Designing ability

R & D team

patent

A power device die
temperature estimation Calculation
method and equipment

Sensorless motor
control system system
and control method

11 Invention
Patents

14 Utility
Model Patents

Nonlinear variable carrier
frequency system, method
and storage medium based
on PFC harmonic suppression

A torque compensation
system and method for
compressor

How to start a
position sensorless motor

7 Software
Copyrights

A self-adaptive
zero-crossing detection
method for brushless
DC motor

performance test equipment

150KW electric dynamometer
50KW eddy current dynamometer
2KW hysteresis dynamometer
Grid Simulator
15KW electronic load
Air volume tester
Water pump test system
Power Analyzer

Electromagnetic Compatibility Test Equipment

Conduction test shielded room
Disturbance power test system
Disturbance voltage test system
Dynamometer
Cyclic voltage drop tester
Electrostatic discharge tester
Lightning surge tester
Group pulse tester

Reliability Test Equipment

High and low temperature damp heat test chamber
High and low temperature impact test chamber
Vibration Tester
Salt spray test chamber
Insulation withstand voltage tester
Voltage residual
High temperature aging room
Button life machine
0

Patent

0

Utility model patents

0

Software copyright

characteristic

Zero-speed high-torque start

Starting current waveform

Fan closed-loop starts up against the wind

4页-25 4页-24

Start against the wind

Tailwind start

AC voltage beat frequency suppression

5页-29 5页-28

before inhibition

After inhibition

voltage drop suppression

voltage drop suppression

Low Noise Single Resistor Solution

6页-33 6页-32

Single Resistor Noise Spectrum

Three Resistor Noise Spectrum

The above UVW modulation method is a traditional single-resistor scheme, which will inevitably introduce electromagnetic noise. Using Zhouju’s self-developed single-resistor solution can minimize electromagnetic noise and obtain almost the same noise effect as the three-resistor.

Modulation ratio 1.1

Modulation ratio 1.1

Adaptive Compensation for Torque Fluctuation of Single Rotor Compressor

7页-35 7页-34

Before torque compensation is turned on

After torque compensation is turned on

Dead zone harmonic compensation

Comparison before and after compensation

Carrier frequency optimization strategy

8页-39 拷贝 8页-38 拷贝

Optimize the front amplitude frequency characteristics

Optimized amplitude-frequency characteristics

Perfect PFC solution

current voltage waveform

Case