Regenerative Drive Control Device for Vertical Carrier Machine
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Solution Overview
Problem
The existing drive control devices for vertical carrier machines are inefficient in utilizing regenerative power, as they either discard it as heat or incur voltage conversion losses, especially when the machine operates primarily for regenerative operations, leading to increased consumption of alternating-current primary power.
Innovation Solution
A drive control device with a capacitor connected between the direct-current output lines of the converter part, which stores regenerative power generated during regenerative operations and supplies it to the inverter for power operations, minimizing primary power consumption and avoiding voltage conversion losses through bidirectional DC/DC converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If regenerative power is stored in an electric double layer capacitor using a bidirectional DC/DC converter, then regenerative energy can be reused, but voltage conversion losses occur and the system becomes more complex
Solution Approach 1:
The patent extracts the capacitor from the complex bidirectional DC/DC converter system and connects it directly to the DC bus, eliminating the need for voltage conversion while retaining the energy storage function. This simplifies the system by removing the converter components while still achieving regenerative energy reuse.
Solution Approach 2:
The capacitor serves multiple functions: it stores regenerative energy, provides voltage support during power consumption periods, and eliminates the need for a bidirectional DC/DC converter. This multi-functionality reduces system complexity while maintaining energy reuse capabilities.
2Reliability
If a braking unit with transistor is used to process regenerative energy, then direct-current bus circuit voltage can be controlled, but regenerative energy is discarded as heat
Solution Approach 1:
Instead of discarding regenerative energy as heat through the braking resistor, the patent redirects this energy to charge the capacitor. The energy that would have been wasted is now stored and can be reused during power consumption periods, converting a harmful waste product into a beneficial resource.
Solution Approach 2:
The patent recovers regenerative energy that would otherwise be discarded by the braking unit. By connecting the capacitor to the DC bus, the system captures and stores the regenerative energy, then recovers it later when power is needed, eliminating the waste associated with traditional braking units.
3Loss of energy
If regenerative power is fed back to the inverter side, then energy can be reused, but direct-current bus circuit voltage increases causing regeneration failure
Solution Approach 1:
The capacitor acts as an intermediary between the regenerative power source and the DC bus. It absorbs the regenerative energy, preventing direct voltage spikes on the bus, and then releases energy gradually when needed. This mediation stabilizes the voltage while enabling energy reuse.
Solution Approach 2:
The capacitor is charged in advance with regenerative energy before it is needed. By storing energy preliminarily during regenerative periods, the system prepares for future power consumption needs, smoothing out voltage fluctuations and ensuring stable operation during both charging and discharging phases.
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 configuration effectively utilizes regenerative power by storing and reusing it, reducing the consumption of alternating-current primary power and enabling efficient velocity control of the vertical carrier machine, while protecting the capacitor from overvoltage and optimizing costs.
Implementation Method 1
a capacitor (12) that is connected between a positive terminal (P11) and a negative terminal (N11) of a direct-current output line not via a resistor but directly, to store direct-current regenerative power generated at an input portion of the first inverter part (4) during regenerative operation
Implementation Method 2
a converter part that converts an alternating-current voltage supplied from an alternating-current primary power source into a direct-current voltage
Implementation Method 3
a first inverter part that converts the direct-current voltage smoothed by the first smoothing circuit part into an alternating-current voltage at a variable voltage variable frequency
Data Source
AI summary
The drive control device for a drive system including a vertical carrier machine includes: a drive control device (A) for an electric motor (M1) mainly for regenerative operation; a drive control device (B) for an electric motor (M2) mainly for power operation; and a regenerative power storage capacitor (12) that is connected between a positive terminal (P11) and a negative terminal (N1) of a direct-current output line of a converter part (1) via a third inrush current suppression circuit (11) in which a third resistor (R3) and a switch (SW3) are connected in parallel, wherein the capacitor (12) has an electrostatic capacitance and a direct-current internal resistance to produce a current value with which braking torque required for velocity control of the electric motor (M1) mainly for regenerative operation is generated by a charging current flowing at storage of the regenerative energy generated by the electric motor (M1).