Parallel Interleaved Regenerative Drives for Elevator Power Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conveyance systems, such as elevator systems, face challenges in providing varying power levels efficiently, leading to high design costs and lengthy development times due to the lack of suitable high-power drives, and existing solutions for power conversion often result in excessive costs and complexity.
Innovation Solution
A three-phase paralleled active front-end drive system is implemented, comprising interphase inductors, converters, and inverters connected in parallel to distribute power efficiently and generate motor excitation signals, with controllers managing PWM signals to ensure equal motor excitation currents and minimize common-mode noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single high-power drive is used to meet large elevator duty requirements, then the power capability is sufficient, but the design costs and development time become excessive
Solution Approach 1:
The patent divides a single high-power drive into multiple lower-power drive units (first drive and second drive) that operate in parallel. Each drive unit has its own converter and inverter, allowing the system to achieve high power capability through aggregation of multiple smaller units, thereby reducing design costs and development time associated with a single large drive.
Solution Approach 2:
The patent combines multiple drive units in parallel configuration where the first converter and second converter both connect to a common DC bus, and their inverters both supply a common motor. This merging approach allows the system to achieve the power capability of a single large drive while using multiple smaller, more cost-effective drive units.
2Device complexity
If multiple drive units are connected in parallel to reduce costs, then design costs decrease, but common-mode noise and circulation currents increase
Solution Approach 1:
The patent introduces interphase inductors as intermediary elements connected between the first inverter and second inverter. These inductors act as mediators that filter out circulation currents and reduce common-mode noise generated by the parallel connection of multiple drive units, thereby eliminating the harmful effects while maintaining the cost benefits of using multiple smaller drives.
3Productivity
If parallel drive configuration is used, then power distribution efficiency improves, but control complexity increases
Solution Approach 1:
The patent implements a control system with feedback mechanisms that monitor the operation of parallel drive units and adjust their performance accordingly. The controller receives feedback from both drive units and coordinates their operation to maintain balanced power distribution, thereby managing control complexity while preserving the efficiency benefits of parallel configuration.
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 allows for efficient power distribution and reduced common-mode noise, enabling cost-effective and timely development of conveyance systems that meet high load demands without the need for a single, high-power drive, thereby reducing design and operational costs.
Implementation Method 1
a first plurality of interphase inductors configured for connection to a three phase alternating current (AC) power source and operable to distribute power from a three phase alternating current source to a first converter and a second converter
Implementation Method 2
a first converter and a second converter configured to transfer power to a first and an second direct current (DC) bus respectively
Implementation Method 3
a first inverter operably connected to the first DC bus; a second inverter operably connected the second DC bus, the first inverter and second the inverter each configured to provide a plurality of motor excitation signals
Implementation Method 4
a second plurality of interphase inductors operable to combine the plurality of motor excitation signals from the first inverter with the plurality of motor excitation signals from the second inverter
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A paralleled drive having a first plurality of interphase inductors to distribute three phase alternating current power to a first and a second converter that transfer power to a first and a second direct current (DC) buses respectively, a bus coupler connecting the first and second DC buses, a first and a second inverter connected to the first and second DC buses respectively. The drive also includes a controller connected to the first and second converters and the first and second inverters, the controller generates control signals to cause the first and second converter to transfer power to the first and second direct current (DC) buses respectively, and the controller configured to generate control signals to cause the first and the second inverters to generate a plurality of motor excitation signals respectively, and a second plurality of interphase inductors operable to combine the plurality of motor excitation signals.