Performance in every detail
AC technology starts with typically 6-7% higher efficiency than DC drives, averaged over the duty cycle. To that, we add a great array of improved control functions:
Automatic brake blending provides seamless, single-pedal retard and stopping
Full-time slip/slide control maximizes traction continuously for peak performance and operator safety
The retard system automatically keeps the truck within mine speed limits
Anti-rollback control permits one-pedal operation when stopping on grade
Automobile-style "cruise control" operates in both propel and retard modes
Differential torque control enhances turning and reduces tire wear
Safety first
Operator control translates into safety when it increases the truck’s safe operating area. The high retard power reduces stopping distances. Automatic speed control holds the truck within the mine’s intended operating range. Single-pedal retard operation with continuous slip/slide control and anti-rollback functions help keep the driver in control at all times.
Less maintenance
AC drives bring us closer to the ideal of "no maintenance." Without commutators or brushes, AC motor maintenance simply means lubrication once a year. The heart of the drive system, its power electronics, are inherently maintenance-free, having no power contactors or components subject to wear. In addition, the Siemens AC drive system features state-of-the-art diagnostics and a modular structure that simplifies repairs and minimizes the Mean Time To Repair (MTTR). Everything counts when it comes to truck availability.
Low operating costs
Increased efficiency, reduced maintenance, and smart controls all lower operating costs. Greater efficiency means lower fuel and oil costs, and AC motors eliminate the costs of brushes and periodic commutator re-builds. Differential torque control for the wheels reduces front tire scuffing and increases tire life. And under normal driving conditions the operator never needs to use the mechanical service brakes, greatly reducing brake wear.
Proven reliability
Siemens AC drives have a worldwide reputation for reliability in open-pit mining, transportation and many other industries. Our AC drive systems power not only electric rope shovels and draglines, but also bucket wheel excavators, SAG mills, crushers, and conveyors for open-pit mining. In addition, more than 15,000 GTO inverter modules, like the ones used on the Siemens haul truck drive, operate in thousands of heavy freight locomotives around the world. Simovert® AC drives are the worldwide standard for variable-speed industrial applications.
An AC drive system makes your hauler more valuable. Better performance, greater availability, and significant reductions in operating and maintenance costs — it all adds up to more tons for your money.
Siemens makes the most powerful electric truck drives available on the market today. It’s our response to the trend — larger trucks, bigger payloads, and faster cycles times combined with low life cycle ownership costs.
More rimpull
To achieve maximum speed on grade, the drive system must utilize all the horsepower today’s engines can deliver. The AC drive efficiently channels this power to the ground at all speeds. We deliver high rimpull at stall to power away from the shovel, high speed on grade climbing the ramp, and high top speed running on the flat. Our AC motors accomplish all this because they have no commutator restrictions, like DC motors. With up to 6,000 HP of on-board retard capability, the truck tackles downgrades with confidence, at higher speeds than DC trucks, and with smooth electric braking right to standstill.
That’s Siemens AC power — in a haul truck drive that sets the standard.
AC drive technology is the perfect choice for open-pit mining because it offers increased performance, low maintenance, and excellent compatibility with the harsh environment
How it works – Propel: The traction alternator converts the mechanical energy of the diesel engine into DC current, charging the DC bus capacitors. The electric power passes through the capacitors to two inverters, which produce AC current for the traction motors. The output frequency and voltage of the inverters is controlled to provide precise motor torque and speed.
How it works – Retard: In retard, the inverters generate electric power by slowing down the motors. Braking choppers, connected to the inverters, channel that power straight into a power resistor grid that continuously dissipates the energy until the truck reaches standstill. So braking is smooth, like driving a car, but without mechanical brake wear.
Intelligent diagnostics SiBAS™ monitor program
SiBAS™ control unit continuously monitors important internal signals to prevent failures. In the event of a fault, the fault history and diagnostic and repair information can be transferred with a few mouse clicks to the notebook of the service technician for analysis.
SiRAS™ remote diagnostics
With SiRAS™ remote diagnostics, we can "keep the factory on the truck." Remote-access hardware and software connects the drive system to the Internet and allows Siemens service technicians as well as other experts to log on to the truck from around the world for monitoring, troubleshooting and maintenance.
Vital signs can be monitored for trends, and maintenance can be planned before failures occur. Software upgrades can be downloaded to the truck and installed during lunch breaks. The net result is a substantial reduction in MTTR, greater system availability, and reduced maintenance costs.
From online monitoring to intervention to troubleshooting – we offer flexible service concepts and highly qualified service personnel to maximize your trucks’ availability.
Power, Rimpull and Truck Speed: Each drive system has very high tractive effort (rimpull) for pulling away in soft ground, and fully utilizes all available engine horsepower. Additional power available during trolley assist translates into higher on-grade speeds. Retard utilizes the full power capability of the AC drive system for the highest safe downhill speeds.
View Charts to see how the AC Drive improves operations 360 Ton | 300 Ton | 240 ton