Advance Power Conversion Testing with the Hioki PW8001 Power Analyzer

A small efficiency improvement can be difficult to demonstrate when the difference between input and output power is small compared with either reading. Repeatability, channel configuration and the measurement chain become central to the result. A headline accuracy figure is only the beginning of selecting an appropriate system.

This guide explains how to approach a PW8001 configuration for an inverter, motor-drive or other power-conversion test. Start with the quantities to be measured, then select the hardware and analysis options needed to produce evidence that another engineer can review.

U7001 or U7005: which input unit fits?

The PW8001 accepts up to eight input units, with the module selection specified when ordering. The following manufacturer specifications show why a single description of the main unit cannot represent every configuration.

These are summary figures. Apply the full reading-plus-range accuracy expressions, frequency conditions and current-sensor contributions from the current specification. Input voltage, voltage to ground and measurement category must each be checked for the proposed connection.

Define the power boundary before counting channels

Decide what the efficiency figure is intended to describe. An inverter-only result and a complete drive-system result can use different measurement boundaries. Auxiliary supplies, cooling equipment and other loads should be handled consistently with the stated test objective, rather than included or excluded without explanation.

Draw the system and mark each voltage and current measurement point. Then map the required wiring method to the available power channels. Include any additional electrical stages that must be measured simultaneously. This exposes channel requirements before the configuration is quoted and helps avoid comparing readings taken under different operating conditions.

For changing loads, coordinate the measurements and the period over which they are evaluated. Record the operating point, control state and averaging settings with the result. A table of efficiency numbers becomes much more useful when the conditions behind each row are clear.

Evaluate accuracy across the complete measurement chain

The analyzer, input units, current sensors and connection arrangement all contribute to the measurement. Review the specified performance at the actual signal frequency, range and power factor. Do not apply a basic low-frequency accuracy headline unchanged to a switching waveform or a low-power-factor loss measurement.

HIOKI offers automatic phase correction with compatible current sensors. Compatibility must be confirmed for the selected sensor; the feature does not eliminate every source of measurement uncertainty.

Consider a simplified loss calculation: subtracting 99 kW output from 100 kW input gives 1 kW loss. An error that is small compared with either power reading can still be significant compared with that 1 kW difference. This arithmetic illustrates why loss evaluation deserves a complete uncertainty review; it is not a claim about the error of a particular PW8001 configuration.

Before relying on a small improvement, check whether it remains visible across repeated runs under comparable conditions. Document range changes, sensor setup and relevant temperature conditions. Where the test requires a formal uncertainty budget, include the complete chain and the laboratory's method.

Match bandwidth and sampling to the question

Sampling rate and measurement bandwidth describe different properties. More samples do not, by themselves, make a sensor or input path respond to frequencies beyond its specified capability. Conversely, selecting a wideband input unit without reviewing sensor response can leave the current channel as the limiting part of the setup.

For converter development, state whether the objective is overall efficiency, harmonic behaviour, loss investigation or detailed switching-waveform analysis. These questions may call for different settings and supporting instruments. Decide which information must be retained for later review before starting a long test campaign.

Keep the voltage and current measurement paths consistent with the intended analysis. Record any filtering, scaling or correction settings. If two runs use different configurations, identify that difference before attributing the change in measured power entirely to the device under test.

Specify analysis and interface options explicitly

The PW8001 family offers motor-analysis and interface configurations, including CAN/CAN FD capabilities in applicable variants. Required options should appear explicitly in the quotation and test plan.

For a motor test, identify the torque and speed signals, their electrical interfaces and the required number of simultaneous measurement points. For integration into a test stand, describe the data destination, update needs and control workflow. A product-family feature list does not establish that every option is included in a particular order code.

The PW8001-02 product page describes a D/A-output variant. Confirm the main-unit variant, input units, sensors and software requirements together; do not assume that the linked version includes all motor or network functions discussed for the family.

Configuring a PW8001 for a Canadian test team

Send RCC Electronics a measurement diagram, voltage and current ranges, expected frequency content, required channel count and analysis objectives. Include interface and reporting needs so the proposed system covers the complete workflow. Discuss applicable calibration and service requirements for the selected configuration.

FAQ: HIOKI PW8001 configuration

Does the 1,500 V DC input unit also provide 15 MS/s sampling?
No. Those headline capabilities refer to different modules, as shown in the table. Select each channel's input unit according to its measurement requirements.

Is the basic accuracy figure the uncertainty of my complete test?
No. Apply the detailed analyzer specification and include sensor performance, operating conditions and the test method. A system-level uncertainty assessment is separate from a headline instrument specification.

Are eight channels always enough?
Count the measurement elements required by the wiring methods and power boundaries in your test. The number of devices or motors alone does not determine the channel requirement.

Should I choose sensors only by maximum current?
No. Review usable range, frequency response, phase performance, conductor fit and compatibility with the intended connection and correction functions.

What should be included in a configuration request?
Provide the system diagram, expected operating points, electrical ranges and intended analysis. Identify required interfaces and accessories so that the quotation can be checked against a complete measurement plan.

* Summary specifications: HIOKI PW8001 product information and manufacturer brochure. Confirm current accuracy conditions, module ratings, sensor compatibility and ordered options. Application examples do not replace a test-specific uncertainty assessment.