【宮城・仙台】電力会社、電気工事会社向け特殊機器の製造・販売・レンタル

13-20, HigashiKuromatsu, Izumi-ku, Sendai-shi Miyagi, 981-8005 Japan
TEL/FAX 81-22-234-2789

Cordless VCT combination test system (CVE-27)

Current CVE-27 is only for Japan market. We are planning to develop oversea version of CVE-27.
We have a Japanese patent for this product (Japanese Patent No.5142167). We are handling to get international patent too.

Overview

When a switchboard is repaired or remodeled in a power station and a substation, VCT combination test and voltage matching test are performed. This test measures phase difference of voltages and currents between a reference point and a comparison point. In this test, 2 measurement points are connected to one measurement device by long, heavy and plural cables to transfer voltage and current signals. This is to secure simultaneity. (See Fig.1)

"Cordless VCT combination test system (CVE-27)" is a solution without long, heavy and plural cables for VCT combination test and voltage matching test. The following is an overview of this system: 2 measurement units are set to both a reference point and a comparison point, and "very accurate" internal clock in these units are used to secure simultaneity. After that, measurement units send measurement data to Control unit (Notebook computer) via wireless LAN and/or mobile phone. Then Microsoft Excel displays measurement result on Control unit. (See Fig.2)

We developed "Cordless VCT combination test system (CVE-27)" with Sendai technical center of Tohoku Electric Power Co., Inc. in fiscal 2010. Advantages of this system are to save engineer resource and avoid human error in a VCT combination test and a voltage matching test.

Main application

• VCT (Voltage Current Transformer) combination test in a power station and a substation.
• Voltage matching test in a power station and a substation.
• CT (Current Transformer), VT (Voltage Transformer) test in a power station and a substation.

Advantages

Without cables, you can measure by 3 or lower degree phase difference for voltage and current between a reference point and a comparison point.

Error of internal clock is 10usec or lower (i.e. 0.2 degree or lower). This is enough performance for VCT combination test and voltage matching test.

Without cables, you can perform test between different floors easily.

If there are some barriers for wireless LAN like a test between difference floors (See Fig.3), wireless LAN repeater can extend communication range. This system includes battery box for wireless LAN access point and repeater. You can put wireless LAN access point and repeater easily on some places without considering outlet.

You can perform VCT combination test and voltage matching test even if these are long distance.

If you want to perform long distance test (for example, a comparison substation is far from reference power station), it is unable to perform VCT combination test and voltage matching test by usual method with cables. "Cordless VCT Combination Test System (CVE-27)" is a solution of this case.

In case of long distance test, GPS sets internal clocks in 2 measurement units to standard time. Then wireless LAN and mobile phone are used to transfer measurement data.

Measurement data is inputted and displayed on Excel worksheet automatically.

2 measurement units measure voltage and current RMS and phase at same time and send measurement data to control unit automatically. Then control unit inputs them to Excel worksheet and display them (See left figure). So you don't need to write down data and input it to computer by hand.

In left figure, the red cell means a standard phase. You can move it by clicking other cell simply. If you have already had your own Excel worksheet for VCT combination test and voltage matching test, you can use cell-link method of Excel. I.e. you set cell link between Excel worksheet of CVE27 and your Excel worksheet before test. Then after measurement finishes, CVE27 opens own worksheet. At this time, Excel link sends data to your worksheet automatically. So you can see measurement data on your own worksheet immediately.

System contents

Control unit

Control unit and accessories

Battery charger is for NiMH batteries of measurement units and wireless LANs.

Control unit and accessories in trunk.

Measurement unit

External form

Block diagram of measurement unit

Measurement unit and accessories

Measurement unit and accessories in trunk

Wireless LAN access point (repeater) with battery box

Wireless LAN access point (repeater) with battery box on steel wall

You can put it on steel equipment by magnet easily.

Front side of battery box

Back side of battery box

Specification

Measurement items

Current: Three-phase alternating current ... 4 items consist of three phases(R-S-T) and neutral
Voltage: Three-phase alternating voltage ... 6 items consist of phase voltages(R-N, S-N, T-N) and line voltages(R-S, S-T, T-R)

Range and accuracies

		RMS		Phase
		Range	Accuracy※	Range	Error
Current		1 to 20A	+- 1.0%	0 to 360degree	+- 3degree
		0.1 to 1A	+- 1.0%
		0.003 to 0.1A	+- 1.5%
Voltage	Phase voltage	10 to 150V	+- 1.0%	0 to 360degree	+- 3degree

Note: Standard of calculation is a full scale value. (((Measured value - Full scale value)/ full scale value) * 100)
Range is changed automatically. (There is no manual mode)

Inputs

Current: Via clamp sensor
Voltage: Direct input to terminals

Power

Control unit: AC100V 65W or build-in battery of notebook computer
Measurement unit: AC100V 50W or 12 C-size NiMH batteries (Unit works about 1.5 hours with batteries)
Wireless LAN access point: 5 AA-size NiMH batteries (Access point works about 2 hours with batteries)

Communication way

2 Wireless LANs (short distance test)
One wireless LAN and one mobile phone (long distance test)
Note: Japan DoCoMo type mobile phone only

Dimensions (without projection) and Weight

	Dimensions(mm)			Weight(kg)
	W	D	H
Control unit	374	248	37	3
Measurement unit	400	280	130	7

※ Without notification, we may change external forms, specifications and price.