Kollmorgen AKD/S700 series servo drive

Kollmorgen AKD/S700 series servo drive

In the field of modern industrial automation and precision motion control, the performance, reliability, and electromagnetic compatibility (EMC) of servo drive systems are crucial. Kollmorgen's AKD and S700 series digital servo drives, as mainstream solutions in the market, rely not only on the drives themselves but also on a complete and compliant accessory ecosystem for their outstanding performance. This article is based on the official AKD/S700 Parts Guide and combines a systems engineering perspective to deeply analyze the technical principles, selection criteria, installation specifications, and optimization strategies of key components. The aim is to provide a complete integration framework from theory to practice for system integrators and equipment manufacturers.

Chapter 1: Overview of System Architecture and Core Components

A complete digital drive system is much more than just drivers and motors. The system architecture varies depending on the application voltage and power level:

Low voltage systems (AKD-P00306 to 02406) typically require an external main power filter to meet EMC standards, and may be equipped with motor reactors to suppress long cable effects.

High voltage systems (AKD-P00307 to 02407 and S700 series): Most have built-in filters, but high-power models (such as S748/S772) must have an external main power reactor to prevent abnormal DC bus voltage rise (up to 800V) when the grid asymmetry exceeds 3%.

Core accessory categories: System construction requires comprehensive consideration of mechanical installation tools, shielding and grounding accessories, power conditioning devices (filters/reactors), braking/regenerative energy processing modules, motor reactors, and various communication and power cables.

Chapter 2: Electromagnetic Compatibility (EMC) and Shielding Grounding Practice

EMC is the lifeline for the stable operation of industrial drive systems, and improper shielding and grounding are the root causes of the vast majority of interference problems.

1. Composition of shielding system:

Shielding board: Specific models of drivers (such as AKD-z-00307/00607/01207) come with dedicated shielding boards for guiding and concentrating the grounding cable shielding layer, forming a low impedance high-frequency noise discharge path.

Shielding clip: It is recommended to use brands such as Phoenix Contact SK14 (6-13mm tension range) and clip it into the reserved slot on the front panel of the drive to ensure extensive contact with the metal panel.

External shielding busbar: In multi axis or complex systems, brass busbar (section 10x3mm) can be used for centralized grounding. During installation, metal spacing columns should be used to maintain a distance of 50mm from the ground, and at least 2.5mm ² wires should be used for single point grounding to the main grounding bar of the cabinet.

2. Grounding philosophy:

Separation of high-frequency noise and safety grounding: The shielding system deals with high-frequency interference at the MHz level, requiring low inductance and large-area contact; And safety (PE) is related to personal safety and must comply with the standard wire diameter. The two should converge at the star shaped grounding point of the system.

Cable shielding layer treatment: All shielding layers must be connected in a 360 degree loop at the driver and motor ends. Use metalized connector housings or shielding clips to avoid using "pig tail" single point leads, which can exhibit high impedance at high frequencies.

Chapter 3: Power Conditioning and Energy Management

The quality of the power supply directly affects the lifespan and performance of the driver.

1. Main power reactor:

Function: Suppress rapid current rise caused by commutation and protect semiconductors; Reduce voltage drop in the power grid; Smooth the ripple current of the DC link and extend the lifespan of the capacitor.

Selection: Multiple drivers can share one reactor, and its rated current must be greater than or equal to the total current of the connected drivers. For example, when the power grid is asymmetric, the S748/S772 requires the use of 3L series reactors with a short-circuit voltage of 2% (uk).

2. Selection and calculation of main power filter:

For AKD models that require an external filter, power verification is required for selection:

Maximum throughput capacity of the filter: P_maxF=√ 3 * U-N * I2 * NF

Maximum power consumption of the driver: P_maxV=g * √ 3 * U-N * ∑ (IpeakVi)

Maximum feedback power of motor: P_maxM=g * ∑ (k_Ei * n_i/1000 * IpeakFi * √ (3/2))

The rated current of the filter, I2 NF, must simultaneously meet the following requirements: I2 NF ≥ 2 * ∑ (I2 NF) and I2 NF ≥ P_maxM/(√ 3 * U-N). Where g is the simultaneous coefficient and k_E is the motor back electromotive force constant.

3. Regenerative energy treatment plan:

The regenerative energy generated during motor deceleration must be properly handled, and there are three solutions:

Braking resistor: converts energy into heat and dissipates it. Kollmorgen offers BAFP (U), BAR (U), and BAS (U) series, with differences in protection level (IP20/IP40) and installation method. The selection should be based on matching the braking power, duty cycle, and resistance value. Warning: The surface temperature of the resistor can exceed 250 ° C and must be installed on a non combustible surface with sufficient heat dissipation space.