OnLine Power Power Wave 4 - Manual (Page 16)

6005-145 Rev. A 1-5
1.2. Features and Advantages
(a) Reliable input protection: Circuit breakers are placed in each individual
input loop to ensure power can continue through another loop in case of
breaker trip caused by an abnormal condition in either rectifier or load.
(b) Input surge protection: An MOV (surge protector) is added at the input,
providing protection to both ELI and the load from any lightning surges,
or surges caused by neighboring large loads.
(c) EMI suppression: An EMI filter is added to meet the international EMC
limits. Therefore, very low noise is emitted, and no interference is
supplied to other equipment connected to the same AC source.
(d) Ruggedness: The rectifier employs phase control technology to regulate
the DC bus voltage. This is the most efficient method to charge the
batteries. The SCR used are inherently rugged. Additionally, a large
inductor is added at the input to avoid deforming the AC source
waveform.
(e) High frequency design: The inverter uses high frequency, high efficiency
IGBT, PWM methodology to convert the DC power to AC power.
Therefore, the number of components is fewer, reliability is improved, and
the size and weight of ELI is reduced, performance is improved, and
acoustic noise is minimized.
(f) True Galvanic isolation: An isolation transformer is placed at the output.
This can solve the problem of poor input grounding, can allow a different
ground between input and output, can avoid the annoying problem of
ground leakage current, and can be tied to any potential provided on site.
The AC output is isolated under every mode of operation. Additionally, the
user gets the bonus of attenuation of common mode noise from the output
isolation transformer.