Vacuum Pump Drive Star-Delta Switchover Control
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Solution Overview
Problem
Existing vacuum pump drive systems are limited in adapting their performance data to varying operating conditions, such as pressure and temperature changes, due to constraints in the maximum current supply and available mains voltage, which affects motor efficiency and safety, especially when handling different gases or media.
Innovation Solution
An electronic control device connected to sensors monitors operating parameters like temperature, pressure, and speed, automatically switching the motor windings between star and delta configurations to adapt the motor characteristic, enabling dynamic torque adjustment and power management based on real-time operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the motor is operated at high current to provide sufficient torque for strong pressure or temperature changes, then the torque requirement is met, but the maximum current limit of the drive converter is exceeded
Solution Approach 1:
The patent applies dynamics by making the motor winding connection configuration variable rather than fixed. The control device dynamically switches between star and delta connections based on real-time operating conditions (pressure, temperature, speed), allowing the motor to adapt its electrical characteristics to match the instantaneous torque requirements without exceeding current limits
Solution Approach 2:
The patent changes the electrical parameters of the motor by switching the winding configuration. In star connection, the motor operates with reduced current and lower torque, while in delta connection, it operates with higher current and higher torque. This parameter change allows the system to access different torque-current operating points to satisfy varying pump conditions
2Speed
If the motor operates at high speed to meet pump demands, then productivity increases, but the available voltage reserve is insufficient for further acceleration
Solution Approach 1:
The switching between star and delta connections dynamically adjusts the motor's voltage characteristics. In star connection, the motor receives reduced voltage suitable for high-speed operation, while delta connection provides full voltage for acceleration. This dynamic adaptation ensures voltage reserve is available when needed for speed increases
3Force
If the motor windings are connected in delta to provide high torque, then torque availability increases, but power losses in the motor increase
Solution Approach 1:
The system dynamically selects the optimal connection mode based on torque requirements. When high torque is needed, delta connection is activated despite higher losses. When torque demands are lower, star connection is used to minimize power losses. This dynamic selection optimizes the trade-off between torque delivery and energy efficiency throughout the operating range
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for safer, more reliable, and faster torque adjustments, optimizing drive power and reducing power losses, while accommodating different gases and conditions without relying solely on data from the drive unit, thus enhancing the vacuum pump's operational flexibility and efficiency.
Implementation Method 1
An electric motor (18) which is supplied by a frequency converter (20) with a three-phase AC voltage as the motor input voltage. The frequency converter (20) generates the motor input voltage from a mains supply voltage
Implementation Method 2
The switching device (22) has two electrical switches (24, 26) and is assigned to connect the motor windings as a star or as a delta, depending on a switch position
Implementation Method 3
The measuring device is provided with sensors for detecting physical operating parameters of the vacuum pump, such as the pump temperature, the vacuum pump pressure and/or the speed of the vacuum pump
Data Source
AI summary
The invention relates to a vacuum pump drive (12) comprising at least one electric motor (18) which is connected to the rotor (14) of a vacuum pump (13) via a drive shaft (16), a frequency converter (20) which is electrically connected to the motor (18) and which supplies a motor input voltage to the motor, and a switchover device (22) with at least one electric switch (24, 26). The switchover device (22) is designed to connect the motor windings in a star or delta shape depending on the switching position of the switch (24, 26) in order to change the motor characteristic curve. The vacuum pump drive also comprises a measuring device (32) with sensors for detecting physical operating variables of the vacuum pump (13) and a controller (30) which is electrically or optically connected to the switchover device (22) and the measuring device (32) and which is designed to actuate the at least one switch (24, 26) on the basis of the measured value of the operating variable of the vacuum pump (13) in order to produce the star-delta switchover.