Sine-Wave Filters; Design And Operating Principle - Siemens SINAMICS G130 Engineering Manual

No limits apply with respect to permissible pulse patterns of the gating unit, i.e. pulse-edge modulation can be used
without restriction, which means that the attainable output voltage is virtually equal to the input voltage.
The voltage drop across the dv/dt filter plus VPL or dv/dt filter compact plus VPL equals approximately 1 %.
The dv/dt filters must be selected with parameter setting P0230 = 2 when the drive is commissioned. This ensures
that optimum allowance will be made for the effect of the filter in the vector control model.
dv/dt filters can be used in both grounded systems (TN/TT) and non-grounded systems (IT).
1.10.3

Sine-wave filters

1.10.3.1 Design and operating principle

Sine-wave filters are LC low-pass filters and constitute the most sophisticated filter solution. They are significantly
more effective than dv/dt filters plus VPL and dv/dt filters compact plus VPL in reducing voltage rates-of-rise dv/dt
and peak voltages V , but operation with sine-wave filters imposes substantial restrictions in terms of the possible
PP
pulse frequency settings and utilization of the inverter current and voltage.
As the schematic diagram below illustrates, the sine-wave filter extracts the fundamental component of the inverter
pulse pattern. As a result, the voltage applied to the motor terminals is sinusoidal with an extremely small harmonic
content.
Schematic diagram of the voltage v(t) at the inverter output and motor terminals with a sine-wave filter
Sine-wave filters very effectively limit both voltage rate-of-rise dv/dt and the peak voltage V
the following values:
·
Voltage rate-of-rise dv/dt << 50 V/ms
·
Peak voltage V
As a result, the voltage stress on the motor winding is virtually identical to the operating conditions of motors directly
connected to the mains supply. Bearing currents are also reduced significantly. Using these filters therefore allows
standard motors with standard insulation and without insulated bearing to be operated on SINAMICS. This applies to
both Siemens motors and motors supplied by other manufacturers.
Due to the very low voltage rate-of-rise on the motor cable, the sine-wave filter also has a positive impact in terms of
electromagnetic compatibility. As a result, in cases where the motor cables are relatively short, it is not absolutely
essential to use shielded motor cables for EMC reasons.
Since the voltage applied to the motor is not pulsed, the converter-related stray losses and additional noise in the
motor are also reduced considerably and the noise level of the motor is approximately equivalent to the level
produced by motors operating directly on the line supply voltage.
Sine-wave filters are available
·
in the 380 V to 480 V voltage range up to a converter rated output of 250 kW at 400 V,
·
in the 500 V to 600 V voltage range up to a converter rated output of 132 kW at 500 V,
The table below specifies the permissible motor cable lengths in systems with sine-wave filter for SINAMICS G130,
G150, S150, S120 Motor Modules (Chassis and Cabinet Modules).
Fundamental Principles and System Description
< 1.1 √2 V
PP * * Line
Engineering Information
SINAMICS Engineering Manual – November 2015
on the motor winding to
PP
155/528
Ó Siemens AG