Electric Motor Drive Apparatus Battery Utilization
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Solution Overview
Problem
In electric vehicles, series-connected batteries with varying initial capacities and internal resistances lead to differences in charge/discharge characteristics, resulting in decreased battery capacity and output power, and low battery utilization due to uneven power distribution.
Innovation Solution
A motor driving apparatus with a three-phase alternating current driving circuit and a main controller that adjusts the output voltage of electric driving units based on the voltages of individual storage batteries, ensuring each battery outputs power independently, with bypass switch units to manage back electromotive force, thereby achieving voltage equalization and improved utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If series-connected storage batteries are used in the driving circuit, then the system can provide high voltage and power output, but the charge/discharge characteristics of individual batteries diverge due to different initial capacities and internal resistances, resulting in decreased battery capacity and output power
Solution Approach 1:
The patent divides the battery system into multiple independent battery groups (first battery group, second battery group, third battery group) instead of using a single series-connected battery string. Each group can be independently controlled and managed, allowing the system to maintain high power output while preventing the divergence of charge/discharge characteristics that occurs in series-connected configurations. The controller can balance the state of charge across different groups, ensuring reliable operation.
Solution Approach 2:
The patent implements independent voltage adjustment for each battery group through separate driving units (first driving unit, second driving unit, third driving unit). Each driving unit can independently adjust the output voltage of its corresponding battery group based on the specific state of charge and characteristics of that group. This local quality control allows the system to optimize performance while maintaining battery reliability by addressing the specific needs of each battery group rather than treating them uniformly.
2Power
If series-connected storage batteries are used, then high voltage output is achieved, but the storage battery utilization decreases due to uneven power distribution among batteries
Solution Approach 1:
The battery system is segmented into multiple parallel battery groups rather than a single series string. This segmentation allows the controller to independently manage and utilize each battery group, preventing the situation where one weak battery limits the entire system's utilization. The system can draw power from multiple groups simultaneously or selectively, maximizing overall battery utilization while maintaining high voltage output through proper configuration and control.
Solution Approach 2:
The patent dynamically adjusts the output voltage parameters of each battery group through independent driving units. By changing the voltage output parameters based on the real-time state of charge and characteristics of each battery group, the system optimizes power distribution and utilization. The controller can modulate the contribution of each battery group to the total power output, ensuring maximum utilization of available battery capacity while maintaining the required voltage level.
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 enhances storage battery utilization by ensuring high-voltage batteries output more energy and low-voltage batteries output less, prolongs motor service life by reducing harmonic distortion, and improves reliability by preventing abnormal output conditions.
Implementation Method 1
each electric driving unit includes an H-bridge inverter and a unit controller, where an input end of the H-bridge inverter serves as an input end of the corresponding electric driving unit, and an output end of the H-bridge inverter serves as an output end of the corresponding electric driving unit
Implementation Method 2
a signal end of the unit controller serves as a signal end of the corresponding electric driving unit; and the unit controller samples a voltage of a storage battery connected to the corresponding electric driving unit, sends the voltage to the main controller, and adjusts an output voltage of the H-bridge inverter based on the output voltage adjustment coefficient
Implementation Method 3
the main controller specifically determines, for each electric driving circuit in the driving circuit, an average voltage of the n storage batteries in the electric driving circuit, and determines the output voltage adjustment coefficient of each of the n electric driving units in the electric driving circuit based on the average voltage. In actual implementation, the main controller may specifically determine, for each of the n electric driving units in the electric driving circuit, a ratio of a voltage of the corresponding storage battery to the average voltage as the voltage adjustment coefficient of the electric driving unit
Data Source
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AI summary
A motor driving apparatus is disclosed, including a driving circuit (201) outputting a three-phase alternating current and a main controller (202). The driving circuit (201) includes a U-phase electric driving circuit (2011), a V-phase electric driving circuit (2012), and a W-phase electric driving circuit (2013). Each of the electric driving circuits includes n storage batteries and n electric driving units in one-to-one correspondence with the n storage batteries. Signal ends of the n electric driving units are connected to the main controller (202), input ends of the n electric driving units are connected to the corresponding storage batteries, and output ends of the n electric driving units are cascaded to output one phase of the three-phase alternating current, where n is a positive integer. The main controller (202) determines, for each electric driving circuit in the driving circuit (201), an output voltage adjustment coefficient of each of the n electric driving units in the electric driving circuit based on voltages of the n storage batteries in the electric driving circuit, and outputs the output voltage adjustment coefficient to the corresponding electric driving unit. The apparatus can improve storage battery utilization.