Single-Phase Capacitor Motor Starting With Phase-Angle Standby Control
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Solution Overview
Problem
Existing single-phase asynchronous electric motors with permanent capacitors face challenges in achieving low standby energy consumption while ensuring efficient motor starting and operation, as increasing impedance to reduce standby power consumption can hinder motor startup.
Innovation Solution
A method and device that utilize an electronic control unit with a zero-crossing detection system to control a switch in phase angle and full wave modes, optimizing the series impedance of a resistive circuit to maintain low standby energy consumption while ensuring motor startup and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If the series impedance value of the resistive circuit is increased to reduce standby energy consumption, then standby power consumption is reduced, but the electrical energy available for motor starting is reduced which may prevent the motor from starting
Solution Approach 1:
The patent applies dynamic impedance control by switching between two different series impedance configurations: a first impedance value during standby mode to minimize power consumption, and a second impedance value during motor starting to ensure sufficient electrical energy availability. This dynamic adjustment resolves the contradiction between low standby consumption and reliable motor starting.
Solution Approach 2:
The patent changes the impedance parameter of the resistive circuit based on operational state. By detecting whether the motor is in standby or starting phase, the system adjusts the series impedance value accordingly, optimizing both energy efficiency during standby and starting performance when needed.
2Reliability
If full-wave control is used to maintain motor rotation, then motor operation is maintained, but energy consumption increases
Solution Approach 1:
The patent employs periodic phase-angle control instead of continuous full-wave control. By applying control pulses at specific phase angles relative to the AC waveform and maintaining them periodically, the system achieves reliable motor operation with reduced energy consumption compared to continuous full-wave control.
Solution Approach 2:
The patent uses partial wave control where control pulses are applied only during necessary portions of the AC cycle rather than the entire cycle. This partial action is sufficient to maintain motor rotation while significantly reducing energy consumption compared to full-wave control.
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
The solution allows the electric motor to start and operate efficiently with minimal standby energy consumption, meeting energy efficiency standards while maintaining reliable rotational drive.
Implementation Method 1
the other winding called the auxiliary winding is electrically connected in series with a phase-shifting capacitor
Implementation Method 2
single-phase asynchronous electric motor
Implementation Method 3
An electronic control unit comprising a device for detecting the sector zero crossing
Implementation Method 4
the triac receives a single ignition pulse, the ignition pulse causing a brief phase shift
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a method for starting an electric motor (MOT) comprising a stator having two windings (L1, L2), each of the two windings having one end connected to a common node (N0) electrically connected to a neutral conductor (ACN) via a switch (TR), and another end connected to a respective phase terminal (P1, P2), a phase conductor (ACP) being selectively connected to one of the two phase terminals to control the rotation of the motor in one direction (DIR1) or in the opposite direction (DIR2), the switch being controlled by a control unit (CC), the control unit commanding, during a starting period, the switch (TR) at an angle of phase with respect to the alternating voltage (U0), then, following the starting period, commands the switch at full wave with respect to the alternating voltage (U0).