Copley Controls Corp. Xenus XTL, Руководство пользователя

Страница: 14 / 180

Operational Theory Xenus XTL User Guide
14 Copley Controls Corp.
2.1: Amplifier Internal Power
Power distribution within Xenus is divided into three sections: +24 Vdc, logic/signal, and high
voltage. Each is isolated from the other.
2.1.1: Logic/Signal Power
An internal DC/DC converter operates from the +24 Vdc Logic Supply input and creates the
required logic/signal operating voltages, the isolated voltages required for the high-voltage control
circuits, and a +5 Vdc supply for powering the motor encoder and Hall circuits. All the digital and
analog inputs, digital outputs (with the exception of OUT4), Hall and encoder inputs are referenced
to the same signal common. OUT4 is controlled through an opto-isolator, and is referenced to the
+24 Vdc return. The CAN interface is also optically isolated.
Deriving internal operating voltages from a separate source enables the amplifier to stay on-line
when the mains have been disconnected for emergency-stop or operator-intervention conditions.
This allows CAN bus and serial communications to remain active so that the amplifier can be
monitored by the control system while the mains power is removed.
2.1.2: High Voltage
Mains power drives the high-voltage section. It is rectified and capacitor-filtered to produce the DC
bus: the DC “link” power that drives the PWM inverter, where it is converted into the voltages that
drive a three-phase brushless or DC brush motor. An internal solid-state switch, together with an
external power resistor, provides dissipation during regeneration when the mechanical energy of
the motor is converted back into electrical energy. This prevents charging the internal capacitors
to an overvoltage condition.