Rotating Electric Machine Control Device Torque Variation
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Solution Overview
Problem
Existing control technologies for wound-field-type rotating electric machines face challenges in maintaining consistent electric generation torque during mode switching due to response delays in field current, leading to torque variations and inefficiencies between inverter and alternator electric generation modes.
Innovation Solution
A control device that includes an energization amount generator and an energization signal generator to manage switching between inverter and alternator electric generation modes by synchronizing field and armature current command values, ensuring consistent electric generation torque through maps and feedback control, thereby minimizing torque variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If switching between inverter electric generation mode and alternator electric generation mode is performed, then electric generation efficiency is improved, but electric generation torque varies and torque shock occurs
Solution Approach 1:
The control device determines switching timing in advance by monitoring rotation speed and electric load amount, and prepares for mode transition by adjusting field current and armature current command values before actual switching occurs. This preliminary preparation ensures smooth torque transition and prevents torque shock when switching between inverter and alternator electric generation modes.
Solution Approach 2:
The control device continuously monitors rotation speed, electric load amount, and current states, and adjusts field current and armature current command values based on feedback from these parameters. This feedback mechanism ensures that torque remains stable during mode switching by dynamically adjusting control parameters according to actual operating conditions.
2Adaptability or versatility
If inverter switching is performed frequently to adapt to varying driving conditions, then electric generation voltage control is improved, but switching loss increases and efficiency deteriorates
Solution Approach 1:
The control device changes operating parameters (field current command value and armature current command value) according to rotation speed and electric load amount, allowing the system to adapt to varying driving conditions without frequent mode switching. This parameter adjustment approach reduces switching frequency and associated losses while maintaining voltage control capability.
Solution Approach 2:
The control device can operate in both inverter electric generation mode and alternator electric generation mode, selecting the appropriate mode based on driving conditions. This multi-functionality allows the system to handle various voltage control requirements while minimizing switching losses by using the most efficient mode for each operating condition.
3Stability of the object's composition
If field current is increased gradually after mode switching to reduce torque variation, then torque stability is improved, but response delay occurs
Solution Approach 1:
The control device adjusts field current and armature current command values before mode switching occurs, based on predicted switching timing determined from rotation speed and electric load amount. This preliminary adjustment ensures that current values are already optimized when switching occurs, eliminating the need for gradual post-switching adjustment and avoiding both torque variation and response delay.
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 reduces electric generation torque variation and suppresses torque shock during mode switching, enhancing the efficiency and stability of the electric generation process.
Implementation Method 1
a wound-field-type rotating electric machine is widely employed for which induced voltage can be easily control in accordance with the rotation speed
Implementation Method 2
it is necessary to charge the battery after stepping up the electric generation voltage while using an inverter as a step-up chopper by performing switching for the inverter
Implementation Method 3
it is desirable to obtain target electric generation voltage by performing rectification by a diode and controlling the energization amount of field current
Data Source
AI summary
A control device for rotating electric machine, which controls a rotating electric machine as a charging electric generator, using an inverter circuit, the control device including: an energization amount generating unit for generating a first electric generation mode in which an energization amount for a field winding and an energization amount for an armature winding of the rotating electric machine are controlled and the inverter circuit is driven to perform electric generation, and a second electric generation mode in which an energization amount for the field winding is controlled to perform electric generation; and an energization signal generating unit for, on the basis of variation-related information relevant to variation in one of electric generation torque and electric generation current of the rotating electric machine, performing switching between the first electric generation mode and the second electric generation mode, and generating energization signals for the field winding and the armature winding.