore the power supply part of this module in depth and provide you with a concise overview. The Book-Size series power supply modules have a wide power range, ranging from 5KW to 120KW, which meets the needs of different machine tools. These modules are divided into three types: adjustable type (ALM), intelligent type (SLM) and basic type (BLM). Among them, ALM and SLM also have regenerative feeding function, which can effectively improve energy utilization efficiency. Next, we will take the three-phase AC400V incoming line as an example to introduce the characteristics and applications of various modules in detail.
1.ALM Module
ALM, or Active Line Module, is known as the “regulatory power module”. It has a wide range of rated power specifications, including 16KW, 36KW, 55KW, 80KW and 120KW, and is equipped with a DRIVE-CLIQ interface for easy connection with the CU (control unit). As a regenerative feedback power module, ALM injects energy into the DC bus when the motor is running, and feeds back energy from the DC bus to the workshop power grid when the motor is braking, thereby realizing the power generation function. The module adopts IGBT technology and is equipped with a high-performance boost power factor regulation circuit (Boost PFC) to ensure that the DC bus voltage remains stable in both rectification and inverter modes, such as DC600V. Its incoming and feedback current waveforms are excellent, close to the standard sine wave, the power factor is close to 1, the harmonic content is low, and it supports regenerative feedback and bidirectional energy flow. In addition, ALM also has excellent control accuracy, which makes the motor speed fluctuation very small, which is very suitable for high-precision servo motion control needs.
The ALM’s incoming and feeding current waveforms both present standard sinusoidal shapes.
2.SLM Module
SLM, or Smart Line Module, is known as “intelligent power module” or “unregulated power module”. Its rated power specifications include 5KW, 10KW, 16KW, 36KW and 55KW. It is particularly worth mentioning that the 16KW, 36KW and 55KW modules are equipped with DRIVE-CLIQ interface and CU connection, while the 5KW and 10KW modules are not equipped with DRIVE-CLIQ interface.
SLM also uses IGBT modules and is a regenerative feedback power module. When the motor is running, SLM is responsible for providing energy to the DC bus; when the motor is braking, SLM feeds back energy from the DC bus side to the workshop power grid side, and SLM is in the power generation state. However, unlike ALM, the DC bus voltage of SLM is not constant, but fluctuates with the change of the incoming line voltage, roughly maintaining a relationship range of 1.3 to 1.4 times (depending on the working state), usually about 1.35 times. For example, when the incoming line voltage is 380V, the DC bus voltage is approximately 510V.
3. BLM module
BLM, or Basic Line Module, is called “basic power module”. Its rated power specifications include 20KW, 40KW and 100KW, and are all equipped with DRIVE-CLIQ interfaces. Unlike SLM, BLM is a non-feeding power module that only has the rectification function from the AC line to the DC bus, and does not have the inversion capability, so it cannot achieve energy regeneration feedback. During braking, the BLM module converts energy into heat energy through the braking resistor for consumption. Its output DC bus voltage also fluctuates with the change of the incoming line voltage, roughly maintaining within a relationship range of 1.35 times. For example, when the incoming line voltage is 400V, the DC bus voltage is about 540V.
For machine tool equipment, due to its high motion accuracy requirements and frequent start and stop, the ALM/SLM module is more suitable due to its higher control accuracy and energy-saving characteristics. Therefore, in the machine tool S120 drive, the use of ALM/SLM modules is more common. At the same time, the “3+1” integrated Combi drive is also popular. Its power supply part integrates the SLM module, and its performance characteristics are no different from ordinary SLM modules.
