AC Vehicle Control Device Regenerative Torque for Static Inverter
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Solution Overview
Problem
Existing control apparatuses for AC electric motor vehicles require increased size or additional hardware to maintain static inverter operation during overhead power loss, such as pantograph bounce or section passage, which is undesirable.
Innovation Solution
A control apparatus that includes a converter, inverter, motor, and a torque-command calculating unit to calculate regenerative torque command values based on rotor frequency and input current, allowing the static inverter to continue operation by utilizing regenerated power without increasing hardware capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the capacity of smoothing filter capacitor is increased to prevent SIV from stopping during overhead power loss, then the reliability of SIV operation is improved, but the size and weight of electric components increase
Solution Approach 1:
The motor serves dual purposes: as a drive motor during normal operation and as a generator during overhead power loss to supply power to the SIV. The control apparatus calculates regenerative torque command values based on SIV power consumption requirements, enabling the motor to self-supply power during emergencies without requiring additional energy storage hardware.
Solution Approach 2:
The control apparatus dynamically changes the operating parameters of the motor (torque command values) based on the operational state. During overhead power loss, the controller adjusts the torque command to generate regenerative power that matches the SIV's power consumption, calculated using the formula: torque command value = (SIV input voltage × SIV input current) / motor angular velocity.
2Reliability
If energy accumulating means is added to continue SIV operation during power loss, then the reliability of SIV operation is improved, but the device complexity increases
Solution Approach 1:
The motor-inverter system performs multiple functions: propulsion during normal operation and power generation for SIV during overhead power loss. The same converter and inverter hardware serve both the main propulsion system and the auxiliary power supply function, eliminating the need for separate energy accumulating means.
Solution Approach 2:
The patent merges the propulsion system and auxiliary power supply system into a single integrated system. The motor, converter, and inverter that normally drive the vehicle are combined with the SIV power supply function, allowing regenerative power from the motor to directly supply the SIV without requiring separate energy storage devices.
3Device complexity
If the SIV is stopped during overhead power loss to simplify control, then the device complexity is reduced, but the reliability of power supply deteriorates
Solution Approach 1:
The control apparatus continuously monitors the operational state of the SIV and calculates the required power consumption. Based on this feedback, the system dynamically adjusts the regenerative torque command values to ensure the motor generates sufficient power to maintain SIV operation during overhead power loss.
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
Enables continuous operation of the static inverter during overhead power loss without increasing size or adding hardware, reducing energy consumption and the need for additional hardware.
Implementation Method 1
a converter that converts an AC voltage input from an AC overhead wire via a transformer into a DC voltage
Implementation Method 2
an inverter that converts the DC voltage into an AC voltage
Implementation Method 3
a motor that is driven and controlled by the inverter
Implementation Method 4
a static inverter that is connected to the output of the converter so as to act as an auxiliary power supply which supplies auxiliary power to the electric motor vehicle
Data Source
Figure 1
Figure 2
AI summary
A control apparatus for an AC electric motor vehicle including a converter 3 that converts an AC voltage input from an AC overhead wire via a transformer 2 into a DC voltage, an inverter 4 that converts the DC voltage into an AC voltage, and a motor 6 that is driven and controlled by the inverter 4 includes: torque-command calculating units 11 and 12 that calculate a torque command value of the motor 6 and output the torque command value to the inverter 4; and a static inverter 7 that supplies electric power to a load mounted on the AC electric motor vehicle. When the AC voltage is not applied to the converter 3, the regenerative-brake-torque-command calculating unit 11 calculates a regenerative torque command value TRQ1 corresponding to power consumption of the static inverter 7, and the inverter 4 supplies, according to the regenerative torque command value TRQ1, regenerated power generated by the motor 6 to the static inverter 7.