Here is some information from equipment manufacturers for DC motor drives.
DIGITAL DRIVE DC MOTOR SPEED
This information is a summary of the installation manual and operation of variable speed DC motor, Brand: Allen Bradley, model: 1395.
NOMINAL SPECIFICATIONS:
The characteristics of the equipment we have in the lab 710 (input voltage 460 VAC standard) are: CAT: 1395-B67-C1-P10-P51-X1, which is detailed;
1395 indicates the number of bulletin prepared by the manufacturer.
B67 tells us it is a regenerative drive of 10HP.
C1 informs us that the contactor is standard and supports up to 30HP.
P10 tells us that includes a 115VAC adapter card discreetly on port A.
P51 tells us that has a multi-adapter card communication on port B.
X1 indicates that we have auxiliary contacts (1 NO and 1 NC).
HARDWARE DESCRIPTION:
Figure 4-7 presents an overview of the hardware associated with the team.
Armor bridge components:
Figures 4-8 and 4-9 are observed components used, which are described below.
AC Line Reactor - Used to protect the power bridge against sudden changes in current (di / dt). If you use an isolation transformer unit rate, does not require the use of such reactor. They are fast acting fuses F1, F2 and F3 to protect the power semiconductors.
Sync .- The three-phase line feeds directly into the power board, which is scaled and used to synchronize the work of the power semiconductors.
AC current feedback - Current transformers ACT1 and ACT2 are used to provide current feedback information to the card PSI / Switcher. This card scale rectified and a DC voltage representing the current feedback. Then this signal is sent to the main control board.
Surge protective .- The peak suppressor MOV4 MOV1 to the power CARD armor protect the bridge against voltage surges on the line.
Encapsulation consists of two SCR SCR .- per module.
.- Pulse transformers installed on the board supplied power isolated firing pulses to the gate of each SCR.
Protection against overvoltage .- The RC network card installed in the power SCR protect against voltage transients (dv / dt).
DC Current Sensor. - An over-current sensor DC is supplied using the transducer TD1.
Contactor DC .- The bridge output is connected to the motor armature through the main contactor M1. The coil is 115VAC and is controlled by the pilot relay K3 (in PSI card / switch) through the terminal TB2-2 and TB2-3.
Bridge output connections .- Named A1 and A2 are connected to the motor armature. If dynamic braking is used, connect a braking resistor bank terminals in DB1 and DB2.
View of operation .-
Figure 4-10 shows a presentation of the majority of blocks associated with the control functions. The control functions in 1395 can be executed through the use of parameters which are changed with the programming terminal. Following is a brief description of each block.
Communication .- Control controls all data transfers. The programming terminal is connected to the drive via a serial communication link RS-422. Two communication ports A and B are available.
Inverter control logic. - Controls the state of drive operation in response to logic input command. Selecting multiple benchmarks (eg reference speed) and control modes (eg loss. Droop), are executed in this block. It also notes the present operating conditions and provides this information as feedback to control external devices.
Selection of speed reference. - It has 05 speeds pre ¬ defined reference parameters stored in the drive. Additionally, an external reference and a two-speed jog inputs can be selected as the speed reference. Block speed reference selection using information from the drive control logic to determine which references are used as input to the speed control. The selected reference enters a ramp before being sent as input for speed reference to speed control.
Selection of speed feedback. - You can use one of three modes of speed feedback. The armature voltage is monitored constantly by the drive and can be used as feedback. The hardware for communicating information to speed with a digital encoder is supplied as standard. If using a DC tachometer and speed feedback, the drive should be equipped with the discrete adapter card connected to port A.
Speed Control .- Compare the reference speed with the speed of feedback to determine the speed error.
Torque Reference Selection 1395 .- The drive can operate as a regulator of speed or torque regulator and therefore has the ability to accept a speed reference or torque reference. The block selection of the reference torque to operate as a torque regulated drive and still have the speed control operation. In this case, the drive can receive referrals while speed and torque.
Armature current control. - The armature current reference is compared to the armature current feedback from current transformers. The control block armature current produces a voltage reference which is applied to the block synchronization logic armor and shot.
Armor Lock and tripping logic. - The output voltage reference of the previous block is converted to a reference phase angle and then a time reference to be sent as control of the SCRs of the bridge armor.
Flow Control field .- Use the reference flow field from the speed control to develop a field current reference. This reference is then compared with current feedback from field transformers AC line current of the field. The error between the reference and field current feedback produces a firing angle which is sent to the logic of shooting and field sync.
Sync logic of the field and shot .- The output of the phase angle from the field current control is converted to a time reference which is synchronized to the line sync signal from the synchronism of armor and tripping logic to produce the firing pulses to the SCRs gate.
Here are some suggestions to consider when installing a variable speed DC motor:
Security Notice
This equipment contains voltages that can reach 600 volts. Electrical shock can cause serious injury or death. Only qualified personnel should attempt to start or troubleshoot this equipment.
This equipment can be connected to other machines that have parts (pieces) rotary (rotating) or parts that are driven by the equipment itself. Improper use can cause serious injury or death.
Only qualified personnel should attempt to start or troubleshoot this equipment.
WARNING: Do not touch any card (plate) circuit, power device or electrical connection without first ensuring that the power has been disconnected and did not have high voltages in this equipment or other equipment it is connected. Electrical shock can cause serious injury or death. Only qualified personnel should attempt to start or troubleshoot this equipment.
WARNING: This unit has an automatic restart feature that starts the engine whenever input power is fed and we issue a RUN command (FWD or REV). If an automatic restart of the engine could result in injury to persons, you must disable the automatic restart feature parameter switching to Manual Restart Auto / Man of the block of Miscellaneous, Level 2.
WARNING: Make sure you are completely familiar with the safe operation of this equipment. This equipment can be connected to other machines that have rotating parts or parts that are controlled by the same team. Improper use can cause serious injury or death. Only qualified personnel should attempt to start or troubleshoot this equipment.
WARNING: Make sure the system is properly grounded before applying power. Do not apply AC power before you ensure that all instructions have been met on ground. Electrical shock can cause serious injury or death.
WARNING: Do not remove the cover before he has completed a minimum of five (5) minutes after disconnecting the AC power to allow capacitors to discharge. Dangerous voltages are present inside the equipment. Electrical shock can cause serious injury or death.
WARNING: Improper operation of control may cause violent motion of the shaft (arrow) of the motor and driven equipment. Make sure that a sudden movement of the motor shaft will not cause injury to personnel or damage to equipment.
Some failure modes of control can produce peak pairs (tip) that are several times the rated motor torque.
WARNING: Motor circuit may have high voltage present whenever AC power is applied, even if the engine is not rotating. Electrical shock can cause serious injury or death.
