Pros and cons of both:

Size and Weight:

• Switch mode is smaller and lighter. However, this may not be an advantage when combined with a battery bank, as the battery is the heavy and bulky component in a typical substation application.

Reliability/Durability:

• Phase control is much more reliable. It has two energy conversions compared to five for switched mode. In its basic form, a phase-controlled rectifier can operate reliably for 40 years. It can operate in a dusty environment with much higher temperature and humidity.

• Due to its input transformer, a phase-controlled DC system has a much greater tolerance to electrical noise and input voltage spikes/transients.

• A thyristor used in a phase-controlled rectifier is physically larger and more robust than a transistor used in a switched-mode rectifier.

Input/output power quality:

• Switched mode technology has a much higher input power factor than phase controlled technology.

• Both switched-mode and phase-controlled rectifiers can have low output ripple content.

Functionality and features:

• Phase controlled chargers/rectifiers have exactly the same functionality and features as switch mode chargers/rectifiers as these functions are provided by the controller, which is common between the two technologies.

Service Life:

• Phase controlled technology has a much longer lifespan. In a typical substation application, a phase-controlled rectifier/charger can last 25 to 30 years.

In summary – how to select a charger:

For reliability and longevity, phase-controlled technology is the best choice.

For a hot, dusty and humid environment, phase control is the best choice.

If you need a rectifier of smaller size and weight, the keyed rectifier is the best option.

For restricted budgets, keyed mode may be cheaper.

If input power factor is important, switched mode is a better choice.