PATENT CLAIM ANALYSIS

Application Number: 15980794
Application Type: Utility
Filing Date: 2018-05
Publication Date: 2019-02
Patent Classification: ["363", "132000"]

Abstract:
A method and a device for voltage balancing of DC bus capacitors of an NPC four-level inverter are disclosed. The method includes: determining an optimal zero-sequence voltage, determining an actual reference voltage of each phase based on the optimal zero-sequence voltage; comparing respectively three preset carrier signals with the actual reference voltage of each phase to obtain three first control signals; determining three duty-cycle adjustment values based on a voltage of the intermediate bus capacitor; adjusting correspondingly the three first control signals based the three duty-cycle adjustment values to obtain three second control signals; inputting correspondingly the three second control signals to three first switches of an upper bridge corresponding to each phase; and inputting correspondingly complementary signals of the three second control signals to three second switches of a lower bridge corresponding to each phase.

Claim (Index 2):
The method according to  claim 1 , wherein determining the optimal zero-sequence voltage based on the voltage of the upper bus capacitor, the voltage of the lower bus capacitor and the initial reference voltage of each phase, comprises:\n calculating all key zero-sequence voltages based on initial reference voltages of all phases; calculating a bus neutral-point current corresponding to each key zero-sequence voltage based on currents of all phases; calculating a target neutral-point current based on a difference between the voltage of the upper bus capacitor and the voltage of the lower bus capacitor; comparing the bus neutral-point current corresponding to each key zero-sequence voltage with the target neutral-point current; and selecting a key zero-sequence voltage that minimizes the difference between the target neutral-point current and the bus neutral-point current as the optimal zero-sequence voltage.

Metadata:
- Claim Count in Document: 1.0
- Percentile: 93.0
- Lexical Diversity: 2.41667
- Patent Class: 363.0
- Transitional Phrase Type: none
- Component Type: 0
- Foreign Priority: True
- Related Applications: ['15109219', '15662044', '13912398', '14153103', '15823192']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.7963551862187513
- 35 USC 102 Novelty (BERT): 0.5053820310679978
- Combined Prediction Score: 0.767257870703676
- Mean Citation Score: 228.819082
- Max Citation Score: 246.3851
- Similarity Product: 172.21454994550942

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test