6
Measure the primary and secondary sides of inverters
(Performance evaluation of motors and inverters)
Accurately and easily measure the power of inverters and motors for a wide range of measurements, from research and development to field tests
Advantages
1. Isolated input of voltage and current lets you measure the power on the primary and secondary sides of inverters simultaneously.
2. Using a non-invasive current sensor makes the connection simple and easy. A vector diagram display ensures connections are checked.
Proprietary HIOKI Technology
3. Accurately measure the Fundamental wave voltage and current values related to the motor axis output with confidence
4. All data is measured simultaneously and updated every 50 ms.
5. In addition to the harmonic analysis required to evaluate the inverter control, noise components can also be measured at the same time - ideal for
determining the leakage of inverter noise
6. Use of a current sensor reduces the effect of in-phase noise from inverters when measuring the power
Inverter
To ensure accurate measurements:
1
• Understand the connections and input states while looking at the connection diagram screen
Checking unsure connections allows you to perform measurements without worry
Three-phase
three-wire
Motor
Measurement parameters
Voltage, current, power, power factor, ±electrical
energy, harmonic analysis, noise measurement,
frequency
Measure the primary side of inverters Measure the secondary side of inverters
(Using channels 1, 2, and 3)
(Using channels 1, 2, and 3)
PC measurements and multiple-unit synchronized measurements
2
• Dedicated application software allows you to perform PC measurements
right out of the box
• Acquire all data even when multi-unit measurements are performed
Two units can be connected using the CONNECTION CABLE 9683 (option) to
synchronize the internal clocks and control signals.
LAN and USB compabitility facilitates efficient data collection and remote
operation. Bundled application software allows you to control up to 4 units.
Interval measurements with the two units allow the acquisition of perfectly synchronized data,
making it easy to collect completely harmonized data with a CF card without using a PC.
Interval measurement with LAN or USB connection
CONNECTION CABLE 9683
Inverter
PC
Three-phase power supply
Motor
Interval measurement enables the
acquisition of perfectly synchronized data
CF card
CF card
● Conventional measurement method
■ What's so special about inverter motors?
Inverter motors are indispensable as the power source of industrial equipment
The rotation of an induction motor depends on the input frequency, so if this input
frequency can be made variable, the rotation can be controlled freely. Development
of a frequency conversion technology called an inverter has made it possible to
freely control the rotation of motors.
Traditional methods use the average rectified RMS indication (Mean) in order to obtain
a component value close to the fundamental wave frequency from a pseudo sinusoidal
waveform (fundamental wave + carrier wave) to be input. To measure an accurate fundamental
component, frequency analysis was required; however, the conventional processing method
was not practical because it could barely perform real-time measurements with FFT as a result
of the limited computing power.
In recent years, the mainstream inverter control method is the PWM (Pulse-width
Modulation) method.
Mean value
● What is the PWM method?
A pseudo sinusoidal waveform (fundamental wave) is comprised of a pulse train
called a carrier frequency (at about several kHz to 15 kHz) as the fundamental wave
frequency that determines the rotation of a motor.
Full-wave rectification
Mean-value processing & coefficient processing
Mean value (average rectified RMS indication value)*
* Method to measure RMS values at a single frequency
PWM waveform
● Performance evaluation and electrical measurement of motor
The axis output of a motor is closely related to the fundamental wave frequency
to be input, so an accurate measurement of this fundamental wave component is
required to evaluate the input characteristics.
●
The 3390 is capable of measuring the fundamental wave component accurately
The 3390 performs this frequency analysis using high-speed harmonic computation
processing at an interval of 50 ms and displays the true fundamental wave
component.
ASM-SENSOR [ ASM GMBH ]
